RSS Mesoscale Discussions from Storm Prediction Center
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1116 AM CDT Sat Mar 14 2026
Valid 141630Z - 151200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE SOUTHERN FLORIDA PENINSULA...
...SUMMARY...
Isolated severe hail and gusty winds may occur with thunderstorms
that develop across parts of the southern Florida Peninsula this
afternoon.
...Florida...
Isolated to scattered thunderstorms should develop this afternoon
across parts of the FL Peninsula and the Keys, with agitated cu
noted on recent visible satellite imagery across east-central to
southeast FL. Greater low-level moisture is present across
central/south FL, where 60s to low 70s surface dewpoints exist per
latest observations. Continued daytime heating of this moist airmass
will support the development of moderate instability through the
afternoon. Modest mid-level lapse rates (reference 00Z MFL and 12Z
KEY observed soundings) and weak low/mid-level winds may tend to
limit updraft strength. Even so, modestly enhanced upper-level winds
and related deep-layer shear around 25-30 kt could support isolated
severe hail and gusty downdraft winds with the strongest cores that
develop. Have added a Marginal Risk for this potential across parts
of the southern FL Peninsula and vicinity where the greatest
concentration of convection is expected.
...Northern Rockies/High Plains...
Moisture will remain meager today (surface dewpoints generally in
the teens and 20s) across the northern Rockies and High Plains as an
upper trough amplifies and a surface cold front advances southward
over this region. Even so, cold temperatures aloft may support very
weak MUCAPE and occasional lightning flashes with low-topped
convection that should develop from eastern ID/southern MT into much
of WY and vicinity this afternoon/evening. While gusty winds may
occur with this activity, the very limited thermodynamic environment
should preclude organized severe thunderstorms.
...Upper Midwest...
Low-level warm/moist advection will increase tonight into early
Sunday morning across parts of the Upper Midwest as a
south-southwesterly low-level jet strengthens. Weak MUCAPE
(generally less than 1000 J/kg) along and north of a warm front and
strong large-scale ascent preceding the upper trough ejecting
eastward over the northern Plains may support elevated thunderstorms
late tonight (mainly after 15/06Z) across parts of IA/MN/WI. Small
hail could occur with the strongest cores, and lightning flashes
appear possible with mixed/wintry precipitation well north of the
warm front into MN/WI.
..Gleason/Lyons.. 03/14/2026
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SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0255 PM CDT Sat Mar 14 2026
Valid 142000Z - 151200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE SOUTHERN FLORIDA PENINSULA...
...SUMMARY...
Isolated severe hail and gusty winds may occur with thunderstorms
that develop across parts of the southern Florida Peninsula this
afternoon.
...20Z Update...
No changes to the ongoing forecast are necessary. Recent observed
soundings from central/south Florida showed potential for marginally
severe storms, though a mid-level subsidence layer was noted with
northern extent. Additional short-term details can be found in MD
#237.
..Wendt.. 03/14/2026
.PREV DISCUSSION... /ISSUED 1116 AM CDT Sat Mar 14 2026/
...Florida...
Isolated to scattered thunderstorms should develop this afternoon
across parts of the FL Peninsula and the Keys, with agitated cu
noted on recent visible satellite imagery across east-central to
southeast FL. Greater low-level moisture is present across
central/south FL, where 60s to low 70s surface dewpoints exist per
latest observations. Continued daytime heating of this moist airmass
will support the development of moderate instability through the
afternoon. Modest mid-level lapse rates (reference 00Z MFL and 12Z
KEY observed soundings) and weak low/mid-level winds may tend to
limit updraft strength. Even so, modestly enhanced upper-level winds
and related deep-layer shear around 25-30 kt could support isolated
severe hail and gusty downdraft winds with the strongest cores that
develop. Have added a Marginal Risk for this potential across parts
of the southern FL Peninsula and vicinity where the greatest
concentration of convection is expected.
...Northern Rockies/High Plains...
Moisture will remain meager today (surface dewpoints generally in
the teens and 20s) across the northern Rockies and High Plains as an
upper trough amplifies and a surface cold front advances southward
over this region. Even so, cold temperatures aloft may support very
weak MUCAPE and occasional lightning flashes with low-topped
convection that should develop from eastern ID/southern MT into much
of WY and vicinity this afternoon/evening. While gusty winds may
occur with this activity, the very limited thermodynamic environment
should preclude organized severe thunderstorms.
...Upper Midwest...
Low-level warm/moist advection will increase tonight into early
Sunday morning across parts of the Upper Midwest as a
south-southwesterly low-level jet strengthens. Weak MUCAPE
(generally less than 1000 J/kg) along and north of a warm front and
strong large-scale ascent preceding the upper trough ejecting
eastward over the northern Plains may support elevated thunderstorms
late tonight (mainly after 15/06Z) across parts of IA/MN/WI. Small
hail could occur with the strongest cores, and lightning flashes
appear possible with mixed/wintry precipitation well north of the
warm front into MN/WI.
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SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1230 PM CDT Sat Mar 14 2026
Valid 151200Z - 161200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN THE
ARK-LA-TEX/ARK-LA-MISS TO THE WABASH/LOWER OH VALLEYS...
...SUMMARY...
