877
FXUS63 KIWX 150530
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
130 AM EDT MON SEP 15 2025
KEY MESSAGES
- WARM, DRY AND SUNNY THROUGH MUCH OF THIS WEEK WITH HIGHS IN THE
MID/UPPER 80S.
- LOW AFTERNOON HUMIDITIES COULD INTRODUCE A FIRE WEATHER CONCERN AS
FINE FUELS DRY OUT BUT WINDS WILL REMAIN LIGHT.
- THE NEXT CHANCE OF RAIN ARRIVES LATE FRIDAY INTO THE WEEKEND.
DISCUSSION
ISSUED AT 232 PM EDT SUN SEP 14 2025
ANOTHER LONG STRETCH OF QUIET WEATHER IS EXPECTED THIS WEEK AS A
PAIR OF UPPER LOWS OVER THE SOUTHEAST CONUS AND NORTHERN PLAINS KEEP
A STRONG RIDGE LOCKED OVER THE GREAT LAKES. SURFACE HIGH PRESSURE
OVER THE LOWER GREAT LAKES IS MAINTAINING A LIGHT BUT STEADY
EASTERLY FLOW OF DRY/STABLE AIR PREVENTING EVEN ANY CU DEVELOPMENT
TODAY. FLOW BECOMES MORE MUDDLED AS THE WEEK GOES ON ALLOWING FOR
SOME MINOR MOISTURE ADVECTION AT TIMES. THE ONLY "IMPACT" WILL BE AN
INCREASE IN DIURNAL CU THOUGH WITH NO RAIN CHANCES THROUGH AT LEAST
THURSDAY. THE DIFFERENCE IN THIS DRY SPELL COMPARED TO EARLIER THIS
MONTH IS THAT THIS IS BEING DRIVEN BY A STRONG MID/UPPER RIDGE
DIRECTLY OVER THE AREA WITH NO SUPPLY OF COOL, CANADIAN AIR. DRY
CONDITIONS EACH DAY WILL SUPPORT DEEP MIXING (TO ALMOST 700MB AT
TIMES) PUSHING AFTERNOON HIGHS INTO THE MID/UPPER 80S WHICH IS
ROUGHLY 10-15 DEGREES ABOVE NORMAL FOR THIS TIME OF YEAR. AFTERNOON
DEWPOINTS WILL ALSO CRASH INTO THE LOW/MID 50S YIELDING RH VALUES
LIKELY AROUND 30 PERCENT. THUS, FIRE WX WILL BE THE MAIN THING TO
WATCH THIS WEEK. LUCKILY, WINDS WILL BE LIGHT AND FUEL MOISTURES
(ESPECIALLY AFTER YESTERDAY'S RAIN) ARE STILL RUNNING HIGH GIVEN
MOST VEGETATION AND AGRICULTURE IS STILL ON THE GREEN SIDE. SEVERAL
DAYS OF HOT, SUNNY AND DRY CONDITIONS WILL TAKE IT'S TOLL THOUGH AND
FINE FUELS WILL BEGIN TO DRY OUT BY WED/THU.
THE RIDGE FINALLY BREAKS DOWN BY NEXT WEEKEND, THOUGH MODELS STILL
SHOW VERY DIFFERENT SOLUTIONS ON THE EXACT TIMING AND EVOLUTION OF
HOW THIS HAPPENS. ENSEMBLE-BASED NBM SHOWS PRECIP CHANCES BEGINNING
BY THU NIGHT. PREFER TO LEAN MORE ON DETERMINISTIC RUNS WHICH ALL
INDICATE FRIDAY AT THE EARLIEST AND LIKELY NOT UNTIL FRI NIGHT OR
SAT FOR OUR EASTERN ZONES. STILL PLENTY OF TIME FOR ADJUSTMENTS BUT
FOR NOW PREFER TO LEAN ON THE LATER SIDE OF GUIDANCE GIVEN DEGREE OF
DRY/STABLE AIR IN PLACE AND OVERALL LACKLUSTER FORCING FROM INCOMING
TROUGH.
AVIATION /06Z TAFS THROUGH 06Z TUESDAY/
ISSUED AT 127 AM EDT MON SEP 15 2025
RIDGING REMAINS IN PLACE PROVIDING ANOTHER ROUND OF TRANQUIL
TAFS. THIS MORNING, VISIBILITY GUIDANCE IS HINTING AT MOISTURE
ADVECTION OFF LAKE ERIE PERHAPS BRINING PATCHY FOG INTO
NORTHWEST OH. THIS OUGHT TO STAY EAST OF KFWA (MEDIUM-HIGH
CONFIDENCE), BUT UPSTREAM OBSERVATIONS WILL BE MONITORED.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...NONE.
DISCUSSION...AGD
AVIATION...BROWN
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