834
FXUS63 KIWX 100917
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
517 AM EDT MON AUG 10 2026
KEY MESSAGES
- SEVERAL ROUNDS OF STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE
INTO TUESDAY. DAMAGING WINDS AND LARGE HAIL ARE THE MAIN
CONCERNS, BUT AN ISOLATED TORNADO OR 2 IS POSSIBLE.
- FLOODING CONCERNS MAY INCREASE DEPENDING ON RAINFALL AMOUNTS
ACROSS THE AREA WITH EACH ROUND OF STORMS.
- SEASONABLE TEMPERATURES ARE EXPECTED TO PERSIST.
UPDATE
ISSUED AT 509 AM EDT MON AUG 10 2026
AS ADVERTISED BY SOME OF THE MODELS, THE AREA ESSENTIALLY WAS
SPLIT FOR THE STRONGEST CONVECTION WITH ONE AREA MAINLY IN LOWER
MI AND THE PREVIOUSLY MENTIONED SUPERCELL CLUSTER EVENTUALLY TO
AN OUTFLOW DOMINANT CLUSTER THAT CLIPPED WHITE COUNTY AS IT RODE
THE OUTFLOW BOUNDARY. IN BETWEEN, LIGHTER RAIN AND A FEW STORMS
WAS ALL THAT WAS OBSERVED. IR SATELLITE TRENDS INDICATE THE
THREAT FOR ADDITIONAL STORMS IS LIKELY OVER WITH THE NEXT ROUND
POSSIBLY WAITING TILL MID TO LATE AFTERNOON WITH THE ARRIVAL OF
THE NEXT WAVE. IF NOTHING OCCURS BEFORE THIS WAVE, THE AREA WILL
HAVE PLENTY OF TIME TO DESTABILIZE TO AID THE SEVERE THREAT.
GRIDS HAVE BEEN CLEANED UP SOME TO REFLECT THE CURRENT TRENDS.
WITH REGARDS TO THE FLOOD WATCH, GIVEN THE LACK OF RAINFALL
OVERNIGHT CONSIDERED CANCELING IT EARLY. HOWEVER, SINCE IT IS IN
EFFECT UNTIL 11 AM EDT WILL DEFER TO INCOMING DAY CREW TO
DECIDE IF THEY WISH TO EXTEND OR ADJUST IT TO ACCOUNT FOR ANY
POTENTIAL LATER TODAY.
DISCUSSION
ISSUED AT 111 AM EDT MON AUG 10 2026
FOCUS OF DISCUSSION AND ANY FORECAST UPDATES WILL BE ON NEXT 24 TO
36 HOURS WITH REGARDS TO SEVERE AND HYDROLOGIC CONCERNS. GETTING
DISCUSSION OUT EARLY TO TO POTENTIAL STORMS OVER NEXT COUPLE OF
HOURS.
WE ARE MONITORING A CLUSTER OF THUNDERSTORMS FROM SE WI INTO
NORTHERN IL. WHILE SOME OCCASIONAL SEVERE REPORTS CAME FROM EARLIER
STORMS, THE MAIN STORM OF INTEREST (HP SUPERCELL) IS ROOTED ON THE
OUTFLOW BOUNDARY FROM THE EARLIER STORMS WITH SOME HINTS AT THIS
MOVING MORE SE WITH TIME. OTHER STORMS CONTINUE TO TRY TO DEVELOP
AND EXPAND, INCLUDING FAR NW PARTS OF THE AREA. THIS LEAVES A LOT OF
UNCERTAINTY AS TO WHAT OCCURS OVERNIGHT. PLENTY OF INSTABILITY
REMAINS ACROSS THE AREA, BUT NEAR SFC INHIBITION MAY LIMIT WIND
POTENTIAL OVERNIGHT. SUFFICE TO SAY, RISK OF SEVERE REMAINS IN PLAY
ACROSS THE AREA. FOR THE LATEST UPDATES ON THE MESOSCALE FEATURES,
MONITOR SPC PRODUCTS. IN ADDITION, A FLASH FLOOD WATCH WAS ISSUED
EARLIER TO COVER SEVERAL COUNTIES TO COVER THE RECENT RAINFALL AND
POTENTIAL FOR SOME AREAS SEEING MORE HEAVY RAIN OVERNIGHT. THIS IS
CURRENTLY IN EFFECT UNTIL 11 AM EDT, BUT GIVEN THE CONCERNS OF THE
CONVECTIVE EVOLUTION OVERNIGHT NO CHANGES ARE PLANNED AT THIS TIME.
