693
FXUS61 KILN 120600
AFDILN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
200 AM EDT WED AUG 12 2026
WHAT HAS CHANGED
FLOOD WATCH WAS EXTENDED UNTIL WEDNESDAY EVENING.
KEY MESSAGES
1) SEVERE WEATHER AND FLASH FLOOD POTENTIAL REMAINS ELEVATED EARLY
THIS MORNING AND THROUGHOUT TODAY, PRIMARILY FOR SOUTHEAST INDIANA,
SOUTHWEST OHIO AND NORTHERN KENTUCKY.
2) ADDITIONAL ROUNDS OF RAINFALL ARE EXPECTED THROUGH THE REMAINDER
OF THE FORECAST, BUT PERIODIC BREAKS OF DRY WEATHER WILL ALSO OCCUR.
DISCUSSION
KEY MESSAGE 1)
AT THE TIME OF THIS WRITING, THUNDERSTORMS HAVE ERUPTED OVER EASTERN
INDIANA ALONG A CONVERGENCE AXIS ASSOCIATED WITH THE 850 MB THETA-E
RIDGE. THIS THETA-E GRADIENT WILL ATTEMPT TO SHIFT EASTWARD INTO
DAYBREAK, BUT IT WILL BE COMPETING AGAINST THE THUNDERSTORM GROWTH
THAT WILL RESIST THE MOVEMENT EAST. PWATS ARE NOT INCREDIBLY HIGH,
BUT THEY ARE STILL ANOMALOUS WITH VALUES AROUND 1.6" ADVECTING INTO
THIS CORRIDOR. SOUTHEAST INDIANA AND SOUTHWEST OHIO HAVE RECEIVED
SOME RAIN FROM THE PREVIOUS ROUNDS OF THUNDERSTORMS, BUT FLOODING IS
NOT ACTIVELY ONGOING. THIS WILL REQUIRE MULTIPLE THUNDERSTORMS TO
MOVE THROUGH A LOCALIZED AREA TO ELEVATE THE POTENTIAL FOR FLASH
FLOODING. THE MOST RECENT SPC HREF LPMM SUGGESTS RAINFALL MAXIMUMS
COULD REACH BETWEEN 4-6" LOCALLY. IF THE BAND CAN SLIP SLOWLY
EASTWARD OVER THE NEXT 3-5 HOURS, THIS SHOULD LIMIT THE MORE
SIGNIFICANT FLASH FLOOD POTENTIAL THAT MATERIALIZE IF THE LINE
REMAINS STAGNANT.
AFTER DAYBREAK, PLENTIFUL HEATING WILL TAKE PLACE OVER THE COLD POOL
AIR MASS CURRENTLY LAID OUT OVER THE ENTIRE OHIO VALLEY. SURFACE
BASED INSTABILITY VALUES WILL RESPOND, AND WILL BECOME SUPPORTIVE OF
DIURNALLY DRIVEN THUNDERSTORM DEVELOPMENT. THE BAND OF THUNDERSTORMS
OVERNIGHT LIKELY DETERMINE THE EASTWARD EXTENT OF THE BEST HEATING
FOR AFTERNOON THUNDERSTORMS. A SHORTWAVE DROPPING THROUGH THE LOWER
MIDWEST INITIATES THUNDERSTORMS OVER ILLINOIS AND INDIANA BY THE
LATE MORNING. THROUGH THE AFTERNOON, THESE THUNDERSTORMS WILL DROP
SOUTH- SOUTHEASTWARD, MERGING WITH THE REMAINDER THUNDERSTORMS
LINGERING FROM THIS MORNING. EFFECTIVE BULK SHEAR IS A BIT LOWER
TODAY WHEN COMPARED TO YESTERDAY'S SIGNIFICANT DAMAGING WIND
OUTBREAK. LARGE HAIL AND DAMAGING WINDS ARE STILL A THREAT, BUT THE
HIGHER WIND VALUES WILL BE LESS WIDESPREAD. DUE TO THE LOCATION OF
THE MORNING STORMS, CONFIDENCE IS HIGH THAT THE SEVERE THREAT WOULD
BE FAVORED OVER SOUTHEAST INDIANA, SOUTHWEST OHIO, AND THE WESTERN
PORTION OF NORTHERN KENTUCKY. IF THESE MORNINGS STORMS FAIL TO MOVE
EAST, THE FLASH FLOOD THREAT WOULD BE HIGHER BUT THE SEVERE THREAT
WOULD TREND LOWER.
