Mesoscale Discussion 0837
NWS Storm Prediction Center Norman OK
1116 AM CDT Sat May 17 2025
Areas affected...Upstate New York into Vermont and far western
Massachusetts
Concerning...Severe potential...Watch possible
Valid 171616Z - 171845Z
Probability of Watch Issuance...60 percent
SUMMARY...Storms will increase in coverage and intensity through the
day, with areas of hail, wind, and a couple brief tornadoes
possible.
DISCUSSION...In the wake of the early day activity over northern NY,
southerly winds continue to destabilize the area, well ahead of the
cold front and upper trough moving in from the west. Visible imagery
and radar indicate widespread boundary layer cumulus with a few
storms beginning to form near the lake breezes and over other well
heated terrain features.
Cooling aloft overspreading the warming surface air mass will lead
to steepening lapse rates and further destabilization. While not
particularly strong, deep layer shear and veering winds with height
will generally favor cellular development ahead of the cold front.
These cells could produce hail, localized wind damage or even brief
tornadoes as 0-3 km CAPE is maximized.
As the primary cold front moves in later, additional activity over
western NY and PA could pose more of a wind threat, sweeping in
behind the leading daytime activity. The wind shift will be
prominent, with over 30 kt westerly low-level flow.
..Jewell/Hart.. 05/17/2025
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...GYX...BTV...ALY...BGM...BUF...
LAT...LON 45057223 43617227 43187247 42837305 42537348 42237515
42207605 42237722 42337792 42537824 42947827 43247788
43417685 43587650 44247615 45037492 45057223
MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN
Category: Watches, Warnings, Advisories, & Hazards