The Northeast Weather Blog...

Unsettled week ahead...

By: Blizzard92, 02:56 GMT le 24 janvier 2012

"Current Temperature"


"Current Dewpoint"


"Current Surface Map and Weekly History of Jet Stream Position"


"Regional Radar"


"Regional Satellite"


"Regional Advisories"


"Soil Moisture Anomalies and 5-day Precipitation Amounts from Hydro Prediction Center"


"Severe Weather Outlooks from Storm Prediction Center Days 1, 2, and 3"


"12hr Estimated Precipitation"


"Forecast Max Temperatures"


"Forecast Min Temperature"


"Forecast Weather at 2pm"


"Current Storm Reports"


"Fire Outlooks from Storm Prediction Center Days 1, 2, and 3"

(All maps courtesy of NOAA and Penn State Meteo.)

"Forecast Model Links"
-NAM model 12z...Link
-GFS model 12z...Link
-NMM model 12z...Link
-SREF model 9z...Link

"Severe Weather Links"
-Atmospheric Soundings Skewt T charts...Link
-SPC Mesoscale Analysis Pages...Link
-Public Spotter Reports for State College NWS...Link
-Severe Weather Model Forecast indices...Link
-Severe Weather Parameter Definitions...Link

"Flooding Links"
-Automated Pennsylvania Rainfall Recording Stations...Link
-Flash Flooding Guidance...Link
-HPC Forecasts for Excessive Rainfall...Link
-Hydrology Predictions for Lakes, Rivers, and Streams...Link

Lower Susquehanna Valley Doppler...

(Courtesy of WGAL)

Follow my 24hr forecasts on Twitter... Link and Facebook... Link.

"10mi northeast of Harrisburg 2011-2012 winter statistics"
(Snow Stats)
Monthly Total (October)- 5.5in
Monthly Total (November)- 0.0in
Monthly Total (December)- 0.4in
Monthly Total- (January)- 5.2in
Seasonal Total- 11.1in
Winter Weather Advisories- 2
Winter Storm Warnings- 1
Ice Storm Warnings- 0
Blizzard Warnings- 0
Freezing Rain Advisories- 1
Winter Storm Watches- 1

(Temperature Stats)
Lowest High Temperature- 29F
Lowest Low Temperature- 10F
Wind Chill Advisories- 0
Wind Chill Warnings- 0

(Snow Storms Stats)
Historic October Nor'easter - October 29 - 5.5in of wet snow
322 Lake Effect Snow Band - December 17 - 0.3in of wet snow
Weak Clipper - December 29 - 0.1in of snow
322 Lake Effect Snow Band - January 18 - 0.2in of snow
Southwest Flow Event - January 21 - 5.0in of dry snow

Observation Blogs

Updated: 14:37 GMT le 24 janvier 2012

Permalink

First Significant Winter Storm; Northeast...

By: Blizzard92, 16:41 GMT le 20 janvier 2012

A weak shortwave and warm air advection will spark a shield of precipitation across the Northeast where a recent arctic air mass has moved in allowing for widespread wintry precipitation. This will be the first significant winter storm for the Northeast this season causing some moderate travel and other problems.

Current Surface Plot...

(Courtesy of HPC)

January 21 Southwest Flow Event (SWFE) Timeline and Discussion...
Current surface observations across the Northeast indicate a relatively dense arctic air mass over the region. Dew points remain generally in the single digits across northern areas while temperatures will struggle to reach freezing as far south as Washington DC. A zonal flow accompanied by a shortwave dropping out of the Rockies will set the stage for the first widespread winter storm this winter season across the eastern United States. The progressive jet stream will maintain a fast progression of the shortwave as it advances eastward across the contiguous United States. A southeast ridge associated with increasing upper level heights will attempt to push an area of warmer air into the Northeast. But the passing of a cold front overnight Thursday has allowed for a dry and cold air mass to reach as far south as Virginia. This battleground for temperatures will set up a thermal gradient from west to east around a latitude line near Washington DC. This position will assist in the exact track of the shortwave.

Actual dynamics for the shortwave remain relatively weak with little amplification as it translates east. This is a classic southwest flow event with the precipitation primarily fueled by warm air advection acting as a lifting mechanism over the region.

Looking at past climatology several things can be noted in these types of setups. There will often be a widespread precipitation shield that stretches farther north than computer models are able to detect. Precipitation rates can be very significant closer to the track of the 850hPa low. Typically there are two belts of the heaviest snowfall. One belt exists 50-100mi due north of the track of the 850hPa low. Another heavy snow belt exists in the coldest sector of the storm where ratios in the arctic air mass account for ideal dendritic growth.

Many people in recent days have noted that these southwest flow events often shift northward as the event approaches. This is likely the case due to the underestimated strength of the southeast ridge an anomalous warm air advection. But in this case the shortwave is meager and therefore the dynamics are actually be squashed by the northern stream. This likely was the reason we saw a southerly shift in model guidance. Also many SWFE's are accompanied by an underestimated warm tongue. Therefore while areas 25-50mi north of the H85 0C line are only receiving sleet instead of snow; this is because there is a warm tongue in the mid levels of the atmosphere. I have accounted for this possibility in my forecast.

The cold air damming in this setup is quite impressive given a 1028mb anticyclone to the north accompanied by an arctic air mass. Dew points in the single digits to teens will allow surface temperatures and the entire thermal column to cool by evaporational cooling and wetbulbing during the first hour or two of the storm system. Given this possibility, I believe a 1-2 hour period of snow is even possible as far south as Washington DC.

Looking at mesoscale features of this event, these SWFE's often produce a heavy burst of the snow on the front end typically accompanied by high snow rates. If the warm tongue can remain push backed by the density of the cold air mass, then some areas may see more snow than forecast. I would expect the development of several mesoscale bands including the formation of a possible CIS band across areas about 50mi north of the mix line. This band may affect areas around the Pennsylvania turnpike north to I-80. This may affect areas also such as NYC, Connecticut, and Rhode Island. The weak dynamics of this shortwave will prevent heavy QPF despite a relatively good flow from the Gulf of Mexico. QPF will likely be in the range .35-.6in range for most locations. Snow ratios in the coldest sector of the storm system around I-80 will be nearly 20:1. Soundings in this region indicate excellent dendritic snow growth in the -15C sector. Large flakes are possible during the height of the event.

The quick progressive nature of the jet will allow precipitation to only last in one location for no more than 6-8 hours and will be well out of the Northeast by Saturday afternoon and early evening. Low dew points should allow for some virga on the onset, but I am increasing my start time due to the past history of SWFE warm air advection precipitation to break out earlier than anticipated. Confidence in this forecast remains relatively high with only a few discrepancies noted for snow amounts towards the mix region.

7-10pm Friday: Stratus and cirrus decks over the Northeast will begin to thicken as the shortwave begins to approach the region. Warm air advection precipitation will begin to break out across northern Pennsylvania and southern New York State in the form of light snow. Visibilities will remain around 2-4mi with weak forcing and meager lift at this point.

10-12am Friday: This period will define the majority of the precipitation developing over the region in the form of light snow across the entire Northeast south to Washington DC. Snow rates will begin to increase across western Pennsylvania with 1in accumulation possible in this period. Light snow will move into NYC and southern New England in this period also.

