Day 4-8 Outlook

Day 4-8 Convective Outlook  
NWS Storm Prediction Center Norman OK
0256 AM CST Tue Dec 16 2025

Valid 191200Z - 241200Z

...DISCUSSION...
A line of storms will likely be ongoing from portions of the
Northeast into the mid-Atlantic and Carolinas Friday morning. If
sufficient destabilization can occur, a few isolated damaging wind
gusts will be possible before the front moves offshore. In the wake
of this cold front, an extended period of low severe potential
begins. By Saturday afternoon, moisture is forecast to advect inland
across East Texas and Louisiana, but no thunderstorm activity is
expected. 60s dewpoints will remain along the Gulf Coast from Texas
to inland Louisiana and Mississippi through the weekend and into
early next week. However, building heights aloft will limit
thunderstorm potential for much of the extended. Even if some
thunderstorms occur early next week, as indicated by the 00Z ECMWF
across MS/TN, they will likely remain south of the stronger
mid-level flow and without strong destabilization, will be unlikely
to be severe.

No watches are valid as of Tue Dec 16 08:59:02 UTC 2025.

No Mesoscale Discussions are in effect as of Tue Dec 16 08:59:02 UTC 2025.

SPC 0830Z Day 3 Outlook

Day 3 Convective Outlook  
NWS Storm Prediction Center Norman OK
0229 AM CST Tue Dec 16 2025

Valid 181200Z - 191200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF THE LOWER OHIO AND TENNESSEE VALLEYS...

...SUMMARY...
Isolated damaging wind gusts are possible across portions of the
Lower Ohio and Tennessee Valleys on Thursday.

...Synopsis...
A strong mid-level jet streak will round the base of the mid-level
trough across the central Plains early Thursday and emerge across
the Ohio Valley by Thursday afternoon/evening. This trough will
continue east and take on a more neutral to perhaps negative tilt by
early Friday across the East Coast. A strong (sub 990mb) surface low
will move from the Upper Midwest to southern Quebec with a trailing
cold front sweeping from the Midwest to the East Coast. 

...OH/TN Valleys...
A line of convection will likely be in its infancy along the cold
front in Illinois and Missouri at the beginning of the period.
Low-level moisture will continue to advect north ahead of this cold
front and result in some weak destabilization. The mid-50s dewpoints
will likely struggle to make it north of the Ohio River given the
snowpack across the region, despite very strong low-level moisture
advection. However, south of this snowpack there will likely be a
zone where the strong forcing along the cold front can overcome only
marginally unstable surface parcels. This strongly forced convective
line amid 60-70 knots of background flow (as low as 1km) will
support isolated damaging wind gusts through the afternoon. 

Greater instability is expected south of the TN/MS/AL border where
upper 50s to low 60s dewpoints are forecast. However, despite the
more favorable thermodynamics, the upper-level forcing will be
weaker. Therefore, it is unclear whether the line of storms will
continue that far south, and additional convection ahead of the
front will likely struggle given the weak lapse rates/minimal
heating. 

...Eastern Virginia into North Carolina...
Late in the period, as the cold front crosses the Appalachians,
moisture is expected to advect inland across eastern North Carolina
and eastern Virginia. A strong wind field will continue across the
region, and if sufficient instability can develop, a damaging wind
threat could materialize early Friday morning. However, the degree
of destabilization remains uncertain and will depend on how quickly
the cold air damming can erode. A solution such as the 00Z NAM (with
60F dewpoints into the DelMarva) would certainly result in some
threat, but most other guidance keeps dewpoints in the mid 50s with
minimal instability. Trends will be monitored closely in this region
in later outlooks and probabilities may be added if the forecast
trends towards greater instability.

..Bentley.. 12/16/2025

SPC 0700Z Day 2 Outlook

Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1254 AM CST Tue Dec 16 2025

Valid 171200Z - 181200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
A few isolated thunderstorms are possible in the Texas Coastal Plain
and the northern Rockies vicinity Wednesday morning. Isolated to
scattered thunderstorms are possible early Thursday morning from the
Ozarks to the Lower Ohio River Valley.

...Synopsis...
A strong mid-level jet streak and associated mid-level trough over
the Pacific Northwest will amplify as it advances east through the
day. A very strong surface low (~985mb) will move from British
Columbia to the Upper Midwest through the period. A strong cold
front will extend southwest from this surface low. This surface low
will begin the day in the vicinity of northern Idaho/eastern
Washington into eastern Oregon. It will move quickly southeast
through the day. It will move across the Plains Wednesday evening
and into the Midwest by early Thursday morning. 

