507
ACUS03 KWNS 120719
SWODY3
SPC AC 120718
DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0218 AM CDT SUN APR 12 2026
VALID 141200Z - 151200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF
THE SOUTHERN PLAINS TO THE GREAT LAKES...
..SUMMARY
ISOLATED TO SCATTERED SEVERE THUNDERSTORMS ARE EXPECTED ON TUESDAY
AND TUESDAY NIGHT FROM THE SOUTHERN PLAINS TO THE GREAT LAKES.
..SYNOPSIS
SOUTHWESTERLY DEEP-LAYER FLOW WILL PERSIST FROM THE SOUTHERN PLAINS
TO THE GREAT LAKES ON TUESDAY. AN UPPER TROUGH OVER THE WESTERN U.S.
WILL SLOWLY PIVOT EASTWARD, EMERGING OVER THE CENTRAL/SOUTHERN HIGH
PLAINS BY SUNDAY MORNING. SURFACE LOW PRESSURE WILL REMAIN CENTERED
OVER THE CENTRAL PLAINS, WITH TROUGHING EXTENDING SOUTHWESTWARD INTO
WEST TX. A COLD FRONT WILL SLOWLY SAG SOUTHWARD ACROSS PORTIONS OF
THE UPPER MIDWEST/GREAT LAKES VICINITY. THE SURFACE TROUGH/DRYLINE
AND THE BOUNDARY ACROSS THE GREAT LAKES WILL BECOME A FOCUS FOR
THUNDERSTORM ACTIVITY THROUGH THE FORECAST PERIOD.
..LOWER MO VALLEY TO THE GREAT LAKES VICINITY
CONVECTION MAY BE ONGOING ACROSS PORTIONS OF THE REGION TUESDAY
MORNING. THIS ACTIVITY SHOULD SPREAD EAST, AND PERSISTENT WARM
ADVECTION SHOULD ALLOW FOR AIRMASS RECOVERY DURING THE AFTERNOON.
STEEP MIDLEVEL LAPSE RATES WILL OVERSPREAD MID 60S F DEWPOINTS, AND
MODERATE TO STRONG DESTABILIZATION IS FORECAST. STRONGER HEIGHT
FALLS ARE NOT EXPECTED ACROSS THE REGION, AS THE MAIN UPPER TROUGH
WILL BE FOCUSED WELL TO THE SOUTHWEST. HOWEVER, WARM ADVECTION ATOP
A SOUTHWARD-SAGGING SURFACE BOUNDARY SHOULD SUPPORT ISOLATED TO
SCATTERED STORM DEVELOPMENT BY LATE AFTERNOON/EVENING. SUPERCELL
WIND PROFILES ARE EVIDENT IN FORECAST SOUNDINGS, SUGGESTING AN
ALL-HAZARDS RISK. GIVEN UNCERTAINTY RELATED TO POTENTIAL AIRMASS
CONTAMINATION FROM EARLY DAY CONVECTION AND CLOUD COVER, AND
POTENTIAL CAPPING CONCERNS, WILL MAINTAIN SLIGHT RISK (LEVEL 2 OF
5). HOWEVER, A RATHER VOLATILE THERMODYNAMIC AND KINEMATIC
ENVIRONMENT WILL EXIST ACROSS PORTIONS OF THE REGION, AND HIGHER
PROBABILITIES MAY BE NEEDED IN SUBSEQUENT OUTLOOKS DEPENDING ON
FORECAST TRENDS AND MESOSCALE DETAILS.
..SOUTHERN PLAINS VICINITY
LARGE-SCALE ASCENT WILL BEGIN OVERSPREADING THE REGION BY LATE
AFTERNOON/EVENING AS THE WESTERN UPPER TROUGH FINALLY BEGINS TO
EJECT EASTWARD. AS THIS OCCURS, MIXING AND CONVERGENCE ALONG A
SURFACE DRYLINE SHOULD SUPPORT AT LEAST ISOLATED STORM DEVELOPMENT
BY AROUND 00Z. STEEP MIDLEVEL LAPSE RATES AND MID/UPPER 60S F
DEWPOINTS WILL SUPPORT STRONG DESTABILIZATION AMID SUPERCELL WIND
PROFILES. LARGE TO VERY LARGE HAIL WILL BE POSSIBLE IN ADDITION TO
STRONG WIND GUSTS AND A TORNADO OR TWO.
..LEITMAN.. 04/12/2026
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page