Potential Major Storm for Eastern US for January 26-27...
Current wavelengths are supporting a large synoptic storm east of the Mississippi River Valley during the January 26th to the 27th with widespread moisture from the Southeaast to New England. This setup is corresponded with highly favorable teleconnections. The NAO (North Atlantic Oscillation) remains negative but has shifted the higher heights more east-based. This causes less blocking upstream. Blocking is typically associated with suppression and tracks of coastal lows well over 100mi off the coast. Also blocking allows for a slower movement of low pressures ushering in cold air to the right of the low in the large cold sector of the storm. When the blocking is allowed to relaxed or becomes displaced as in this instance, it allows cyclogenesis to often occur a bit farther to the west offering warmer air with a southeasterly flow off the Atlantic. This upcoming coastal threat will favor the later with dampened upstream blocking. Also the MJO (Madden-Jullian Oscillation) is entering phases 7-8. The MJO is a measure of the positioning of the monsoonal rains across the Indian Oceans. Since all global weather patterns are interconnected, differing wavelengths of pressure in the Indian Ocean will in time affect areas downstream in the jet stream across North America. Here is the current composite 500mb mean charts for an MJO phase 7 during January from a meteorological study by Allan Huffman...
Link
As noted above, increasing ridging across the western United States with a deep trough over the east coast often occurs. This corresponds to the current teleconnective pattern over North America with a positive PNA (Pacific/North American Pattern) which favors high pressure over the western United States coupled with upper level ridging.
The teleconnections are certainly signaling the classic jet stream setup for eastern cyclonegesis. But several 'issues' will likely prevent a major east coast snowstorm for areas in the major metropolitan region of the United States. Paul Kocin and Louis Uccellini's monograph of Northeast snowstorms signals the classic setup for widespread historical snowfalls to be accompanied by an arctic high pressure to the north of the storm. Typically we would root for a large anticyclone to the north or north-northeast of New England across southern Canada. This helps usher in cold air funneling in the western periphery of the low pressure. Also this helps prevent the low pressure from running too far inland.
The current synoptic setup shows the high pressure to the north of the low quickly scooting to the northeast and eventually too far east to save many from the expected rainfall. The 1/21/11 12utc ECMWF shows the banana high displaced to the east in an unfavorable location.
Kocin/Uccellini's near miss historic east coast snowstorm often featured a high pressure in a similar displaced location. Typically this would then favor inland snows with a mix or rain across eastern areas. While a severe arctic air mass will be in place along with a fresh snow pack over the Northeast, oftern these air masses can disperse quicker than one would assume. Current GGEM/UKMET/ECMWF guidance supports the upper level trough becoming negatively tilted towards the easteern Mississippi Valley. With these higher amplitude trough, the banana high is quick to depart and allows the cyclogenesis to occur farther along the coast. The 1/21/11 12utc GFS shows this evolution a tad differently, but does appear to be an eastern outlier. The 12utc GEFS mean shows a farther west solution, which often argues that the operational model is too far east. Most of my analogs support the heaviest snows well northwest of I-95 as warmer invades from the east. Despite several global models showing the low becoming vertically stacked allowing H85s to crash, there will likely be a southeast maritime flow across eastern areas.
The track of the H5 low tracks across Virginia, which is a bit too far north for a favorable snowstorm for most areas south of Washington DC for certain. Given the departing arctic air mass I would expect areas that receive mainly rainfall still to receive snow accumulations on the front end of the storm. The ECMWF mentioned earlier supports a quick 4-8in along most of I-95 before rainfall.
At this point, those farther east will be hoping to look for the 500mb low to track farther south, the banana high to become more situated north and not northeast, and the exact placement of the negatively titled trough.