12am-4am Saturday: Precipitation will increase in intensity in this period across Pennsylvania and Maryland. We will also begin to see warm air aloft moving northward into southwestern Pennsylvania and parts of Maryland. Areas will begin to change to freezing rain and sleet as far north as a line from Pittsburgh, PA to Frederick, MD. Snow rates will be near .5in or 1in/hr especially over Pennsylvania. Light snow will continue to be falling in southern New England also. Areas towards central and southern Maryland will change to rain.

4-7am Saturday: The heaviest snows will pull out of Pennsylvania into southern New England. Warm air advection will allow mid levels to rise above freezing as far north as the Pennsylvania turnpike with sleet and freezing rain possible as far south as extreme northern Maryland to the northwest Philadelphia suburbs. Snow rates of 1-2in/hr are possible in southern New England down into New York City.

7-11am Saturday: The heaviest snows will pull into eastern New England with only light to moderate precipitation back eastward into New Jersey. Most precipitation will be pulling out of Pennsylvania. The mix line will reach the southern New England coastline with rain over Nantucket and Martha's Vineyard.

Regional Radar...
(Courtesy of Intellicast)

Regional Advisories...

(Courtesy of NOAA)

This is my current freezing rain/rain line...
Winchester, VA - Baltimore, MD - Wilmington, DE - Southampton, NJ - Middletown, NJ - Brentwood, NY - Chatham, MA

***Areas north of the line will stay primarily below freezing for the entire event with a mix of snow/sleet/freezing rain. Areas south of the line may see some wintry precipitation also, but will be primarily rain for the majority of the event.

This is my current mix/snow line...
Butler, PA - Indiana, PA - Altoona, MD - Harrisburg, PA - Reading, PA - Allentown, PA - Newark, NJ - New London, CT - Plymouth, MA

***Areas north of the line will stay primarily snow through the entire event. Areas south of the line will start as snow and eventually change to a mix at some point for the event. Advisory criteria snows are possible as far south as 50mi south of this line.

Storm Reports...
None.

Storm Impacts...
1. First widespread winter event of the season affecting the entire I-95 corridor.
2. Significant ice accretions in excess of .25in are possible for the higher elevations in southern Pennsylvania and parts of Maryland.
3. Quick thump of snow will allow for a period of 1-2in/hr rates.
4. Snow accumulations will be near warning criteria of 6in for some locations.
5. Cold temperatures in the teens and twenties will allow for easy accumulations of ice and snow.

Snow Maps...


***The areas in the mix region may also see accumulations of 1-2in of snow/sleet. The large region of 5-10in will likely be in reality a region of 4-8in amounts. I do not expect any 10in snow totals for any locations. If any changes to this map were to be made, it probably is to shift the snow totals a bit to the north across southern Pennsylvania given the warm mid layer may be underestimated. But for now no changes look necessary.



***The area of lowest confidence is along southern Pennsylvania where mixing concerns are a possibility especially in central and eastern Pennsylvania. The Laurel Highlands have a stronger confidence forecast given the high likelihood of freezing rain after some light snow accumulations.

Current Great Lakes Water Temperatures...

(Courtesy of NOAA)

Selected City Accumulations for the Northeast...
Hagerstown, MD- 1-3in of snow followed by .25in of freezing rain
Baltimore, MD- 1-2in of snow followed by .25in of freezing rain
Salisbury, MD- Up to 1in of snow followed by a mix then rain
Pittsburgh, PA- 2-4in of snow followed by freezing rain up to .25in
State College PA- 4-8in of snow
Williamsport, PA- 4-8in of snow
Altoona, PA- 3-7in of snow followed by .1in of freezing rain or sleet
Harrisburg, PA- 3-7in of snow followed by .1in of freezing rain or sleet
Lancaster, PA- 2-4in of snow followed by .25in of freezing rain
Philadelphia, PA- 1-3in of snow followed by .1in of freezing rain then rain
Allentown, PA- 4-6in of snow possibly mixing with sleet
Scranton, PA- 4-8in of snow
Washington, DC- Up to 1in of snow with a trace of freezing rain then rain
Wilmington, DE- 1-2in of snow then freezing rain and rain
Dover, DE- Mix of precipitation followed by rain
Trenton, NJ- 2-5in of snow followed by sleet and freezing rain with trace accumulations
New York City, NY- 3-6in of snow followed by a bit of sleet/freezing rain
Poughkeepsie, NY- 4-6in of snow
Binghamton, NY- 3-6in of snow
Ithaca, NY- 2-4in of snow
Albany, NY- 2-4in of snow
Hartford, CT- 4-7in of snow
Concord, NH- 1-3in of snow
Providence, RI- 3-7in of snow followed by a freezing rain/sleet mix
Worcester, MA- 2-4in of snow
Boston, MA- 2-4in of snow
Nantucket, MA- 1-4in of snow followed by plain rain
Hyannis, MA- 2-4in of snow followed by a mix then plain rain
Burlington, VT- 1-2in of snow
Portland, ME- Less than 1in of snow
Bangor, ME- Less than 1in of snow
"Subject to Change"

Current Northeast Snow Depth and Northeast Wind chills...

(Courtesy of Wunderground)

Model Analysis
The main model discrepancies exist in the position and strength of the 850hPa low. The latest NAM runs indicate a track across southern Pennsylvania. Given snow climatology rules, this would put the heaviest track of snow along and just north of I-80. The NAM closes of the 850hPa low, which allows for more significant mid level warming across southern Pennsylvania and New Jersey. Therefore in these runs ice would be a significantly higher threat with lower snow amounts. The GFS and ECMWF are running a tad colder and remain weaker with the strength of the 850hPa low. This allows for minimal mid level warming with the snow line hovering around the H85 0C line instead of 50mi north of it like the NAM. Given the density of the arctic air mass, I am expecting the NAM to be running a tad too warm. A few recent model runs of the GFS suggest a more dense warm tongue causing sleet in some areas that originally looked like snowfall. The most difficult forecast will be for areas along the Pennsylvania turnpike into central and northern New Jersey up through the New York City metro region. High resolution models including the 4km NMM keep thermals a bit cooler, but they also have a slight cold bias. This cold bias also exists with the latest GGEM and RGEM, which seem to be a bit too cold in this scenario. Also QPF remains in question for this event with the ECMWF running below .5in for all areas while the NAM has the highest totals. The weak dynamics of the shortwave will likely allow QPF totals to lean toward the ECMWF, although I think in the end it will verify too dry.

After the Storm
Latest guidance is suggesting some light QPF over central Pennsylvania up through the Northeast during the Sunday night period. Given cold air damming maintaining the cold sector over the region, it is likely pockets of sub 30F temperatures will exist over much of the region. While QPF looks to be at .2in or less, cloud crystal growth will remain minimal. This will allow for a light freezing rain potential Sunday night. Amounts will remain at advisory levels or lower, but could cause some travel headaches into the night. Given a fresh snow pack over the region, guidance is likely even underestimating 2m temperatures. Later on Monday a strong southwest flow will finally undermine the cold air allowing the warm sector to creep well into the Northeast with temperatures in the 50s as far north as the Mason-Dixon line. Plain rain is likely over main areas later in the day. As I suspected earlier, the torch week that was expected next week does not look likely at this point. Temperatures will only remain slightly above normal. Towards the end of the month global teleconnections are supporting another change in the global regime with a negative AO. Latest ECMWF ensembles continue to show also the development of a west-based negative NAO. While I am not biting yet on this major pattern change, I think it is likely that February will be the most winter-like this season. If a pattern change does occur, the lasting strength of the regime will be critical. Also as I mentioned earlier, we are nearing 90 days for a similar teleconnection pattern. Usually by this many days, the pattern begins to swing. We shall see and I will have more updates later next week.

