572
ACUS03 KWNS 151930
SWODY3
SPC AC 151929
DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0229 PM CDT FRI MAY 15 2026
VALID 171200Z - 181200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM CENTRAL
NEBRASKA TO SOUTHWEST MINNESOTA...
..SUMMARY
SEVERE STORMS ARE EXPECTED SUNDAY AFTERNOON INTO SUNDAY NIGHT FROM
PORTIONS OF THE CENTRAL PLAINS INTO THE UPPER MIDWEST. SUPERCELLS
WITH VERY LARGE HAIL AND TORNADOES ARE POSSIBLE, BEFORE UPSCALE
STORM GROWTH LEADS TO AN INCREASE IN THE WIND DAMAGE THREAT.
..SYNOPSIS
THE PRIMARY MIDLEVEL TROUGH OVER THE NORTHERN GREAT BASIN SUNDAY
MORNING WILL PROGRESS TO THE FOUR CORNERS BY MONDAY MORNING. A
SUBTLE, LEAD SHORTWAVE TROUGH (NOW OVER NORTHERN CA) WILL EJECT
NORTHEASTWARD DURING THE DAY FROM NM TO WESTERN KS/CENTRAL NE, AND
IT WILL REACH MN BY EARLY MONDAY. A WEAK REFLECTION OF THE INITIAL
LEE CYCLONE WILL LIKEWISE MOVE NORTH-NORTHEASTWARD ACROSS NE TO MN,
ALONG A PRE-EXISTING BAROCLINIC ZONE. THE BOUNDARY LAYER WILL
CONSIST MOSTLY OF ROUGHLY MID 60S DEWPOINTS EAST OF THE DRYLINE AND
SOUTH OF THE WARM FRONT SUNDAY, WHILE THE FULLY MODIFIED (MARITIME
TROPICAL) AIR MASS WILL RETURN TO TX THROUGH SUNDAY NIGHT.
..NE TO MN
THE ELEVATED REMNANTS OF OVERNIGHT CONVECTION ACROSS NE/IA, AND AN
ASSOCIATED MCV, SHOULD MOVE NORTHEASTWARD TOWARD THE UPPER MS VALLEY
AND WEAKEN. IN THE WAKE OF THE EARLY CONVECTION, SURFACE HEATING IN
CLOUD BREAKS WILL CONTRIBUTE TO DESTABILIZATION AND STORM
DEVELOPMENT WILL BECOME PROBABLE BY SUNDAY AFTERNOON/EVENING ALONG
THE STALLED FRONT IN NE, IN ADVANCE OF THE WEAK SURFACE CYCLONE AND
SUBTLE/EJECTING MIDLEVEL TROUGH. MESOSCALE DETAILS ARE FAIRLY
UNCERTAIN THIS FAR IN ADVANCE. STILL, THE FORECAST ENVIRONMENT
APPEARS FAVORABLE FOR INITIAL SUPERCELLS WITH VERY LARGE HAIL AND
TORNADOES, AND SOME INCREASE IN THE THREAT FOR DAMAGING WINDS AS
CONVECTION GROWS UPSCALE ALONG THE FRONT AND SPREADS NORTHEASTWARD
INTO SOUTHEAST SD, NORTHWEST IA AND SOUTHWEST MN THROUGH SUNDAY
NIGHT.
..WESTERN KS TO TX PANHANDLE DRYLINE
A RELATIVELY WARM ELEVATED MIXED LAYER AND NO OBVIOUS FORCING FOR
ASCENT BOTH SUGGEST THAT STORM INITIATION WILL RELY ON SUFFICIENTLY
DEEP MIXING ALONG THE DRYLINE, AND THAT STORM FORMATION IS VERY MUCH
IN QUESTION. IF A STORM OR TWO FORMS LATE AFTERNOON/EVENING BEFORE
THE DRYLINE RETREATS OVERNIGHT, THERE BE A CONDITIONAL THREAT FOR
SUPERCELLS WITH LARGE HAIL.
..THOMPSON.. 05/15/2026
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