526
ACUS02 KWNS 161828
SWODY2
SPC AC 161827
DAY 2 CONVECTIVE OUTLOOK CORR 1
NWS STORM PREDICTION CENTER NORMAN OK
0127 PM CDT TUE JUN 16 2026
VALID 171200Z - 181200Z
...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
CENTRAL ILLINOIS INTO NORTHWEST INDIANA...
CORRECTED FOR TORNADO PROBABILITIES
..SUMMARY
AN OUTBREAK OF SEVERE THUNDERSTORMS IS EXPECTED ACROSS PORTIONS OF
ILLINOIS AND INDIANA ON WEDNESDAY. INTENSE TORNADOES, SWATHS OF
DAMAGING GUSTS TO 80 MPH AND HAIL TO 2.5 INCH DIAMETER ARE EXPECTED.
..SYNOPSIS
A STRONG MID-LEVEL JET STREAK WILL OVERSPREAD PARTS OF THE MIDWEST
AND LOWER GREAT LAKES ON WEDNESDAY. A DEEP SURFACE LOW INITIALLY
WITHIN THE UPPER MIDWEST IS FORECAST TO EVOLVE ACROSS THE LOWER
GREAT LAKES AND SOUTHERN ONTARIO/QUEBEC. A STRONG LOW-LEVEL JET WILL
ADVECT RICH SURFACE MOISTURE AHEAD OF A COLD FRONT THROUGH THE
PERIOD. A WARM FRONT, LIKELY REINFORCED BY MORNING CONVECTION IS
EXPECTED TO LIFT NORTHWARD INTO PARTS OF CENTRAL/NORTHERN ILLINOIS
AND NORTHERN INDIANA/OHIO. POTENT WIND FIELDS FOR THIS POINT IN JUNE
WILL SUPPORT A THREAT FOR SCATTERED TO NUMEROUS SEVERE STORMS
CAPABLE OF ALL SEVERE HAZARDS -- INCLUDING STRONG TO INTENSE
TORNADOES, VERY-LARGE HAIL, AND 75+ MPH WINDS.
..MID-MISSISSIPPI VALLEY INTO NORTHERN INDIANA/FAR WESTERN OHIO
A MAJORITY OF THE CAMS AS WELL AS REGIONAL/GLOBAL GUIDANCE SUGGEST
CONVECTION WILL BE ONGOING IN PARTS OF EASTERN IOWA EARLY WEDNESDAY
MORNING. THIS ACTIVITY WILL SHIFT THROUGH NORTHERN/CENTRAL ILLINOIS
INTO INDIANA. SOME RISK FOR DAMAGING WINDS WILL PROBABLY ACCOMPANY
THIS ACTIVITY. THE DEGREE TO WHICH THIS CLUSTER OF CONVECTION CAN
INTENSIFY THROUGH MID/LATE MORNING IS NOT CLEAR. THE ENVIRONMENT
WITH EASTWARD EXTENT WILL BEGIN DRIER AND LESS UNSTABLE. THE MOST
PROBABLE OUTCOME IS THAT THIS CONVECTION SHIFTS EAST-SOUTHEAST
RELATIVELY QUICKLY AND WEAKENS WITH TIME.
THE MORE SUBSTANTIAL SEVERE THREAT IS EXPECTED TO DEVELOP PERHAPS BY
EARLY/MID AFTERNOON AND DEPEND STRONGLY UPON HOW MORNING CONVECTION
EVOLVES SPATIALLY. GIVEN THE STRONG MOISTURE ADVECTION INTO THE
REGION, IT IS REASONABLE TO EXPECT AN AREA OF RELATIVELY RAPID
AIRMASS RECOVERY FROM THE QUAD CITIES VICINITY INTO PARTS OF CENTRAL
ILLINOIS. STORMS THAT FORM IN THIS ENVIRONMENT NEAR THE SURFACE
LOW/WARM FRONT WILL LIKELY BE DISCRETE AND TAKE ADVANTAGE OF STRONG
LOW-LEVEL SHEAR. LARGE TO VERY-LARGE HAIL, SIGNIFICANT WIND GUSTS,
AND STRONG/INTENSE TORNADOES WILL ALL BE POSSIBLE. AS CONVECTION
CONTINUES EASTWARD INTO INDIANA, THE LOW-LEVEL MOISTURE WILL BE
IMPROVING WITH TIME.
..SOUTHEAST KANSAS INTO MISSOURI
ALONG THE COLD FRONT, SCATTERED STORMS ARE EXPECTED TO DEVELOP BY
MID/LATE AFTERNOON. WITH MID-LEVEL HEIGHT FALLS NOT BEING OVERLY
STRONG AND EFFECTIVE SHEAR VECTORS HAVE A LARGE ORTHOGONAL COMPONENT
ACROSS THE FRONT, STORMS WILL LIKELY BE SUPERCELLULAR FOR A FEW
HOURS. STEEP MID-LEVEL AND LOW-LEVEL LAPSE RATES WILL PROMOTE A RISK
OF LARGE/VERY-LARGE HAIL AS WELL AS POTENTIALLY 75+ MPH WIND GUSTS.
DESPITE BEING WEST OF THE LOW-LEVEL JET CORE, LOW-LEVEL WIND FIELDS
WILL STILL SUPPORT A RISK OF TORNADOES, SOME OF WHICH COULD BE
STRONG.
..CENTRAL GULF COAST
POTENTIAL TROPICAL CYCLONE 1 IS FORECAST TO MOVE NORTHEASTWARD WITH
TIME. THE MARGINALLY ENHANCED LOW-LEVEL WIND FIELDS WILL SUPPORT
WEAK SUPERCELL STRUCTURES THAT MAY PRODUCE BRIEF, WEAK TORNADOES.
GIVEN THE POOR THERMODYNAMIC ENVIRONMENT AND THE MAIN TIMING OF THE
THREAT BEING DURING THE EVENING/OVERNIGHT, THE OVERALL THREAT SHOULD
REMAIN MARGINAL.
..WENDT.. 06/16/2026
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