Scattered to widespread damaging winds along with tornadoes should
develop on Sunday afternoon, persisting through Sunday night across
a large portion of the South-Central/Southeast States into the
Midwest/Ohio Valley. The greatest strong tornado and significant
severe wind threats appear to be from the Ark-La-Miss to the Lower
Ohio Valley on Sunday evening.
...Synopsis...
An upper trough will amplify across the central states on Sunday and
become centered from WI to the Ark-La-Tex by 12Z Monday. Associated
surface cyclone will track from the IA/MO border to Lower MI,
deepening Sunday evening/night. As this occurs, attendant cold front
will accelerate eastward across the Mid-MS to the OH Valleys.
Trailing portion of the front will sweep south-southeast into the
northwest Gulf to central Gulf Coast through Monday morning.
Primary changes with the level 3-ENH risk are to include a
10-percent tornado area, southward expansion of 45-percent wind, and
addition of 15-percent and CIG1 hail areas. Expansion of level
1-2/MRGL-SLGT risk areas has occurred over the Southeast for mainly
the 06-12Z period Monday. Uncertainty is greatest on the western
extent for where convection should become severe, and the northern
extent within a thermodynamically challenged environment.
...South-Central/Southeast States to the Midwest...
In the wake of morning elevated convection over a portion of the
Mid/Upper MS Valley, midday convective development should occur
along the highly convergent surface front across a part of the
Mid-MS Valley to the Ozarks. This activity may initially remain
shallow, before deepening and greatly expand in coverage through the
afternoon as it impinges on richer boundary-layer moisture towards
the Ark-La-Tex and the Mid-South portion of the MS Valley. By late
afternoon, an extensively long QLCS should become established from
IL south-southwestward. Semi-discrete supercell development appears
most favored along the southern portion of the broader convective
plume near the front and downstream within a strengthening
warm/moist conveyor. This should support potential for large hail
and a couple strong tornadoes before supercells become absorbed
within the broader QLCS during the evening. This scenario should
also yield an increasingly pinched-off warm-moist sector from the
Mid-South to TN Valley. Despite this aspect, substantial
strengthening of 700-mb winds on either side of the front, initially
across the Mid-South vicinity and expanding to the OH to TN Valleys,
will yield a setup conductive for scattered to widespread damaging
wind swaths through the evening.
On Sunday night, the northern extent of the severe threat should
become more sporadic as surface-based instability becomes/remains
minimal. But the very fast lower-level wind fields may yield
persistence of some damaging wind/brief tornado potential eastward
in the OH Valley/southern Great Lakes. Farther south, there are
increasing signals for renewed low-level warm conveyor convective
development across the central to northeast Gulf Coast vicinity
early Monday morning. Deep-layer shear profiles will be conducive to
semi-discrete supercells just ahead of/merging into the progressive
QLCS. This should foster a period of increased large hail/sustained
tornado potential. Otherwise, damaging winds will remain favored
from at least the FL Panhandle to the southern Appalachians.
..Grams.. 03/14/2026
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SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0238 PM CDT Sat Mar 14 2026
Valid 161200Z - 171200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM SC TO
SOUTHERN PA...
...SUMMARY...
Scattered to widespread severe storms are likely on Monday for parts
of the Mid-Atlantic States and Southeast. The greatest potential for
strong tornadoes and significant damaging winds appears centered on
parts of South Carolina to Maryland during the late morning to
afternoon.
...Mid-Atlantic and Southeast...
Primary changes this outlook are to add a 45 total severe
probability along with minor northeast and southeast expansion to
the categorical risk areas. Portions of the region, centered on SC
to MD, may warrant an upgrade to a level 4/Moderate Risk in later
outlooks.
A large and deepening upper trough will eject east/northeastward out
of the MS/OH/TN Valleys and across the Appalachians and into the Mid
Atlantic/Northeast on Monday, with an expansive area of strong to
intense wind fields aloft. A deep cyclone will move from Lower MI
into QC, with an occluding cold front arcing southeast across the
northern Appalachians, then south-southwest into the northern Gulf.
This front will clear all but the FL Peninsula by Monday evening.
Ahead of the front, seasonably rich low-level moisture characterized
by 60s surface dew points will spread northward from the eastern
Gulf/western Atlantic. Convection will likely be ongoing at 12Z
Monday, low-topped along the Upper OH Valley to central Appalachian
portion of the front to deep convection in the lee of the southern
Appalachians to eastern FL Panhandle. A diurnal uptick in storm
intensity, including potential for semi-discrete supercells ahead of
the front, should occur from north FL to the Carolina Piedmont.
Further intensification is anticipated midday into the afternoon as
a confined corridor of moderate buoyancy likely develops just ahead
of morning storms.
Enlarged low-level hodograph curvature, in conjunction with
favorable elongation of the mid/upper hodograph, should foster a mix
of broken supercells south with line-embedded supercells in the
reinvigorated QLCS north. With such intense 700-mb flow aptly timed
with the diurnal heating cycle overlying rich low-level moisture,
setup could yield an expansive severe weather day, including strong
tornadoes and significant damaging winds. The degree of
boundary-layer heating, as well as timing of convection that may
outpace the front late D2 into early D3, will play key roles in how
intense severe magnitudes may become. At present, the most likely
corridor for significant/widespread severe appears centered on the
eastern Piedmont to coastal plain from SC to MD around midday into
the afternoon.
..Grams.. 03/14/2026
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