Please post storm reports in this blog from across the Northeast during the winter storm and please post location of observation in each report...

This blog is in progress. Check back soon...

Winter Forecast 2011-2012... Link

Follow my 24hr forecasts on Twitter... Link and Facebook... Link.

Lower Susquehanna Valley Doppler...

(Courtesy of WGAL)

"10mi northeast of Harrisburg 2011-2012 winter statistics"
(Snow Stats)
Monthly Total (October)- 5.5in
Monthly Total (November)- 0.0in
Monthly Total (December)- 0.4in
Monthly Total- (January)- 5.2in
Seasonal Total- 11.1in
Winter Weather Advisories- 2
Winter Storm Warnings- 1
Ice Storm Warnings- 0
Blizzard Warnings- 0
Freezing Rain Advisories- 1
Winter Storm Watches- 1

(Temperature Stats)
Lowest High Temperature- 29F
Lowest Low Temperature- 10F
Wind Chill Advisories- 0
Wind Chill Warnings- 0

(Snow Storms Stats)
Historic October Nor'easter - October 29 - 5.5in of wet snow
322 Lake Effect Snow Band - December 17 - 0.3in of wet snow
Weak Clipper - December 29 - 0.1in of snow
322 Lake Effect Snow Band - January 18 - 0.2in of snow
Southwest Flow Event - January 21 - 5.0in of dry snow

Winter Storm Blog

Updated: 01:57 GMT le 24 janvier 2012

Permalink

Widespread light snow for Northeast...

By: Blizzard92, 18:35 GMT le 18 janvier 2012

Light snow is likely associated along the cold front with an area of warm air advection. Amounts will remain light and around 1-3in for most areas. A strong storm system will approach the region towards the weekend with widespread wintry weather. I will post a new blog for this next event on Friday. For now this blog will focus primarily on the nuisance snows Thursday night.

Current Surface Plot...

(Courtesy of HPC)

January 19 Clipper/Occluded Front Timeline and Discussion...
12pm-2pm Thursday: A reinforcing shot of cold air behind a cold front will begin to move across western New York and western Pennsylvania. Warm air advection ahead of the cold front will add a bit of additional lift ahead of the front with widespread light snows from the mountains of Maryland up through western New York in this period. Dry air will inhibit moisture aloft preventing snow rates reaching much higher than .5in/hr. Orographic lift across the higher elevations in western areas will assist in light snow totals of 1-3in.

2pm-4pm Thursday: The fast movement of the cold front and weak shortwave over northern New York will keep snows rapidly advancing east. Light snows will move into central New York and central Pennsylvania. Downsloping east of the higher elevations will begin to weaken snows across Pennsylvania south into Maryland. Light snows will only last at one location for no more than 2-4hrs with visibilities primarily ranging from 1-3mi. Given the northern track of the shortwave, it is not a favorable track for most areas for the heaviest snow swath. Warm air advection will continue to along for a minor area of frontogenesis-enhanced light snow before coming to an end from west to east. Snows will already begin to be moving out of extreme western areas.

4pm- 7pm Thursday: The stratiform light snow shield will begin to move into southern New England and into eastern New York and Pennsylvania. The precipitation shield will begin to deteriorate across eastern Pennsylvania courtesy of downsloping and minimal lift given the large displacement from the shortwave. Snow amounts for most areas will be in the 1-3in range through this period and again will only last for 2-4 hours at any one location. Snow will already be out of areas such as Pittsburgh and Buffalo.

7pm- 10pm Thursday: As the shortwave progresses east along the cold front, a southeasterly flow off the Atlantic will add a bit of additional moisture across eastern New England. Light snow will begin to break out ahead of the main WAA snow shield, but accumulations will be minimal and limited to a coating. The main WAA snows will be progressing across central New England down through New York City. The steadiest snows will be limited north of the New York City metro region limiting accumulations in this region.

10pm- 2am Friday: Light snow will continue to move into eastern New England and begin to push off into the Atlantic coast. The shortwave will begin to amplify as it moves east; a weak southeasterly flow will also exist. These factors will aid in a narrow band of snow along the area of highest frontogenic forcing. Snow totals will be enhanced in this region ranging from 2-5in. This advisory criteria snow will be limited to far eastern New England. By 3am or so, most all snow will be pushed off the coast.

Quick Discussion: Temperatures at the surface will remain below freezing for all areas and will not be a major concern. A bit of light rain/snow is possible for Long Island, but all other areas will be pure snow. H85s around -8C and warm air advection aloft will add to snow ratios at nearly 15:1 or 20:1 with a widespread light and fluffy snow. Most amounts will be light and nuisance, but given impacts around evening rush, there may be some travel impacts. Also the lack of snow this year makes this appear to be a bigger event than normal for this winter. Behind the cold front, a northwest flow will allow for a bit of lake effect snow, but increased shear levels aloft will limit organization. Any additional accumulations will be below 4in for the general snow belt regions. Another storm system will approach the region by Saturday morning with precipitation breaking out across the northeast before dawn on Saturday.

Regional Radar...

(Courtesy of NOAA)

Regional Advisories...

(Courtesy of NOAA)

Storm Reports...
None.

Storm Impacts...
1. Widespread light snow from the Mason-Dixon line on northward.
2. Light snow accumulations for many areas that have not seen much snow this winter.
3. Higher snow amounts in eastern New England due to some eastern enhancement.
4. Snow ratios nearly 20:1 for many areas.
5. Amounts generally at nuisance levels of 1-3in.

Snow Maps...


***Areas not included in the 1-4in snow range may see spotty coating to one inch snow amounts especially just southeast of the 1-4in vs. 0in border

Current Great Lakes Water Temperatures...

(Courtesy of NOAA)

Selected City Accumulations for the Northeast...
Hagerstown, MD- Dusting of snow
Baltimore, MD- Dusting of snow
Salisbury, MD- A few flurries; no accumulation
Pittsburgh, PA- Light snow; 1-3in
State College PA- Light snow; 1-3in
Williamsport, PA- Light snow; 1-3in
Altoona, PA- Light snow; 1-3in
Harrisburg, PA- Light snow; C-1in
Lancaster, PA- Light snow; C-1in
Philadelphia, PA- Light snow; dusting
Allentown, PA- Light snow; C-1in
Scranton, PA- Light snow; 1-3in
Washington, DC- Flurries; 0in-dusting
Wilmington, DE- Light snow showers; dusting
Dover, DE- Light snow showers; dusting
Trenton, NJ- Light snow; C-1in
New York City, NY- Light snow; 1-3in
Poughkeepsie, NY- Light snow; 1-3in
Binghamton, NY- LIght snow; 1-3in
Ithaca, NY- Light snow; 1-3in
Albany, NY- Light snow; 1-3in
Hartford, CT- Light snow; 1-4in
Concord, NH- Light snow; 2-4in
Providence, RI- Light snow; 2-5in
Worcester, MA- Light snow; 2-4in
Boston, MA- Light snow; 2-4in
Nantucket, MA- Light snow; 1-4in
Hyannis, MA- Light snow; 2-5in
Burlington, VT- Light snow; 1-3in
Portland, ME- Light snow; 2-5in
Bangor, ME- Light snow; 2-5in
"Subject to Change"

Current Northeast Snow Depth and Northeast Wind chills...

