337
FXUS63 KIWX 282238
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
638 PM EDT MON SEP 28 2026
KEY MESSAGES
- DRY AND PLEASANT WEATHER CONTINUES THROUGH WEDNESDAY WITH
HIGHS IN THE 70S TO AROUND 80.
- RAIN IS EXPECTED LATE THURSDAY INTO EARLY FRIDAY. AROUND AN
INCH IS ANTICIPATED FOR MOST LOCATIONS. NO SEVERE WEATHER OR
SIGNIFICANT FLOODING IS EXPECTED.
- RAIN SHOWERS MAY LINGER INTO THE WEEKEND BUT CONFIDENCE IS
LOW.
DISCUSSION
ISSUED AT 147 PM EDT MON SEP 28 2026
ANOTHER DAY WITH A LARGELY PERSISTENCE FORECAST AS MIDLEVEL RIDGE
AND ASSOCIATED SURFACE ANTICYCLONE REMAIN LOCKED OVER THE GREAT
LAKES. NEW ENGLAND UPPER LOW FINALLY OPENS UP AND LIFTS TOWARD THE
CANADIAN MARITIMES TOMORROW ALLOWING OUR RIDGE TO DRIFT EASTWARD AND
SOUTHWEST RETURN FLOW TO INCREASE BY LATE IN THE DAY. ONE MORE
CLEAR/CALM NIGHT FIRST THOUGH WITH LOWS IN THE UPPER 40S TO AROUND
50F. PATCHY FOG IS POSSIBLE ONCE AGAIN BUT CROSSOVER TEMPS MAY BE A
LITTLE HARDER TO EXCEED THAN PREVIOUS NIGHTS. NOT EXPECTING ANY
WIDESPREAD, DENSE FOG BUT NEARLY IDEAL RADIATIONAL COOLING ALWAYS
RAISES THE POSSIBILITY FOR SOME LOCALIZED IMPACTS AS WE HAVE SEEN
THE PAST TWO DAYS.
ATTENTION THEN TURNS TO THE NORTHERN STREAM PACIFIC JET CURRENTLY
ENTERING BRITISH COLUMBIA AND THE UPPER LOW DIGGING THROUGH
CALIFORNIA. THE EASTWARD MIGRATION OF THESE TWO FEATURES WILL DRIVE
OUR SENSIBLE WEATHER THROUGH THE SECOND HALF OF THE WEEK. THE
INITIAL COLD FRONT STILL LOOKS TO STALL TO OUR NORTHWEST ON WED AS
IT BECOMES INCREASINGLY DIVORCED FROM THE LEADING MIDLEVEL SHORTWAVE
AND STRONG SOUTHWEST FLOW DEVELOPS IN THE UPPER MIDWEST DOWNSTREAM
OF EJECTING UPPER LOW. CAN'T ENTIRELY RULE OUT A STRAY SHOWER IN OUR
FAR NW WED EVENING BUT BY AND LARGE EXPECT ONE MORE DAY OF DRY AND
PLEASANT WEATHER WITH HIGHS NEAR 80F. THIS FRONT DOESN'T REALLY
CROSS OUR AREA UNTIL LATE THU, POSSIBLY EXTENDING INTO FRI, AS WE
AWAIT THE ARRIVAL OF A SECONDARY, MUCH MORE POTENT NORTHERN STREAM
TROUGH. GOOD 850MB THETA-E WILL BE PUMPED INTO THE REGION AHEAD OF
THE SOUTHERN STREAM UPPER LOW BY THU BUT SURFACE DEWPOINTS ARE STILL
ONLY IN THE LOW/MID 60S WITH POOR LAPSE RATES ALOFT YIELDING VERY
MEAGER INSTABILITY PROFILES. THIS IS ESPECIALLY TRUE IF PRECIP HOLDS
OFF UNTIL THU NIGHT AS IS CURRENTLY TRENDING. SOME EMBEDDED
THUNDERSTORMS CERTAINLY POSSIBLE BUT SEVERE WEATHER IS NOT EXPECTED.
MARGINAL INSTABILITY WILL AID RAIN COVERAGE/INTENSITY BUT WITHOUT A
STRONG CONVECTIVE ELEMENT EXPECT MORE OF A WIDESPREAD, MODERATE RAIN
EVENT. RAIN AMOUNTS AROUND AN INCH ARE LIKELY FOR MOST WITH POCKETS
OF 1.5" POSSIBLE. GIVEN RECENT STRETCH OF DRY WEATHER, OUR AREA
SHOULD BE ABLE TO TOLERATE THAT WITH MINIMAL IMPACTS. STILL SOME
UNCERTAINTY WITH THE WEEKEND FORECAST AND WHETHER OR NOT THIS
FRONTAL BOUNDARY COMPLETELY CLEARS OUR CWA AS REMNANT UPPER LOW/
MOISTURE PLUME SLOWLY EJECT EASTWARD. NO CHANGES TO CONCENSUS
INITIALIZATION HERE.
AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/
ISSUED AT 635 PM EDT MON SEP 28 2026
PREVIOUS THINKING REMAINS INTACT WITH NO SIGNIFICANT FLIGHT
ISSUES ANTICIPATED. THE LINGER CHALLENGE REGARDING PATCHY,
SHALLOW GROUND FOG AT EITHER SITE REMAINS UNCERTAIN AS PLENTY OF
DRY AIR IS IN PLACE AND SLIGHTLY WARMER NIGHT/HIGHER DEWPOINTS
MAY LIMIT DEVELOPMENT. WILL ONCE AGAIN PUNT TO THE NEXT SHIFT TO
MONITOR, BUT IF ANY ISSUES DEVELOPED IT WOULD BE IN THE 9Z TO
14Z PERIOD.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...NONE.
DISCUSSION...AGD
AVIATION...FISHER
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