RSS Mesoscale Discussions from Storm Prediction Center
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1044 AM CDT Thu Mar 12 2026
Valid 121630Z - 131200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
EASTERN SOUTH CAROLINA AND SOUTHERN/EASTERN NORTH CAROLINA...
...SUMMARY...
Strong to severe thunderstorms may produce occasional damaging winds
across parts of the eastern Carolinas through this afternoon. A
brief tornado or two could also occur with this activity. Strong
convective wind gusts are possible across the northern Plains this
afternoon as well.
...Carolinas and North Florida...
A broken line of low-topped thunderstorms will continue to move
quickly northeastward this afternoon across parts of the Carolinas
in tandem with a mid-level shortwave trough across the Southeast.
Strong low to mid-level southwesterly flow should promote some
threat for occasional severe/damaging winds with this line as
filtered daytime heating fosters modest steepening of low-level
lapse rates and weak destabilization. Even so, poor mid-level lapse
rates will tend to limit the development of any more than modest
instability overall. While low-level winds have generally veered to
southwesterly per recent VWPs from LTX/MHX, there is still
sufficient speed shear in the 0-1 km layer to support embedded
circulations within the line, and perhaps a brief tornado or two.
The Slight Risk has been adjusted for latest observational and
guidance trends to reflect the mainly damaging wind threat with the
line this afternoon, before it moves offshore into the western
Atlantic. A small Marginal Risk area has also been maintained for
parts of north FL where an isolated damaging wind threat should
exist in the short term with the far southern portion of the line.
...Northern Plains...
Very strong mid-level winds (around 100-120 kt at 500 mb) will
spread southeastward across the northern Plains this afternoon in
tandem with a low-amplitude mid-level shortwave trough moving over
the northern Plains. Latest NAM/RAP forecast soundings suggest very
weak instability may develop south of a front across the northern
Plains, such that shallow convection may develop with some threat of
lightning. This convection could augment the already strong
west-northwesterly low/mid-level flow, resulting in strong surface
wind gusts. Isolated significant wind gusts (65+ kt) could occur
with any sustained convection that develops, but confidence in this
scenario remains low.
..Gleason/Chalmers.. 03/12/2026
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SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1222 PM CDT Thu Mar 12 2026
Valid 131200Z - 141200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Severe thunderstorms are not expected on Friday.
...Synopsis...
A cold front currently pushing east towards the southeastern U.S.
coast will continue to migrate offshore and southward along the FL
peninsula through Friday morning. This boundary will eventually
stall across south FL before gradually lifting north as a very
diffuse warm frontal zone. Diurnal heating of a moist and largely
uncapped environment will support thunderstorm development by early
to mid-afternoon - especially along the southwestern FL coastline
where sea-breeze interactions will locally augment ascent. Very weak
flow through 6 km will limit the potential for organized severe
thunderstorms, though the thermodynamic profiles may support very
isolated strong downburst winds.
Further north, an intense cyclone will traverse the lower Great
Lakes into the Northeast through the day. Cold mid-level
temperatures may support adequate instability for sporadic lightning
flashes along the NY/PA border. Strong (40-50 knot winds) just above
the surface may be mechanically mixed to the surface by any shallow
convection that can develop, as hinted by recent HRRR solutions.
However, morning guidance depicts considerable spread regarding CAPE
availability that limits confidence in the overall lightning (or
severe wind) potential.
..Moore.. 03/12/2026
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