951
FXUS63 KIWX 202321
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
721 PM EDT TUE OCT 20 2026
KEY MESSAGES
- DENSE FOG POSSIBLE EARLY WEDNESDAY MORNING, ESPECIALLY ALONG AND
EAST OF I-69.
- TRANQUIL FALL WEATHER CONTINUES WITH MILD TEMPERATURES AND
SUNSHINE THROUGH THIS WEEK INTO THE WEEKEND.
DISCUSSION
ISSUED AT 1245 PM EDT TUE OCT 20 2026
WITH HIGH PRESSURE OVER SOUTHERN ONTARIO AND PROMINENT UPPER LEVEL
RIDGING OVER THE CENTRAL CONUS EXPECTED TO BUILD INTO THE GREAT
LAKES OVER THE NEXT SEVERAL DAYS, A TRANQUIL WEEK IS AHEAD. EXPECT
LOTS OF SUNSHINE, LIGHT WINDS, AND HIGHS GENERALLY IN THE UPPER 60S
TO LOW 70S EACH DAY. LITTLE TO NO RAINFALL IS EXPECTED OVER THE NEXT
7 DAYS AND MAINLY DRY CONDITIONS LOOK TO CONTINUE THROUGH AT LEAST
THE END OF THE MONTH. WE MAY SEE SOME SHOWERS OUT OF A COLD FRONTAL
PASSAGE EARLY NEXT WEEK BUT FOR NOW CHANCES REMAIN VERY LOW (15% OR
LESS).
DESPITE SOME CLOUDS OVER NORTHWEST OHIO AND NORTHEAST INDIANA
OVERNIGHT WITH A WEAK BACKDOOR COLD FRONT FROM LAKE ERIE,
PATCHY TO WIDESPREAD DENSE FOG IS POSSIBLE OVERNIGHT INTO
WEDNESDAY MORNING. LIGHT EASTERLY FLOW MAY ALLOW FOR ADVECTION
FOG TO DEVELOP, ESPECIALLY ALONG AND EAST OF I-69. FORECAST
SOUNDINGS INDICATE POTENTIAL FOR SMALL DEWPOINT DEPRESSIONS AS
TEMPERATURES AND DEWPOINTS ARE BOTH EXPECTED TO BE IN THE LOW TO
MID 40S TONIGHT. THE BEST TIMEFRAME FOR DENSE FOG WILL BE
BETWEEN 3 AM TO 9 AM EDT WEDNESDAY, WITH THE LOWEST VISIBILITIES
AT OR JUST BEFORE DAYBREAK. CURRENT NBM PROBABILITIES ARE ABOUT
20-30% FOR VISIBILITIES LESS THAN 3 MILES WHILE HREF GUIDANCE
SUGGESTS VISIBILITIES MAY GO DOWN TO LESS THAN 1 MILE ESPECIALLY
IN NW OHIO; GIVEN THAT THERE ARE STILL UNCERTAINTIES AND THAT
FOG CAN BE QUITE FICKLE TO FORECAST, FUTURE SHIFTS MAY NEED TO
HOIST AN SPS OR EVEN A DENSE FOG ADVISORY DEPENDING ON HOW LOW
VISIBILITIES DROP.
AVIATION /00Z TAFS THROUGH 00Z THURSDAY/
ISSUED AT 720 PM EDT TUE OCT 20 2026
MAIN AVIATION CONCERN IS POTENTIAL FOR FOG/STRATUS AT KFWA LATE
TONIGHT GIVEN COOL/MOIST NE FLOW OFF LAKE ERIE. CONFIDENCE IS
NOT HIGH THAT FOG WILL REACH THAT FAR INLAND BUT SOME GUIDANCE
MEMBERS DO SUGGEST DENSE FOG COULD PUSH AS FAR WEST AS KFWA.
WILL HOLD WITH A TEMPO 1SM/BKN008 MENTION FOR NOW AND LET THE
OVERNIGHT SHIFT REASSESS FOR THE 06Z TAF'S. VFR EXPECTED TO
PERSIST AT KSBN.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...NONE.
DISCUSSION...JOHNSON
AVIATION...AGD
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