665
FXUS63 KIWX 080538
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
138 AM EDT WED JUL 8 2026
KEY MESSAGES
- QUIET TODAY WITH HIGHS IN THE MID/UPPER 80S.
- THUNDERSTORMS ARE LIKELY THURSDAY EVENING AND OVERNIGHT.
ISOLATED SEVERE STORMS AND HEAVY RAIN ARE POSSIBLE WITH THE
BEST CHANCES SOUTH OF US-30.
- LOW CHANCES FOR A FEW STORMS FRIDAY AND SATURDAY BUT TURNING
DRY AND HOT AGAIN NEXT WEEK.
DISCUSSION
ISSUED AT 138 AM EDT WED JUL 8 2026
ANOTHER TRANQUIL WEATHER DAY TODAY AS BROAD MID/UPPER LEVEL RIDGING
AND LOW LEVEL THETA-E SINK REMAIN CENTERED DIRECTLY OVER OUR CWA.
SOME PATCHY FOG IS POSSIBLE THIS MORNING BUT LIMITED NEAR-
SURFACE MOISTURE AND SOME CLOUDS IN THE SE WILL KEEP COVERAGE
AND DENSITY IN CHECK. HIGHS TODAY LIKELY VERY SIMILAR TO
YESTERDAY THOUGH PERHAPS A DEGREE OR TWO WARMER GIVEN SOME
SUBTLE WAA AND AIRMASS MODIFICATION UNDER STRONG JULY SUN. LOWS
TONIGHT ONLY IN THE MID/UPPER 60S DUE TO SLOWLY INCREASING LOW
LEVEL MOISTURE AND A SLIGHTLY WARMER AFTERNOON.
MAIN FORECAST CONCERN IS THUNDERSTORM POTENTIAL THU EVENING/
OVERNIGHT. A WEAK (CONVECTIVELY MODIFIED) MIDLEVEL SHORTWAVE WILL
APPROACH THE AREA THU EVENING. A MODEST INCREASE IN LOW LEVEL SW
FLOW AHEAD OF THIS WAVE WILL BRING BETTER MOISTURE INTO THE REGION
BUT IT'S WORTH NOTING FAR BETTER THETA-E SURGE REMAINS FOCUSED OVER
CENTRAL AND SOUTHERN IL/IN. MIDLEVEL LAPSE RATES REMAIN PALTRY
AND 0-1KM MLCAPE VALUES LIKELY STRUGGLE TO GET MUCH ABOVE 1000
J/KG. WIND/SHEAR PROFILES ARE ALSO LIGHT WITH ONLY AROUND 20 KTS
OF FLOW AT 850MB AND 0-6KM BULK SHEAR VALUES ARE 25-30 KTS AT
BEST. THESE PARAMETERS ARE MARGINALLY SUPPORTIVE OF A FEW
STRONG/SEVERE STORMS. HOWEVER, EXPECT COVERAGE OF STRONG STORMS
TO REMAIN LOW GIVEN WEAK MID/UPPER LEVEL SUPPORT FOR UPWARD
ASCENT AND BETTER MOISTURE CONVERGENCE FOCUSED TO OUR SOUTH. THE
BEST CHANCES FOR A FEW STRONG STORMS CURRENTLY APPEAR TO BE
ROUGHLY 22-04Z SOUTH OF US-30 BUT THAT COULD CHANGE OVER THE
NEXT 24-36 HOURS. WILL ALSO HAVE TO KEEP AN EYE ON THE OVERNIGHT
HOURS AS SOME SOLUTIONS SEND AN MCS THROUGH CENTRAL IL/IN LATE
THU NIGHT INTO FRI MORNING THAT COULD CLIP OUR SOUTHERN ZONES
WITH SOME HEAVY RAIN. STILL THINK BETTER CHANCES FOR THIS WILL
BE JUST SOUTH OF OUR AREA ALONG THE MAIN MOISTURE GRADIENT BUT
CONFIDENCE ISN'T HIGH AND WILL WATCH THIS CLOSELY OVER THE NEXT
FEW FORECAST CYCLES.
THE REST OF THE FORECAST IS MAINLY QUIET. A FEW SCT STORMS WILL
BE POSSIBLE AGAIN LATE FRIDAY AND PERHAPS ON SAT. FRIDAY'S
CHANCES WILL BE DEPENDENT ON EXACT TIMING AND EVOLUTION OF
POTENTIAL MORNING MCS BUT SUSPECT A RETURN TO DRY/STABLE NE FLOW
BEHIND THIS WAVE WILL KEEP MOST OF THE AREA DRY FOR MOST OF
THIS TIME. AGAIN, BEST CHANCES FOR A STRAY SHOWER/STORM WILL BE
SOUTH OF US-30. NO SEVERE WEATHER EXPECTED GIVEN EVEN MORE
MARGINAL INSTABILITY AND SHEAR PROFILES.
LARGE/STRONG (600+ DAM) MIDLEVEL RIDGE THEN EXPECTED TO DEVELOP
OVER THE CENTRAL CONUS EARLY NEXT WEEK AND LIKELY NOSE INTO OUR
REGION AT SOME POINT. STILL SOME DISAGREEMENT HERE WITH GFS
KEEPING THE RIDGE JUST TO OUR WEST AND ALLOWING A BACKDOOR COLD
FRONT MIDWEEK WHILE ECMWF (AND TO A LESSER EXTENT THE CANADIAN)
BULLDOZE THE RIDGE INTO OUR REGION LEAVING US HOTTER AND DRIER.
SLIGHT PREFERENCE FOR THE LATTER BUT OVERALL NO CHANGES TO THE
CONCENSUS INITIALIZATION AT THIS TIME.
AVIATION /06Z TAFS THROUGH 06Z THURSDAY/
ISSUED AT 138 AM EDT WED JUL 8 2026
PATCHY FOG/BR IS THE MAIN AVIATION CONCERN THIS MORNING. OVERALL
MOISTURE PROFILES DON'T SUPPORT A WIDESPREAD/DENSE FOG THREAT BUT
SOME PATCHY BR CAN'T BE RULED OUT, ESPECIALLY AT KFWA. WILL HOLD
WITH JUST A TEMPO MVFR MENTION FOR NOW GIVEN LOW CONFIDENCE.
OTHERWISE VFR CONDITIONS WITH JUST A FEW DIURNAL CU AND LIGHT SW
WINDS.
IWX WATCHES/WARNINGS/ADVISORIES
IN...AIR QUALITY ALERT UNTIL MIDNIGHT CDT WEDNESDAY NIGHT FOR
INZ103-203.
OH...NONE.
MI...AIR QUALITY ALERT UNTIL MIDNIGHT EDT TONIGHT FOR MIZ078-177-
277.
MARINE...NONE.
DISCUSSION...AGD
AVIATION...AGD
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