630
ACUS03 KWNS 280720
SWODY3
SPC AC 280719
DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0219 AM CDT SAT MAR 28 2026
VALID 301200Z - 311200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PORTIONS OF THE
UPPER MISSISSIPPI RIVER VALLEY AND LAKE MICHIGAN VICINITY...
..SUMMARY
ISOLATED STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE ACROSS PORTIONS
OF THE UPPER MISSISSIPPI RIVER VALLEY AND LAKE MICHIGAN VICINITY
LATE MONDAY NIGHT INTO EARLY TUESDAY MORNING.
..SYNOPSIS
ZONAL FLOW OVER THE CENTRAL TO NORTHERN ROCKIES IS FORECAST TO
INCREASE OVER THE NEXT 48-72 HOURS AS AN UPPER RIDGE SHIFTS TOWARDS
THE SOUTHEAST AND A LOW-AMPLITUDE UPPER WAVE BEGINS TO TRANSLATE
ALONG THE U.S./CANADIAN BORDER. LEE CYCLONE DEVELOPMENT IS
ANTICIPATED ACROSS THE NORTHERN HIGH PLAINS BY EARLY MONDAY WITH
STEADY INTENSIFICATION EXPECTED AS IT MIGRATES EAST AHEAD OF THE
UPPER WAVE. THE DEEPENING SURFACE LOW WILL PROMOTE NORTHWARD
MOISTURE RETURN THROUGH THE MS VALLEY AND INTO THE UPPER GREAT LAKES
REGION WHILE EASTWARD ADVECTION OF 7-8 C/KM MID-LEVEL LAPSE RATES
TAKES PLACE ALOFT. THUNDERSTORM DEVELOPMENT APPEARS PROBABLE
OVERNIGHT ACROSS THE UPPER MS VALLEY AND UPPER GREAT LAKES REGION AS
ISENTROPIC ASCENT INCREASES ALONG THE TIGHTENING WARM FRONTAL ZONE
OF THE CYCLONE.
ELSEWHERE, MORE ISOLATED THUNDERSTORMS ARE POSSIBLE ALONG THE
WESTERN FL GULF COAST WHERE SEA-BREEZE ASCENT WITHIN A MOIST AND
WEAKLY CAPPED ENVIRONMENT SHOULD SUPPORT A FEW THUNDERSTORMS.
SIMILARLY, ISOLATED CONVECTION IS POSSIBLE ACROSS PARTS OF THE LOWER
MS VALLEY WITHIN A PLUME OF RICH LOW-LEVEL MOISTURE. ANOTHER DAY OF
ISOLATED, HIGH-BASED THUNDERSTORMS IS EXPECTED ACROSS PORTIONS OF
THE SOUTHWEST. WEAK DEEP-LAYER WIND SHEAR ACROSS THESE REGIONS WILL
LIMIT SEVERE THUNDERSTORM POTENTIAL.
...UPPER MS VALLEY/LAKE MICHIGAN
THE COMBINATION OF LOW-LEVEL MOISTENING AND STEEPENING LAPSE RATES
ALOFT WILL SUPPORT STEADY DESTABILIZATION THROUGH MONDAY AND INTO
MONDAY NIGHT. MODEL CONSENSUS IS THAT 1500-2000 J/KG MUCAPE SHOULD
BE IN PLACE BY MONDAY EVENING ACROSS THE SOUTHERN WI REGION.
INITIALLY DRY AND CAPPED LOW-LEVEL PROFILES WILL LIKELY PRECLUDE
THUNDERSTORM DEVELOPMENT DURING THE DAY, THOUGH INCREASING ASCENT
WITHIN THE 925-850 MB WARM FRONTAL ZONE SHOULD INCREASE THUNDERSTORM
CHANCES DURING THE 00-06 UTC PERIOD. WHILE ELEVATED CONVECTION
APPEARS LIKELY, HODOGRAPH ELONGATION THROUGH THE CAPE-BEARING LAYER
SHOULD SUPPORT STORM ORGANIZATION, INCLUDING THE POTENTIAL FOR A
SUPERCELL OR TWO. ALTHOUGH STORM MOTIONS ALONG THE FRONTAL ZONE HINT
THAT SOME DEGREE OF CLUSTERING IS PROBABLE, AT LEAST A LOCALIZED
HAIL THREAT SHOULD MATERIALIZE GIVEN THE FAVORABLE BUOYANCY/SHEAR
ENVIRONMENT.
..MOORE.. 03/28/2026
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