RSS Mesoscale Discussions from Storm Prediction Center
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1252 AM CDT Sun Mar 15 2026
Valid 151200Z - 161200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS LATE THIS
AFTERNOON THROUGH TONIGHT ACROSS PARTS OF THE MID SOUTH INTO LOWER
OHIO VALLEY AND ACROSS PARTS OF THE EASTERN GULF COAST STATES...
...SUMMARY...
Widespread strong to severe wind gusts may accompany a developing
squall line across and east of the middle into lower Mississippi
Valley late this afternoon into this evening. A couple of strong
tornadoes are also possible within and just ahead of this line
across parts of the lower Ohio Valley into Mid South, with a couple
of strong tornadic supercells also possible across parts of the
Florida Panhandle and southeastern Alabama into adjacent Georgia
late tonight.
...Discussion...
To the north of an expanding blocking mid-level high, centered off
the southern California coast, models indicate that large-scale
ridging will continue to build inland of the British Columbia/U.S.
Pacific coast, through the Canadian Rockies and U.S. Intermountain
West during this period. Downstream, a significant short wave
trough is forecast to continue amplifying southeastward across the
Great Plains and Mississippi Valley, preceded by building ridging
near and east of the Atlantic Seaboard.
Downstream of the digging short wave trough, a broad and deep
cyclone has already formed to the east of the Colorado Rockies, with
a plume of warm elevated mixed-layer air overspreading the central
and southern Great Plains toward the lower Mississippi Valley. The
center of the cyclone is forecast to redevelop east-northeast into
the St. Joseph MO vicinity by daybreak, before continuing to deepen
while migrating northeastward toward lower Michigan today through
tonight. It appears that the northeastern periphery of the elevated
mixed-layer plume will spread across the lower Missouri Valley
before becoming suppressed southeastward.
In the wake of a preceding surface cyclone and associated cold
frontal passage, Gulf boundary-layer moistening and inland return
flow remain limited at this time. Although it should improve some,
aside from a narrow corridor of better boundary-layer moisture
return across the southeastern Great Plains toward the lower Ohio
Valley, and broader corridors across the southern through middle
Atlantic Seaboard, as well as across the eastern Gulf Coast vicinity
by late tonight, warm sector dew points may not exceed lower/mid 50s
F. This may prove a limiting factor to the overall severe threat.
Nevertheless, guidance continues to indicate the development of a
fairly extensive squall line along much of the length of a cold
front advancing across and east of the Mississippi Valley toward the
Appalachians late this afternoon through tonight.
...Lower Mississippi Valley into Great Lakes...
Latest model output suggests that the stronger 850 mb jet core may
tend to shift ahead of the deepening surface cyclone, north of the
Ohio Valley into and through the lower Great Lakes region during the
afternoon. However, 40-50+ kt southerly flow may tend to trail back
ahead of the cold front to the southwest, at least as far as the Mid
South vicinity through late afternoon, as a narrow corridor of
better boundary-layer moisture return (characterized by lower 60s F
surface dew points) surges across northeastern Arkansas and
southeastern Missouri into southern Illinois, western Kentucky and
Tennessee.
North-northeast and east of this vicinity, toward the Great Lakes
and upper Ohio Valley, the narrow corridor of better pre-frontal
moisture is likely to be more modest and supportive of rather modest
to weak CAPE. And there is concern that deeper boundary-layer
warming and mixing in the drier pre-convective environment may
actually be more efficient at mixing down stronger momentum to the
surface than the thunderstorm activity.
However, based on the latest forecast soundings, there does still
appear potential for widespread potentially damaging wind gusts at
least approaching or exceeding 50 kts, with an evolving pre-frontal
squall line as it spreads across and east of the middle to lower
Mississippi Valley vicinity. Gusts exceeding 65 kts, and potential
for tornadoes, may tend to be confined to meso-vortices evolving
along the leading edge of the convective outflow, particularly
within the more moist environment across the lower Ohio Valley into
Mid South.
There may also be a late afternoon into early evening window of
opportunity, across this same corridor, for either initially
discrete supercell development or discrete supercell development
just ahead of the evolving eastward advancing line. If this occurs,
there will probably be at least somewhat greater potential for
strong tornadoes. However, this remains unclear, particularly given
the limited breadth of the moist sector, and the tendency for it to
be rather quickly overtaken by the cold front.
...Eastern Gulf Coast States...
