SPC Mar 12, 2026 1300 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 1300Z Day 1 Outlook


Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0732 AM CDT Thu Mar 12 2026

Valid 121300Z - 131200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHEAST
GEORGIA AND CENTRAL/SOUTHERN SOUTH CAROLINA...

...SUMMARY...
Isolated strong to severe thunderstorms may produce damaging winds
across parts of the Southeast this morning into the early afternoon.
A tornado can not be ruled out early with this activity. Strong wind
gusts are possible across the northern Plains this afternoon as
well.

...Southeast into the Carolinas...
Early-morning satellite imagery shows phased shortwave troughs
within the broad upper troughing across the eastern CONUS, with the
southern shortwave progressing through the Southeast and the
northern shortwave moving into the Middle OH Valley. A convective
line, aided by ascent attendant to the southern shortwave, continues
to progress eastward/northeastward across GA and the FL Panhandle. A
warm, moist, and modestly buoyant environment precedes this line,
with temperatures in the upper 60s to low 70s and dewpoints ranging
from the low 60s across the Carolinas to the low 70s across northern
FL. Expectation is for this line to persist as it continues
eastward/northeastward, with perhaps some slowing of the southern
portion of the line as it becomes displaced south of the better
forcing for ascent. Central portion of this line nearest the
strongest forcing will likely have the deepest updrafts for the next
several hours before progressing northeastward of the better
moisture and buoyancy as it moves across NC. Robust low to mid-level
flow will remain in place, supporting the potential for damaging
gusts and brief line-embedded tornadoes through the afternoon.

...Northern Plains...
Intense mid-level flow (i.e. 100-120 kt at 500 mb) will spread
southeastward across the northern Plains this afternoon, in tandem
with a low-amplitude shortwave trough progressing through the
region. Forecast soundings suggest weak buoyancy will evolve south
of the front across the northern Plains such that shallow convection
is expected to develop, along with the threat of some lightning.
This convection could augment the already strong
westerly/northwesterly flow, resulting in strong surface wind gusts.
Significant wind gusts (65+ kt) are possible.

..Mosier/Dean.. 03/12/2026


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SPC Mar 12, 2026 0600 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 1200Z Day 1 Outlook


Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1231 AM CDT Thu Mar 12 2026

Valid 121200Z - 131200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF THE SOUTHEAST...

...SUMMARY...
Isolated strong to severe thunderstorms may produce damaging winds
across parts of the Southeast this morning into the early afternoon.
A tornado can not be ruled out early with this activity.

Southeast: A well-developed squall line has evolved ahead of a
pronounced low-latitude short-wave trough. This line of convection
currently extends across the central Gulf states and is advancing
steadily east in line with latest model guidance. Early-morning
water-vapor imagery depicts a short wave that is becoming a bit more
negative-tilt as it approaches the lower MS Valley. This feature
will eject into AL by the start of the day1 period with substantial
midlevel height falls forecast across much of the Southeast early in
the period. Upper 60s to lower 70s surface dew points have returned
inland across the FL Panhandle and southern AL, and a narrow wedge
of modified Gulf air should be in place across the eastern FL
Panhandle into extreme southwest GA at sunrise. Current trends
suggest the leading edge of strong/severe convection will propagate
into this portion of the Southeast around 12z. Strong deep-layer
shear favors organized updrafts and given the large-scale support
ahead of the trough, activity should remain organized at the start
of the period. Some consideration was given to increasing severe
probabilities for a narrow wedge immediately ahead of the front for
early in the period. If the squall line continues severe this may be
warranted at 13z. Locally damaging winds and perhaps a tornado are
the expected hazards.

Isolated strong/severe thunderstorms may also develop along the
progressive front as it spreads across portions of the Carolinas.
Severe threat is primarily before 18z, as the cold front will surge
off the Carolina coast by this time.

Northern Plains: Strong midlevel jet will dig southeast across MT
into SD with 500mb speeds expected in excess of 120kt into the
northern High Plains. AB clipper will dig southeast into the upper
Red River region by late afternoon and northwesterly flow will
strengthen across this region as the cyclone shifts east. Forecast
soundings suggest weak buoyancy will evolve south of the front
across the northern Plains such that shallow convection is expected
to develop, along with the threat of some lightning. While strong
winds will likely develop across eastern MT into SD as lapse rates
steepen, thunderstorms are not expected to be the primary driver of
severe wind gusts. For this reason severe probabilities will not be
introduced.

