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Day 2 Outlook Categorical Probabilistic
Categorical Day2 0700Z Outlook

Images courtesy of the NWS Storm Prediction Center
 Forecast Discussion

ACUS02 KWNS 261731
SPC AC 261729

Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1229 PM CDT Sun May 26 2024

Valid 271200Z - 281200Z


Severe thunderstorms are possible from the Mid Atlantic to the
Southeast Monday into Monday night, with severe wind, hail and
potentially a tornado or two expected.

A strong (sub 1000mb) surface low will exist near Lower Michigan
Monday morning. This surface low will deepen through the day as it
moves northeast of Lake Superior by the evening. A cold front will
extend from this surface low across western Lake Erie to the
Mid-Mississippi Valley at 12Z and cross the Appalachians by 00Z.
Strong to severe thunderstorms are possible along and ahead of this
cold front during the afternoon into the evening hours. This cold
front will stall near the Gulf Coast and back into northern Texas. A
dryline will retreat westward during the day as weak lee troughing
and strengthening southwesterly flow advects low-level moisture

...Mid-Atlantic into North Carolina...
A decaying MCS will likely result in cloud cover across this region
Monday morning. However, some clearing is expected by late morning
to early afternoon. Convective temperatures near 80F should be met
by early afternoon with scattered thunderstorm development ahead of
the cold front. Effective shear between 30 and 35 knots will support
both multicell and supercell clusters. Thermodynamically the best
environment should be across Virginia and North Carolina. However,
stronger flow across eastern Pennsylvania may be more supportive of
supercells and thus a greater hail threat despite the weaker
thermodynamics. In addition, RAP forecast soundings show low-level
shear supportive of a tornado or two across most of the warm sector
from North Carolina into eastern Pennsylvania and the Delmarva.

There is considerable uncertainty regarding the expected overnight
MCS and how it may impact severe weather across Alabama, Georgia,
and South Carolina on Monday. Most forecast soundings show
significant inhibition which would support CAM solutions which show
the MCS decaying during the morning. Strong westerly flow and an EML
may allow for recovery in the wake of any morning MCS with a threat
for storms along the cold front during the afternoon as temperatures
warm into the 80s to near 90 and strong instability develops. Large
hail and damaging wind gusts will be the primary threat with this
activity. A lack of convergence along the front and weaker
large-scale ascent should result in more sparse storm development
farther west along the front through MS and LA during the

...Texas and southwest Oklahoma...
Moisture will recover northwest through the day south of a stalled
front as a result of strengthening southwesterly flow. As boundary
layer moisture deepens from southeast to northwest through the day,
a few storms may develop as the airmass becomes uncapped. Forcing
should be quite nebulous which will keep storm coverage isolated,
but environmentally, extreme (5000+ J/kg) MLCAPE and effective shear
over 60 knots would support a conditional threat for large to very
large hail and potentially a tornado. The best chance for storm
development will likely be across northwest Texas during the late
evening as the low-level jet strengthens and low-level moisture
advection and isentropic ascent increases. 

Storms are expected to develop from southern Minnesota and move
quickly southeast across Iowa and into Illinois Monday
afternoon/early evening amid cold air advection aloft and sufficient
remnant moisture for 500-1000 J/kg MLCAPE. Strong unidirectional
westerly flow may support some stronger downdrafts capable of wind

..Bentley.. 05/26/2024