RSS Mesoscale Discussions from Storm Prediction Center
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1125 AM CDT Sun Mar 22 2026
Valid 221630Z - 231200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS FAR
EASTERN OHIO AND WESTERN/CENTRAL PENNSYLVANIA...
...SUMMARY...
Scattered severe thunderstorms appear likely this afternoon and
evening across parts of the Ohio Valley into the Mid-Atlantic,
particularly from far eastern Ohio into central Pennsylvania. Large
to very large hail and damaging winds should be the main threats,
but a tornado or two may also occur.
...Ohio Valley into the Mid-Atlantic...
Early-morning soundings reveal a plume of steep mid-level lapse
rates (i.e. greater than 8 deg C per km from 700 to 500 mb)
extending from the southern Plains northeastward into the Upper OH
Valley. This plume of steeper lapse rates is largely oriented along
and west of a cold front that extends from a low in south-central KS
to another low in western NY. The airmass preceding this front is
seasonally warm and moist, with temperatures in the 70s and
dewpoints in the 50s across much of the OH Valley. The expectation
is for continued airmass modification today as moisture advects
northeastward. However, this moistening will be offset by strong
mixing, with dewpoints likely ranging from the upper 50s across the
Lower OH Valley into the low 50s across western/central PA. This
low-level moisture, combined with temperatures in the upper 70s/low
80s, should result in an erosion of surface-based convective
inhibition ahead of the front from eastern OH through central PA.
Additionally, given the steep mid-level lapse rates in place, weak
instability (MLCAPE around 500-1000 J/kg) is expected to develop
ahead of the front.
Current expectations are for robust thunderstorms to develop by
19-21Z from eastern OH into western/central PA along and just ahead
the front, forced by low-level convergence along the front and in
the vicinity of a weak surface low moving across the region.
An initially discrete mode is anticipated, with strong deep-layer
shear favoring the development of supercells. Long/straight
hodographs and steep mid-level lapse rates suggest that large to
very large hail (up to 1.5-2.5 inches in diameter) is the main
threat with these supercells. High LCLs and steep low-level lapse
rates also support the potential for strong downbursts as well as
trend towards upscale growth and a more linear mode as it moves
east-southeastward across PA through the evening. Primary severe
threat should transition from hail to damaging gusts throughout the
evening. Given the high LCLs and limited low-level moisture, the
tornado risk appears low, although not zero given the supercell mode
anticipated.
Farther west across the low to mid OH Valley, thunderstorm
initiation should occur a bit later (i.e. closer to 00Z) as modest
ascent attendant to a low-amplitude shortwave trough augments
low-level convergence along the front. Much of this convection may
tend to become elevated along/north of the undercutting cold front.
Even so, steep mid-level lapse rates and strong shear will support a
continued risk for large hail. Some isolated very large hail is
possible with the initially more cellular development across
southern IL, central IN, and west-central OH. A trend towards more
linear structures is expected with time, and warm/dry low to
mid-levels could still support some strong gusts despite the
elevated storm structures.
..Mosier/Weinman.. 03/22/2026
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SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0244 PM CDT Sun Mar 22 2026
Valid 222000Z - 231200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS FAR
EASTERN OHIO...THE WEST VIRGINIA PANHANDLE...AND PARTS OF
WESTERN/CENTRAL PENNSYLVANIA...
...SUMMARY...
Scattered severe thunderstorms appear likely this afternoon and
evening across parts of the Ohio Valley into the Mid-Atlantic,
particularly from far eastern Ohio into central Pennsylvania. Large
to very large hail and damaging winds should be the main threats,
but a tornado or two may also occur.
...20z Update - Ohio Valley to the Mid-Atlantic...
Overall the previous forecast remains on track. Only minor
adjustments were made to the southern extent of the level 2 of 5
(Slight) risk area in KY. This adjustment was made based on latest
trends in timing/intensity derived from CAMs and RAP forecast
soundings across the southwest extent of the severe risk area.
While limited low-level moisture is expected to temper instability
across the region, the 18z RAOB from PIT showed the presence of very
steep mid and low-level lapse rates amid strong unidirectional
vertical wind profiles. This environment should support scattered
damaging gusts, and large to very large hail from any initially
discrete supercell structures. For more details regarding short term
severe potential, reference MCD 284 and Severe Thunderstorm Watch
72.
..Leitman.. 03/22/2026
.PREV DISCUSSION... /ISSUED 1125 AM CDT Sun Mar 22 2026/
...Ohio Valley into the Mid-Atlantic...
