820
ACUS03 KWNS 230743
SWODY3
SPC AC 230742
DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0242 AM CDT MON JUN 23 2025
VALID 251200Z - 261200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN A CORRIDOR
FROM THE NORTHERN HIGH PLAINS INTO THE MIDWEST AND NORTHEAST...AND
ALSO ACROSS PARTS OF THE SOUTHEAST...
..SUMMARY
STRONG TO POTENTIALLY SEVERE STORMS ARE POSSIBLE WEDNESDAY IN A
CORRIDOR FROM THE NORTHERN HIGH PLAINS INTO THE MIDWEST AND
NORTHEAST, AND ALSO ACROSS PARTS OF THE SOUTHEAST.
..SYNOPSIS
AN UPPER RIDGE IS FORECAST TO PERSIST ACROSS PARTS OF THE OHIO
VALLEY AND SOUTHEAST ON WEDNESDAY, WITH SOME GRADUAL WEAKENING OF
THE RIDGE EXPECTED THROUGH THE FORECAST PERIOD. MULTIPLE
LOW-AMPLITUDE MIDLEVEL SHORTWAVE TROUGHS WILL MOVE ALONG THE WESTERN
AND NORTHERN PERIPHERY OF THE RIDGE, FROM THE CENTRAL/NORTHERN
PLAINS INTO THE UPPER MIDWEST AND GREAT LAKES. ALONG THE SOUTHERN
PERIPHERY OF THE RIDGE, A SLOW-MOVING MID/UPPER-LEVEL LOW WILL IS
FORECAST TO APPROACH FLORIDA FROM THE BAHAMAS.
..PARTS OF THE CENTRAL/NORTHERN PLAINS INTO THE UPPER MIDWEST
A REMNANT MCS MAY BE ONGOING SOMEWHERE FROM THE NORTH-CENTRAL PLAINS
INTO PARTS OF SOUTHERN MN/NORTHERN IA WEDNESDAY MORNING. THIS SYSTEM
IS CURRENTLY EXPECTED TO GRADUALLY DIMINISH WITH TIME AS THE
NOCTURNAL LOW-LEVEL JET WEAKENS. A LOCALIZED SEVERE COULD ACCOMPANY
THIS REMNANT MCS THROUGH PART OF THE MORNING.
IN THE WAKE OF THIS MCS, DIURNAL HEATING OF A RICHLY MOIST
ENVIRONMENT WILL SUPPORT STRONG DESTABILIZATION NEAR AN
OUTFLOW-REINFORCED FRONT. STORM DEVELOPMENT WILL BE POSSIBLE ALONG
THIS FRONT/OUTFLOW BY LATE AFTERNOON, WITH MLCAPE POTENTIALLY IN
EXCESS OF 3000 J/KG SUPPORTING VIGOROUS UPDRAFTS. DEEP-LAYER FLOW
WILL BE RELATIVELY MODEST, THOUGH LOCALLY BACKED WINDS NEAR THE
BOUNDARY COULD SUPPORT INITIAL SUPERCELL DEVELOPMENT, BEFORE STORM
CLUSTERING BECOMES MORE PROMINENT WITH TIME. DAMAGING WINDS,
ISOLATED HAIL, AND POSSIBLY A TORNADO COULD ACCOMPANY THE STRONGEST
AFTERNOON/EVENING STORMS. A CORRIDOR OF GREATER SEVERE PROBABILITIES
MAY EVENTUALLY BE NEEDED, IF CONFIDENCE INCREASES REGARDING THE
EVOLUTION OF MORNING CONVECTION AND PLACEMENT OF REMNANT SURFACE
BOUNDARIES.
FARTHER WEST, A RELATIVELY MOIST POST-FRONTAL REGIME COULD AGAIN
SUPPORT STRONG TO POTENTIALLY SEVERE STORMS ACROSS PARTS OF THE
CENTRAL/NORTHERN HIGH PLAINS. THERE IS SOME POTENTIAL FOR THIS
REGION TO BE IN THE WAKE OF A DEPARTING MIDLEVEL SHORTWAVE TROUGH
DURING THE AFTERNOON AND EVENING, MAKING DIURNAL STORM COVERAGE
UNCERTAIN. DEEP-LAYER SHEAR WILL BE SUFFICIENT FOR AT LEAST AN
ISOLATED SEVERE THREAT IN THE REGION DURING THE AFTERNOON AND
EVENING.
..LOWER GREAT LAKES INTO THE MID ATLANTIC/NORTHEAST
SCATTERED STORM DEVELOPMENT WILL BE POSSIBLE WEDNESDAY AFTERNOON
ACROSS PARTS OF THE LOWER GREAT LAKES INTO THE MID ATLANTIC AND
NORTHEAST, ALONG/SOUTH OF A COLD FRONT. WHILE TEMPERATURES ALOFT
WILL BE RATHER WARM, DIURNAL HEATING WILL SUPPORT MODERATE TO
LOCALLY STRONG BUOYANCY. DEEP-LAYER FLOW/SHEAR IS FORECAST TO BE
RELATIVELY WEAK, BUT UNIDIRECTIONAL WEST-NORTHWESTERLY FLOW COULD
SUPPORT OUTFLOW-DOMINANT CLUSTERS CAPABLE OF AT LEAST ISOLATED WIND
DAMAGE.
..PARTS OF THE SOUTHEAST/CAROLINAS
A POCKET OF STEEP MIDLEVEL LAPSE RATES WILL BE IN PLACE ACROSS PARTS
OF THE SOUTHEAST AND CAROLINAS ON WEDNESDAY. THE FAVORABLE LAPSE
RATES COMBINED WITH STRONG DIURNAL HEATING OF A VERY MOIST AIRMASS
WILL RESULT IN DEVELOPMENT OF STRONG TO EXTREME INSTABILITY BY
AFTERNOON. WITH SOME FURTHER WEAKENING OF THE UPPER RIDGE, STORM
COVERAGE MAY INCREASE COMPARED TO PREVIOUS DAYS.
20-30 KT OF NORTHEASTERLY FLOW ALOFT WILL ALSO DEVELOP ACROSS PARTS
OF THE REGION, TO THE NORTHWEST OF THE OFFSHORE UPPER LOW. THIS
MODESTLY ENHANCED FLOW COULD SUPPORT AT LEAST TRANSIENT STORM
ORGANIZATION WITHIN THE VERY UNSTABLE ENVIRONMENT. DAMAGING WINDS
AND ISOLATED HAIL WILL BE POSSIBLE WITHIN THIS REGIME. ANY LOOSELY
ORGANIZED CLUSTERING COULD RESULT IN LOCALIZED CORRIDORS OF MORE
CONCENTRATED WIND DAMAGE.
..DEAN.. 06/23/2025
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