RSS Mesoscale Discussions from Storm Prediction Center
No watches are valid as of Thu Dec 18 07:00:02 UTC 2025.
No Mesoscale Discussions are in effect as of Thu Dec 18 07:00:03 UTC 2025.
SPC 1200Z Day 1 Outlook
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
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SPC 0700Z Day 2 Outlook
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
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SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1135 PM CST Wed Dec 17 2025
Valid 181200Z - 191200Z
...CRITICAL FIRE WEATHER AREA FOR CENTRAL KANSAS INTO FAR NORTHERN
OKLAHOMA...
...Synopsis...
A cold front will push through the Plains into the Mississippi/Ohio
Valleys today. On the western flank of the upper-trough, behind the
cold front, strong northwesterly winds will persist through the
morning and into the early/mid afternoon within the central/southern
Plains. The cold air will lag behind the actual front.
...Central/southern Plains...
Winds of 20-30 mph (with higher gusts) are probable across Kansas
into northern Oklahoma. The strongest winds will occur in Kansas
where surface temperatures will remain cooler. Despite the cold
advection, clear skies and dry air will support RH in the 15-25%
range in Texas/Oklahoma. RH in Kansas will likely be above 25% in
most areas. However, the strong winds and drying fine fuels will
still support rapid fire spread in these marginally critical RH
conditions. Critical conditions are expected where the greatest
overlap of strong surface winds and at least marginally low RH.
Near-critical conditions are possible in parts of Oklahoma and
Texas, but marginal fuels and less intense surface winds preclude
expansion of highlights into these areas.
..Wendt.. 12/18/2025
...Please see www.spc.noaa.gov/fire for graphic product...
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SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1137 PM CST Wed Dec 17 2025
Valid 191200Z - 201200Z
...Synopsis...
Shortwave ridging aloft will break down through the day Friday and
another strong mid-level jet will move across the Rockies. In the
Plains, a broad and moderately deep surface trough will develop and
shift eastward. These features will combine to promote another
strong downslope wind regime in the immediate lee of the Rockies.
...Central/southern High Plains...
Strong downslope winds will occur in the I-25 corridor again on
Friday. Sustained winds of 20-30 mph, especially in Wyoming and
Colorado, are expected. Wind gusts of greater than 60 mph could
occur in the typically wind-prone gaps/foothills. Winds in New
Mexico will generally be 15-20 mph. As with the last downslope wind
event, RH will be uncertain during the afternoon. Higher confidence
in 15-20% exists in New Mexico. With northward extent, RH will
generally be higher, though pockets of 15-20% are at least possible.
Cloud cover near the terrain is partly driving this uncertainty.
Given the strength of winds and continued drying of fuels, elevated
to locally critical conditions are expected.
...Southern Plains...
Winds of 15-20 mph will develop by the afternoon as the surface
trough deepens. Dry return flow should foster 15-25% RH. Enhanced
winds within the lowest 2-3 km should also foster stronger wind
gusts, particularly during the afternoon/peak heating.
..Wendt.. 12/18/2025
...Please see www.spc.noaa.gov/fire for graphic product...
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