(Courtesy of Wunderground)

Model Analysis
General model guidance differences exist in QPF totals across most areas. NAM and ECMWF tend to be a bit drier especially for southern areas along and east of the Appalachians. NAM indicates QPF less than .01in across southern and eastern portions of New Jersey and Pennsylvania. Meanwhile the GFS shows a more widespread area of snow showers with QPF totals about 0.05-0.1in higher. Given the increase in warm air advection ahead of the cold front, it is likely the higher QPF totals from the GFS will verify. Latest high resolution guidance including the 4km NMM indicates a bit of enhancement across eastern areas in New England particularly towards eastern Massachusetts up through Maine. This enhancement is also signaled by global guidance. The enhanced area of QPF is associated with a digging shortwave as the low begins to strengthen as it moves east over the Atlantic. Snow rates will generally stay below 0.5in/hr for most all areas as visibilities will range from 1-3mi. This will keep conditions at IFR or MVFR at aviation fields. Timing differences in the models are very minimal, at general consensus for my forecast is about 60/30/10 for GFS/ECMWF/NAM, etc.

After the Storm
A weak shortwave in the western United States will translate eastward by the weekend spreading a shield of precipitation courtesy of strong WAA into the Middle Atlantic and New England regions. This southwest flow event (SWFE) is very consistent in La Nina-like patterns. A 1024mb high pressure to the north will stay wedged across the region in southern Quebec, but will begin to slowly lift away to the northeast. This anticyclone will allow for a wedge of cold air to remain lodged in across the Northeast south towards the Mason-Dixon line for areas along and east of the Appalachian mountains. Overrunning precipitation along a thermal boundary will allow QPF totals from .25in-.6in. Weak dynamics and some dry air advecting south out of Canada will limit higher QPF totals. Given the close proximity of the thermal gradient and the enhanced area of warm air advection, precipitation type will likely be a major concern for this storm system. It remains too early to begin to note precipitation transition lines, but given past history with SWFE's, it is likely the cold air at the surface will be underestimated by models, while mid level warmth is also underestimated. Therefore many areas that are just about the 0C H85 line will see sleet due to a warm tongue. Also models typically underestimate the extent of the QPF shield, so therefore a bit of snow is likely for many areas before the warmth advects into the region. Freezing rain will be a big concern, but will depend will the thermal gradient sets up. Dry air across northern New England will likely inhibit most precipitation in this region and therefore most of the QPF will stay south of southern Vermont and southern New Hampshire. It should be noted the NAM is farther north than most guidance, but for now it remains an outlier.

As I mentioned the other day, I am not on the heat wave bus anymore for next week. I would expect cool air to hang around for a few days with chances of wintry precipitation. There will be a 1-2 very warm period ahead of a Great Lakes cutter, but that does not likely until the end of the week or so.

Snow Map Storm 2...


***This is a rough estimate of precipitation types for the Saturday event. The precipitation types were determined by the type of precipitation during the height of the event for each individual locations. It is likely many southern areas start as snow and changing to freezing rain and then perhaps plain rain. But I chose to indicate types based on the height of the event. Snow accumulations are possible even in some parts of the freezing rain area.

Please post storm reports in this blog from across the Northeast during the winter storm and please post location of observation in each report...

This blog is in progress. Check back soon...

Winter Forecast 2011-2012... Link

Follow my 24hr forecasts on Twitter... Link and Facebook... Link.

Lower Susquehanna Valley Doppler...

(Courtesy of WGAL)

"10mi northeast of Harrisburg 2011-2012 winter statistics"
(Snow Stats)
Current Snow Cover- 0.0in
Monthly Total (October)- 5.5in
Monthly Total (November)- 0.0in
Monthly Total (December)- 0.4in
Monthly Total- (January)- 0.2in
Seasonal Total- 6.1in
Winter Weather Advisories- 1
Winter Storm Warnings- 1
Ice Storm Warnings- 0
Blizzard Warnings- 0
Freezing Rain Advisories- 0
Winter Storm Watches- 1

(Temperature Stats)
Lowest High Temperature- 29F
Lowest Low Temperature- 10F
Wind Chill Advisories- 0
Wind Chill Warnings- 0

(Snow Storms Stats)
Historic October Nor'easter - October 29 - 5.5in of wet snow
322 Lake Effect Snow Band - December 17 - 0.3in of wet snow
Weak Clipper - December 29 - 0.1in of snow
322 Lake Effect Snow Band - January 18 - 0.2in of snow

Winter Storm Blog

Updated: 13:36 GMT le 19 janvier 2012

Permalink

Heavy Snow Squalls for Northeast Post Storm...

By: Blizzard92, 19:23 GMT le 11 janvier 2012

A double low system will move through the Northeast generally with heavy rain for most areas along with some wintry precipitation for northern New England. Behind the low complex, arctic air will move across the region in correspondence with a very impressive jet streak. This vortex will enhance an area of snow squalls, which will affect many areas with advisory or sub advisory snows. Flash freezes are likely for many areas on Friday along with an increasing lake effect snow cyclonic flow. Winter will be in full force on Friday and Saturday. Winds will also increase to advisory criteria.

Current Surface Plot...

(Courtesy of HPC)

Thoughts on January 11-14 Storm System and Lake Effect Snow...
2-5pm Wednesday: Strong WAA and a southerly jet will continue to allow temperatures to rise over the region in correspondence with the max diurnal heating of the day. 1pm surface observations indicate temperatures above freezing for all locations across Pennsylvania, Maryland, and Delaware. Also temperatures across New England are above freezing given clear skies on the visible satellite. Dew points are beginning to rise across southern areas as the southerly jet increases moisture and milder temperatures. A departing 1024mb anticyclone over New England will allow a CAD situation to unfold for northerly locations across New York State, Vermont, New Hampshire, Massachusetts, and Maine. By 5pm rain will be spreading across Pennsylvania and New Jersey with rates around .1in/hr in some areas. Cirrus will begin to thicken over New England by evening preventing temperatures from falling due to radiational cooling. Therefore temperatures will range from 34-38F across the areas north of the Massachusetts Pike into Vermont and New Hampshire. Dew points will remain in the 20s.

5-10pm Wednesday: Stratiform rain will continue to spread over the entire Northeast edging into southern New England. Rates will range from .1in/hr to .2in/hr especially towards New Jersey. As rain moves into areas north of the MA pike, evaporational cooling will allow for a quick drop in H85 thermals below 0C. But WAA will prevail under a strengthening LLJ. Any snow will not last as guidance indicates a mid level warm layer around 925mb. Snow accumulations will generally be under 1in as far north as southern Vermont and New Hampshire. As the warm tongue positions across southern New England, sleet will increase in some areas from Worcester on northward. Sleet amounts will also remain below 1in. 2m temperatures will fall from the mid to upper 30s into the lower 30s. Rain will fall heavy by 10pm over parts of Maryland and Washington DC with QPF totals up to .75in up to this point.

10pm-12am Wednesday- As WAA continues to increase thermal heights over southern New England, any sleet will change to freezing rain. This will be prevalent across parts of the Adirondacks through the Green and White Mountains. Freezing rain will also occur across the Berkshires and as far south as the hills near Worcester. But 2m temperatures will rise from the low 30s into the upper 30s slowly. Any freezing rain amounts will be less than .1in. Rain will begin to end across southern areas by early morning Thursday with QPF totals around 1in near Washington DC.