..Darrow/Halbert.. 03/12/2026


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SPC Mar 12, 2026 0100 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 0100Z Day 1 Outlook


Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0754 PM CDT Wed Mar 11 2026

Valid 120100Z - 121200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE MIDDLE ATLANTIC AND OVER MUCH OF THE GULF STATES...

...SUMMARY...
Isolated to scattered severe thunderstorms are expected tonight from
the Gulf Coast into parts of the Mid-Atlantic.

...01z Update...

Middle Atlantic: Narrow corridor of yet-to-be overturned instability
extends across eastern WV into the Middle Atlantic. Several short
line segments have developed ahead of the primary short wave, but
the leading convection over eastern MD/northern DE into NJ is the
primary concern, as this activity has a bit more buoyancy to work
with than the trailing convection across central PA into western WV.
Strong deep-layer shear remains favorable for organized storms to
spread across this region over the next few hours before ingesting
cooler marine layer near the Atlantic coast.

Gulf States: Expansive MCS has evolved over the lower MS Valley
early this evening. This complex has developed ahead of a
low-latitude upper low over south central TX that is becoming more
negative tilt with time. Exit region of midlevel jet will translate
along the Gulf coast overnight, and this will encourage eastward
propagation through sunrise. 00z sounding from LIX exhibited strong
shear, but a substantial warm layer is noted around 4-5km. This warm
layer should gradually cool as the aforementioned upper low advances
east tonight.

..Darrow.. 03/12/2026


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SPC Mar 11, 2026 1630 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 1630Z Day 1 Outlook


Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1131 AM CDT Wed Mar 11 2026

Valid 111630Z - 121200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON
INTO TONIGHT FROM THE OHIO VALLEY AND CENTRAL APPALACHIANS TO THE
GULF COAST...

...SUMMARY...
Isolated to scattered severe thunderstorms are expected through
tonight from the ArkLaTex and Lower Mississippi Valley northeastward
through the Ohio Valley and Mid-Atlantic.

...OH Valley/Appalachians through late evening...
A surface cyclone now in southeast Lower MI will move northeastward
across the lower Great Lakes/Saint Lawrence Valley and deepen, in
advance of an amplifying northern-stream shortwave trough now over
the upper MS Valley. The warm sector of the cyclone is
characterized by boundary-layer dewpoints in the low-mid 60s into
OH/western PA/WV as of midday. Clouds/convection have been
prevalent this morning across OH/western PA in advance of a subtle
MCV, and the warmer surface temperatures have been confined to areas
immediately south of this morning convection. Additional
thunderstorm development is expected by early afternoon from
southern IN/northern KY into southern OH/WV/western PA, and storms
will spread generally eastward within the warm sector through this
evening. SBCAPE of 1000-1500 J/kg and wind profiles with long
low-level hodographs will support of a mix of line segments and
supercells capable of producing a few tornadoes and swaths of
damaging gusts before the threat begins to diminish by late evening.

...Southeast TX to MS/AL through tonight...
Thunderstorms are ongoing along a surface trough approaching
southeast TX, and additional convection extends northeastward along
a residual outflow/differential heating zone into the Ark-La-Miss.
Daytime heating/destabilization and forcing for ascent downstream
from a midlevel trough (now over the Edwards Plateau) will support a
continued increase in storm coverage/intensity this afternoon from
southeast TX into the Ark-La-Miss. Though regional soundings are
limited in the main part of the moist sector this morning, surface
observations and model forecast soundings suggest a corridor of
moderate buoyancy (MLCAPE near 1500 J/kg) through the afternoon in
advance of the ongoing storms. Deep-layer southwesterly shear,
largely oriented along the convective band, will help maintain
clusters and line segments, though embedded supercells are also
possible. Low-level hodographs will be long enough to justify the
potential for a few tornadoes with embedded circulations and/or
favorable storm mergers into the band of storms. Otherwise, wind
damage will be the main threat with the line segments through
tonight.

..Thompson/Chalmers.. 03/11/2026


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