SPC has Slight Risk for Eastern New England
The SPC has a slight risk out for most of Eastern New England. Main severe threat appears to be damaging winds from this event with severe hail possible as well, however that threat is further north. A surface low and shortwave are over Eastern Canada in the vicinity of Quebec, Canada. Its associated surface cold front is now in upstate NY and is moving eastward. A large cold air mass is entering the region from the west. Sunshine and surface dewpoints in the low to upper 50s should yield enough moisture to allow for afternoon thunderstorms to develop. With a strong shear environment in place and sunshine for most of eastern New England, this would allow for thunderstorm development as the front enters the region after noon today. Within the strongest cells large hail and damaging wind gusts appear to be the main threats from these storms. Possible organization will have to be watched for an enhanced threat for severe weather including strong damaging winds. Update will come as storms begin to develop. We have a much better chance at seeing severe weather then yesterday because we a strong forcing mechanism which is a rather strong sheared cold front moving through the region. Yesterday did not fall through because of the lack of forcing as the main frontal system moved to the north. This system will be further south then the last one and therefore will allow for a better or more widespread severe threat.
GFS and NAM show severe weather for Eastern Interior Massachusetts
Both the GFS and NAM models show a possibility for severe weather on Sunday. Most likely time for this episode is 18z on Sunday. LSI is around 2 or less, shear is 30-50 knots, 500-1000j/kg CAPE values, good amount of surface based CAPE, cold front moving SEward and a strong upper level vort maxima. Main aspect of severe weather would be damaging winds given that the wet bulb temperatures are quite low and hail parameter is low on both models. Lapse rates are at least 6C on both models with NAM having strong lapse rates. With a long period of solar heating likely for SE interior MA its more then likely for this area to receive big strong to severe storms from Springfield, MA eastward to a Boston, MA to Taunton, MA line. Anywhere east of this line are subject to marine influenced air off the ocean as winds back to a SSW or SW direction. Strong sunshine is expected given the rise of instability and storms may be able to organize given the strong wind shear. I will have more on this tomorrow.
Showers and Storms possible on Friday, non severe
Non severe weather is expected or anticipated on Friday. The GFS has recently backed off its high CAPE and SHEAR is now lower and is non existent for Massachusetts. For now showers and storms are expected.
Severe Thunderstorms for Western and Central Southern New England
Severe thunderstorm risk was elevated by the Storm Prediction Center in Norman, OK for western Southern New England and points further west and south. Shear of 30-40knots will help aid in some storm organization within the slight risk region. Eastern Southern New England will see some risk of thunderstorms but they will weaken substantially before they reach our area. Stable Marine Boundary Layer flow from the south will aid in stabilizing the atmosphere here on the South Coast of MA, RI and CT. Severe storms will be possible from the Mass Pike southward and westward.
Chances for storms tomorrow is low
Given the latest guidance, severe weather is very unlikely tomorrow. However given if a few storms are able to develop rapidly then we could see severe weather. Given that there is a strong CAP tomorrow, limited CAPE, positive LI and SI as well as a strong CINH there will be difficulty developing any convection. However favoring factors include wind shear, dew points 55-60F, low wet bulb temps at 10,000 feet and a hail potential of .75" diameter. Given these factors any storms that reach more then 10,000ft into the atmosphere then severe hailstorms will be the norm. However given that we have a strong inversion in place we won't see much of anything but possible convective showers as the front swings through in the evening hours tomorrow. Highest threat for severe weather will be western New England which includes a line from Springfield, MA to Bridgeport, CT and points north and west. A slight risk will be likely for areas to the west of this line. East of this line storms will be possible at the best isolated and possibly strong to severe if rapid excelleration occurs within these isolated cells. If sunshine occurs more then expected then we could have higher CAPE values and less of a CAP in place which would allow further development of scattered thunderstorms possible after 12pm EDT tomorrow. More to come tomorrow morning.
Chances for Storms today and tomorrow
There is an increasing chance for thunderstorms today and tomorrow, with tomorrow being the best chance for strong to maybe severe storms. Sunshine is a major factor tomorrow. If we can get a lot of sunshine then chances increase dramatically for strong to severe storms. If this doesn't happen then isolated storms are possible with interior areas most likely to receive any storm. Next week will be quiet on Monday and Tuesday with the rest of the week potentially unsettled. More to come tomorrow if severe storms are likely.
Slim chance for Thunderstorms on Friday for Southern New England
THere is only a slim chance at best for thunderstorms as mid level instability is lacking according to the NWS in Taunton, MA. However they are a little more optimistic today then they were yesterday. Sea breeze possible tomorrow with highs near 70F for Cape and Islands. Showers aren't likely as there is no real moisture available as well as instability.
Slight Risk for Severe Thunderstorms for Central New England
SPC has a slight risk for severe thunderstorms today in Eastern NY, NH, VT and MA. Supercells are possible as well as hail and damaging winds the main threat. Tornadoes are possible too. Humidity is climbing, daytime heating is drying to break through the cloud deck in place, but this is the main inhibition right now. Dew point is in the mid 50s so instability is marginal, but wind shear is quite strong as a cold front approaches the region. High temperatures in the mid 60s. Thunderstorms are developing in Canada and over Lake Ontario and it will be these storms that will get going as they reach eastern NY and then central New England. 15% chance of hail and damaging winds today.
