618
ACUS02 KWNS 210555
SWODY2
SPC AC 210554
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1254 AM CDT MON APR 21 2025
VALID 221200Z - 231200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE
SOUTHERN HIGH PLAINS INTO PARTS OF SOUTHERN KANSAS...
..SUMMARY
ISOLATED SEVERE THUNDERSTORMS ARE POSSIBLE ON TUESDAY ACROSS
PORTIONS OF THE SOUTHERN PLAINS.
..SYNOPSIS
LOW-AMPLITUDE WEST/SOUTHWEST MID/UPPER FLOW WILL PREVAIL ACROSS THE
SOUTH-CENTRAL AND SOUTHEAST STATES ON TUESDAY. A BELT OF STRONGER
WESTERLIES ALOFT WILL RESIDE ACROSS THE NORTHERN TIER OF THE U.S. AS
A SERIES OF UPPER TROUGHS MIGRATE EASTWARD FROM THE NORTHERN PLAINS
TO THE NORTHEAST. AT THE SURFACE, LOW PRESSURE OVER QUEBEC AND AN
ASSOCIATED COLD FRONT WILL BE LOCATED FROM THE HUDSON VALLEY INTO
THE NC/VA PIEDMONT. FURTHER WEST, LOW-LEVEL MOIST ADVECTION ON
SOUTH/SOUTHEASTERLY LOW LEVEL FLOW WILL ALLOW MODIFIED GULF MOISTURE
TO SPREAD NORTHWARD FROM THE LOWER MS VALLEY INTO THE SOUTHERN HIGH
PLAINS.
..SOUTHERN PLAINS TO SOUTHERN KS
MODEST GULF MOISTURE WILL SPREAD NORTH AND WEST THROUGH THE DAY TO
NEAR THE NM/TX BORDER AND ACROSS MUCH OF OK INTO SOUTHERN KS.
FORECAST GUIDANCE SUGGEST A WEAK SHORTWAVE IMPULSE WILL EJECT ACROSS
THE SOUTHERN ROCKIES IN MODEST WEST/SOUTHWESTERLY FLOW ALOFT. WHILE
HEIGHT TENDENCIES WILL REMAIN NEUTRAL, PRECLUDING MUCH IN THE WAY OF
SURFACE CYCLOGENESIS, A SHARPENING DRYLINE IS FORECAST TO EXTEND
FROM SOUTHWEST KS INTO THE OK/TX PANHANDLES, THEN SOUTHWARD NEAR THE
NM/TX BORDER. LOW-LEVEL MOIST ADVECTION BENEATH STEEP MIDLEVEL LAPSE
RATES WILL SUPPORT MODERATE DESTABILIZATION (MLCAPE 1500-2500 J/KG).
WHILE DEEP-LAYER FLOW WILL REMAIN MODEST, VERTICALLY VEERING WIND
PROFILES WILL CONTRIBUTE TO SUPERCELL WIND PROFILES, WITH
ELONGATED/STRAIGHT HODOGRAPHS. ISOLATED SUPERCELLS WILL POSE A RISK
FOR LARGE HAIL. FURTHERMORE, STRONG HEATING WILL RESULT IN STEEP
LOW-LEVEL LAPSE RATES AND A WELL MIXED BOUNDARY LAYER, SUPPORTING
ISOLATED STRONG TO SEVERE OUTFLOW GUSTS. AS A SOUTHERLY LOW-LEVEL
JET INCREASES DURING THE EVENING, SOME POTENTIAL WILL EXIST FOR
CONVECTION TO DEVELOP INTO AN EASTWARD DEVELOPING MCS. IF THIS
OCCURS, SOME SEVERE POTENTIAL COULD PERSIST EASTWARD AWAY FROM THE
DRYLINE INTO PORTIONS OF WESTERN NORTH TEXAS AND WESTERN OK.
..IA/WI/IL
A STALLED FRONTAL BOUNDARY WILL EXTENT ACROSS THE MID-MO VALLEY INTO
SOUTHERN WI. MODEST MOISTURE RETURN AND PERSISTENT ISENTROPIC ASCENT
ALONG THIS BOUNDARY MAY BE SUFFICIENT FOR ISOLATED THUNDERSTORM
DEVELOPMENT AMID WEAK DIURNAL DESTABILIZATION. LOW TO MIDLEVEL FLOW
WILL REMAIN RATHER WEAK, BUT RAPIDLY INCREASE ABOVE 700 MB,
SUPPORTING EFFECTIVE SHEAR MAGNITUDES GREATER THAN 40 KT. COLD
TEMPERATURES ALOFT (-17 C NEAR 500 MB) WILL SUPPORT MLCAPE TO AROUND
500 J/KG, AND ISOLATED CONVECTION COULD PRODUCE SPORADIC HAIL.
..CAROLINAS
A COLD FRONT ASSOCIATED WITH A SURFACE LOW OVER QUEBEC WILL DEVELOP
SOUTHEAST ACROSS THE MID-ATLANTIC AND CAROLINAS DURING THE
AFTERNOON/EVENING. STRONG HEATING OF A MODESTLY MOIST BOUNDARY LAYER
AHEAD OF THE FRONT WILL SUPPORT A CORRIDOR OF MLCAPE UP TO 1000-1500
J/KG. WEAK LOW-LEVEL SOUTHWESTERLY FLOW WILL INCREASE WITH HEIGHT,
SUPPORT EFFECTIVE SHEAR MAGNITUDES UP TO 35 KT. THIS SHOULD BE
SUFFICIENT FOR A FEW STRONGER/ORGANIZED CELLS. STEEP LOW-LEVEL LAPSE
RATES AND SOMEWHAT ELONGATED HODOGRAPHS SUGGEST TRANSIENT SUPERCELLS
CAPABLE OF STRONG GUSTS AND ISOLATED HAIL WILL BE POSSIBLE.
..LEITMAN.. 04/21/2025
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