Mesoscale Discussion 0384
NWS Storm Prediction Center Norman OK
0851 PM CDT Wed Mar 29 2023

Areas affected...Eastern NY...VT...western NH...far western MA...and
far northeastern PA

Concerning...Snow Squall 

Valid 300151Z - 300545Z

SUMMARY...Rapid visibility reductions with bursts of heavy snow are
possible with any snow squalls that develop into the overnight
hours.

DISCUSSION...Latest surface observations depict an eastward-
advancing cold front extending south-southwestward across eastern
NY. While surface temperatures ahead of the front remain in the
upper 30s to middle 40s (warmer with southward extent), temperatures
are rapidly falling along/behind the cold front into the lower 30s.
Behind the cold front, a mix of rain and moderate to heavy snow are
being observed across east-central NY, and this precipitation shield
will spread eastward with the cold front into the overnight hours.
Nocturnal cooling combined with cold-air advection behind the front
should generally support a transition to mostly snow with eastward
extent -- especially over higher elevations. In addition, strong
linear forcing for ascent accompanying the frontogenetic circulation
should intersect the dendritic growth zone -- favoring bursts of
heavy snow and the potential for snow-squall conditions, given steep
antecedent low-level lapse rates and 30-35-kt 0-2-km flow (per
regional VWP data). Rapid visibility reductions and strong gusts
could accompany the stronger/more-organized snow bands into the
overnight hours.

..Weinman.. 03/30/2023

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...GYX...BOX...BTV...OKX...ALY...BGM...

LAT...LON   42967482 44337376 45017333 45087251 45117180 45427113
            45317082 44327111 43457180 41737399 41427480 41777585
            42107581 42967482 

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0749 PM CDT Wed Mar 29 2023

Valid 300100Z - 301200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Severe thunderstorms are not expected tonight.

...01z Update...

Several notable mid-level troughs are progressing across the CONUS
this evening. One low-latitude feature is digging east-southeast
toward the FL Peninsula. Isolated-scattered thunderstorms continue
across south FL where buoyancy is appreciable, along with steep
lapse rates. However, much of this activity has moved off the south
FL Atlantic Coast and any lingering inland convection should
eventually move offshore as well. Locally gusty winds are the
primary concern with these storms.

Upstream, mid-level closed circulation is located roughly 90 miles
west of SFO. This feature will dig southeast tonight as 90+kt 500mb
speed max translates inland along the southern CA Coast by the end
of the period. Cold mid-level temperatures/steep lapse rates are
contributing to weak buoyancy just ahead of a cold front that
currently arcs from near the SFO Bay, off the southern CA Coast. An
elongated band of convection is noted ahead of this boundary with
some lightning evident in the deeper updrafts. Even so, instability
appears too weak to warrant any meaningful risk of severe tonight.

..Darrow.. 03/30/2023