492
FXUS63 KIWX 182232
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
632 PM EDT FRI SEP 18 2026
KEY MESSAGES
- SEVERAL ROUNDS OF RAIN AND EMBEDDED THUNDERSTORMS EXPECTED
TONIGHT INTO THIS WEEKEND, POSSIBLY LINGERING INTO MONDAY. A
FLASH FLOOD WATCH IS IN EFFECT FROM PORTIONS OF NORTHERN
INDIANA, SOUTHERN MICHIGAN, AND NORTHWEST OHIO TONIGHT INTO
SUNDAY MORNING. 1-3 INCHES OF RAIN IS EXPECTED LATE TONIGHT
INTO SUNDAY MORNING, GREATEST TOTALS EXPECTED NORTH OF US 6.
AREAS FURTHER SOUTH THAT RECEIVED EXCESSIVE RAINFALL THIS PAST
WEEK COULD SEE AN EXACERBATION TO ANY LINGERING FLOODING.
- THERE IS A MARGINAL RISK FOR ISOLATED STRONG TO SEVERE STORMS
SATURDAY. THE MAIN THREAT IN SEVERE STORMS WOULD BE DAMAGING
WINDS. CONFIDENCE IS LOW.
- COOLER AND TRENDING DRIER TUESDAY THROUGH FRIDAY. HIGHS IN THE
60S, LOW 70S.
DISCUSSION
ISSUED AT 357 PM EDT FRI SEP 18 2026
THE ACTIVE WEATHER PATTERN CONTINUES, WITH ADDITIONAL HEAVY RAINFALL
POTENTIAL TONIGHT INTO SUNDAY MORNING, POSSIBLY LINGERING INTO
MONDAY. WPC HAS PORTIONS OF OUR AREA IN A MODERATE RISK FOR
EXCESSIVE RAINFALL, WITH THE REMAINING PORTIONS OF OUR AREA IN
SLIGHT/MARGINAL RISK FOR EXCESSIVE RAINFALL. OPTED TO ISSUE A
FLASH FLOOD WATCH FOR PORTIONS OF IN/MI AND A SMALL PART OF NW
OH (VAN WERT/PAULDING COUNTIES, OH). WE STILL REMAIN ON THE
NORTHERN PERIPHERY OF AN UPPER LEVEL RIDGE/TROUGH TO THE NORTH,
WHICH KEEPS US IN ZONAL FLOW WITH VARIOUS SHORTWAVES MOVING
THROUGH. THE FIRST ARRIVES LATE TONIGHT INTO SATURDAY, AND THE
SECOND SATURDAY NIGHT INTO SUNDAY MORNING. THE SECOND IS
ASSOCIATED WITH A SURFACE LOW THAT DRIFTS FROM IL INTO OUR
FORECAST AREA AND OVER TO NW OH (OR THE LOWER GREAT LAKES
DEPENDING ON THE MODEL). THERE IS CONSIDERABLE UNCERTAINTY WITH
REGARDS TO EXACT TIMING, SO WENT BROAD BRUSH WITH POPS
(LIKELY/CATEGORICAL). THERE IS ALSO UNCERTAINTY AS TO WHERE
EXACTLY THE HEAVIEST RAIN WILL FALL, BUT FOR NOW IT LOOKS LIKE
AREAS ALONG AND NORTH OF US 6 WILL SEE 2-3 INCHES OF ADDITIONAL
RAINFALL, WHILE FURTHER SOUTH AROUND 1-2". LOCALLY HIGHER
AMOUNTS ARE POSSIBLE WHERE TRAINING OF STORMS COULD OCCUR, AND
IT'S POSSIBLE THE HIGHER TOTALS SHIFT FURTHER SOUTH. GIVEN
ONGOING IMPACTS WITH RIVER FLOODING AND WATER OVER ROADS (IN THE
AREAS THAT RECEIVED 6-10" OF RAIN THIS WEEK JUST SOUTH OF FORT
WAYNE/ALLEN CO, IN)...DECIDED TO ERR ON THE SIDE OF CAUTION AND
ISSUE THE WATCH. AREAS FURTHER NORTH SAW AROUND 1-3" (LOCAL MAX
OF AROUND 4" NEAR OUR OFFICE), BUT DESPITE THESE LOWER AMOUNTS
THIS MAY HAVE PRIMED THE PUMP FOR FLOODING IF WE GET THE HIGHER
AMOUNTS AS FORECAST.
