SPC Apr 22, 2025 2000 UTC Day 1 Convective Outlook

SPC 2000Z Day 1 Outlook

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0250 PM CDT Tue Apr 22 2025

Valid 222000Z - 231200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE SOUTHERN/CENTRAL PLAINS...

...SUMMARY...
Isolated to scattered severe thunderstorms will be possible across
parts of the southern/central Plains, mainly this afternoon and
evening. Large hail and severe gusts should be the main threats.

...20z Update...
The primary change for this forecast update is an inclusion of
significant hail/wind areas to portions of western TX into far
southwestern OK. Recent GOES visible imagery shows developing
cumulus across the Trans Pecos region of southwest TX and across
parts of the southern TX Panhandle. This lends confidence in
convective development within the coming hours as anticipated by
recent high-res guidance. The combination of low-level moisture
return and steep/very steep (8-9 C/km) mid-level lapse rates is
supporting lifted indices of -8 to -10 C across the Stockton and
eastern Edwards plateaus. This thermodynamic environment, coupled
with 30-40 knots of effective bulk shear, should favor robust
supercell development with the potential for significant (2+ inch)
hail. Recent WOFS guidance appears to be capturing ongoing
convective trends in southwest TX well, and also hints at this
potential. Further north, very steep low-level lapse rates should
promote downdraft accelerations that may favor isolated gusts
upwards of 70-80 mph. This potential is also hinted in recent WOFS 
and HRRR solutions. See MCD #516 for additional near-term details
regarding western TX. 

...Southeast Virginia...
Hail/wind risk probabilities are also expanded into far southeast VA
downstream of ongoing strong/severe thunderstorms where broken cloud
cover has allowed temperatures to warm into the low 80s with an
attendant increase in buoyancy. See MCD #515 for additional details.

..Moore.. 04/22/2025

.PREV DISCUSSION... /ISSUED 1117 AM CDT Tue Apr 22 2025/

...Central/Southern Plains...
Morning water vapor imagery shows broad zonal flow across the
central US, with the main upper jet across the northern states. 
Mostly clear skies and southerly low-level winds across much of west
TX/OK and central KS will help to destabilize the air mass along a
developing dryline, leading to afternoon MLCAPE values around 1500
J/kg and minimal cap.  Large scale forcing is weak, but dryline
circulations will likely lead to scattered afternoon and early
evening thunderstorm development.  Relatively slow-moving storms
capable of large hail and damaging wind gusts are expected.  Several
12z CAM solutions suggest upscale growth of convection over
northwest TX after dark, with some risk of strong/severe storms
reaching central TX overnight.

...IA/MO/IL...
A weak surface boundary extends across southern IA this morning. 
The southern fringe of stronger westerly flow aloft lies across this
region, with water vapor imagery suggesting a subtle shortwave
trough over NE approaching the region.  A few thunderstorms are
expected to form along the boundary by late afternoon/early evening,
with some risk of hail and gusty winds in the strongest storms.

...Southeast States...
A diffuse surface boundary extends from LA northeastward across
MS/AL/GA into the Carolinas.  Ample low and mid-level moisture along
the boundary will lead to scattered afternoon thunderstorms. 
Forecast soundings show relatively weak low-level winds and poor
mid-level lapse rates.  While a few storms could produce gusty
winds, organized severe storm risk appears marginal today.

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