895
ACUS01 KWNS 102001
SWODY1
SPC AC 101959
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0259 PM CDT WED JUN 10 2026
VALID 102000Z - 111200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS PORTIONS OF THE
UPPER MISSISSIPPI VALLEY INTO PARTS OF THE PLAINS...
..SUMMARY
SCATTERED TO NUMEROUS SEVERE THUNDERSTORMS WITH POTENTIAL FOR LARGE
HAIL IN EXCESS OF TWO INCHES IN DIAMETER, A FEW STRONG TORNADOES AND
DAMAGING WINDS WITH GUSTS OVER 75 MPH ARE EXPECTED THIS AFTERNOON
AND EVENING ACROSS PARTS OF THE UPPER MISSISSIPPI VALLEY AND
MIDWEST.
..20Z UPDATE
ONLY MINOR ADJUSTMENTS WERE MADE TO THE ONGOING FORECAST BASED ON
RECENT CONVECTIVE TRENDS AND RECENT HIGH-RES GUIDANCE.
..UPPER MS VALLEY/GREAT LAKES
AS OF 20 UTC, REGIONAL RADAR MOSAICS DEPICT A MATURE MCS ONGOING
ACROSS NORTHERN IL INTO NORTHERN WI WITH MULTIPLE SEVERE GUSTS
REPORTED OVER THE PAST FEW HOURS (SEE MCD #1066 FOR ADDITIONAL
SHORT-TERM DETAILS). BEHIND THE MCS, A STOUT COLD POOL IS IN PLACE
FROM NORTHEAST MO INTO EASTERN IA AND SOUTHEAST MN FEATURING
TEMPERATURES IN THE LOW 70S UNDER A CIRRUS CANOPY. THIS COLD POOL
CASTS SOME UNCERTAINTY ON THE DEGREE OF AIR MASS RECOVERY, AND
RECENT HIGH-RES GUIDANCE SUGGESTS THAT THE PRIMARY SEVERE THREAT MAY
HAVE PASSED FOR PORTIONS OF THE REGION. 30% WIND PROBABILITIES WERE
REDUCED TO REFLECT THIS TREND; HOWEVER, SOUTHWESTERLY FLOW FROM THE
SURFACE THROUGH 500 MB IS ADVECTING HIGHER THETA-E AIR IN THE LOW
LEVELS AND STEEPER MID-LEVEL LAPSE RATES EAST/NORTHEASTWARD INTO THE
COLD POOL. THIS WILL SUPPORT RE-DEVELOPMENT OF STRONG TO SEVERE
THUNDERSTORMS LATER THIS EVENING WITH PRIMARILY A RISK FOR VERY
LARGE HAIL, SO MAINTAINED ENHANCED-CALIBER HAIL PROBABILITIES TO
REFLECT THIS POTENTIAL.
..CENTRAL KANSAS/NORTHWEST MISSOURI
A VOLATILE ENVIRONMENT IS EMERGING FROM CENTRAL KS TO NORTHWEST MO
WHERE MLCAPE IS INCREASING TO 3000-3500 J/KG PER AN 18 UTC TOP RAOB
AND RECENT MESOANALYSIS ESTIMATES. ADDITIONALLY, THE 18 UTC RAOB
SAMPLED EFFECTIVE BULK SHEAR ON THE ORDER OF 50 KNOTS AS WELL AS
STRONG VEERING THROUGH THE LOWEST KILOMETER. THIS ENVIRONMENT IS
HIGHLY FAVORABLE FOR INTENSE SUPERCELLS, WHICH APPEAR LIKELY IN THE
COMING HOURS BASED ON RECENT GOES VISIBLE IMAGERY (SEE MCD #1067 FOR
ADDITIONAL SHORT-TERM DETAILS). RECENT HRRR/RRFS TIME-LAGGED
ENSEMBLE GUIDANCE AND WOFS SOLUTIONS ALL SUGGEST THE HIGHEST HAIL
AND TORNADO THREAT WILL LIKELY EMERGE FROM THE SALINA, KS AREA
NORTHEASTWARD INTO NORTHWEST MO THROUGH THE EVENING. STORM MODE
REMAINS A MODULATING FACTOR WITH UPSCALE GROWTH LIKELY, BUT A WINDOW
EXISTS FOR VERY STRONG DISCRETE/SEMI-DISCRETE SUPERCELLS. BOTH
TORNADO AND HAIL RISK CONTOURS WERE ADJUSTED WEST/SOUTHWESTWARD TO
REFLECT THESE RECENT TRENDS.
