080
FXUS63 KIWX 131843
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
243 PM EDT SAT SEP 13 2025
KEY MESSAGES
- SCATTERED SHOWERS AND STORMS ARE POSSIBLE THIS EVENING AND
EARLY OVERNIGHT ALONG AND SOUTH OF US 30. STORMS WILL BE
CAPABLE OF PRODUCING SMALL HAIL AND GUSTY WINDS.
- A PERSISTENT DRY AND WARM PATTERN SETS UP STARTING ON SUNDAY
AND LASTING THROUGH NEXT WEEK. EXPECT HIGHS IN THE UPPER 80S
TO LOW 90S EACH DAY.
- MINIMUM RELATIVE HUMIDITIES AS LOW AS 30% TO 40% NEXT WEEK MAY
BE CONDUCIVE FOR ELEVATED FIRE DANGER.
DISCUSSION
ISSUED AT 242 PM EDT SAT SEP 13 2025
IN THE WAKE OF THE WIDESPREAD, STEADY RAIN THAT MOVED THROUGH
EARLIER TODAY, SCATTERED SHOWERS AND STORMS ARE POSSIBLE THIS
EVENING AND EARLY OVERNIGHT. DEVELOPMENT IS ALREADY OCCURRING
SOUTHEAST OF CHICAGO IN NORTHWEST INDIANA. SHOWERS AND STORMS WILL
MOVE SOUTHEAST THIS EVENING ALONG A REMNANT BOUNDARY, WITH GUSTY
WINDS, SMALL HAIL, AND HEAVY RAIN. SPC HAS MAINTAINED THE MARGINAL
SEVERE RISK FOR TODAY ALTHOUGH THE THREAT APPEARS ISOLATED. MID
LEVEL LAPSE RATES ARE DECENT BUT THE BETTER INSTABILITY GRADIENT IS
TO OUR WEST. THE BEST CHANCES FOR ANY ADDITIONAL RAIN OR STORMS
TODAY WILL BE ALONG AND SOUTH OF THE US 30 CORRIDOR. OVERNIGHT,
EXPECT SKIES TO GRADUALLY CLEAR AND SHOWERS TO DIMINISH. WITH
LINGERING GROUND MOISTURE, LIGHT WINDS, AND CLEARING SKIES, AREAS OF
PATCHY FOG MAY DEVELOP EARLY SUNDAY MORNING.
FOR SUNDAY AND INTO EARLY NEXT WEEK, AN OMEGA BLOCK PATTERN SETS UP.
AN UPPER LEVEL RIDGE AXIS WILL BUILD OVER THE MIDWEST AND GREAT
LAKES REGIONS, ALLOWING FOR WARMER TEMPERATURES AND PERSISTENT DRY
CONDITIONS. HIGHS WILL BE IN THE UPPER 80S TO NEAR 90 DEGREES EACH
DAY FROM SUNDAY THROUGH THE MIDDLE OF NEXT WEEK. THE HUMIDITY WILL
BE NOTICEABLE WITH DEWPOINTS IN THE MID 60S. WHILE NOT UNCOMMON
THIS LATE IN THE SUMMER, THE HEAT WILL ALSO ALLOW FOR LARGE
DIURNAL TEMPERATURE SWINGS AS DRY CONDITIONS PERSIST THROUGH THE
WEEK. IN FACT, GIVEN THAT WE HAVE BEEN LACKING SIGNIFICANT
RAINFALL SINCE MID AUGUST, DROUGHT IS LIKELY TO PERSIST AND/OR
DEVELOP IN THE COMING WEEKS.
BY FRIDAY AND INTO NEXT WEEK, A RETURN TO SEASONABLE
TEMPERATURES APPEARS POSSIBLE. LONG RANGE GUIDANCE HINTS AT A
PATTERN CHANGE COMING AROUND THIS TIME NEXT WEEK. THE UPPER LEVEL
RIDGE PATTERN BREAKING DOWN AND ALLOWING FOR A COLD FRONT TO SWEEP
THROUGH SOMETIME BETWEEN FRIDAY AND NEXT SUNDAY, WHICH WOULD USHER
IN A COOLER CANADIAN AIRMASS AND OPPORTUNITIES FOR RAIN.
ONE ADDITIONAL CONCERN FOR NEXT WEEK GIVEN THE ABOVE NORMAL
TEMPERATURES AND DRY CONDITIONS IS FIRE DANGER. SUNNY SKIES AND
PERSISTENT WARMTH SHOULD ALLOW FOR MINIMUM AFTERNOON RELATIVE
HUMIDITY VALUES TO DROP BETWEEN 30 TO 40 PERCENT. HOWEVER,
SHOULD ANY GRASS OR BRUSH FIRES DEVELOP, WINDS SHOULD BE LIGHT
ENOUGH THAT IT LIKELY WON'T SPREAD QUICKLY. AVOID OUTDOOR
BURNING!
AVIATION /18Z TAFS THROUGH 18Z SUNDAY/
ISSUED AT 123 PM EDT SAT SEP 13 2025
PRIMARY AREA OF RAIN ASSOCIATED WITH PASSING SHORTWAVE HAS
DISSIPATED AND EXITED THE TERMINALS. HOWEVER, MARGINAL MOISTURE
AND INSTABILITY IN A REGION OF WEAK ISENTROPIC UPGLIDE WILL
CONTINUE TO SUPPORT SCT SHOWERS THROUGH THE AFTERNOON. MUCAPE
APPEARS TOO LIMITED TO WARRANT A THUNDER MENTION BUT IT CAN'T BE
ENTIRELY RULED OUT, ESPECIALLY AT KSBN. DRY/QUIET WEATHER
RETURNS OVERNIGHT WITH JUST SOME HIGH-BASED CU EXPECTED THROUGH
SUNDAY.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...NONE.
DISCUSSION...JOHNSON
AVIATION...AGD
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