551
FXUS63 KIWX 210728
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
328 AM EDT TUE APR 21 2026
KEY MESSAGES
- SHOWERS AND SCATTERED THUNDERSTORMS ARE EXPECTED LATE TODAY
AND TONIGHT. SEVERE STORMS ARE NOT EXPECTED, BUT LOCALLY HEAVY
RAINFALL IS LIKELY.
- MORE SHOWERS AND SCATTERED THUNDERSTORMS ARE AHEAD FRIDAY.
SEVERE STORMS ARE NOT EXPECTED.
- HIGHS WILL BE ABOVE TO MUCH ABOVE NORMAL FROM AROUND 70 TO 80
DEGREES THROUGH SATURDAY.
DISCUSSION
ISSUED AT 324 AM EDT TUE APR 21 2026
RETURN FLOW WAS UNDERWAY WITH A LARGE HIGH PRESSURE AREA ALONG
THE EAST COAST AND A TROF OF LOW PRESSURE ACROSS THE HIGH
PLAINS. AT THE ONSET, THIS SCENARIO WAS CAUSING WARM AIR
ADVECTION ACROSS THE OHIO VALLEY AND THE MISSISSIPPI VALLEY. THE
AIRMASS WAS QUITE DRY WITH DEW POINTS IN THE 20S. WARM AND
INITIALLY DRY AIR ADVECTION WILL BE ABLE TO MIX DOWN MILDER AIR.
HIGHS TODAY SHOULD REACH AROUND 70 TO 75. DUE TO THE STRONG MID
LEVEL CAP, STRAY THUNDERSTORMS ARE NOT EXPECTED; HOWEVER, THE
BEST CHANCE FOR STORMS WILL BE THIS EVENING AS MOISTURE POOLS
ALONG AND SOUTH OF THE FRONT. IT STILL LOOKS LIKE CHANCES FOR
SEVERE STORMS IS LOW GIVEN LIMITED INSTABILITY AND UNIDIRECTIONAL
WINDS PER GFS BUFKIT.
UNSEASONABLY MILD WEATHER IS AHEAD WEDNESDAY THROUGH FRIDAY AS
AN UPPER LEVEL RIDGE BUILDS NORTH ACROSS THE OHIO RIVER VALLEY.
850 MB TEMPERATURES FROM +9C TO +12C WARMED DRY ADIABATICALLY
TO THE SURFACE SUPPORT HIGHS IN THE MID 70S TO AROUND 80. RECORD
HIGHS IN THE MID TO UPPER 80S APPEAR OUT OF REACH AT THIS TIME.
GIVEN A NUMBER OF RIVERS STILL IN ACTION TO MINOR FLOOD STAGE,
RAINFALL AMOUNTS TODAY AROUND A HALF AN INCH ARE NOT EXPECTED TO
CAUSE RISES ON AREA RIVERS; HOWEVER, THESE RAINFALL AMOUNTS
COULD CASE A DELAY IN THE WATER LEVELS RECEDING.
AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/
ISSUED AT 102 AM EDT TUE APR 21 2026
WEAK LOW PRESSURE MOVING THROUGH THE GREAT LAKES SENDS A SLOW-
MOVING FRONT SOUTHWARD THROUGH THE TERMINALS LATE IN THE DAY.
MODEST GULF MOISTURE ADVECTION RESULTS IN SCATTERED
THUNDERSTORMS DEVELOPING ALONG THIS FRONT. REASONABLY HIGH
CONFIDENCE IN A BRIEF MVFR VISIBILITY RESTRICTION AS THESE
SHOWERS AND STORMS MOVE THROUGH. OTHERWISE, BREEZY TODAY WITH
GUSTS NEAR 30 KNOTS.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...NONE.
DISCUSSION...SKIPPER
AVIATION...BROWN
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