12am-4am Thursday: The double barrel low will begin to move up through Pennsylvania and New York state with H85s increasing to near +5C over southern Pennsylvania. Rain will be ending as far north as the Mason-Dixon line. An increasing southerly flow will allow temperatures to rise into the mid 40s into the I-95 corridor from Connecticut on southward. The anticyclone to the northeast will begin to weaken and depart allowing the confluence flow to wane. Heavy snow will begin to fall across northern Vermont and northern New Hampshire will amounts around 4-6in. 925mb temperatures will rise to near +1C to the Canadian border changing any snow to sleet and freezing rain. The surface lows will be rapidly advancing into Canada quickly shutting off precipitation as far north as the tristate region.

4am-8am Thursday: This period will feature any wintry precipitation changing to light rain and drizzle over southern New England. Total QPF in this region will be around 1-1.25 inches. Heavy snow will be falling across northern Maine. Amounts will exceed warning criteria in this small area. Meanwhile an arctic front will begin to move into the eastern Great Lakes. Clouds and warmer air across the entire Northeast will only provide areas of drizzle and low level fog. Temperatures will rise into the lower 50s across the I-95 corridor. Any ice or snow that accumulated along and south of the MA pike will quickly melt even across Pennsylvania and New York State in the higher elevations.

8am-2pm Thursday: The arctic front and associated ULL over Ohio will quickly advance towards western Pennsylvania at the end of this period. A bit of sunshine may occur in the dirty warm sector especially for southern and eastern areas. H85s will drop below 0C once again into western New York and western Pennsylvania. Generally cloudy with occasional drizzle and mild temperatures will be ongoing across the entire Northeast. Any snow or sleet over northern Maine will begin to come to an end.

2pm-8pm Thursday: A 992mb low over Michigan will slowly advance east associated with a strong pool of cold air associated with a series of vortices spinning into Pennsylvania. The arctic front will slowly progress over western Pennsylvania, western New York State, and western Maryland. An increasing pressure gradient will allow winds to increase behind the front along with a developing area of QPF as lapse rates increase in correspondence with a vigorous piece of energy. The atmospheric column will begin to cool over western areas rapidly changing rain to heavy snow with strong winds.

8pm-12am Thursday: A blossoming area of QPF over western and central Pennsylvania will be associated with a high-impact snow event. Total QPF will be around .25-.6in. This will be associated with a period of heavy snow from western Maryland north into western New York State. 1000-500mb thicknesses will drop sub 530dm with rapidly increasing snow rates. The strong northwest flow will along wind sustained to increase near 20-30mph with gusts up to 55mph. This will be wind advisory criteria. Temperatures will rapidly fall sub 30F. Snow ratios will increase to 20:1 in addition with increased orographic lift combined with lake enhancement. This will be a 2-4hr period of heavy snow with amounts around 3-6in along and west of the Alleghany Front.

12am-6am Friday: This band of QPF will shift northeastward as a 988mb surface low moves into central New York State. As the post frontal precipitation moves eastward, it will extend ahead of the 0C H85 line. This will allow precipitation to initially be rain, but rapidly change to snow. Flash freezes are likely all the way to the coast. High temperatures will be reached in the morning hours and fall into the 20s throughout the day for all areas. The best dynamics will shift into New York State and western New England. Squalls will begin to weaken as they head east of the Alleghany Front. Snow accumulations will begin to focus across central New York. Spotty 1-2in amounts are likely from Washington DC to White Plains, NY but generally most areas will be at a coating or less. Snow accumulations of 3-7in are possible into western New England especially along and west of the favored upslope regions in the Berkshires and on northward. Advisories will likely be issued for a widespread area given flash freeze, falling temperatures, high winds, and temporary heavy snow. Short periods of blizzard conditions are possible into north central Pennsylvania and central New York State.

6am-12pm Friday: The arctic front will push towards I-95 and the Atlantic coast with brief rain changing to snow showers as the column cools. Little to no accumulation is likely. Winds will be easily advisory criteria across the entire Northeast viewing area. Temperatures will continue to fall and the deformation axis of snow will be waning and moving through northern New England. A west-northwest flow will prevail as temperatures drop below H85s drop below -10C. The lake effect snow machine will begin to kick in across the typical snow belts associated with a 300 degree flow. The initial flow will be westerly with bands setting up near Buffalo and Watertown. The Ontario band will shift south into Oswego county, New York.

12pm-8pm: The lake effect snow machine will rapidly increase in this time period as the flow shifts to the northwest. Bands will be organized in a multi-band setup with only moderate accumulation. This flow will aid the upslope favored regions from western Maryland through the Laurel Highlands in Pennsylvania. Heavy upslope snows will begin across the Berkshires into the Greens.

8pm-Saturday morning: The northwest flow will begin to relax as the pressure gradient weakens and winds begin to drop below advisory criteria. Upslope snows will be ongoing in this period with total accumulations of 12in+ for northern Vermont particularly towards Mt. Mansfield and Stowe. Amounts of 6-12in will be more likely across the upslope regions in the White Mountains and Berkshires. 6-12in amounts are also likely over western Maryland into the Laurel Highlands through the snow belt regions of northern Pennsylvania. New York State accumulations will generally be a widespread 1-4in with localized 6-12in amounts for the favored banding locations across the eastern finger lakes towards Cortland county.

By Saturday afternoon, high pressure and increasing heights will begin to end the lake effect snow machine.

Regional Radar...

(Courtesy of NOAA)

Regional Advisories...

(Courtesy of NOAA)

Storm Reports...
None.

Storm Impacts...
1. Heavy stratiform rain with total amounts ranging from 1-1.5in. Recent dryness will likely prevent any flooding.
2. Freezing rain and sleet is likely for parts of northern New England affecting travel through Thursday late morning.
3. Heavy snow squalls likely across the entire Northeast Thursday night into Friday with light accumulations.
4. Winds will increase to 20-30mph sustained with gusts to 55mph; advisory criteria.
5. Flash freezes likely all the way to the coast with rapidly falling temperatures Friday. Widespread travel impacts.

Snow Maps...




***The final snow map for the entire Northeast includes total accumulations for the entire event including the synoptic storm, ULL, and lake effect. This does not indicate total snow depth as snow may melt before the arctic air floods into the region. The Pennsylvania snow map includes both lake effect and snows from the upper level low.

Current Great Lakes Water Temperatures...

(Courtesy of NOAA)

Current Lake Erie Wind Direction and Speed...

(Courtesy of NOAA)

Current Lake Erie Water Temperature...

(Courtesy of NOAA)

