SPC May 18, 2025 1630 UTC Day 1 Convective Outlook

SPC 1630Z Day 1 Outlook

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1116 AM CDT Sun May 18 2025

Valid 181630Z - 191200Z

...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FOR SOUTHWEST
AND CENTRAL KANSAS INTO FAR NORTHWEST OKLAHOMA...

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN
MISSISSIPPI...CENTRAL ALABAMA...AND SOUTHERN GEORGIA...

...SUMMARY...
Severe thunderstorms capable of all severe hazards are expected this
afternoon and evening across portions of the central and southern
Plains.  Several strong to intense tornadoes are possible.

...KS/OK...
A large upper trough continues to deepen over the western US, with a
band of 60-70 knot southwesterly mid-level flow extending across NM
into western KS/OK.  The surface dryline will mix eastward into
western KS and along the TX/OK border by mid-afternoon, with the air
mass to the east becoming extremely unstable with dewpoints in the
upper 60s and MLCAPE values over 4000 J/kg.  Strong
southerly/southeasterly low-level winds throughout the warm sector
will provide a conditionally favorable environment for intense
supercells capable of very large hail, damaging winds, and
tornadoes.  However, morning model guidance continues to show
diverse solutions regarding coverage of convection later today.  

The area of greatest confidence in storm development and intensity
will be near the warm front/dryline triple point over south-central
KS.  Discrete supercell development appears likely here, with
forecast soundings showing favorable hodograph structures to promote
a risk of strong tornadoes.  The MDT risk has been extending
slightly eastward along the warm front.  Farther south along the
dryline in western OK, confidence in initiation is lower.  However,
any storm that can form will be capable of all hazards.

...Western North TX...
Another region of higher confidence in convective initiation will be
over western north TX along the dryline.  Hot surface temperatures
in vicinity of a dryline bulge will aid in storm development.  These
storms will likely expand eastward and into southwest OK through the
evening, with very large hail and damaging winds possible.

...MS/AL/GA...
A narrow corridor of SLGT risk has been added for this afternoon
from eastern MS across central AL and southern GA.  Multiple MCSs
are ongoing in this corridor, with associated outflow boundaries
present.  These boundaries may be the focus for further development
this afternoon, with sufficient CAPE/shear combinations to pose a
risk of damaging winds in the strongest cells.

..Hart/Moore.. 05/18/2025

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