529
FXUS63 KIWX 241037
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
637 AM EDT SAT OCT 24 2026
KEY MESSAGES
- DENSE FOG WILL IMPACTS PORTIONS OF THE AREA THROUGH LATE
MORNING. AN ADVISORY IS IN EFFECT.
- OTHERWISE, PLEASANT WEATHER PERSISTS THROUGH THE UPCOMING WEEK
WITH HIGHS AROUND 70, LOWS IN THE 40S, AND NO RAIN EXPECTED.
DISCUSSION
ISSUED AT 240 AM EDT SAT OCT 24 2026
ANOTHER DAY WITH FOG AS THE ONLY SENSIBLE WEATHER CONCERN. LATEST
SATELLITE AND SURFACE OBS SHOW DENSE FOG RAPIDLY EXPANDING ACROSS
OUR EASTERN CWA THANKS TO ANOTHER NIGHT OF LIGHT EASTERLY FLOW OFF
LAKE ERIE AND PRIME RADIATIONAL COOLING. HIGH CLOUDS THAT WERE IN
PLACE EARLIER THANKS TO UPSTREAM TROUGH HAVE NOW LARGELY DISSIPATED
FOR MOST OF THE AREA AND SEE NO REASON WHY FOG WON'T CONTINUE TO
EXPAND AND PERSIST THROUGH THE LATE MORNING AS SUGGESTED BY PLETHORA
OF LATEST GUIDANCE. ONLY QUESTION IS HOW FAR WEST AND SOUTH IT WILL
BUILD. WITH LIGHT E TO EVEN ESE FLOW, CONFIDENCE IS NOT HIGH FOR OUR
SOUTHWEST ZONES. LATEST SATELLITE SHOWS A RAPID EXPANSION TO THE NW
BUT VERY LITTLE SOUTHWARD EXPANSION. ISSUED A DENSE FOG ADVISORY BUT
LEFT OFF THE FAR WEST AND SOUTHERN COUNTIES FOR NOW. WILL CONTINUE
TO MONITOR OBS AND EXPAND AS NECESSARY. SURFACE WINDS FINALLY VEER
TO THE SOUTH TONIGHT AND MORE HIGH CLOUDS SHOULD LIMIT FOG POTENTIAL
(SAVE PERHAPS FOR OUR EXTREME NE AREAS WHERE LAKE ERIE COULD STILL
BE A FACTOR).
HIGHS TODAY A NEAR CARBON COPY FROM YESTERDAY GIVEN NO THERMAL
ADVECTION. HIGHS DO CREEP UP A FEW DEGREES SUN AND MON AS VERY LIGHT
SOUTHERLY FLOW/MINOR WAA TAKES SHAPE. A WEAK BACKDOOR FRONT THEN
BRINGS A BRIEF RETURN TO COOL EASTERLY FLOW FOR TUE BUT WAA
INCREASES AGAIN FOR WED AND THU AS A DECAYING COLD FRONT APPROACHES
THE REGION. THIS FRONT LOOKS TO STALL AND WASH OUT JUST TO OUR NW
WITH JUST SOME VERY LOW CHANCES FOR LIGHT RAIN NEAR LAKE MI THU INTO
FRI. BETTER RAIN CHANCES ARRIVE OVER THE WEEKEND BUT THERE IS STILL
A HIGH DEGREE OF SPREAD REGARDING EXACT TIMING AND AMOUNTS.
AVIATION /12Z TAFS THROUGH 12Z SUNDAY/
ISSUED AT 635 AM EDT SAT OCT 24 2026
SATELLITE IMAGERY AND SFC OBSERVATIONS INDICATE CONTINUED
WESTWARD MIGRATION OF WIDESPREAD LIFR CIGS/VSBYS. EARLIER
FORECAST THINKING WITH BEST POTENTIAL OF DENSE FOG EAST OF KSBN
HAS BEEN AMENDED TO INCLUDE A PERIOD OF DENSE FOG AT KSBN IN THE
12-14Z TIMEFRAME. VERY POOR MIXING IN WEAK EASTERLY LOW LEVEL
REGIME WILL MAKE IMPROVEMENTS SLOW TODAY, PARTICULAR AT KFWA
WHERE VFR CONDITIONS MAY NOT RETURN UNTIL AFTER 16Z. OTHERWISE
FOR TODAY INTO THIS EVENING, SOME MID/HIGH CLOUDS WILL LIKELY
DROP SOUTHEAST ACROSS SOUTHERN GREAT LAKES AS EASTWARD MIGRATION
OF MID/UPPER LEVEL RIDGE AXIS ALLOWS FOR SOME WARM ADVECTION
FORCING. WILL HAVE TO MONITOR POTENTIAL OF SOME ADDITIONAL FOG
TONIGHT, PARTICULARLY IN KFWA VICINITY WITH SIMILAR SYNOPTIC
PATTERN IN PLACE. THE COMBINATION OF LOW LEVEL FLOW VEERING
LIGHT SOUTHERLY TONIGHT AND THE POSSIBILITY OF SOME HIGH LEVEL
CLOUDINESS LEADS TO SOMEWHAT LOW CONFIDENCE AT THIS FORECAST
DISTANCE, BUT IT IS POSSIBLE ADDITIONAL FORECASTS/AMENDMENTS
WILL NEED TO BE MORE AGGRESSIVE WITH BR/FG MENTION AT KFWA
TOWARD END OF THIS VALID PERIOD.
IWX WATCHES/WARNINGS/ADVISORIES
IN...DENSE FOG ADVISORY UNTIL 10 AM EDT /9 AM CDT/ THIS MORNING FOR
INZ005>009-014-015-017-018-023>027-032>034-103-104-116-
204-216.
OH...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR OHZ001-002-
004-005-015-016-024-025.
MI...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR MIZ078>081-
177-277.
MARINE...NONE.
DISCUSSION...AGD
AVIATION...MARSILI
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