IN THE WAKE OF THE OVERNIGHT/EARLY AM STORMS, THE ATMOSPHERE WILL
RECHARGE ONCE AGAIN WITH PLENTY OF CAPE AND SUFFICIENT SHEAR TO BRING
YET ANOTHER SEVERE THREAT MONDAY AFTERNOON AND EVENING. MUCH LIKE
TODAY, THE MAIN THREAT WILL BE DAMAGING WIND ALONG WITH SOME LARGE
HAIL. IF ANY OUTFLOW BOUNDARIES LINGER IN THE AREA, THESE COULD HELP
WITH A LOCALIZED TORNADO THREAT. ALSO IN PLAY WILL BE THE CONTINUED
THREAT OF HEAVY RAINFALL AS PWATS REMAIN ABOUT 1.75" AND WARM CLOUD
DEPTHS OF 14 K TO 15KFT. MAY NEED TO EXPAND THE FLOOD WATCH IN AREA
AND TIME DEPENDING ON WHAT EVOLVES OVERNIGHT. SADLY, TRENDS IN THE
MODELS DO SHOW YET MORE STORMS DEVELOPING LATER MONDAY EVENING INTO
TUESDAY MORNING (POSSIBLY THE 4TH ROUND OF STORMS SINCE SUNDAY
EVENING). NOT EVEN GOING TO TRY TO DO ANYTHING IN THE FORECAST WITH
THIS GIVEN THE PLETHORA OF CHALLENGES FROM PREVIOUS ROUNDS OF STORMS
THAT CANNOT BE FULLY RESOLVED THIS FAR OUT.
DEEPENING ON THE LOCATION OF THE STATIONARY BOUNDARY TUESDAY, ONE
MORE ROUND OF CONVECTION COULD OCCUR FOCUSED SOUTH OF US-30. AGAIN,
NO CHANGES TO FORECAST WITH REGARDS TO THIS, JUST SOMETHING TO KEEP
IN MIND WITH THE FLOOD THREAT POSSIBLY STILL THERE.
BEYOND TUESDAY NIGHT, MODELS SEEM TO PUSH THE EFFECTIVE BOUNDARY
SOUTH OF THE AREA TO GIVE US A REPRIEVE FROM THE RAIN AND STORMS.
HOWEVER, THE OVERALL UPPER LEVEL FLOW DOESN'T CHANGE MUCH SO LOW
CONFIDENCE AT THIS POINT AND MODEL BLEND WILL BE LEFT ALONE.
AVIATION /12Z TAFS THROUGH 12Z TUESDAY/
ISSUED AT 509 AM EDT MON AUG 10 2026
THREAT FOR ADDITIONAL CONVECTION AND MOST LIKELY ANY FLIGHT
IMPACTS LOOKS TO BE DONE THROUGH THIS MORNING. CAMS SUGGESTING
NEW DEVELOPMENT UPSTREAM THAT WOULD MOVE IN AFTER 18Z AND
POSSIBLY LATER. WILL HANDLE THE TIMING WITH A TEMPO GROUP FOR
NOW AND LET LATER FORECASTS FINE TUNE THINGS. ADDITIONAL STORMS
COULD ALSO OCCUR AFTER 6Z TUE BUT EVEN LOWER CONFIDENCE WARRANTS
LEAVING A DRY FORECAST.
IWX WATCHES/WARNINGS/ADVISORIES
IN...FLOOD WATCH UNTIL 11 AM EDT /10 AM CDT/ THIS MORNING FOR
INZ005>009-012>015-017-018-023>025-103-104-116-203-204-
216.
OH...NONE.
MI...FLOOD WATCH UNTIL 11 AM EDT THIS MORNING FOR MIZ078>080-177-
277.
MARINE...NONE.
UPDATE...FISHER
DISCUSSION...FISHER
AVIATION...FISHER
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