Selected City Accumulations for the Northeast...
Hagerstown, MD- Rain then a coating to 1in of snow with snow squalls.
Baltimore, MD- Rain followed by snow squalls; coating to 1in.
Salisbury, MD- Rain followed by scattered snow showers; no accumulation.
Pittsburgh, PA- Rain then a period of heavy snow then snow showers; accumulations 2-5in
State College PA- Rain followed by heavy snow squalls; accumulations 1-4in
Williamsport, PA- Rain then heavy snow squalls; accumulations 1-2in
Altoona, PA- Rain then a period of moderate snow showers followed by snow showers; accumulations 2-4in
Harrisburg, PA- Rain then scattered snow squalls; c-2in of snow possible
Lancaster, PA- Rain followed by scatted snow squalls; c-1in of snow possible
Philadelphia, PA- Rain then scatted snow showers; no accumulation
Allentown, PA- Rain then scatted snow showers; a coating of snow possible
Scranton, PA- Rain then scatted snow squalls; 1-2in of snow possible
Washington, DC- Rain then scattered snow showers; a coating of snow possible
Wilmington, DE- Rain then scattered snow showers; little to no accumulation
Dover, DE- Rain then scattered snow showers; no snow accumulation
Trenton, NJ- Rain followed by scattered snow showers; a coating of snow possible
New York City, NY- Rain then scattered snow showers; no snow accumulation likely
Poughkeepsie, NY- Rain then scattered snow squalls; 1-2in of snow possible
Binghamton, NY- Rain then a period of moderate snow; 1-4in of snow possible
Ithaca, NY- Rain then a period of heavy snow followed by scattered snow showers; 3-7in of snow possible
Albany, NY- Rain then scattered snow squalls; 1-2in of snow possible
Hartford, CT- Rain then scattered snow squalls; c-2in of snow possible
Concord, NH- Light snow 1in accumulations, freezing rain .1in accumulation then rain followed by snow 1-4in
Providence, RI- Rain then scattered snow showers; little to no accumulation
Worcester, MA- Freezing rain .1in accumulation then rain followed by snow squalls 1-3in possible
Boston, MA- Rain followed by scattered snow showers; little to no accumulation
Nantucket, MA- Heavy rain and gale force winds
Hyannis, MA- Heavy rain and gale force winds
Burlington, VT- Wintry mix followed by rain and then heavy snow squalls; 3-6in of snow accumulation
Portland, ME- Wintry mix then rain followed by scattered snow squalls; 1-2in possible
Bangor, ME- Wintry mix followed by heavy snow squalls; 3-6in possible
"Subject to Change"

Current Northeast Snow Depth and Northeast Wind chills...

(Courtesy of Wunderground)

Model Analysis
The only model inconsistencies remain for the upper level low forecast position and the intensity of the vortex responsible for snow squall activity with the arctic frontal passage. The exact position and track will be critical to the snowfall max accumulations track. GFS tends to maintain the best dynamics across northern Pennsylvania and western New York State while the NAM and other guidance suggest a more sustained band of rain/snow moving across the entire northeast. Current boundary layer progs by high resolution guidance indicate temperatures above freezing for the majority of the QPF suggesting limited snow accumulations east of the Alleghany Front. Skewt charts also indicate the strongest winds will remain around 925-950mb and will likely only mix to the surface during an energy momentum transfer during the frontal passage. ECMWF guidance is even weaker with the ULL with minimal snow accumulations for all areas generally below advisory criteria. Lake effect snow shower activity will increase by Friday. NAM simulated radar shows several longer bands stretching east of the mountains in New York State and Pennsylvania, but exact location remains uncertain until we get closer to the event. Total SREF QPF for lake effect snows are generally .4in or less. This is due to the unorganized activity with a multi band setup.

After the Storm
As to be expected given this winter's track record, guidance and global teleconnections are no longer supporting a sustained pattern change. Recent ECMWF weeklies and NAEFS prognostics indicate a brief cold period this weekend followed by increasing anomalies towards weeks 2 and 3. It still appears earlier indications of a gradient pattern are likely, but the recent retreat in the expected -NAO appears to have lifted the thermal gradient farther north. This will allow for a more amplified southeast ridge with warmer temperatures reaching farther north locations. Current teleconnections look terrible for a sustained pattern change with a +NAO, -PNA, and questionable MJO phase change. While the pattern will become more stormy, long range guidance suggests very mild weather in the 2-3 week period. ECMWF weeklies were near +5F for the northern Middle Atlantic. Any colder weather will remain across Canada and towards Alaska. There will likely be some sort of snow accumulation before the end of the month for all locations, but east coast cyclogenesis remains unlikely. Towards February a few wavelengths show a return to brief colder weather early in the month, but given the state of the increasing solar activity and madden jullian monsoonal patterns, this remains questionable. Wavelengths suggest stormy periods towards the 16th and 21st of January, but rain vs snow will be a problem through the entire Northeast.

Please post storm reports in this blog from across the Northeast during the winter storm and please post location of observation in each report...

This blog is in progress. Check back soon...

Winter Forecast 2011-2012... Link

Follow my 24hr forecasts on Twitter... Link and Facebook... Link.

Lower Susquehanna Valley Doppler...

(Courtesy of WGAL)

"10mi northeast of Harrisburg 2011-2012 winter statistics"
(Snow Stats)
Current Snow Cover- 0.0in
Monthly Total (October)- 5.5in
Monthly Total (November)- 0.0in
Monthly Total (December)- 0.4in
Monthly Total- (January)- 0.2in
Seasonal Total- 6.1in
Winter Weather Advisories- 1
Winter Storm Warnings- 1
Ice Storm Warnings- 0
Blizzard Warnings- 0
Freezing Rain Advisories- 0
Winter Storm Watches- 1

(Temperature Stats)
Lowest High Temperature- 29F
Lowest Low Temperature- 10F
Wind Chill Advisories- 0
Wind Chill Warnings- 0

(Snow Storms Stats)
Historic October Nor'easter - October 29 - 5.5in of wet snow
322 Lake Effect Snow Band - December 17 - 0.3in of wet snow
Weak Clipper - December 29 - 0.1in of snow
322 Lake Effect Snow Band - January 18 - 0.2in of snow

Winter Storm Blog

Updated: 15:50 GMT le 18 janvier 2012

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Midweek Ice for Interior New England...

By: Blizzard92, 19:34 GMT le 10 janvier 2012

"Current Temperature"


"Current Dewpoint"


"Current Surface Map and Weekly History of Jet Stream Position"


"Regional Radar"


"Regional Satellite"


"Regional Advisories"


"Soil Moisture Anomalies and 5-day Precipitation Amounts from Hydro Prediction Center"


"Severe Weather Outlooks from Storm Prediction Center Days 1, 2, and 3"


"12hr Estimated Precipitation"


"Forecast Max Temperatures"


"Forecast Min Temperature"


"Forecast Weather at 2pm"


"Current Storm Reports"


"Fire Outlooks from Storm Prediction Center Days 1, 2, and 3"

(All maps courtesy of NOAA and Penn State Meteo.)

"Forecast Model Links"
-NAM model 12z...Link
-GFS model 12z...Link
-NMM model 12z...Link
-SREF model 9z...Link

"Severe Weather Links"
-Atmospheric Soundings Skewt T charts...Link
-SPC Mesoscale Analysis Pages...Link
-Public Spotter Reports for State College NWS...Link
-Severe Weather Model Forecast indices...Link
-Severe Weather Parameter Definitions...Link

"Flooding Links"
-Automated Pennsylvania Rainfall Recording Stations...Link
-Flash Flooding Guidance...Link
-HPC Forecasts for Excessive Rainfall...Link
-Hydrology Predictions for Lakes, Rivers, and Streams...Link

Lower Susquehanna Valley Doppler...

(Courtesy of WGAL)

Follow my 24hr forecasts on Twitter... Link and Facebook... Link.

"10mi northeast of Harrisburg 2011-2012 winter statistics"
(Snow Stats)
Current Snow Cover- 0.0in
Monthly Total (October)- 5.5in
Monthly Total (November)- 0.0in
Monthly Total (December)- 0.4in
Monthly Total (January)- 0.0in
Seasonal Total- 5.9in
Winter Weather Advisories- 1
Winter Storm Warnings- 1
Ice Storm Warnings- 0
Blizzard Warnings- 0
Freezing Rain Advisories- 0
Winter Storm Watches- 1

(Temperature Stats)
Lowest High Temperature- 29F
Lowest Low Temperature- 10F
Wind Chill Advisories- 0
Wind Chill Warnings- 0

(Snow Storms Stats)
Historic October Nor'easter - October 29 - 5.5in of wet snow
322 Lake Effect Snow Band - December 17 - 0.3in of wet snow
Weak Clipper - December 29 - 0.1in of snow

Observation Blogs

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Major Pattern Change???

