Sunday, February 26, 2017

February 25 is a Big Severe Weather Day in Southern New England

Update 6:52 PM The NWS has just confirmed that an EF-1 tornado did touch down in Conway, MA last night.  This is the first recorded tornado in state history during the month of February.  WOW!  Max wind is estimated at 110 MPH.


Like any good spring warm up, the Northeast was cooled off by severe thunderstorms yesterday afternoon and evening.  As is often the case in the early part of the year the storms fell apart long before they got to Eastern MA and N RI.  The difference yesterday is that the calendar still reads February and the National Weather Service is sending out storm survey teams to determine what caused this kind of damage in Conway, MA.  Conway is up in Franklin County near Greenfield, a little west of 91 and south of Rt 2.
WWLP photo of damage in Conway, MA on 2/25/2017
 I don't conduct storm survey's but that looks like a microburst to me.  There is significant structural damage to some homes but it is confined to a small area.  The severe reports in the northeast are impressive.
SPC Preliminary Storm Reports Saturday, February 25, 2017
Believe it or not, this isn't the worst severe weather outbreak on February 25 in New England history.  Just last year most of Southern New England woke up to heavy rain, lightning, and damaging winds.  Most of the severe weather occurred on February 24. 2016 including tornadoes in Pennsylvania.  The storms reached Southern New England after midnight.
February 24-25, 2016 7 AM to 7 AM Severe Weather Reports (SPC)
These were two different weather systems as the 2016 storm had origins Texas while this year's storm was born out of the Rockies.  This year the storm lifted well to our west as high pressure offshore protected the region until a cold front finally brought an air mass change.  In 2016 Candian high pressure to the north was in charge.  Some light snow fell the morning before the thunderstorms thanks to a good overrunning setup.  A subtropical high has been anchored in the Western Atlantic for the past few days.
Daily Weather Map February 24-25, 2016
Compare this to 2017 when the storm is further west.  The upper atmospheric set up is much different in the NE Pacific as well.  The parent low-pressure system driving the frontal system was closer and much stronger in 2016 which is why the entire SNE region saw the severe weather.
Daily Weather Map February 24-25, 2017
Suffice to say there are multiple ways to get severe weather in Southern New England, apparently! A list of all watches and warnings from the 2016 event can be found here. At first glance, the temperatures on 2/24 and 2/25 of 2016 look impressive (prior to this week).

It was only over 50 degrees from approx 10 PM on 2/24/16 until 2 PM 2/25/16 in Worcester.  The 2016 warmth was brief but it was enough to produce wind gusts 50-80 MPH across Southern New England.  I remember most rare weather events that happen in Southern New England but this one slipped my mind until this morning.  The storms raged from midnight until 5 AM so most people slept right through it.

Once the NWS is done their storm survey in Conway I think they will estimate winds of a similar magnitude last night.  Here is the radar image from 730 PM when the storm was bearing down on Conway.
NEXRAD radar image 730 PM Saturday
I'm still processing and reviewing the warmth we saw last week.  It was historic and will take a bit longer to break down, but I'm already working on it.  We are going back to the 50's and potentially 60 by Wednesday.
ECMWF 10 day max/min temps

Take days 6-10 with a grain of salt but it does look like a return to seasonably cool weather is on the table.  It will be breezy tomorrow with temps in the 50s but sunny skies.  Showers for Tuesday and Wednesday with thunder also possible Wednesday afternoon.  Mid spring in late winter continues.

-Zack Green

No comments:

Post a Comment

National Weather Service Issues Winter Storm Warning

T he National Weather Service Boston office has issued a * Winter Storm Warning * for most of Southern New England, except for the South Sou...