While the threat is several days away, current climatology and guidance supports a very high threat of a large storm system over the eastern United States in this time frame. Whether it is rain or snow, there appears to be a large amount of moisture involved with ECMWF QPF up to 4in in northern Delaware and southeastern Pennsylvania. I know many are critical of predictions of storms well in advance, but meteorology is about understanding the synoptic setup that leads to the development of these storms. Watching the evolution of this situation will be very interesting and I am becoming increasingly enthused for those well inland. Even along the coast heavy rain and high winds are possible with a western storm track so threats will be high with any storm scenario. Stay tuned for updates throughout the weekend. For now if I had to make a forecast, this would be the precipitation scenario map.
The exact placements of the trough/shortwaves/high pressures will change, but I have not seen such consistency in the computer models for a large event in a very long time. This is also backed up by a favorable wavelength pattern as mentioned earlier in the blog. I think there is a higher possibility of this tracking farther west and inland than it tracking east. The odds of all snow along I-95 to the coast remain low given the departing high pressure. Another concern is the poor modeling this winter and the trend for storms to phase later than expected. Something to keep reminded of... Stay tuned!
Short Computer Model Introduction
This is a pretty decent quick intro on computer model forecasts along with beneficial links. Computer models use the complex calculus algorithms to print out the forecasts. Despite our complaning with the models, without them much of us would be lost except in the short time. Some of the earlier computer models consisted of the ETA, NGM, and AVN, which forecasted generally less than 84hrs. They were highly inaccurate, but provided a basis. The ETA was actually the computer model that helped meteorologists predicted the "storm of the century" in March of 1993 so well in advance. But now more than ever we have a myriad of computer models available to the general public with many mesoscale models only available to NOAA. Lets start with the general. All current computer models are based off on the Zulu time. Zulu time is also known as UTC or Greenwich time . Generally to forecast timing of storms my special BUFKIT data transitions UTC time to EST time, which is helpful. But BUFKIT is a special download, which I won't get into, but the transition is helpful as for some reason I never am able to understand time zones too well, hahaha. Anyways let me start with each computer model...
-GFS (Mentioned most of all as it is a global model (Global Forecasting System))
~Available in 0z (initiates at 10:30pm), 6z (initiates at 4:30am), 12z (10:30am), 18z (4:30pm)
~Forecasts out to 384hrs
~Typical biases
Cold bias on long range on 18z run
6z and 18z slightly unreliable
Northwest trend on lows within 84hrs of event
-ECMWF (This is another global model run by an international organization (European Centre for Medium-Range Weather Forecasts))
~Available in 0z (initiates at 1:30am), 12z (initiates at 1:30pm)
~Forecasts out to 240hrs
~Typical biases
Overphases lows in 168hr range
Holds too much energy in southwest
Known as extremely accurate within 140hrs
-NAM (Mesoscale short range model)
~Available in 0z (Initiates at 9:30pm), 6z (Initiates at 3:30am), 12z (initiates at 9:30am), 18z (Initiates at 3:30pm)
~Forecasts out to 84hrs
~Typical biases
Highly inaccurate towards the 84hrs
Handles coastal storms very well and southwest overrunning events
Tendency for way too much QPF
Those three above are the most common models for a beginner in computer models, but there are many more. All of the global models consistent of ensemble models also, such as the GFS has a myriad of ensemble (small models) that create a mean solution known as GEFS. They typically are too cold and southeast with low pressures, but some reason the NWS seems to enjoy using them. There are also more global models than the GFS and ECMWF... The UKMET is run by an internation organization and forecasts out to 144hrs. This model typically comes out an hr before the ECMWF and usually is pretty similar to the ECMWF. The ECMWF may also be known as the EURO by the way. There is also a Canadian model known as the GGEM/CMC, which again contains ensemble models. All of the internation models only run 0z and 12z runs. This is probably for the best as all models only receive new upper air data in 0z and 12z runs, so this is why the American model runs of the 6z and 18z are usually worthless. There is also a high resolution Canadian model known as the RGEM, which is very similar to the American NAM. High resolution (mesoscale models) are important as they usually are able to pick up on fine details such as frontogenesis, advection, adebiatic cooling, convection, etc. Some of this high resolution models include the WRF, HIRES NMM, RUC, ARW. They all are usually very accurate, but the WRF and HIRES NMM usually have wet bias.