By: Blizzard92, 20:58 GMT le 04 janvier 2012

"Afternoon Thoughts" (Updated 1/4)
You are at a stop light. You are in a rush. You look to the person sitting in the car beside you. Facial expressions can tell quite a bit about a person. Malcom Gladwell's "Blink" details the series of facial expressions allowing a person to make instant predictions in a way of mind reading. You have likely made a subconscious determination on the type of day that person is having in the car beside you.

I bring this up at the end of a very hectic and volatile period for many consumers as the mad holiday shopping scene comes to a close. During this period our subconscious seems preoccupied with worries about the next gift that needs to be purchased or meal which needs to exquisite to impress the inlaws. We quickly forget our sense of manners. Retail is a very difficult position given the high interaction with the general public. To put it politely, the general public is a very rude. For many people they do not seem to care about other's emotions. It most cases the problems at retail stores exist with the 'higher ups' and not so much the people on the floor. People may say customer service is on the decline, but courtesy by the customer is declining even more rapidly. Consumers will not take no as an answer and have no care for the stores where they make their purchases. Instead of returning an unwanted item back to where they found it, they sit it on a completely opposite location. They rely on 'someone else' to return it for them instead of spending a minute to reposition the object. Many times I have waited in lines to see consumers ahead of me nearly yelling at retailers for their dissatisfaction. Humans are not wired to be perfect; in fact our poor qualities are often evident.

The next time when interacting as a consumer, take a moment to make a conscious choice to notice the facial expression of the other person. They may be having a great day. Or maybe they are having a terrible day. We are all equals and we must take a moment to slow down our fast paced 21st century lives while becoming a more understandable person.

"Current Surface Plot"

(Courtesy of HPC)

"Regional Radar"

(Courtesy of Wunderground)

"Regional Advisories"

(Courtesy of NOAA)

"Forecast Discussion"(Updated 1/4)
A very quiet 7-day weather period is likely over the Northeast associated with a very progressive flow. Wednesday night will feature a weak series of vortices sparking a light snow returns on the radar across southern Pennsylvania and northern Maryland. Current meso obs are reporting dew points in the single digits, which will likely prevent any organized light snow activity from forming. Recent HRRR model runs and other guidance suggest a period of flurries and light snow showers forming over this area despite the widespread dry air. QPF remains less than .05in with any snow accumulations limited to a dusting to maybe 1in over very isolated locations. None the less given the very cold temperatures, even a dusting can cause travel problems. Current infrared thermometer reports indicate road temperatures remain in the upper 20s or lower. As the series of shortwaves move through, the flow will shift to the northwest despite a gradual WAA flow. This will increase snow shower activity especially southeast of Lake Ontario. Any lake effect snow accumulation will be limited to a few inches or less over isolated locations. WAA and increasing subsidence will cap any snow shower activity by Thursday morning. H85 thermals will begin to slowly rise above 0C on Thursday, but boundary layer temperatures will generally average near normal.

An increasing westerly and southerly flow with increasing heights will support a mild period from Friday to Sunday as temperatures average well above normal ahead of the next cold front. Sunshine will prevail over much of the region Friday before a cirrus deck enters the Northeast and begins to thicken and lower on Saturday associated with a lee trough. The cold front will move through Saturday night into Sunday, but weak forcing will inhibit any precipitation. QPF totals are meager and most guidance ranges from 0.00 to 0.1in over isolated locations. Precipitation will be in the form of rain with 1000-500mb thicknesses as high as 555dm up to I-80. The push of cold air on Sunday will be gradual as the air mass will have Pacific origins. High pressure will also move over the region preventing any lake effect and upslope snows from forming.

Overall the next seven days will be very quiet weather wise with temperature means above normal for all climatological reporting stations. A few global models have hinted at a storm system by midweek next week, but given the lack of blocking, precipitation has a higher chance for rain for most locations with any storm system probably cutting up through the Ohio Valley.

"Regional Satellite"

(Courtesy of Penn State Meteo.)

"Current Water Vapor Loop"

(Courtesy of Penn State Meteo.)

"Lake Effect Snow Conditions" (Updated 1/4)
Two vortices will be rotating through the Northeast Wednesday night, but dynamics are relatively meager. In fact temperatures will begin to rise Wednesday night associated with some weak warm air advection. Despite this flow of Lake Ontario will give way to light lake effect snow Wednesday night through Thursday morning with a northwest flow. High resolution guidance is only printing out around 0.05in QPF, but a few disorganized bands are possible. Light snow accumulations southeast of Lake Ontario are possible towards the northern finger lakes and southern Tug Hill plateau. These accumulations will range from 1-4in from Utica to Cortland to Dryden, NY. Also a few HRRR runs have produced a light band off Erie up through Buffalo, but any accumulations will be less than 1-2in most likely. As warm air advection continues to increase Thursday, subsidence will cut off any lake effect snow showers by midday. The lakes will take a break from any snow production for several days as upper level heights increase with ridging over much of the region. Temperatures will rise to well above normal by the weekend. A weak cold front will move through in the Sunday time frame, but high pressure will quickly move in for the beginning of next week preventing any lake effect snow formation. The next seven days look relatively quiet in this regard.

Over the last few days lake effect squalls have widely impacted travel across much of the snow belt regions, but general accumulations especially across New York state were generally less than expected especially around the Finger Lakes and Tug Hill Plateau region. Bands remain disorganized off of Lake Ontario likely due to an area of subsidence ahead of the arctic front and then increasing shear values after the frontal passage. Most accumulations were around 4-10in over the Tug Hill plateau and only 1-2in for the Finger Lakes region. These accumulations were around 50% lower than expected. Accumulations ranged around 6-12in for the Laurel Highlands in Pennsylvania and 12-15in across western Maryland. These accumulations were expected by forecasts and definitely increased snow levels for many ski areas. Outside the lower accumulations in New York state, most snowfall panned out generally as expected. The highest snow accumulations were from northeastern Ohio into northwestern Pennsylvania and into the Chautauqua Ridge area in southwestern New York ranging from 20-24in. Given the cold air mass and very dry snowfall, much of the snow has sublimated and compacted so snow depths are already rapidly waning. Most of the snow pack will be depleted by this coming Sunday as temperatures increase above normal. This will continue to cause near record low levels of snow in the snow belt regions.

"Current Great Lakes Water Temperatures"

(Courtesy of NOAA)

"Current River Ice Reports and Ski Conditions" (Updated 1/4)
The recent mild weather has prevented any ice formation along major waterways including rivers and lakes. In fact Lake Erie is even remaining nearly 5F above normal with very little if any ice formation. Most smaller farm ponds have recently acquired ice given this recent 2-3 day arctic blast as low temperatures dropped from -10F across the Alleghany plateau to +10F in the southeastern parts of Pennsylvania. Elsewhere in the Northeast ice formation on most ponds is certainly too thin for ice fishing as far north as Maine and generally remains less than 4in in thickness. The weather will begin to shift towards the coldest part of the climatological winter and therefore ice thicknesses will increase especially for northern New England. The ice fishing industry has certainly taken a hit from Pennsylvania to Maine, but conditions will be improving. It appears several arctic blasts are possible around the day 10 period and this will assist in a more winter like regime outdoors.

