963
ACUS01 KWNS 270455
SWODY1
SPC AC 270454

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1054 PM CST Wed Nov 26 2025

Valid 271200Z - 281200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
The risk for thunderstorms appears negligible across much of the
U.S. today through tonight.

...Discussion...
Models indicate that an initially significant, and now occluding,
cyclone will gradually weaken across Quebec today through tonight,
as a weaker secondary cyclone also occludes across and
north-northeast of the Canadian Maritimes.  In mid-levels, it
appears that large-scale troughing will be reinforced and undergo
amplification while progressing into and across the Atlantic
Seaboard, in response to a pair of initially digging short wave
perturbations across and east of the Mississippi Valley.  As this
occurs, a notable associated surface cold front is forecast to
progress away from the Atlantic Seaboard, and through much of the
remainder of the Florida Peninsula and Gulf Basin.

Within split westerlies emanating from the northern and mid-latitude
Pacific, a pair of short wave impulses are forecast to dig inland
across the Cascades and Canadian Rockies, downstream of building
larger-scale mid/upper ridging.  However, it appears that generally
stable conditions will be maintained across much of the West, in
addition to most areas east of the Rockies.

...Florida Peninsula...
Downstream of the amplifying large-scale mid-level trough axis,
models continue to indicate that one area of developing large-scale
forcing for ascent may overcome mid-level inhibition and support a
couple of generally weak thunderstorms across the Lower Florida Keys
into southeastern Florida coastal vicinities this morning into
afternoon.  In the presence of another developing area of
large-scale ascent, weak destabilization may also support at least
lower threshold probabilities for thunderstorms, ahead of the
southward advancing cold front across interior central into east
central coastal portions of the peninsula this afternoon.

...Lower Great Lakes...
Cold air overspreading the relative warm waters of Lakes Erie and
Ontario may contribute to thermodynamic profiles increasingly
conducive to convection capable of producing occasional lightning,
particularly as temperatures cool below -20 to -25 C in the 700-600
mb layer this afternoon into tonight, based on forecast soundings.

..Kerr.. 11/27/2025

$$