Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1138 PM CST Wed Dec 17 2025

Valid 181200Z - 191200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Severe potential will be limited today, but isolated strong wind
gusts are possible across portions of the Lower Ohio and Tennessee
Valleys.

...Lower Ohio/TN Valleys...

Strong midlevel trough is advancing quickly across the
northern/central High Plains late this evening. This feature is
forecast to progress into the MS Valley by late afternoon then eject
negative-tilt into the OH Valley during the overnight period.
Intense 12hr height falls, on the order of 210m, will spread across
the OH Valley and this is expected to aid large-scale forcing along
a sharp cold front that will surge into IN/KY/TN by 19/00z. Poor
destabilization is expected ahead of the front and forecast
soundings exhibit meager instability, and this is mostly with an
elevated parcel. While buoyancy will be weak, a strongly forced band
of frontal convection is expected to develop and spread east. Given
the level of parcel ascent, current thinking is a stable boundary
layer will minimize the risk of severe gusts near the surface. Even
so, isolated strong winds may accompany some portions of the
convective line, but the risk of severe gusts in excess of 50kt
appears too low to warrant a MRGL risk at this time.

..Darrow/Wendt.. 12/18/2025

Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1255 AM CST Thu Dec 18 2025

Valid 191200Z - 201200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Thunderstorms may occur over the Mid Atlantic and Northeast early
Friday, and in the Pacific Northwest Friday afternoon through Friday
night.

...Discussion...
A line of thunderstorms is expected along a strong cold front
extending from eastern New York to eastern North Carolina Friday
morning. This line of storms is expected to be mostly elevated from
Pennsylvania northward. From northern Virginia southward, some weak
instability is possible ahead of the front as upper 50s to near 60s
dewpoints advect northward. Forcing will be weaker farther south,
and 00Z CAM guidance supports this with a more broken line of storms
that far south. If a more consolidated, strong frontal band can
continue where the near 60s dewpoints are present, a few isolated
strong wind gusts may occur for a few hours in the morning before
the front moves offshore. 

In the wake of this front, benign conditions are expected across
most of the CONUS on Friday. Scattered thunderstorms are possible
across western Washington and far northwest Oregon, but this
thunderstorm activity should remain weak.

..Bentley.. 12/18/2025

Day 3 Convective Outlook  
NWS Storm Prediction Center Norman OK
0227 AM CST Thu Dec 18 2025

Valid 201200Z - 211200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Isolated thunderstorms are possible across western Washington and
far northwest Oregon on Saturday.

...Synopsis...
A strong mid-level jet streak over the northern Plains Saturday
morning will move east as a mid-level trough amplifies across the
Great Lakes. As this occurs, a surface cold front will move from the
Plains Saturday morning to near the Appalachians and extending back
into East Texas by early Sunday morning. 

...East Texas into Louisiana...
Low-level moisture return will bring low to mid 60s dewpoints
northward across East Texas and Louisiana on Saturday and Saturday
evening. Weak to potentially moderate instability is forecast to
develop. However forcing will be minimal with rising heights aloft
and a weakening low-level jet. In addition, forecast soundings show
warm mid-level temperatures which will likely keep the airmass
capped. Therefore, thunderstorms are not expected across East Texas
and Louisiana on Saturday night/early Sunday.

...Pacific Northwest..
Persistent onshore flow with cool temperatures aloft will result in
persistent convective activity across western Washington and
northwest Oregon on Saturday. Forecast soundings show weak
instability and equilibrium levels near or slightly above -20C which
may support some isolated thunderstorms.

..Bentley.. 12/18/2025