..EASTERN NEBRASKA/FAR WESTERN IOWA
LATEST FORECAST GUIDANCE CONTINUES TO SHOW A SIGNAL FOR ELEVATED
CONVECTION NEAR THE TERMINUS OF A LOW-LEVEL JET ACROSS EASTERN
NE/WESTERN IA LATE TONIGHT/EARLY THURSDAY MORNING. FORECAST
SOUNDINGS FROM THESE SOLUTIONS, MOST NOTABLY RECENT RAP RUNS AND THE
12Z NAM, HINT THAT LOW-LEVEL MOISTURE ADVECTION MAY BE SUFFICIENT TO
SUPPORT PARCELS ROOTED NEAR THE SURFACE. WHILE THE POTENTIAL IS
FAIRLY LOW, THERE IS SOME POTENTIAL FOR A TORNADO THREAT IF
LOW-LEVEL MOISTENING IS SUFFICIENT GIVEN AN OTHERWISE FAVORABLE
NEAR-SURFACE WIND PROFILE, WARRANTING THE INTRODUCTION OF 2% TORNADO
PROBABILITIES.
..MOORE.. 06/10/2026
PREV DISCUSSION
/ISSUED 1256 PM CDT WED JUN 10 2026/
..MID/UPPER MS VALLEY INTO THE CENTRAL PLAINS
REGIONAL RADAR IMAGERY SHOWS AN ONGOING CLUSTER OF STRONG
THUNDERSTORMS ACROSS SOUTHERN IA AND NORTHERN MO, SUPPORTED BY A
RESIDUAL LOW-LEVEL JET THAT CURRENTLY EXTENDS FROM KS/NORTHERN OK
INTO THE REGION. HEATING OF THE VERY MOIST AIRMASS DOWNSTREAM WILL
RESULT IN LIMITED CONVECTIVE INHIBITION AND STRONG TO VERY STRONG
BUOYANCY BY THE EARLY AFTERNOON. REINTENSIFICATION OF THE ONGOING
CLUSTER IS ANTICIPATED AS IT MOVES WITHIN THIS DESTABILIZING
AIRMASS. DEEP-LAYER SHEAR WILL BE MODEST BUT STILL SUFFICIENT FOR
SOME ORGANIZATION, AND THE DEVELOPMENT OF A STRONG TO OCCASIONALLY
SEVERE BOWING LINE SEGMENT APPEARS PROBABLE, PARTICULARLY FROM
NORTHEAST IA INTO SOUTHERN WI AND NORTHERN IL. NEW UPDRAFTS AHEAD OF
THE LINE COULD ALSO PRODUCE HAIL EARLY IN THE CONVECTIVE CYCLE,
WHILE ALSO POTENTIALLY CONTRIBUTING TO UPDRAFT AUGMENTATION AS THEY
MERGE INTO THE LINE. SOME ISOLATED HAIL COULD RESULT FROM THIS
AUGMENTATION AS WELL.
FARTHER NORTH, RECENT SURFACE ANALYSIS PLACED A TRIPLE POINT LOW
OVER NORTHEAST SD. AN OCCLUDED FRONT EXTENDS NORTH-NORTHWESTWARD
FROM THIS LOW ACROSS EASTERN ND INTO CENTRAL MANITOBA, WHILE COLD
FRONT EXTENDS SOUTHWARD TO ANOTHER LOW OVER NORTHEAST NE AND THEN
BACK SOUTHWESTWARD ACROSS THE CENTRAL PLAINS. THE FRONTAL ZONE AND
TRIPLE POINT LOW ARE FORECAST TO PROGRESS EASTWARD INTO THE UPPER
MIDWEST, INTERACTING WITH A DIURNALLY DESTABILIZING AIRMASS TO
SUPPORT THUNDERSTORM DEVELOPMENT. AMPLE LOW-LEVEL MOISTURE (I.E.
DEWPOINTS IN THE UPPER 60S/LOW 70S) WILL SUPPORT STRONG BUOYANCY,
DESPITE MODEST LAPSE RATES, AND MODERATE DEEP-LAYER VERTICAL SHEAR
SHOULD BE SUFFICIENT FOR UPDRAFT ORGANIZATION. AS A RESULT, STRONG
TO SEVERE THUNDERSTORMS ARE EXPECTED ALONG AND JUST AHEAD THE FRONT,
WITH LARGE HAIL AS THE PRIMARY THREAT. ISOLATED VERY LARGE HAIL TO
2" IN DIAMETER COULD OCCUR. SOME DAMAGING GUSTS ARE POSSIBLE AS
STORMS TRANSITION INTO BOWING LINE SEGMENTS OVER TIME. THERE IS ALSO
A LOW-PROBABILITY FOR A FEW BRIEF TORNADOES, PARTICULARLY WITH ANY
MORE CELLULAR DEVELOPMENT FROM CENTRAL INTO EASTERN WI FROM 21 TO
00Z.