THE FLOOD WATCH WAS EXTENDED THROUGH THE EVENING TODAY BECAUSE THE
SHORTWAVE COULD STILL BRING LOCALLY HEAVY RAINFALL OVER SATURATED
GROUND OVER CENTRAL OHIO. THE POTENTIAL IS LOWER, BUT IT IS NOT ZERO.
KEY MESSAGE 2)
AFTER WEDNESDAY'S WEATHER EVENT ENDS, ADDITIONAL RAINFALL REMAINS IN
THE FORECAST INTO THURSDAY AND FRIDAY. ADDITIONAL WEAK SHORTWAVES
WITHIN THE PERSISTENT NORTHWESTERLY UPPER LEVEL FLOW WILL PROVIDE
THE POTENTIAL FOR ADDITIONAL CLUSTERS OF THUNDERSTORMS AND PERIODS OF
HEAVY RAIN. THE FOCUS FOR THE HEAVIEST ACTIVITY IS EXPECTED TO BE
FARTHER SOUTH AS THE FRONT MOVES THROUGH WEDNESDAY NIGHT. THEREFORE,
THE SEVERE THREAT IS LIKELY LOWER EVEN WITH THUNDERSTORMS IN THE
FORECAST. TEMPERATURES WILL ALSO BE COOLER WITH AREA HIGHS RANGING
FROM THE LOW TO MID 80S.
GOING INTO THE WEEKEND, THE RIDGE BUILDS NORTHWARD AGAIN, PUSHING ALL
THE WAY INTO THE UPPER MIDWEST. TEMPERATURES WILL INCREASE AS A
RESULT WITH 90S RETURNING. CANNOT RULE OUT LOWER CHANCES FOR
THUNDERSTORMS ON SATURDAY AS THE FRONT LIFTS BACK TO THE NORTH,
HOWEVER COVERAGE SHOULD REMAIN SCATTERED DUE TO THE LACK OF BETTER
UPPER LEVEL FORCING. THAT CHANGES MOVING INTO SUNDAY.
THE NEXT TROUGH PUSHES INTO SOUTHEAST CANADA SUNDAY NIGHT INTO
MONDAY. BULK SHEAR VALUES AROUND 25 KNOTS AND SIGNIFICANT AMOUNTS OF
CAPE SUGGEST THERE WILL BE A RENEWED CHANCE FOR SEVERE WEATHER. DRIER
AIR WOULD THEN FILTER IN BEHIND THE FRONT MONDAY AND TUESDAY.
AVIATION /06Z WEDNESDAY THROUGH SUNDAY/
AFTER A LULL IN THUNDERSTORM ACTIVITY, NEW THUNDERSTORMS HAVE FORMED
NEAR THE INDIANA AND OHIO BORDER. TEMPO GROUPS WERE ADDED FOR THE
WESTERN TAF SITES AS THESE THUNDERSTORMS SLOWLY PROGRESS EASTWARD
TOWARD DAYBREAK. DEPENDING ON THE PROGRESS EASTWARD, THUNDERSTORMS
MAY NOT ARRIVE TO CENTRAL OHIO UNTIL LATE IN THE DAY. SIMILAR TO
YESTERDAY, ANOTHER LINE OF THUNDERSTORMS IS POSSIBLE THIS AFTERNOON,
WITH THE BEST CHANCES FOR CVG/LUK/DAY/ILN. ACTIVITY WILL DIMINISH
AFTER 00Z WITH MVFR TO IFR CIGS POSSIBLE THROUGH 12Z.
WINDS WILL MAINLY BE LIGHT AND VARIABLE OVERNIGHT BEFORE BECOMING
SOUTHWESTERLY ON WEDNESDAY.
OUTLOOK...THUNDERSTORMS ARE EXPECTED AT TIMES THROUGH FRIDAY.
ADDITIONAL THUNDERSTORMS POSSIBLE ON SUNDAY.
ILN WATCHES/WARNINGS/ADVISORIES
OH...FLOOD WATCH THROUGH THIS EVENING FOR OHZ026-034-035-042>046-051>056-
060>065-070>074-077>082-088.
KY...FLOOD WATCH THROUGH THIS EVENING FOR KYZ089>100.
IN...FLOOD WATCH THROUGH THIS EVENING FOR INZ050-058-059-066-073>075-080.
DISCUSSION...MCGINNIS
AVIATION...MCGINNIS
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