809
ACUS02 KWNS 071731
SWODY2
SPC AC 071730
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1230 PM CDT THU AUG 07 2025
VALID 081200Z - 091200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN THE EASTERN
DAKOTAS TO WESTERN LAKE SUPERIOR...
..SUMMARY
SCATTERED SEVERE THUNDERSTORMS ARE POSSIBLE ACROSS PARTS OF THE
UPPER MIDWEST, MAINLY FRIDAY EVENING INTO EARLY MORNING SATURDAY.
SCATTERED DAMAGING WINDS AND LARGE HAIL, ALONG WITH A TORNADO OR TWO
ARE POSSIBLE.
..SYNOPSIS
A MESSY/COMPLEX SETUP REMAINS EVIDENT ON FRIDAY AFTERNOON INTO EARLY
MORNING SATURDAY. IN THE WAKE OF MULTIPLE MCSS ON D1, GUIDANCE
CONSENSUS HAS TRENDED FARTHER EAST WITH THE EFFECTIVE COLD FRONT BY
LATE AFTERNOON. THIS BOUNDARY SHOULD BE CENTERED ON NORTHWEST MN TO
EASTERN NE THEN ARCING WESTWARD BUT PUSHING SOUTHWARD THROUGH THE
CENTRAL HIGH PLAINS. THE BULK OF LARGE-SCALE ASCENT AND STRONG
MID/UPPER-LEVEL FLOW WILL LAG BEHIND THIS FRONT IN THE NORTHERN
GREAT PLAINS, TYPICAL OF AMPLIFIED SHORTWAVE TROUGHS IMPINGING ON A
RIDGE EMANATING NORTH-NORTHEASTWARD FROM A STOUT ANTICYCLONE OVER
THE SOUTHWEST.
..DAKOTAS TO NORTHWEST WI
ELEVATED CONVECTION MAY BE ONGOING AT 12Z FRIDAY AND SHOULD PERSIST
THROUGH THE DAY ACROSS MOST OF ND AND NORTHERN SD, WITHIN A
POST-FRONTAL ENVIRONMENT. ISOLATED SEVERE HAIL AND STRONG TO
MARGINAL SEVERE GUSTS ARE POSSIBLE WITH THIS ACTIVITY. STRENGTHENING
LOW-LEVEL CONVERGENCE AND ASCENT ALONG/AHEAD OF THE FRONT SHOULD
AWAIT FRIDAY EVENING, WITH INCREASING STORM COVERAGE AND SEVERE
POTENTIAL INTO FRIDAY NIGHT. ANAFRONTAL ASPECTS OF THE SYNOPTIC
SETUP AND NEAR-PARALLEL ALIGNMENT OF THE DEEP-LAYER SHEAR VECTOR
WITH RESPECT TO THE FRONT SHOULD SUPPORT A RAPID TRANSITION TO
CLUSTER/LINEAR MODE. WITH VERY LARGE MLCAPE LIKELY PREVALENT AHEAD
OF THE FRONT, POTENTIAL FOR A QLCS PRODUCING DAMAGING WINDS MAY
EVOLVE OVERNIGHT. GUIDANCE DIFFERS SUBSTANTIALLY IN THE CORRIDOR OF
WHERE THIS WOULD BE FAVORED WITH SPLIT SIGNALS ACROSS NORTHERN MN OR
SOUTHERN MN. FOR THIS OUTLOOK CYCLE, HAVE BROADENED THE LEVEL 2-SLGT
RISK AND WILL DEFER TO LATER OUTLOOKS FOR A POTENTIAL WIND-DRIVEN
ENH CENTERED SOMEWHERE IN MN.
..BLACK HILLS/NE PANHANDLE
12Z CAM AND ML GUIDANCE ARE INSISTENT ON AT LEAST AN ISOLATED LARGE
HAIL SCENARIO WITHIN THE POST-FRONTAL ENVIRONMENT CHARACTERIZED BY
NORTHERLY SURFACE WINDS. A LOBE OF DECREASING BUOYANCY SHOULD LINGER
BEHIND THE FRONT BUT WILL SHIFT SOUTH WITH TIME. A FEW DISCRETE
SUPERCELLS ARE POSSIBLE FROM MID-AFTERNOON TO EARLY EVENING AMID A
STRONG SOUTHWESTERLY MID-LEVEL JET. BUT MUCH OF THE CONVECTION
SHOULD BE QUICKLY UNDERCUT AND MAY BECOME RATHER ELEVATED, DEPENDENT
ON TIMING OF THE FRONT AND LOW-LEVEL DRYING BEHIND IT. AS SUCH, HAVE
DEFERRED TO THE D1 OUTLOOKS FOR A MESOSCALE HAIL-DRIVEN SLGT.
..GRAMS.. 08/07/2025
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