Ski conditions have been very poor across the Northeast and limited to snow making machines. The best conditions are being reported in northern Vermont across the favorable upslope locations in the Green Mountains particularly towards Stowe and Killington. Over the past 7 days nearly 2ft of natural snow has fallen in these upslope locations courtesy of Lake Ontario and Lake Champlain enhancement; still only about 50% of the trails remain open. Locations across the Berkshires and in the White Mountains have also been suffering with very little if any natural snow. Natural snow accumulations in this region have been less than 5in over the last two weeks. Ski conditions are improving towards western New York and western Pennsylvania where lake effect snows have laid down a general 5-12in of snow. Seven Springs in the Laurel Highlands is reporting quite a bit of natural snow over the last few days along with machine snow. Locations outside the highest elevations and snow belts have relied on pure man-made snow; fortunately conditions have finally become cold enough for those locations to open to the public.

The outlook for the next seven days looks relatively poor with few chances for snow. Light lake effect snow is possible Wednesday night into Thursday across western New York around the Chautauqua Ridge region, but accumulations will remain less than 4in. Also light upslope snow is possible in this period in northwestern Vermont, but accumulations will only average 1-3in. Temperatures will begin to increase by the weekend averaging nearly 10F above normal on Saturday. Early guidance suggested a storm system associated with a cold front on Sunday, but any QPF will be light and likely rain for most areas. A more sustained colder regime may be possible by mid week next week, but that remains to be seen. For now enjoy the best conditions of the winter for skiing locations over the next 24-48 hours.

-Link to official reports page from NWS... Link.
-Link to local ski resort snow conditions... Link.

"Current Northeast Snow Depth and Northeast Wind chills"

(Courtesy of Wunderground)

"Long Term Outlook" (Updated 1/4)
It originally appeared that January was looking to be another very mild month in this continuous string of above normal temperatures. But several recent changes in global wavelengths are suggesting the very mild regime will be a bit more tamed than originally expected. The forecasted SSW (sudden stratospheric warming event) is showing signs of occurring over the next two weeks with ensemble guidance strongly supported a rapid change. This SSW corresponds with a temporary decline in the CME from the sun as activity quiets for a period before becoming more active once again as suggested by astrometeorologists. The SSW often corresponds to a blocking regime allowing the Arctic Oscillation to average with a negative mean. ECMWF and GFS operational and ensemble guidance continues to indicate a decline in the AO with a drop to negative by mid January. This is also connected with a negative NAO that is now being forecast by GFS and ECMWF ensembles. MJO forecasts also appear to become a bit more favorable. Recent ensemble MJO phase forecasts appear to weaken forcing instead of rotating through phases 3-5 as originally expected. This shift in monsoonal patterns in the Indian Ocean along with suggested SSW event will support a radical change in the global jet stream wavelength patterns. This change will take place by mid January in the 6-10 time frame. While it sounds like this pattern will be ideal for a more wintry regime across the northern Hemisphere, there are several unfavorable factors, which will prevent major east coast snowstorms are a true sustained cold pattern.

The Pacific will generally become more favorable as the polar vortex shifts from Alaska towards the Hudson Bay. This will shift the coldest air southward, but the La Nina pattern will also support the continued placement of the southeast ridge. As warm air tries to move northward up the east coast and cold polar air shifts southward, a tight gradient will develop along the east coast. Placement of this thermal boundary will be critical to the location of snow vs. rain. Also the -NAO will generally be east based preventing ideal upstream blocking. Given the thermal gradient driven by the amplified southeast ridge and still unfavorable Atlantic, east coast storm systems will be limited. There will likely not by any major east coast cyclones through the end of January. Most storm systems will generally be overrunning situations as waves move along the thermal boundary. Once again, the exact placement of this boundary will be very critical for forecasts through the second half of the month. Cold air will definitely be more available in the 10-14+ day time frame, but it will be interrupted by periodic warm up periods. Therefore the two week period will likely average right around normal temperature wise.

None the less, a large pattern change is likely. Despite it still remaining not the best pattern for snow lovers, it will definitely increase the chance for wintry precipitation (especially north of the thermal gradient). And for cold lovers, this appears to be a significant Arctic blast towards the east coast around day 10. While the next 7-10 days will be boring weather wise, changes are coming. Stay tuned!

"Current NAO and PNA Predictions"

(Courtesy of NOAA)

"Anchorage, Alaska Tower Cam"

*Back due to popular demand!

"Monthly Temperature/Precipitation Outlook"(January)(Updated 1/4)
January looks to be another mild month for much of the Northeast, although will be a bit more tamed than January with lower positive temperature anomalies. The weather pattern will begin to shift associated with a SSW event and the repositioning of the polar vortex. This will be occurring towards mid month. But the La Nina pattern will continue to dominate the jet stream allowing for an amplified southeast ridge. This will continue to interrupt any chance for a sustained cold pattern through the end of January. Precipitation chances will be increasing towards the end of January as a large thermal gradient sets up across southern New England or the Middle Atlantic. A +NAO and -EPO will likely be means for the teleconnection indices. While preventing major east coast snowstorms, there will be more widespread cold increasing the probability for wintry precipitation especially for locations with increasing latitude.

Temperature- Temperatures will average slightly above normal to above normal with the highest anomalies across southern locations in the Middle Atlantic. Anomalies will range from +3.0F towards DCA to +1.5F around BOS. Given this is the height of the climatological winter, it is still possible to get snow in above normal temperature regimes. If the NAO averages with a more negative mean, it is possible the southeast ridge remains a bit more suppressed.

Precipitation- Precipitation will likely average near normal for most locations. There appears to be a lower frequency of heavy QPF events given the continued progressive flow, but several lighter events are possible especially in the second half of the month. The higher precipitation anomalies will be across northern areas towards Vermont, New Hampshire, and Maine.

"Temperature and Precipitation Outlooks from Climate Prediction Center for next 30 days"

(Courtesy of NOAA)

"10mi northeast of Harrisburg 2011-2012 winter statistics"
(Snow Stats)
Current Snow Cover- 0.0in
Monthly Total (October)- 5.5in
Monthly Total (November)- 0.0in
Monthly Total (December)- 0.4in
Monthly Total (January)- 0.0in
Seasonal Total- 5.9in
Winter Weather Advisories- 1
Winter Storm Warnings- 1
Ice Storm Warnings- 0
Blizzard Warnings- 0
Freezing Rain Advisories- 0
Winter Storm Watches- 1

(Temperature Stats)
Lowest High Temperature- 29F
Lowest Low Temperature- 10F
Wind Chill Advisories- 0
Wind Chill Warnings- 0

(Snow Storms Stats)
Historic October Nor'easter - October 29 - 5.5in of wet snow
322 Lake Effect Snow Band - December 17 - 0.3in of wet snow
Weak Clipper - December 29 - 0.1in of snow

"Local Harrisburg Radar"

(Courtesy of WGAL)

Winter Forecast 2011-2012... Link

Follow my 24hr forecasts on Twitter... Link and Facebook... Link.

Weekly Forecast

Updated: 21:31 GMT le 09 janvier 2012

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About Blizzard92

Cornell University- Atmospheric Sciences Undergrad; Research Assist.- Onset of Spring Indices Toolbox; Interests- Small spatial scale climatolology

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Personal Weather Stations

Linglestown, PA
Elevation: 520 ft
Température: 24.2 ° F
Point de rosée: 15.2 ° F
Humidité: 68%
Vent: Calme
Rafale de vent: 9.0 mph
Updated: 10:37 EST le 18 janvier 2014

About Personal Weather Stations