474
FXUS63 KIWX 241748
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
148 PM EDT FRI JUL 24 2026
KEY MESSAGES
- GRADUALLY WARMER OVER THE NEXT SEVERAL DAYS. HOT AND HUMID
WITH HIGHS IN THE UPPER 80S TO LOW 90S BY SUNDAY AND MONDAY.
- A COUPLE ROUNDS OF RAIN AND STORMS ARE POSSIBLE LATE SUNDAY
THROUGH EARLY TUESDAY (30-60% CHANCE OF SHOWERS/STORMS).
SEVERE WEATHER IS POSSIBLE BUT LOW CONFIDENCE ON EXACT DETAILS
AT THIS TIME.
DISCUSSION
ISSUED AT 1045 AM EDT FRI JUL 24 2026
A DECAYING AREA OF SHOWERS IS NOTED OVER FAR WESTERN ILLINOIS LATE
THIS MORNING, SLOWLY DRIFTING EAST, AND NWS CHICAGO IS REPORTING
SPRINKLES. PROGRESS WILL BE LIMITED, HOWEVER, DUE TO A STOUT
DRY LAYER BELOW 18,000 FT COURTESY OF RETREATING HIGH PRESSURE
NOW OVER NORTHEAST PA. I DID NOTE THAT SOME HRRR RUNS ATTEMPT TO
BRING LIGHT RAIN TO THE FAR SOUTHWEST FORECAST AREA. WHILE
FORECAST SOUNDINGS ATTEMPT TO SATURATE IN THE UPPER- LEVELS, DRY
AIR ELSEWHERE IN THE PROFILE PRECLUDE INTRODUCING ANY SHOWERS
TO TODAY'S FORECAST. INSTEAD, VARIABLE CLOUDINESS TODAY WITH
HIGH TEMPERATURES JUST A TOUCH WARMER THAN YESTERDAY THANKS TO
SOUTHERLY RETURN FLOW ON AFORMENTIONED HIGH PRESSURE.
THE PRIMARY PERIODS OF INTEREST CONTINUE TO BE SUNDAY NIGHT AND
MONDAY NIGHT WITH THE RISK OF SEVERE THUNDERSTORMS, AND THE HOT,
HUMID CONDITIONS. A 598DM RIDGE OVER THE FOUR CORNERS AMPLIFIES
BY THIS TIME, SPREADING A 50-70 KNOT 500-MB JET OVER THE GREAT
LAKES. THIS, AMID A HOT, HUMID ENVIRONMENT YIELDS VERY LARGE
CAPE VALUES AND BULK SHEAR NEAR 40 KNOTS. THESE ITEMS AWAIT A
TRIGGER FOR CONVECTION IN THE FORM OF AN UPPER-LEVEL VORTICITY
MAXIMUM, THE INCOMING UPPER-LEVEL JET, OR, MORE LIKELY,
LINGERING MCVS OR OUTFLOW BOUNDARIES FROM PRIOR CONVECTION.
THESE FINER DETAILS ARE A BIT FUTILE TO CHASE AT THIS DISTANCE
AND REMAIN TO BE SEEN, SO, MESSAGING AND UNCERTAINTY CARRY ON
LARGELY UNCHANGED. GIVEN THE ANTICIPATED STORM MODE (SQUALL LINE
OR MCS), DAMAGING WIND GUSTS WOULD BE THE PRIMARY HAZARD SUNDAY
NIGHT AND AGAIN MONDAY NIGHT.
BEHIND THESE STORM CHANCES, UPPER-LEVEL TROUGHING OVER THE EASTERN
GREAT LAKES NUDGES THE FOUR CORNERS RIDGE WESTWARD GIVING US A BREAK
FROM HEAT AND STORMS. HOWEVER, THERE ARE INDICATIONS THE RIDGE
BUILDS TO THE EAST THROUGH THE WEEK, RENEWING OUR LOCAL CHANCE OF
STORMS.
AVIATION /18Z TAFS THROUGH 18Z SATURDAY/
ISSUED AT 148 PM EDT FRI JUL 24 2026
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD WITH NO IMPACTFUL
WEATHER. DIURNAL CU WILL GRADUALLY DISSIPATE TOWARDS SUNSET LEAVING
BEHIND WIDESPREAD HIGH CIRRUS. WINDS WILL REMAIN VARIABLE THROUGH
THE TAF PERIOD AT 5KTS OR LESS WITH A PREDOMINATELY NORTHERLY
DIRECTION THROUGH TONIGHT BEFORE BECOMING SOUTHERLY TOMORROW.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...NONE.
DISCUSSION...BROWN
AVIATION...NWS
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