AN ADDITIONAL SEVERE THREAT WILL LIKELY MATERIALIZE THIS EVENING IN
THE WAKE OF THE AFTERNOON MCS WITHIN THE RECOVERED AIRMASS FROM THE
MID MS VALLEY WESTWARD THROUGH THE MID MO VALLEY INTO THE CENTRAL
PLAINS. THE IMPETUS FOR THIS REDEVELOPMENT WILL LIKELY BE A COMPLEX
COMBINATION OF LOW-LEVEL CONVERGENCE ALONG THE APPROACHING FRONT,
LOW-LEVEL CONVERGENCE AND WARM-AIR ADVECTION ALONG REMNANT OUTFLOW,
AND MODEST LARGE-SCALE ASCENT. DEVELOPMENT ALONG THE FRONT APPEARS
MOST LIKELY FROM CENTRAL IA SOUTHWESTWARD INTO NORTHEAST KS, WHILE
DEVELOPMENT ALONG THE OUTFLOW APPEARS MOST LIKELY NORTHWEST IL
ACROSS SOUTHERN IA. THE AIRMASS IN ALL OF THESE AREAS WILL LIKELY
FEATURE AMPLE LOW-LEVEL MOISTURE (I.E. DEWPOINTS IN THE LOW TO MID
70S), WARM SURFACE TEMPERATURES (HIGHS IN THE LOW 90S), AND AT LEAST
MODESTLY STEEP MID-LEVEL LAPSE RATES. THIS WILL RESULT IN STRONG TO
EXTREME BUOYANCY, WITH MLCAPE VALUES EXCEEDING 3000 J/KG FROM
NORTHEAST KS INTO SOUTHERN IA, NORTHERN MO, AND WEST-CENTRAL IL.
COMPLEX SURFACE PATTERN WILL LIKELY YIELD LIMITED PREDICTABILITY FOR
THE PRIMARY SEVERE HAZARD THIS EVENING. GIVEN THE EXTREME BUOYANCY
AND MODERATE MID-LEVEL FLOW, ANY MORE CELLULAR DEVELOPMENT THAT IS
ABLE TO MATURE SHOULD BECOME SUPERCELLULAR, WITH ALL SEVERE HAZARDS
POSSIBLE, INCLUDING VERY LARGE HAIL AND TORNADOES. STORM INTERACTION
AND STRONG DOWNDRAFTS WILL LIKELY MAKE MAINTAINING A DISCRETE MODE
DIFFICULT, BUT LOW-LEVEL HODOGRAPHS SUPPORT THE POTENTIAL FOR A
STRONG TORNADO, PARTICULARLY FROM 00 TO 03Z AMID A STRENGTHENING
LOW-LEVEL JET.
LASTLY, EARLY MORNING STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE
ACROSS CENTRAL/EASTERN NE AS A SECONDARY BRANCH OF THE LOW-LEVEL JET
DEVELOPS IN RESPONSE TO ANOTHER SHORTWAVE TROUGH MOVING INTO THE
CENTRAL HIGH PLAINS.
..OHIO VALLEY/CENTRAL APPALACHIANS/MID-ATLANTIC STATES
A MOIST AND UNSTABLE AIRMASS WILL BE IN PLACE TODAY ACROSS MUCH OF
THE REGION, WITH SURFACE DEWPOINTS GENERALLY IN THE LOWER 70S F.
WHILE SOME THUNDERSTORMS ARE ONGOING EARLY TODAY, ADDITIONAL AND
MORE POTENT THUNDERSTORM DEVELOPMENT IS EXPECTED INTO THE AFTERNOON
AS THE BOUNDARY LAYER DESTABILIZES. THESE STORMS WILL BE FURTHER
INFLUENCED BY A PAIR OF WEAK EASTWARD-MOVING MCVS, ONE OVER THE
UPPER OHIO RIVER VALLEY AND THE OTHER OVER THE CENTRAL APPALACHIANS.
DAMAGING WINDS, ASSOCIATED WITH WATER-LOADED DOWNBURSTS, WILL BE THE
PRIMARY HAZARD REGIONALLY.
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