Mesoscale Discussion 2249
NWS Storm Prediction Center Norman OK
0712 PM CST Tue Dec 02 2025

Areas affected...coastal northern New England

Concerning...Heavy snow 

Valid 030112Z - 030715Z

SUMMARY...Moderate to heavy snow rates on the order of 1/2 to 1+
inches per hour are possible across southern Maine this evening,
with heaviest rates most probable near Down East coastal areas
closer to and after Midnight EST, as strengthening and gusty winds
contribute to reduced visibilities and blowing/drifting.

DISCUSSION...A deepening surface cyclone is forecast to continue an
east-northeastward migration, generally south through east of the
Cape Cod vicinity through mid to late evening.  This will be
accompanied by a zone of strengthening lower/mid-tropospheric
frontogenetic forcing to its north through northeast.  At
mid-levels, the Rapid Refresh indicates that this will shift across
southern Maine through southern New Brunswick, where forecast
soundings indicate that  strengthening lift in (roughly) the 600-500
mb layer may coincide with temperatures most conducive to large
dendritic ice crystal growth (around -15 C).

There is notable spread within and among the various model output
concerning these details, and potentially varying rates of cyclone
and upward vertical motion intensification.  However, in the
presence of sub-freezing thermodynamic profiles, guidance generally
indicates snow rates on the order of 1/2 to 1 inch per hour are
possible this evening across much of southern Maine.  Heaviest rates
appear most probable near immediate coastal areas of Maine,
particularly across Down East coastal Maine closer to and after
05-06Z, when strengthening and gusty east-northeasterly surface
winds may contribute to considerable blowing/drifting and reduced
visibilities.

..Kerr.. 12/03/2025

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

ATTN...WFO...CAR...GYX...

LAT...LON   43277133 44757076 45456714 44046610 43626951 43127081
            43277133 

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1151 PM CST Tue Dec 02 2025

Valid 031200Z - 041200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Thunderstorms will be possible this evening into tonight across the
western Gulf Coast states. Severe storms are not expected.

...DISCUSSION...
At mid-levels today, a trough will dig south-southeastward into the
Desert Southwest, as flow becomes west-southwesterly across much of
the southern U.S. In response, moisture advection will take place
across the western Gulf Coast states. By mid to late evening,
surface dewpoints are expected to reach the middle to upper 60s F
along parts of the Texas Coast. This will result in an increase in
instability supporting isolated to scattered thunderstorm
development. As warm advection continues into the overnight period,
a gradual increase in convective coverage should occur, mainly
offshore where instability and low-level flow are forecast to be
stronger. Due to this, some cell organization could occur just
offshore from the upper Texas Coast after midnight with a few
rotating storms possible. Over land, instability is forecast to
remain relatively weak, which is expected to limit the severe
potential through daybreak on Thursday.

..Broyles/Weinman.. 12/03/2025

Day 1 Fire Weather Outlook  
NWS Storm Prediction Center Norman OK
1148 PM CST Tue Dec 02 2025

Valid 031200Z - 041200Z

...NO CRITICAL AREAS...

...Synopsis...
On the backside of a midlevel trough moving across the Four Corners
region, high pressure over the Intermountain West will promote an
enhanced offshore pressure gradient across southern CA. While
locally dry/breezy conditions are expected (especially across
wind-prone mountains and valleys), marginal fuels should limit most
fire-weather concerns.

..Weinman.. 12/03/2025

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

Day 2 Fire Weather Outlook  
NWS Storm Prediction Center Norman OK
1148 PM CST Tue Dec 02 2025

Valid 041200Z - 051200Z

...NO CRITICAL AREAS...

...Synopsis...
Surface high pressure over the Intermountain West will favor another
day of locally dry/breezy offshore flow across portions of southern
CA. While locally elevated fire-weather conditions are possible,
marginal fuels should limit most concerns.

..Weinman.. 12/03/2025

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