OTHERWISE, HIGHS WILL BE IN THE 70S, LOW 80S THROUGH SUNDAY. THERE
IS A MARGINAL RISK FOR ISOLATED STRONG-SEVERE STORMS SATURDAY,
MAINLY FOR DOWNBURST WIND POTENTIAL (5%) DURING THE DAY IN ANY
EMBEDDED CONVECTION. LOW CONFIDENCE.
ADDITIONAL RAIN CHANCES WITH PERIODS OF THUNDER THROUGH THE WEEK,
BECOMING DRIER TOWARDS THE WED-FRIDAY TIME FRAME. COOLER, WITH HIGHS
DROPPING INTO THE 60S, AND LOWS IN THE UPPER 40S AND 50S.
AVIATION /00Z TAFS THROUGH 00Z SUNDAY/
ISSUED AT 626 PM EDT FRI SEP 18 2026
QUIET AND DRY CONDITIONS THIS EVENING AND TONIGHT GIVE WAY TO
WIDESPREAD HEAVY RAINFALL AND SCATTERED STORMS BY THE DAYBREAK
HOURS SATURDAY MORNING. A SOGGY SATURDAY IS AHEAD AS AN AXIS OF
WIDESPREAD RAIN AND EMBEDDED STORMS IS EXPECTED TO DEVELOP
UPSTREAM AND OVERSPREAD LOWER MICHIGAN BETWEEN 06-12Z. THERE
ARE STILL SOME DISCREPANCIES IN EXACT TIMING, BUT THIS SYSTEM
WILL GRADUALLY SHIFT SOUTHEAST INTO OUR FORECAST AREA SATURDAY
MORNING AND AFTERNOON. RAIN MAY BEGIN AS EARLY AS 9-10Z AT KSBN,
WITH THE HEAVIEST PERIOD OF RAIN AND STORMS EXPECTED BETWEEN
13-17Z. THE TIMING AT KFWA IS SIMILAR WITH RAIN STARTING AS
EARLY AS 12Z AND EXPECTED TO BE MOST IMPACTFUL BETWEEN 15-18Z.
IN ANY STORMS, MVFR CEILINGS AND VISIBILITIES WILL BE POSSIBLE.
PROBABILITIES FOR IFR CEILINGS AND VISIBILITIES VERY LOW AROUDN
10-15% BUT COULD OCCUR IN ANY PARTICULARLY STRONG STORMS.
EVEN OUTSIDE OF STORMS, SOUTHEASTERLY WINDS MAY GUST AS HIGH AS
20 KT ON SATURDAY, ESPECIALLY IN THE VICINITY OF LAKE MICHIGAN
AT KSBN.
IWX WATCHES/WARNINGS/ADVISORIES
IN...FLOOD WATCH FROM 2 AM EDT /1 AM CDT/ SATURDAY THROUGH SUNDAY
MORNING FOR INZ005>009-012-014-015-017-018-023>027-
032>034-103-104-116-203-204-216.
OH...FLOOD WATCH FROM 2 AM EDT SATURDAY THROUGH SUNDAY MORNING FOR
OHZ015-024.
MI...FLOOD WATCH FROM 2 AM EDT SATURDAY THROUGH SUNDAY MORNING FOR
MIZ078>080-177-277.
MARINE...NONE.
DISCUSSION...MCD
AVIATION...JOHNSON
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