RSS Mesoscale Discussions from Storm Prediction Center
No watches are valid as of Sat Mar 21 07:13:02 UTC 2026.
No Mesoscale Discussions are in effect as of Sat Mar 21 07:13:02 UTC 2026.
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1229 AM CDT Sat Mar 21 2026
Valid 211200Z - 221200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE
SOUTHERN APPALACHIAN REGION...
...SUMMARY...
Isolated strong to severe thunderstorms may produce hail to near 1
inch diameter this afternoon and evening across the southern
Appalachian region.
...Southern Appalachians...
Very strong midlevel anticyclone remains anchored over the
southwestern CONUS. This is forcing meaningful short waves across
the northern Rockies/high Plains before digging southeast toward the
eastern portions of the United States. Early this morning,
water-vapor imagery depicts one of these features digging southeast
across eastern SD/NE. By the start of the period this short wave
will extend across IL/southeast MO/northeast AR, then it will
advance into KY/TN by early afternoon.
At the surface, a weak boundary that is draped across VA-northern KY
will gradually lift north and become somewhat diffuse west of the
higher terrain. South of this wind shift, modest boundary-layer
heating will be noted across the Carolinas into the TN Valley such
that 0-3km lapse rates should exceed 7 C/km by peak heating.
Forecast soundings suggest convective temperatures will be
approached, or breached by 21z as temperatures rise through the
upper 70s to near 80F across southeast KY/eastern TN. While
low-level convergence is expected to be somewhat weak, orographic
influences will contribute to the potential for isolated
thunderstorm development ahead of the short wave. Forecast midlevel
flow is expected to be around 30-35kt across this region at 500mb,
so deep-layer shear may prove adequate for a few supercells. If
robust convection develops in this environment then hail on the
order of 1 inch could be noted with the strongest storms. This
activity will spread southeast into the western Carolinas as the
short wave advances downstream. The primary concern for hail will be
during the afternoon/evening hours.
..Darrow/Wendt.. 03/21/2026
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SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
0101 AM CDT Sat Mar 21 2026
Valid 221200Z - 231200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE OHIO VALLEY...
...SUMMARY...
Severe thunderstorms with large hail and severe wind gusts are
expected on Sunday afternoon and evening across parts of the Ohio
Valley.
...Ohio Valley/Mid Mississippi Valley...
At mid-levels on Sunday, an amplifying trough will move quickly
east-southeastward across the north-central U.S, as an associated
jet streak translates eastward into the southern Great Lakes. At the
surface, a cold front will advance southward into the Ohio Valley.
South of the front, moderate instability will develop across a moist
airmass by early afternoon, with surface dewpoints in the lower to
mid 60s F. Warming surface temperatures and increasing low-level
convergence will result in convective initiation along parts of the
front during the mid to late afternoon. Storm coverage is forecast
to gradually increase as several clusters or line segments with a
severe threat move southeastward across the Ohio Valley during the
late afternoon and early evening.
During the afternoon from Cincinnati to Pittsburgh, forecast
soundings gradually increase MLCAPE in the 1500 to 2000 J/kg range.
Forecasts just ahead of the front suggest that winds will be veered
to the southwest near the surface, but that strong speed shear will
exist in the lower to mid-levels. 0-6 km shear is forecast to range
from 40 to 50 knots, which should be favorable for severe
thunderstorm development. 700-500 mb lapse rates in the 7.0 to 7.5
C/km range should support supercells with large hail. The supercell
threat is expected to be greatest early in the event, when cells are
more likely to be discrete. A threat for severe wind gusts is also
expected. The wind-damage threat should be concentrated along short
line segments that form in the late afternoon and early evening. A
marginal tornado threat will also be possible.
Further west-southwest into the lower Ohio Valley and mid
Mississippi Valley, the models are forecasting a stout capping
inversion to the south of the front over much of the warm sector.
Near the front in the early evening, the cap is forecast to weaken.
This combined with increasing low-level convergence near the front
should be enough for isolated convective initiation. A marginal
threat for hail and severe wind gusts would be possible with the
stronger cells that can initiate and persist.
..Broyles.. 03/21/2026
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SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0211 AM CDT Sat Mar 21 2026
Valid 231200Z - 241200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE CAROLINAS AND GEORGIA...
...SUMMARY...
An isolated severe threat is expected on Monday across parts of the
Carolinas and Georgia.
...Carolinas/Georgia...
