370
FXUS63 KIWX 241936
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
336 PM EDT THU SEP 24 2026
KEY MESSAGES
- TEMPERATURES WILL REMAIN SLIGHTLY BELOW NORMAL THROUGH THE
WEEKEND WITH THE COOLEST CONDITIONS EXPECTED ON FRIDAY.
TEMPERATURES WILL MODERATE EARLY NEXT WEEK TO NEAR NORMAL.
- AN EXTENDED PERIOD OF DRY WEATHER IS EXPECTED THROUGH
TUESDAY, WITH NEXT RAIN CHANCES NOT UNTIL THE MIDDLE OF NEXT
WEEK.
DISCUSSION
ISSUED AT 336 PM EDT THU SEP 24 2026
POOR MIXING WITH EASTERLY FLOW IN PLACE HAS ALLOWED SOME LOW CLOUDS
TO HOLD ON ACROSS WESTERN AND SOUTHERN PORTIONS OF THE FORECAST AREA
THIS AFTERNOON. CONTINUED SOUTHEAST PROGRESSION OF THE SOUTHEAST US
UPPER TROUGH WILL ALLOW BACKGROUND UPPER RIDGING ACROSS CENTRAL
CONUS TO EVENTUALLY BUILD EASTWARD ACROSS THE WESTERN GREAT LAKES
AND OHIO VALLEY THROUGH SATURDAY. THIS EVOLUTIONS SHOULD ALLOW LOW
CLOUDS TO DIMINISH THIS EVENING AS MUCH DRIER LOW LEVEL AIR
ADVECTS IN FROM THE EAST. THIS SHOULD LEAVE MOSTLY CLEAR/PARTLY
CLOUDY SKIES DEVELOPING THIS EVENING WITH LOW CLOUDS HAVING
LONGEST RESIDENCE TIME ACROSS NW INDIANA. IN ADDITION, SOME
INCREASE IN HIGH LEVEL CLOUDS IS EXPECTED FROM WEST TO EAST
LATER TONIGHT INTO EARLY FRIDAY. HOWEVER, ARRIVAL TIME OF THIS
THICKER CLOUD COVER SHOULD STILL BE LATE ENOUGH FOR MOST
LOCATIONS TO DIP INTO THE 40S. WARMEST TEMPS ARE EXPECTED ACROSS
FAR NORTHWEST INDIANA WHERE LOW CLOUDS WILL HAVE SOME EXTRA
RESIDENCE TIME TONIGHT ALONG WITH A QUICKER REPLACEMENT BY
HIGHER CLOUD COVER. THIS COULD KEEP LOWS CLOSER TO 50 OR IN THE
LOWER 50S FOR THESE LOCATIONS.
VERY LITTLE PROGRESSION IN THE MID/UPPER LEVEL PATTERN IS EXPECTED
FRIDAY THROUGH SUNDAY WITH A STABLE LONGWAVE PATTERN DEVELOPING THAT
WILL FEATURE PRIMARY SHORT WAVE STORM TRACK ACROSS SOUTHWEST CANADA.
THE UPPER RIDGE AXIS SHOULD REMAIN DISPLACED WEST OF THE LOCAL AREA
THROUGH THE WEEKEND WHICH WILL KEEP A BROAD LOW LEVEL ANTICYCLONE
ANCHORED ACROSS THE GREAT LAKES. WEAK EASTERLY FLOW ON SOUTHERN
PERIPHERY OF THIS HIGH WILL ALLOW FOR WEAK LOW LEVEL THERMAL
ADVECTIONS THROUGH THE WEEKEND WITH ONLY A SLIGHT DAILY MODERATION
IN TEMPERATURES TO THE LOWER 70S FOR SATURDAY AND SUNDAY.
THE QUIET WEATHER WILL CONTINUE INTO THE EARLY NEXT WEEK AS NEXT
UPSTREAM SHORT WAVE STILL APPEARS TO BE GET DAMPENED IN BACKGROUND
UPPER RIDGING. PROSPECTS FOR MORE OF A FULL LATITUDE EASTERN PACIFIC
TROUGH STILL LOOK ON TRACK FOR THE TUESDAY-EARLY THURSDAY. HOWEVER,
SOME FAIRLY LARGE TIMING DISCREPANCIES PERSIST AMONG THE VARIOUS
DETERMINISTIC/ENSEMBLE GUIDANCE WITH OPERATIONAL GFS BEING A
FAST OUTLIER, EVEN COMPARED TO GEFS. A FOCUSED PERIOD OF HIGHER
POPS WILL LIKELY BE NEEDED AT SOME POINT FOR SOME PERIOD EARLY
TO MIDDLE OF NEXT WEEK AS FORECAST CONFIDENCE IN TIMING BEGINS
TO INCREASE.
AVIATION /18Z TAFS THROUGH 18Z FRIDAY/
ISSUED AT 1218 PM EDT THU SEP 24 2026
MVFR/FUEL ALTERNATE CIGS HAVE SETTLED INTO KFWA WITH A POCKET OF
VFR CONDITIONS AT KSBN ABOUT TO BE REPLACED BY MVFR CIGS AS
WELL. THE STRATUS WILL DRIFT SLOWLY WEST AND OVER TIME SHOULD
BREAK DOWN AS DRIER AIR WORKS IN TOWARDS 00Z FRI. THEREAFTER, NO
FLIGHT CONCERNS ARE EXPECTED AT THE PRESENT TIME.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...NONE.
DISCUSSION...MARSILI
AVIATION...FISHER
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