As mentioned above there are ensemble models which come up with a mean solution instead of using one computer model's algorithms like the global models use. These ensemble mean solution are known as the MREF and SREF with MREF being in the medium range and SREF in the short range. SREF is usually pretty accurate and forecasts within 87hrs of an event. There are also other computer models used for hurricane forecasting, but I will not get into them. For instance one is the GFDL, which you may have heard of. I find I use mainly the GFS, NAM, and WRF/NMM in the summer, but use all of the models in the winter.
A few models to avoid...
JMA
KMA
CAMPASS
DGEX
Here is a list of links for explanations on how to interperate the models...
-PennState E Wall, which runs all of the models
http://www.meteo.psu.edu/~gadomski/ewall.html
-PennState E Wall tutorial on computer models (Check it out)
http://www.personal.psu.edu/adb241/eWallTutorial/ Main.htm
-Severe Weather parameters used on models, explanation
http://www.crh.noaa.gov/sgf/n=severe_weather_chec klist_paper
-Forecasting winter weather
http://www.crh.noaa.gov/lmk/soo/docu/precip_type. php
-NCEP; used to find American Computer models
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/
-Severe Weather Models
http://www.wxcaster.com//conus_0012_us_models.htm
-Winter Weather Models
http://www.wxcaster.com/conus_snowfall.htm
-Model Soundings
http://wxweb.meteostar.com/sample/sample.shtml?te xt=KMDT#
The last link is listed above as model soundings which takes all of the data to print out all sorts of information including precipitation type along with dynamics such as Omega. This is very complex and takes some time getting used to. Also you may see this data instead of in charts, it is sometimes used in SKEWT T charts.
I hope all of this information helped out... Keep in mind precipitation amounts is QPF, with 500mb aloft being the jet stream, 700mb aloft measuring relative humidity, 850mb aloft measuring 5,000ft aloft temperatures, 925-1000mb measuring surface temperatures. Generally I would look at the GFS and NAM first to get a hang of it along with reading the tutorial links. Use the 850mb and 2m charts for the GFS especially as they are pretty self explanatory and color coded. You will find some maps for international models are confusing and black and white.
"Here northeast of Harrisburg 2010-2011 winter statistics"
(Snow Stats)
Current Snow Cover- 1-4in
Monthly Total (November)- Trace
Monthly Total (December)- 0.6in
Monthly Total (January)- 11.65in
Seasonal Total- 12.25in
Winter Weather Advisories- 5
Winter Storm Warnings- 0
Ice Storm Warnings- 0
Blizzard Warnings- 0
Freezing Rain Advisories- 1
Winter Storm Watches- 1
(Temperature Stats)
Lowest High Temperature- 23.7F
Lowest Low Temperature- -1.7F
Wind Chill Advisories- 0
Wind Chill Warnings- 0
(Snow Storms Stats)
First accumulating snow - December 10 - 0.50in
Clipper light snow - January 7-8 - 2.25in then another 1in
Double Barrel Low - January 11 - 4.5in of snow
Coastal Low - January 17-17 - 1.8in of snow/sleet
Arctic Front - January 20-21 - 2.1in of snow
Lower Susquehanna Valley Doppler...
(Courtesy of WGAL)
This is the most difficult forecast I have ever had to make for the region. The gradient is going to be very sharp across the north and will make for a very high bust potential. This map is a bit bullish for northern areas. We shall see. Enjoy!