Models continue to indicate a separate area of better low-level
moisture return across the eastern Gulf coast, which may include
surface dew points increasing through the lower/mid 60s across the
western Florida Panhandle, southeastern Alabama and adjacent Georgia
by late tonight. It appears that this will support a corridor of
boundary-layer destabilization characterized by CAPE in excess of
1000 J/kg. Coincident with enlarging, clockwise curved low-level
hodographs beneath 40-45 kt southwesterly 850 mb flow overspreading
the region, and in the presence of sufficient deep-layer shear,
there appears potential for the evolution of longer-lived supercells
which could become capable of producing strong tornadoes.
..Kerr/Thornton.. 03/15/2026
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SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
0107 AM CDT Sun Mar 15 2026
Valid 161200Z - 171200Z
...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FROM NORTHERN
SOUTH CAROLINA ACROSS NORTH CAROLINA AND INTO VIRGINIA AND
MARYLAND...
...SUMMARY...
Widespread severe storms are forecast on Monday for parts of the
Mid-Atlantic States and Southeast. Tornadoes, potentially strong,
and particularly damaging winds are most likely from South Carolina
into Maryland during the afternoon. Significant severe storm
potential overall will extend from eastern Georgia/Florida Panhandle
into Pennsylvania.
...Synopsis...
A large and deepening upper trough will pivot northeastward out of
the OH/TN Valleys, across the Appalachians and into the Mid Atlantic
on Monday, while a surface low deepens into southern Quebec. A sharp
pre-frontal trough will extend southward across NY, PA, and into the
Carolinas/GA by late afternoon, with a corridor of significant
pressure falls timed with the diurnal heating maximum. A cold front
will push rapidly east across GA and the FL Panhandle during the day
with a bit slower progress across the Piedmont and into PA. Gusty
south winds ahead of the cold front will maintain 60s F dewpoints
across the entire region, and as far north as southern PA, just
after warm front passage by late afternoon.
Just above the surface, southerly 850 mb winds will increase from 50
to 75 kt, resulting in extreme shear profiles over a large area.
Large-scale ascent and shear will increase coincident with the peak
heating hours, resulting in a potentially widespread severe weather
event during the afternoon.
...From Georgia and the Florida Panhandle...
Early day storms may be ongoing from the southern Appalachians
toward the FL Panhandle Monday morning, and the environment will
already be favorable for supercells including tornado potential.
Forecast soundings indicate substantial instability with mid to
perhaps upper 60s F along with ample shear. These storms may also
produce hail, as midlevel lapse rates approach 7 C/km.
...Carolinas into MD/PA and vicinity...
Areas of showers may occur early in the day especially but should
rapidly lift north, allowing areas of heating and gradual
destabilization over the entire area. As the surface trough deepens,
low-level wind will back and strengthen throughout the day.
Supercells producing tornadoes appear most likely ahead of the cold
front from SC into NC and southern VA. Models vary with degree of
instability, but strong tornadoes do appear possible with effective
SRH of at least 300-400 m2/s2. Fast storm motions over 50 kt suggest
a long tracked tornado will be possible.
Meanwhile, a robust line of storms will develop as the cold front
pushes east, stretching from the Carolinas to southern NY. With a
moist air mass and large-scale support, this line is expected to
produce particularly damaging winds, along with QLCS tornadoes
across the remainder of SC/NC, VA, MD, and much of southern PA. This
will likely peak during the late afternoon hours. The activity may
eventually interact with cool trajectories off the Atlantic during
the evening.
..Jewell.. 03/15/2026
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SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0204 AM CDT Sun Mar 15 2026
Valid 171200Z - 181200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Severe storms are not forecast on Tuesday.
...Synopsis...
A large upper trough will move from the Great Lakes across the
Northeast, with an upper ridge building over the southwestern US. A
cold front associated with the upper trough will be well offshore
over the Atlantic, though the tail end will clip far southern FL
early in the morning. A band of moisture and perhaps weak elevated
instability may persist well north of this front over southern FL,
with scattered weak convection possible.
..Jewell.. 03/15/2026
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Day 4-8 Outlook
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0350 AM CDT Sun Mar 15 2026
Valid 181200Z - 231200Z
...DISCUSSION...
Severe storms appear unlikely across the CONUS for the D4-8 period,
as an upper ridge holds over the Southwest with a mean upper trough
over the East. This pattern will keep a surface high over much of
the east/southeast CONUS, with northerly winds over the Gulf Of
America for much of the period.
Models do indicate the upper ridge over the Southwest may weaken
into the Sat/D7 and Sun/D8 time frame, with perhaps the pattern
trending toward zonal. Even so, potential for any significant
instability to develop over land remains minimal.
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