284
FXUS63 KGRB 262353
AFDGRB
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
653 PM CDT TUE MAY 26 2026
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
KEY MESSAGES
- HOT THIS AFTERNOON WITH RECORD TO NEAR-RECORD TEMPERATURES IN
THE UPPER 80S TO LOWER 90S.
- 50 TO 70% CHANCE FOR SHOWERS AND THUNDERSTORMS THIS AFTERNOON
AND THIS EVENING, WITH SOME STRONG TO MARGINALLY SEVERE STORMS
POSSIBLE WITH LARGE HAIL AND STRONG WINDS.
- ISOLATED THUNDERSTORMS ARE POSSIBLE WEDNESDAY AFTERNOON ACROSS
CENTRAL WISCONSIN. AN ISOLATED STORM COULD BECOME SEVERE WITH
LARGE HAIL AND DAMAGING WINDS.
- ABOVE NORMAL TEMPERATURES FOR THE NEXT WEEK, WITH HIGHS MAINLY
IN THE UPPER 70S AND 80S.
DISCUSSION
ISSUED AT 120 PM CDT TUE MAY 26 2026
BACKDOOR COLD FRONT/COMPOSITE LAKE BREEZE OFF SUPERIOR IS SLOWLY
DROPPING ACROSS UPPER MICHIGAN INTO NORTHERN WI. AHEAD OF THE FRONT
IT IS HOT AND DRY WITH EARLY AFTERNOON TEMPERATURES ALREADY INTO
THE MID TO UPPER 80S. HIGHS WILL REACH THE LOWER 90S, SO COULD
SEE RECORDS IN SOME LOCATIONS. RECORD HIGH FOR GRB TODAY IS 92
SET IN 2018.
DESPITE THE HEAT, DEWPOINTS ARE LAGGING THE MODELS WHICH IS
LEADING TO MLCAPES ONLY UP TO 200J/KG THUS FAR WHILE SBCAPE IS
OVER 1000J/KG. 18Z SOUNDING AT GRB IS QUITE DRY THROUGH 700-600MB.
OVERALL THINK THE DRIER AIR IS WHY SOME MODELS HAVE BACKED OFF OF
COVERAGE AND INTENSITY OF STORMS THIS AFTERNOON AND EVENING. CI
MOST LIKELY WILL BE CLOSER TO THE FRONT WHERE THERE IS CURRENTLY A
BATCH OF DEVELOPING CU FROM ONEIDA INTO MARINETTE COUNTIES.
EXPECT ISOLATED TO SCATTERED SHOWERS AND STORMS TO EVENTUALLY FORM
IN THIS AREA, THEN SPREAD/EXPAND AS FRONT MOVES SOUTHWARD INTO
THIS EVENING. DRY AIR AND DCAPE OVER 1000 DO LEAD TO DOWNBURST
WINDS AS THE PRIMARY HAZARD. FOR STORMS THAT GET TALLER, CAPE IN
THE HAIL GROWTH ZONE ALSO RESULTS IN HAIL AS HAZARD. OVERALL THE
FORECAST IS PRETTY SIMILAR, BUT THE COVERAGE OF STORMS DOES LOOK A
BIT LESS.
ONCE THE FRONT SLIDES THROUGH NORTH TO SOUTH THIS EVENING, WINDS
TURN NORTHEAST AND COOLER/MOISTURE AIRMASS ARRIVES. COULD BE FOG
LATE TONIGHT, ESPECIALLY WHERE SHOWERS AND STORMS ARE MOST
PREVALENT INTO THIS EVENING. POST FRONTAL AIRMASS WITH GRADIENT
NORTHEAST WINDS ON WEDNESDAY WILL NOT BE AS TOASTY. TRIMMED HIGHS
FROM NBM AND WENT MORE WITH CONSENSUS OF MODELS/ENSEMBLES. RESULT
WILL BE UPPER 60S NEAR LAKE MICHIGAN, UPPER 70S/NEAR 80 FOX VALLEY
AND NORTHERN WI, AND MID 80S OVER CENTRAL WI. GREATEST POTENTIAL
FOR STORMS, MAINLY NON-SEVERE, ON WEDNESDAY WILL BE ACROSS CENTRAL
WI.
HIGH PRESSURE THEN BUILDS IN THE REST OF THE WEEK INTO THE COMING
WEEKEND. DRY WEATHER IS EXPECTED. OTHER THAN THURSDAY WHEN TEMPERATURES
WILL BE AROUND NORMAL, READINGS WILL PUSH ABOVE NORMAL INTO EARLY
NEXT WEEK, WITH HIGHS IN THE MID 70S TO MID 80S. THE WARMEST DAY
WILL BE FRIDAY. DESPITE THE CANADIAN HIGH SETTLING OVERHEAD, TEMPS
AT NIGHT EVEN IN NORTHERN WI WILL REMAIN ABOVE 40, SO NO FROST ISSUES.
AVIATION
FOR 00Z TAF ISSUANCE
ISSUED AT 640 PM CDT TUE MAY 26 2026
SCATTERED SHOWERS AND THUNDERSTORMS WILL COME TO AN END THIS
EVENING INTO EARLY WEDNESDAY MORNING. PATCHY FOG IS POSSIBLE
ACROSS THE NORTH WHERE SKIES MAY BECOME PARTLY CLOUDY OVERNIGHT.
THE CHANCE FOR MORE STORMS DEVELOPS AFTER 16Z WEDNESDAY ACROSS
THE NORTH AND CENTRAL WI, AND THE ACROSS CENTRAL AND EAST-CENTRAL
WI WEDNESDAY AFTERNOON.
GRB WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION.....JLA
AVIATION.......ECKBERG
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