984
FXUS63 KLOT 221718
AFDLOT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE, IL
1218 PM CDT WED JUL 22 2026
KEY MESSAGES
- THE NEXT FEW DAYS WILL BE OFFER SEASONABLY COOL TEMPERATURES,
COMFORTABLE HUMIDITY VALUES, AND NO THREAT OF RAIN.
- CONDITIONS WILL REMAIN HAZARDOUS AT ALL SOUTHERN LAKE MICHIGAN
BEACHES THROUGH THURSDAY MORNING.
- HEAT, HUMIDITY, AND CHANCES FOR STORMS WILL RETURN EARLY NEXT
WEEK.
DISCUSSION
ISSUED AT 142 AM CDT WED JUL 22 2026
IT SURE LOOKS AND FEELS MORE LIKE FALL THAN THE MIDDLE OF JULY
EARLY THIS MORNING WITH DEEP UPPER-LEVEL CYCLONIC FLOW ANCHORED
BY SEASONABLY COOL TEMPERATURES AND POCKETS OF LAKE-INDUCED
STRATOCUMULUS CLOUDS! THE CHANGE IN REGIME IS EXEMPLIFIED BY A
DROP IN 800MB TEMPERATURES OF ABOUT 12C/24 HOURS PER THE LAST
TWO 00Z RAOBS AT GRB, A RANGE FROM ROUGHLY THE 90TH TO 10TH
PERCENTILES. THE STAGE IS THUS SET FOR A BEAUTIFUL STRETCH OF
DAYS WITH SEASONABLY COOL TEMPERATURES, LOW HUMIDITY VALUES, AND
NO THREAT FOR RAIN. HIGHS TODAY WILL TOP OFF IN THE LOW TO MID
70S AND INCREASE BY A FEW DEGREES EACH DAY THROUGH THE END OF
THE WEEK. OVERNIGHT LOWS WILL BE COMFORTABLE AND START IN THE
LOWER 50S TONIGHT RISING TO THE LOWER 60S BY FRIDAY NIGHT. THE
ONLY FLY IN THE OINTMENT IN AN OTHERWISE PLEASANT PERIOD IS
HAZARDOUS WAVES ALONG ALL SOUTHERN LAKE MICHIGAN BEACHES TODAY
THROUGH THURSDAY MORNING.
THE REPRIEVE FROM THE HEAT WILL BE SHORT-LIVED AS UPPER-LEVEL
RIDGING REDEVELOPS ACROSS THE CENTRAL UNITED STATES THIS
WEEKEND. HIGHS WILL CLIMB BACK INTO THE UPPER 80S TO LOWER 90S
AS EARLY AS SUNDAY AND CONTINUE THROUGH NEXT WEEK. HUMIDITY
LEVELS ARE ALSO POISED TO RISE WITH AGRICULTURAL
EVAPOTRANSPIRATION LIKELY AUGMENTING NEAR-SURFACE DEW POINTS
INTO THE MID 70S. THE NEXT OPPORTUNITY FOR STORMS WILL ARRIVE IN
THE SUNDAY/MONDAY (JULY 26/27) TIMEFRAME ALONG THE PRECARIOUS
NORTHEASTERN SIDE OF THE BUILDING UPPER-LEVEL RIDGE. THE EPS IN
PARTICULAR IS BULLISH WITH 51-MEMBER MEAN MUCAPE ALREADY
EXCEEDING 2000 J/KG AND OVER 50% OF MEMBERS WITH A PWAT
EXCEEDING 2 INCHES. THIS WILL BE A PERIOD TO WATCH FOR SEVERE
WEATHER IN THE GENERAL UPPER MISSISSIPPI RIVER VALLEY/GREAT
LAKES REGION.
BORCHARDT
AVIATION /18Z TAFS THROUGH 00Z FRIDAY/
ISSUED AT 1218 PM CDT WED JUL 22 2026
NO MAJOR FORECAST CONCERNS FOR THE TERMINALS AS HIGH PRESSURE
REMAINS OVERHEAD. NORTH-NORTHEAST WINDS WILL PREVAIL THIS
AFTERNOON WITH SPEEDS GENERALLY IN THE 10-12 KT RANGE, BUT SOME
OCCASIONAL 15-20 KT GUSTS ARE POSSIBLE ESPECIALLY NEAR THE LAKE.
WINDS WILL BECOME LIGHT AND VARIABLE OVERNIGHT AS THE CENTER OF
THE HIGH PASSES THROUGH BEFORE DIRECTIONS SETTLE BACK INTO A
WEST-SOUTHWEST DIRECTION THURSDAY MORNING. THE EXCEPTION
HOWEVER, WILL BE AT THE CHICAGO TERMINALS AND GYY WHERE A WEAK
LAKE BREEZE LOOKS TO RESULT IN A EAST-NORTHEAST WINDS THURSDAY
AFTERNOON. OTHERWISE, EXPECT SCT TO BKN VFR SKIES (CEILINGS
AROUND 5000-6000 FT) THROUGH THE TAF PERIOD.
YACK
LOT WATCHES/WARNINGS/ADVISORIES
IL...BEACH HAZARDS STATEMENT UNTIL 10 PM CDT THIS EVENING FOR
ILZ006-ILZ103-ILZ104.
IN...BEACH HAZARDS STATEMENT THROUGH THURSDAY MORNING FOR INZ001-
INZ002.
LM...SMALL CRAFT ADVISORY UNTIL 10 PM CDT THIS EVENING FOR THE IL
NEARSHORE WATERS.
SMALL CRAFT ADVISORY UNTIL 4 AM CDT THURSDAY FOR THE IN
NEARSHORE WATERS.
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