598
FXUS63 KIWX 140522
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
122 AM EDT SUN SEP 14 2025
KEY MESSAGES
- PATCHY FOG, DENSE IN SOME AREAS, EARLY THIS MORNING.
- 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.
UPDATE
ISSUED AT 649 PM EDT SAT SEP 13 2025
SHOWERS ARE DIMINISHING AND ARE NEARLY OUT OF THE AREA AT THIS
TIME. ON VISIBLE SATELLITE IMAGERY, CLEAR SKIES CAN BE SEEN OVER
LAKE MICHIGAN AND CENTRAL LOWER MICHIGAN. EXPECT CLOUDS TO
GRADUALLY DECREASE FROM NORTHWEST TO SOUTHEAST TONIGHT. GIVEN
THAT THERE IS LEFTOVER MOISTURE NEAR THE SURFACE FROM TODAY'S
RAIN, WITH CLEARING SKIES AND LIGHT WINDS OVERNIGHT, STILL
THINKING THAT PATCHY DENSE FOG WILL BE POSSIBLE. THE BEST
TIMING FOR FOG WILL LIKELY BE BETWEEN 5 TO 9 AM EDT, WITH FOG
DISSIPATING PRETTY QUICKLY 1-2 HOURS AFTER SUNRISE. LOWS TONIGHT
DROP DOWN INTO THE UPPER 50S TO MID 60S.
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 /06Z TAFS THROUGH 06Z MONDAY/
ISSUED AT 117 AM EDT SUN SEP 14 2025
A NARROW CORRIDOR OF STRATUS IS HOVERING OVER MUCH OF INDIANA.
A STOUT INVERSION IS NOTED IN THE TIME-HEIGHT CROSS SECTIONS.
WATER VAPOR DEPICTS A TROUGH SLOWLY PUSHING SOUTH ACROSS THE
EASTERN GREAT LAKES. THIS OUGHT TO PERMIT THE STRATUS TO SLOWLY
MIX OUT. HOWEVER, GIVEN THE PERSISTENCE SO FAR THIS MORNING AND
THE CROSS SECTION GUIDANCE, I'LL ERR ON THE LONG SIDE OF
STRATUS STICKING AROUND AT KFWA THROUGH MUCH OF THE MORNING.
SINCE KSBN IS CLEAR, THIS INCREASES THE POSSIBILITY OF BR/FG. A
COUPLE OF UPSTREAM SITES ARE REPORTING 4SM TO 6SM. TRENDS WILL
BE MONITORED CLOSELY.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...NONE.
UPDATE...JOHNSON
DISCUSSION...JOHNSON
AVIATION...BROWN
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page