"Here northeast of Harrisburg 2010-2011 winter statistics"
(Snow Stats)
Current Snow Cover- 4-8in
Monthly Total (November)- Trace
Monthly Total (December)- 0.6in
Monthly Total (January)- 18.15in
Seasonal Total- 18.75in
Winter Weather Advisories- 6
Winter Storm Warnings- 1
Ice Storm Warnings- 0
Blizzard Warnings- 0
Freezing Rain Advisories- 1
Winter Storm Watches- 1
(Temperature Stats)
Lowest High Temperature- 23.7F
Lowest Low Temperature- -1.7F
Wind Chill Advisories- 0
Wind Chill Warnings- 0
(Snow Storms Stats)
First accumulating snow - December 10 - 0.50in of snow
Clipper light snow - January 7-8 - 2.25in then another 1in of snow
Double Barrel Low - January 11 - 4.5in of snow
Coastal Low - January 17-17 - 1.8in of snow/sleet
Arctic Front - January 20-21 - 2.1in of snow
Upper level/coastal low - January 26 - 5.75in of snow
Reader Comments
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first round was 2.2"
second round was 4.6"
liquid equiv. 0.77"
blizzard92,
not sure if i told you but my coop site name was changed from gettysburg 6w to cashtown 1s.
i've been using cashtown for all snowfall reports this year
local pns statement shows york getting 5.5"
Where did you see those 25" readings CTwx?
There was about 10 reports of over 20 inches listed on the local news and 3 of over 25 inches. I didn't mean to say confirmed snowfall totals, not even the NWS's listed totals are confirmed yet. I did however see a convincing picture, one of a guy measuring 24.5 inches in his driveway. Looks pretty even so I don't think it was a drift. I've also seen 3 unconfirmed 20 inch reports from Pomfret, CT. It's important to remember that more of the public/officials report totals to local news agencies and media than they do to the NWS. NWS released totals generally give only a vague idea of the totals and their alignment. Spotters are just about the only ones that ALWAYS report to NWS. Then the NWS tends to compile all the reports from every source and a few days later you get a more exact idea from them.
http://www.flickr.com/photos/nika7k/sets/72157625791767957/
My total measured snowfall = 13"
Morning - 4
Evening - 9
I could be off by an inch. Other observers measured 14" for Media. I think next time I'll measure in two areas to make sure it's accurate.
Thank You, My brother lives in that area.
Is it too early to ask about tonight/tomorrow and Saturday?
also, it looks like we missed out again on the heavier snow. you better do something about this or I am calling Jack Frost to go take his chill somewhere else so I can get out and play some golf. Oh, and don't forget Pardon Me Pete will not see his shadow next week
Ya i wasn't doubting you, just wondering were you heard it. It was quite a storm yet again, another 12" here in Methuen MA.
Care to elaborate more blizz? Didn't the GFS show yet another storm moving up the coast a few days ago for next week?
The only thing that is sure about next week is... very cold air returns. Sooner if there's no storm, holding off until after the storm if there is one.
...NEW YORK COUNTY...
CENTRAL PARK 19.0 630 AM 1/27 CENTRAL PARK ZOO
19" Wow. So that's a 20" storm and a 19" within a one month span and it brings our totals to 56.5" for the season. Just...wow.
Blizz got another one right--how many days out.
I got to get to work but am wondering did Heavy check in? Wonder if he was one of those stranded on the roads.
What a Winter! Events thus far:
12/16 - Clipper - 0.6"
12/16-12/27 - Nor'easter - 10.8"
1/7 - Clipper - 1.2"
1/8 - Clipper - 2.3"
1/11-1/12 - Double Barrel Low/Nor'easter - 7.2"
1/17-1/18 - Coastal Low/Wintry Mix - 1.6" Snow; 0.15" Ice
1/21 - Busted; Arctic Frontal System - 0.3"
1/26-1/27 - Upper Level Low/Nor'easter - Two part event featured thundersleet - 10.3"
December: 11.4"
January thus far: 22.9
2010-2011 thus far: 34.3"
Bring on February!
Congrats to all who got snow yesterday!
Only got 12" in New Rochelle, NY.
How was the concert?
Nice work...
Local state park registered 13.3 inches of Snow!
Local paper says this is the snowiest first month in NJ in 62 years.
