423
ACUS02 KWNS 131730
SWODY2
SPC AC 131729
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1229 PM CDT SAT SEP 13 2025
VALID 141200Z - 151200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF
THE NORTHERN PLAINS EXTENDING INTO THE SOUTHERN HIGH PLAINS...
..SUMMARY
ISOLATED SEVERE STORMS ARE POSSIBLE ACROSS PARTS OF THE NORTHERN
PLAINS INTO THE SOUTHERN HIGH PLAINS TOMORROW (SUNDAY).
..SYNOPSIS
A BROAD NEGATIVE TILT TROUGH WILL EJECT INTO THE CENTRAL PLAINS ON
SUNDAY, RESULTING IN A DEEPENING A SURFACE LOW ACROSS THE DAKOTAS.
AS THE SURFACE LOW DEEPENS, THE SOUTHERLY LOW-LEVEL JET WILL
INCREASE WITH WARM AND MOIST ADVECTION FROM THE SOUTHERN PLAINS INTO
THE NORTHERN PLAINS.
..GREAT PLAINS STATES
THE BROAD AREA OF WARM AND MOIST ADVECTION WILL RESULT IN WIDESPREAD
SHOWER/THUNDERSTORM ACTIVITY ONGOING AT THE START OF THE PERIOD
SUNDAY MORNING. IN THE WAKE OF THIS MORNING CONVECTION, EXTENSIVE
CLOUD COVER IS EXPECTED TO COVER MUCH OF THE REGION FROM THE CENTRAL
PLAINS INTO THE NORTHERN PLAINS. SOME BREAKS IN THE CLOUD COVER MAY
ALLOW FOR POCKETS OF HEATING AND RECOVERY, BUT IT REMAINS UNCERTAIN
HOW MUCH AIR MASS RECOVERY WILL BE ACHIEVED. FORECAST SOUNDINGS
INDICATE TALL SKINNY CAPE PROFILES AND MODEST LAPSE RATES (6-7 C/KM)
WHICH MAY PRODUCE NARROW UPDRAFTS THAT STRUGGLE TO MAINTAIN
INTENSITY.
NONETHELESS, SUFFICIENT DEEP LAYER SHEAR AROUND 30-40 KNOTS WILL
SUPPORT POTENTIAL FOR A FEW ORGANIZED STORMS TO DEVELOP WHERE
RECOVERY OCCURS, WITH DEVELOPMENT OF MULTI-CELL CLUSTERS AND PERHAPS
A FEW SUPERCELLS. A NARROW MARGINAL RISK WAS MAINTAINED ACROSS THE
PLAINS WHERE REDEVELOPMENT IS MOST LIKELY TO START IN THE NORTHERN
PLAINS AND SPREAD SOUTHWARD THROUGH THE AFTERNOON/EVENING. CLOSER TO
SURFACE LOW ACROSS THE DAKOTAS AND ON THE NOSE OF THE LOW-LEVEL JET
AXIS, A CONDITIONAL RISK FOR A TORNADO IS POSSIBLE IF A SUPERCELL
CAN BE MAINTAINED. OVERALL, THE MAIN RISKS WILL BE FOR SPORADIC
STRONG TO SEVERE WIND AND HAIL.
..THORNTON.. 09/13/2025
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