628
ACUS02 KWNS 101751
SWODY2
SPC AC 101750
DAY 2 CONVECTIVE OUTLOOK CORR 1
NWS STORM PREDICTION CENTER NORMAN OK
1250 PM CDT WED JUN 10 2026
VALID 111200Z - 121200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THURSDAY INTO
THURSDAY NIGHT ACROSS PARTS OF SOUTHERN AMD EASTERN
IOWAS....NORTHEASTERN MISSOURI....NORTHERN AND CENTRAL
ILLINOIS...SOUTHERN WISCONSIN...NORTHERN INDIANA AND CENTRAL AND
SOUTHERN LOWER MICHIGAN...
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THURSDAY AFTERNOON
ACROSS THE ALLEGHENY MOUNTAINS THROUGH NORTHERN MID ATLANTIC
VICINITY...
CORRECTED FOR A FEW TYPOS/WORDING
..SUMMARY
STRONG TO SEVERE THUNDERSTORM DEVELOPMENT, INCLUDING ONE OR TWO
ORGANIZING CLUSTERS, WILL PROBABLY BE ACCOMPANIED BY THE POTENTIAL
FOR LARGE HAIL, DAMAGING WIND GUSTS AND PERHAPS A COUPLE OF STRONG
TORNADOES IN A CORRIDOR ACROSS THE MIDWEST INTO GREAT LAKES REGION
THURSDAY THROUGH THURSDAY NIGHT.
..DISCUSSION
MODELS INDICATE THAT MID-LEVEL SUBTROPICAL RIDGING WILL BE
MAINTAINED ACROSS MUCH OF THE SOUTHERN TIER OF THE U.S. THROUGH THIS
PERIOD, WHILE THE WESTERLIES BEGIN TO TREND A BIT MORE ZONAL ACROSS
THE NORTHERN TIER, IN THE WAKE OF A BROAD, DEEP OCCLUDING CYCLONE
SLOWLY MIGRATING NORTHEASTWARD TOWARD SOUTHWESTERN HUDSON BAY. A
SIGNIFICANT SHORT WAVE TROUGH TURNING TO THE EAST OF THE NORTHERN
ROCKIES, TO THE SOUTH OF THE CYCLONE, AT THE OUTSET OF THE PERIOD,
IS STILL FORECAST TO PIVOT ACROSS SOUTHERN PORTIONS OF THE MID
MISSOURI VALLEY THROUGH THE UPPER GREAT LAKES THURSDAY THROUGH
THURSDAY NIGHT. THIS IS LIKELY TO BE ACCOMPANIED BY THE
NORTHEASTWARD MIGRATION OF AN ASSOCIATED SECONDARY SURFACE FRONTAL
LOW, FROM THE CENTRAL GREAT PLAINS ACROSS AND NORTHEAST OF THE UPPER
MIDWEST/GREAT LAKES REGION BY 12Z FRIDAY.
DOWNSTREAM, MID-LEVEL RIDGING APPEARS LIKELY TO BUILD THROUGH THE
DAY ACROSS THE LOWER GREAT LAKES/UPPER OHIO VALLEY VICINITY, WITH
ONE OR TWO PERTURBATIONS DIGGING WITHIN WEAK NORTHWESTERLY FLOW
FURTHER DOWNSTREAM, ACROSS THE ALLEGHENY MOUNTAINS AND NORTHERN MID
ATLANTIC VICINITY.
A SEASONABLY MOIST AIR MASS, SUPPORTIVE OF MODERATE TO LARGE
POTENTIAL INSTABILITY, IS LIKELY TO BE MAINTAINED WITHIN THE WARM
SECTOR OF THE CYCLONE, TO THE NORTH OF THE SUBTROPICAL RIDGE.
HOWEVER, IT APPEARS THAT THIS MAY BE SUBSTANTIVELY MODIFIED, AT
LEAST INITIALLY, BY OUTFLOW FROM THUNDERSTORM DEVELOPMENT TODAY
ACROSS A LARGE PORTION OF THE UPPER MIDWEST INTO GREAT LAKES REGION.
THERE HAVE BEEN SOME ADJUSTMENTS OF CATEGORICAL AND PROBABILISTIC
THUNDER/SEVERE LINES TO ACCOUNT FOR ASSOCIATED UNCERTAINTIES, AND
ALSO ATTEMPT TO BETTER ACCOUNT FOR CONSENSUS OF VARYING MODEL
OUTPUT.
..UPPER MIDWEST/GREAT LAKES INTO SOUTHERN GREAT PLAINS
DOWNSTREAM OF THE APPROACHING SHORT WAVE IMPULSE AND SECONDARY LOW,
LOW-LEVEL WARM ADVECTION ON THE NOSE OF A 40-50 KT SOUTHERLY 850 MB
JET MAY BE PROVIDING SUPPORT FOR AN EVOLVING CONVECTIVE CLUSTER
ALONG/NORTH OF AN OUTFLOW BOUNDARY ACROSS SOUTHWESTERN IOWA AT THE
OUTSET OF THE PERIOD. THIS MAY INCLUDE STORMS WITH POTENTIAL TO
PRODUCE SEVERE HAIL, BEFORE PERHAPS BECOMING ROOTED IN A
DESTABILIZING BOUNDARY LAYER WHILE SPREADING WITH FORCING ACROSS
IOWA THROUGH SOUTHERN WISCONSIN/NORTHERN ILLINOIS THROUGH THURSDAY
AFTERNOON. THIS COULD INCLUDE INCREASING POTENTIAL FOR CONVECTION
CAPABLE OF PRODUCING DAMAGING WIND GUST AND PERHAPS A FEW TORNADOES.
THEREAFTER, THE PRIMARY FORCING FOR STRONGER DESTABILIZATION AND
LIFT TO SUPPORT STRONG/SEVERE THUNDERSTORM DEVELOPMENT SEEMS LIKELY
TO SHIFT TO THE INTERSECTION OF THE TRAILING OUTFLOW/SECONDARY
SURFACE LOW/COLD FRONT ACROSS SOUTHEASTERN IOWA BY LATE AFTERNOON.
THIS MAY INCLUDE SUPERCELL DEVELOPMENT INITIALLY, BEFORE CONVECTION
GROWS UPSCALE AND ORGANIZES IN THE PRESENCE OF STRONG LOW-LEVEL AND
DEEP-LAYER SHEAR, THEN PROPAGATES INTO AND ACROSS THE LOWER LAKE
MICHIGAN/MICHIGAN VICINITIES THROUGH THURSDAY EVENING, WITH
POTENTIAL FOR STRONG, DAMAGING WIND GUSTS AND TORNADOES.
SCATTERED ADDITIONAL STRONG/SEVERE STORM DEVELOPMENT IS POSSIBLE IN
THE CORRIDOR OF STRONGER PRE-FRONTAL INSTABILITY, BUT WEAKER
MID/UPPER SUPPORT AND SHEAR, SOUTHWESTWARD THROUGH PORTIONS OF THE
SOUTHERN GREAT PLAINS.
..ALLEGHENIES/NORTHERN MID ATLANTIC
MODERATE TO LOCALLY STRONG POTENTIALLY INSTABILITY PROBABLY WILL
BECOME SUFFICIENT TO SUPPORT WIDELY SCATTERED STRONG TO SEVERE
THUNDERSTORM DEVELOPMENT WITH POTENTIAL TO PRODUCE DAMAGING WIND
GUSTS THURSDAY AFTERNOON AND EVENING.
..KERR.. 06/10/2026
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