640
ACUS02 KWNS 200551
SWODY2
SPC AC 200549
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1249 AM CDT MON OCT 20 2025
VALID 211200Z - 221200Z
..NO SEVERE THUNDERSTORM AREAS FORECAST
..SUMMARY
ISOLATED THUNDERSTORMS ARE POSSIBLE OVER THE GREAT LAKES, SOUTH
FLORIDA, AND THE NORTHWEST GULF COAST REGIONS TUESDAY. SEVERE
THUNDERSTORMS ARE NOT EXPECTED.
..SYNOPSIS AND DISCUSSION
A STRONG UPPER LOW INITIALLY OVER THE MIDWEST WILL CONTINUE TO
INTENSIFY AS IT MOVES EASTWARD ACROSS THE GREAT LAKES AND INTO THE
NORTHEAST TUESDAY. AS THE UPPER LOW DEEPENS, SO TOO WILL A SURFACE
LOW OVER THE GREAT LAKES. RESIDUAL SURFACE MOISTURE AND COOL
MID-LEVEL TEMPERATURES BENEATH THE UPPER LOW WILL LIKELY SUPPORT
SOME WEAK BUOYANCY AS LAPSE RATES STEEPEN THROUGH THE DAY. WITH
STRONG LIFT OVERSPREADING THE WEAKLY UNSTABLE AIR MASS, ISOLATED
LOW-TOPPED THUNDERSTORMS ARE POSSIBLE ACROSS THE GREAT LAKES AND
UPPER OH VALLEY TUESDAY AFTERNOON.
TRAILING THE SURFACE LOW, A COLD FRONT WILL SWEEP SOUTHEASTWARD WITH
STRENGTHENING SURFACE HIGH PRESSURE BEHIND IT OVER THE CENTRAL US.
OFFSHORE WINDS WILL LIMIT AVAILABLE MOISTURE AND BUOYANCY FOR MUCH
OF THE COUNTRY. THE EXCEPTION WILL BE ACROSS PORTIONS OF THE
NORTHWEST GULF COAST AND SOUTHERN FL. HERE, RICH LOW-LEVEL MOISTURE
WILL ALLOW FOR MODERATE DIURNAL DESTABILIZATION. STILL, WEAK FORCING
DISPLACED TO THE NORTH SUGGESTS ONLY ISOLATED THUNDERSTORM COVERAGE.
WEAK VERTICAL SHEAR AND WARM MID-LEVEL TEMPERATURES SHOULD LIMIT
SEVERE POTENTIAL.
..LYONS.. 10/20/2025
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