An upper-level trough will move eastward to near the Eastern
Seaboard on Monday. At the surface, a cold front is forecast to move
through the Carolinas, and should be positioned from central Georgia
into central South Carolina by Monday afternoon. Ahead of the front,
surface dewpoints in the upper 50s and lower 60s F will contribute
to weak destabilization. Isolated thunderstorms are expected to
develop near the front and move east-southeastward toward the
Atlantic coast during the mid to late afternoon. 0-6 km shear in the
30 to 35 knot range, along with steep low-level lapse rates may be
enough for a marginal wind-damage threat.
..Broyles.. 03/21/2026
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SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1234 AM CDT Sat Mar 21 2026
Valid 211200Z - 221200Z
...CRITICAL FIRE WEATHER AREA FOR PARTS OF CENTRAL/EASTERN
WYOMING...NORTHWEST COLORADO...SOUTHWEST SOUTH DAKOTA...WESTERN
NEBRASKA PANHANDLE...
...Synopsis...
Upper-level ridging will continue across much of the U.S. today.
However, some modest decrease in the amplitude of this feature can
be expected. The strongest upper-level winds will remain across the
northern tier states with some extension into the central Rockies. A
stout surface trough/cold front will begin to move south through the
northern/central Plains.
...Wyoming into far western Nebraska/South Dakota...
The combination of the strongest mid-level winds and the surface low
to the east will promote Critical fire weather conditions during the
afternoon. Winds of 20-25 mph (perhaps locally higher) and RH of
10-15% can be expected. The cold front will move through during the
late evening into the overnight. Gusty north winds are expected in
its wake.
...Colorado Foothills/Front Range...
Conditions within the typical wind prone areas will not likely be
significantly different than farther north given the cross terrain
pressure gradient. Winds of 15-25 mph and RH of 5-15% are probable.
While these meteorological conditions would mean Critical fire
weather, recent precipitation has impacted fuels and updated ERC
data suggest that Critical fire weather may only occur locally. The
cold front will not likely impact this region until around Sunday
morning.
...Southwest into central/southern Plains...
A very broad area of elevated fire weather is forecast to develop
this afternoon. The warm to hot temperatures and lack of rainfall
continue to cure fuels in these areas. Very dry conditions are
likely in the Southwest (RH of 5-15%) with modest improvements to
around 15-25% in the central Plains near the Missouri River. Winds
of 15-20 mph will be most common, but locally higher speeds are
possible especially in the terrain of the Southwest.
..Wendt.. 03/21/2026
...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
1236 AM CDT Sat Mar 21 2026
Valid 221200Z - 231200Z
...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE TEXAS
PANHANDLE/SOUTH PLAINS...ROLLING PLAINS...SOUTHWEST OKLAHOMA...
...Synopsis...
Strong upper-level flow will be maintained across the northern U.S.
on Sunday. The upper ridge will remain largely flattened until some
amplification occurs toward Monday morning. The amplification of the
upper-level pattern will help push a cold front through the southern
Plains during the morning. The front may eventually slow/stall
near/south of the Red River latitude.
...Texas and Oklahoma...
A somewhat complex fire weather setup will develop during the
morning and persist into the afternoon as the cold front makes
southward progress. The overall temperature gradient will be rather
modest and RH recovery behind the boundary will not be overly quick
to occur. Some upper-level clouds can be expected to dampen surface
heating, especially with northern extent. Even so, temperatures
could still reach the 70s into the 80s. Winds behind the front will
range from 20-25 mph along with stronger gusts. RH will be the main
uncertainty in this scenario, but state of fuels and the strong
winds would still keep fire weather concerns high even with 15-25%
RH. Near and south of the front, however, it is more probable to see
10-20% RH. Stronger, gusty winds are also expected just ahead of the
front within the Edwards Plateau and Rolling Plains. There, Critical
conditions are expected as well.
...Kansas...
Winds of around 25 mph are expected to persist the longest across
much of Kansas. RH will likely be 25-35% on account of upper-level
clouds and slightly cooler temperatures. That said, dry grasses will
support ignition/spread due to the strong, gusty winds.
...Southwest...
Very dry conditions will continue as RH falls into the single digits
in many locations during the afternoon. Winds will generally be
weaker here, but 10-15 mph (locally higher in the terrain) will
support an Elevated fire weather threat given dry fuels.
..Wendt.. 03/21/2026
...Please see www.spc.noaa.gov/fire for graphic product...
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