As an aside, and not to get anyones panties in a twist... (with any GW)
when the Iceland Volcano had it's eruption this past summer...
a local farmer... told us about their family records dating from the Krakatoa Eruption. Said farmer, believed this year would be a record snowfall winter and cool summer. Interesting coincidence...
2in slush in am then lightning and pea sized hail about 1830 then 2130 snow began with about five more inches for a total of 7in.
I've seen some long-term computer guidance that is suggesting the majority of the globe will become cooler than average this year. The poles still remain warmer than average though.
Our nicest most dependable snow comes from the clippers - they don't get much hype but they deliver a few inches of fluffy snow with each hit.
The coastal storms on the other hand consistently underperform in my location - I am apparently at exactly the right spot where more often than not there's a glancing blow at best or lousy ice and rain at worst...
I love the winter and the snow but these storms have been been consistently disappointing...
Grand Total of 15". And it is heavy.
1) Will the data from this storm go into future modeling immediately?
2) What caused the "explosion" that most models missed? Simply Timing?
P.S.-If you had extended that heavy band in your final map right thru Jersey, although still under , it woulda' been a direct hit. Nice work.
It was good, thanks, Zotty. That's surprising you "only" got 12. Funny how 12 sounds low now that we have these mega winters. When we came out of the theater the snow was intense and the crowd instantly turned white.
I've been out most of the day, mostly walking around Brooklyn taking photos. I'll put some up in a bit.
EDIT: Oh, I see now that you were only counting the 12 from overnight. Well, we had 14" over night and 5" yesterday morning. Similar.
CENTRAL PARK 27.4 INCHES (1925) 36.0 INCHES
NEWARK 31.6 INCHES (1996) 37.3 INCHES
LAGUARDIA 27.6 INCHES (1996) 32.4 INCHES
BRIDGEPORT 26.2 INCHES (1965) 41.8 INCHES
ISLIP 21.5 INCHES (2005) 34.2 INCHES
NEXT!!
unfortunately, I am greedy for snow and I'm enjoying every inch we got! Totally cheated last year, this is CT's turn!
from what I understand, data from EVERY weather event is input to the computer models. That is how the computer models work, based off of the past. Part of the major reason that the computer models aren't more accurate than they are today is because there simply hasn't been enough well-documented weather notes especially once you go prior to the 1940s and 50s. So the computer models only have half a century worth of data to work off of, which is very little when you consider that the large scale weather patterns on Earth have large scale phases of 30+ years. This means that the really good data input into the models has only spanned a couple of these long-term pattern changes. Sure you have additional data going back further, but it's a lot more spotty and inaccurate. It would be realistic to say we are still at least 50 more years away from computer models providing the accuracy needed to prevent surprises and busts.
Link
Maybe you guys were shafted but I'm at 115 inches since December 2009, I think that's enough!
Anyone have a clue what's happening Feb 1-2?
Definitely not trying to hype up the storm this early in the game, especially considering just yesterday there was a 1,500 mile spread in the track solutions and a full array of strength solutions.
Definately CT's turn. But I've been lucky enough to be a nice chunk of both.
Thanks, but I guess I'm missing something, all I see on that map are snow totals, not QPF.
Just found it under the flyout menu on the right. Thanks.
I'm right at 100" since December 2009.
You ain't kidding! I'm completely whooped. This ain't the fluffy stuff we've been used to.
3.5" between 11pm and midnight last night with about a 10:1 / 11:1 ratio. Imagine if that was 15:1? We'd be talking around 5" per hour. That was right up there with some of the heaviest snowfall rates I've ever seen.
hard to believe that our seasonal snowfall was actually 5 inches above average last year, isn't it?
oh sorry, that was my mistake actually. I usually check QPF based on radar estimates... but I can tell you that when I checked them this morning there was a bullseye of 2+ inches of QPF over southeastern CT, and a swath of 1+ inch QPF running from the mid-atlantic all the way up through southern and eastern CT. Litchfield County had under 3/4 of an inch... well under that in extreme northwest Litchfield County.
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