Early-morning soundings reveal a plume of steep mid-level lapse
rates (i.e. greater than 8 deg C per km from 700 to 500 mb)
extending from the southern Plains northeastward into the Upper OH
Valley. This plume of steeper lapse rates is largely oriented along
and west of a cold front that extends from a low in south-central KS
to another low in western NY. The airmass preceding this front is
seasonally warm and moist, with temperatures in the 70s and
dewpoints in the 50s across much of the OH Valley. The expectation
is for continued airmass modification today as moisture advects
northeastward. However, this moistening will be offset by strong
mixing, with dewpoints likely ranging from the upper 50s across the
Lower OH Valley into the low 50s across western/central PA. This
low-level moisture, combined with temperatures in the upper 70s/low
80s, should result in an erosion of surface-based convective
inhibition ahead of the front from eastern OH through central PA.
Additionally, given the steep mid-level lapse rates in place, weak
instability (MLCAPE around 500-1000 J/kg) is expected to develop
ahead of the front.
Current expectations are for robust thunderstorms to develop by
19-21Z from eastern OH into western/central PA along and just ahead
the front, forced by low-level convergence along the front and in
the vicinity of a weak surface low moving across the region.
An initially discrete mode is anticipated, with strong deep-layer
shear favoring the development of supercells. Long/straight
hodographs and steep mid-level lapse rates suggest that large to
very large hail (up to 1.5-2.5 inches in diameter) is the main
threat with these supercells. High LCLs and steep low-level lapse
rates also support the potential for strong downbursts as well as
trend towards upscale growth and a more linear mode as it moves
east-southeastward across PA through the evening. Primary severe
threat should transition from hail to damaging gusts throughout the
evening. Given the high LCLs and limited low-level moisture, the
tornado risk appears low, although not zero given the supercell mode
anticipated.
Farther west across the low to mid OH Valley, thunderstorm
initiation should occur a bit later (i.e. closer to 00Z) as modest
ascent attendant to a low-amplitude shortwave trough augments
low-level convergence along the front. Much of this convection may
tend to become elevated along/north of the undercutting cold front.
Even so, steep mid-level lapse rates and strong shear will support a
continued risk for large hail. Some isolated very large hail is
possible with the initially more cellular development across
southern IL, central IN, and west-central OH. A trend towards more
linear structures is expected with time, and warm/dry low to
mid-levels could still support some strong gusts despite the
elevated storm structures.
Read more
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1229 PM CDT Sun Mar 22 2026
Valid 231200Z - 241200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF
EASTERN GA/SC INTO SOUTHERN NC...
...SUMMARY...
Isolated strong to severe storms are possible on Monday from eastern
Georgia and South Carolina into southern North Carolina.
...Parts of the Carolinas/Georgia...
A cold front will move southward across parts of the Carolinas and
Southeast on Monday, as a mid/upper-level shortwave trough moves
across New England. Weak to locally moderate buoyancy along/ahead of
the front will support isolated diurnal thunderstorm potential,
though weak midlevel lapse rates will tend to limit storm intensity.
Seasonably strong prefrontal heating and steepening of low-level
lapse rates could support localized strong/damaging gusts during the
afternoon and early evening, if deep convection can be sustained
within the weakly forced environment.
..Dean.. 03/22/2026
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SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0220 PM CDT Sun Mar 22 2026
Valid 241200Z - 251200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Isolated thunderstorms will be possible on Tuesday from far
southeast Georgia to the Florida Peninsula. No severe threat is
forecast.
...Synopsis...
A mid/upper shortwave trough and strong surface low are forecast to
move across parts of British Columbia on Tuesday, as a trailing cold
front moves across the Pacific Northwest. Weak convection may
develop along and in the wake of this cold front, but inland
buoyancy appears too meager for more than very isolated thunderstorm
potential.
Farther south and east, an upper ridge is forecast to amplify
somewhat over the Southwest on Tuesday, with a west-northwesterly
flow regime expected to persist downstream across much of the
central/eastern CONUS. An embedded mid/upper-level shortwave trough
will move across the lower MS Valley and Southeast. A cold front
that moves into north FL late D2/Monday is forecast to slow down and
weaken on Tuesday.
Modest buoyancy may develop near the remnant front, and isolated
storm development will be possible across the FL Peninsula and
adjacent southeast GA, both diurnally, and potentially in response
to the approaching shortwave trough late in the period. Weak
deep-layer shear is expected to limit storm organization. Some weak
destabilization will also be possible near the remnant front across
the central Gulf Coast and lower MS Valley. It appears the shortwave
trough will be displaced north of any appreciable destabilization
along the western portion of the remnant front, but weak convection
cannot be ruled out from LA/MS to the FL Panhandle.
..Dean.. 03/22/2026
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