...Northern Rockies Vicinity...
A line of shallow convection will likely exist along a strong cold
front at 12Z Wednesday somewhere across eastern OR/WA into northern
Idaho. Forecast soundings show only limited instability, but with
additional forcing along the front, some stronger cores within the
line may deepen enough for some lightning generation. In addition, a
very strong wind profile is present which may result in some gusty
winds within this line. Very weak instability is the primary
limiting factor for a Marginal Risk. 

...Midwest...
Moisture will advect northward from the southern Plains and into the
Ozarks Wednesday and Wednesday evening. At the very end of the Day 2
period (09-12Z Thu) this moisture is expected to interact with the
rapidly advancing cold front. Instability will be weak, but
sufficient for storm development along the frontal zone by 12Z
Thursday. In addition, a low-level jet will rapidly strengthen
Wednesday evening and into early Thursday morning. Isentropic ascent
within this low-level jet axis, combined with increasing elevated
instability, may be sufficient for isolated storm development
between 06Z and 12Z.

..Bentley.. 12/16/2025

SPC Day 2 Fire Weather Outlook

Day 2 Fire Weather Outlook  
NWS Storm Prediction Center Norman OK
1235 AM CST Tue Dec 16 2025

Valid 171200Z - 181200Z

...NO CRITICAL AREAS...

...Synopsis...
The northwestern upper trough will move into the central Rockies on
Wednesday. Strong mid-level winds will be roughly perpendicular to
the terrain. In the Plains, a surface low will develop/deepen in the
northern Plains with a trough extending into the central/southern
High Plains.

...Central High Plains...
Confidence in the degree of RH reduction is not overly high, but
given the favorable downslope wind pattern, pockets of 15-25% are
possible. With fuels continuing to dry in the region, they will be
at least marginally receptive to fire spread. Winds are the more
confident portion of the forecast. 15-20 mph can be expected for
most areas, especially the eastern Plains of Colorado. Within
terrain-favored areas, 20-25 mph is more probable along with even
higher wind gusts. These stronger winds will promote elevated fire
weather despite somewhat limited RH reduction and fuel
receptiveness.

...Southern High Plains...
RH of 10-20% can be expected within the region as temperatures
should be warmer than farther north. Winds should still be
relatively strong, particularly near the terrain. 15-20 mph will be
most common with terrain gaps likely being higher. Elevated
meteorological conditions could reach into parts of the Texas
Panhandle/South Plains, but current fuel indices suggest limited
risk for ignitions/spread at this time.

..Wendt.. 12/16/2025

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

SPC Day 1 Fire Weather Outlook

Day 1 Fire Weather Outlook  
NWS Storm Prediction Center Norman OK
1152 PM CST Mon Dec 15 2025

Valid 161200Z - 171200Z

...NO CRITICAL AREAS...

...Synopsis...
As a strong upper trough moves into the Northwest, the upper ridge
across much of the CONUS will begin to flatten today. Surface high
pressure will generally remain in the Southeast. A weak surface
trough/front will move eastward through the Plains. Some locally dry
and breezy conditions are possible in the central/southern High
Plains. Wind speeds will be marginal outside of a few
terrain-favored zones. Locally elevated conditions could occur, but
greater fire weather concerns are not expected.

..Wendt.. 12/16/2025

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

SPC 1200Z Day 1 Outlook

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1137 PM CST Mon Dec 15 2025

Valid 161200Z - 171200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN THE PACIFIC
NORTHWEST...

...SUMMARY...
Sporadic severe gusts may accompany isolated thunderstorms across
parts of the Pacific Northwest on Tuesday night.

...Pacific Northwest...
A vigorous shortwave trough will approach the Pacific Northwest
coast through tonight before shifting inland over WA during the
early morning Wednesday. A deepening surface cyclone will move
across southern BC towards southwest AB, with a Pacific cold front
trailing south-southwestward. Low-topped convection is expected to
accompany the front, initially approaching the WA coast by late
evening. Surface-based buoyancy will remain meager, but strong
gradient winds will shift from the southwest to west-northwest as
the front passes. Sporadic lightning flashes and strong to severe
gusts may accompany passage of this low-topped squall before it
subsides inland in western WA/OR.

Intense lower-level flow will likely peak in the overnight to early
morning hours. Buoyancy should remain quite limited along and east
of the Cascades, but most guidance indicates broken low-topped
convection should spread east along/ahead of the front amid
pronounced large-scale ascent. Background gradient winds will likely
be capable of producing severe gusts, and some of these may be
coincident with sporadic lightning flashes.

..Grams/Wendt.. 12/16/2025