730
FXUS63 KIWX 231017
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
617 AM EDT WED SEP 23 2026
KEY MESSAGES
- EXTENDED STRETCH OF SEASONABLY COOL CONDITIONS WILL PERSIST
THROUGH THE WEEKEND BEFORE TEMPERATURES WARM INTO THE 70S
BETWEEN EARLY AND MIDWEEK NEXT WEEK.
- SOME POCKETS OF LIGHT RAIN AND DRIZZLE POSSIBLE (20-40%)
MAINLY SOUTH OF US-24 TODAY WITH TOTALS STRUGGLING TO REACH
0.25".
- DRY THURSDAY THROUGH THIS WEEKEND.
- THERE IS A MODERATE SWIM RISK THROUGH THIS EVENING FOR NORTHERN
LA PORTE COUNTY.
DISCUSSION
ISSUED AT 239 AM EDT WED SEP 23 2026
AS THE UPPER LOW OVERHEAD SLOWLY SLIDES SOUTHEASTWARD THROUGH THE
DAY TODAY INTO TONIGHT, SHALLOW MOISTURE DEPTHS BELOW 700 MB FINALLY
DRY OUT BELOW 850 MB AFTER 21Z. THIS IS AS DRY AIR ADVECTS EASTWARD
EFFECTIVELY REMOVING DRIZZLE CHANCES AND ALLOWING OVERCAST TO BREAK
UP. THIS ALSO HELPS GUSTS TO RELAX FOR THURSDAY AND FRIDAY. 850
MB TEMPERATURES SLOWLY RISE FROM THE UPPER SINGLE DIGITS INTO
THE LOW TEENS AS EARLY AS THURSDAY MORNING, BUT MIXING HEIGHTS
STRUGGLE TO REACH 850 MB UNTIL THURSDAY SO UPPER 60S TO PERHAPS
AROUND 70 DEGREE HIGHS STILL LOOK LIKELY. THIS FIGHT BETWEEN
LAPSE RATES, 850 MB TEMPS BETWEEN THE UPPER SINGLE DIGITS AND
LOW TEENS, AND TIMES OF NEGATIVE THETA-E ADVECTION CONTINUE
THROUGH THE WEEKEND. DURING THIS TIME, OUR UPPER LOW SHIFTS
TOWARDS THE EAST COAST AND A REX BLOCK SETS UP ACROSS THE
EASTERN SEABOARD, EFFECTIVELY DIRECTING UPPER FLOW NORTH OF THE
AREA ON SATURDAY AND KEEPING THE AREA IN MID LEVEL RIDGING AT
LEAST UNTIL WE GET TO MIDWEEK NEXT WEEK. AS A RESULT, IT IS
POSSIBLE THAT OUR HIGHS ON MONDAY AND TUESDAY ARE BOTH TOO WARM
AND WE MAINTAIN THE UPPER 60S TO AROUND 70 THEN, THEREFORE
WAITING UNTIL TUESDAY OR WEDNESDAY FOR GETTING SECURELY BACK
INTO THE 70S.
AVIATION /12Z TAFS THROUGH 12Z THURSDAY/
ISSUED AT 617 AM EDT WED SEP 23 2026
AN UPPER LOW PRESSURE SYSTEM CONTINUES SLOWLY MOVING SOUTHEASTWARD
THROUGH THE DAY. THROUGH THIS TIME PERIOD, THERE'S STILL ENOUGH LOW
LEVEL MOISTURE ADVECTION TO ALLOW FOR CONTINUED MVFR CIGS, LIKELY
WITH SOME IFR AFTER 14Z PRIMARILY AT FWA BEFORE MODERATING BACK INTO
VFR THE LAST COUPLE HOURS OF THE PERIOD. EAST/NORTHEAST WINDS ALSO
CONTINUE THROUGH THE PERIOD WITH SUSTAINED WINDS AT OR ABOVE 10 KTS
FOR FWA, BUT AT 10 KTS DURING PEAK HEATING AND INTO THE EVENING AT
SBN BEFORE THE GRADIENT SLACKENS WEDNESDAY NIGHT. IT IS POSSIBLE
THAT SOME 20 TO 25 KTS GUSTS COULD BE HAD AS WELL WITH THE BEST
CHANCE OF THESE OCCURRING AT FWA.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...NONE.
DISCUSSION...ROLLER
AVIATION...ROLLER
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