766
FXUS63 KGRB 150336
AFDGRB
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
1036 PM CDT FRI AUG 14 2026
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
KEY MESSAGES
- WIDELY SCATTERED SHOWERS POSSIBLE (10-30% CHANCE) LATE TONIGHT
THROUGH SATURDAY AFTERNOON, BUT MOST AREAS WILL REMAIN DRY.
- A ROUND OF SHOWERS AND ISOLATED THUNDERSTORMS (30-50% CHANCE)
SATURDAY NIGHT AS A COLD FRONT MOVES THROUGH.
- DRYING OUT LATER SUNDAY INTO MONDAY WITH NEXT CHANCE FOR RAIN
AND THUNDERSTORMS TUESDAY AFTERNOON INTO WEDNESDAY.
DISCUSSION
ISSUED AT 223 PM CDT FRI AUG 14 2026
MODELS HAVE TRENDED THE BEST SHOWER AND THUNDERSTORM CHANCES
SOUTH OF OUR AREA TONIGHT AND SATURDAY MORNING, CLOSER TO THE
HIGHER INSTABILITY AND STRONGER LIFT OVER ILLINOIS. STILL,
MODEST ASCENT AND SOME WARM/MOIST ADVECTION SHOULD ALLOW A FEW
SCATTERED SHOWERS TO POP UP. HIGHEST CHANCE OF A SHOWER (30%
CHANCE) WILL BE ACROSS CENTRAL INTO EAST-CENTRAL WISCONSIN, BUT
MOST LOCATIONS ARE EXPECTED TO REMAIN DRY INTO THE AFTERNOON
HOURS SATURDAY.
A COLD FRONT WILL APPROACH SATURDAY EVENING, MOVING SOUTHEASTWARD
ACROSS THE AREA OVERNIGHT INTO SUNDAY MORNING AS A SHORTWAVE
TROUGH CLIPS THE NORTHERN GREAT LAKES. ANOMALOUSLY HIGH
PRECIPITABLE WATER VALUES (1.8 PLUS INCHES) SHOULD ALLOW
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS TO DEVELOP.
STRONGEST FORCING FOR ASCENT PASSING NORTH OF THE AREA SHOULD BE
SOMEWHAT DETACHED FROM THE STRONGEST INSTABILITY SOUTH OF THE
AREA, SO ASIDE FROM ISOLATED HEAVY DOWNPOURS, NOT EXPECTING
WIDESPREAD HEAVY RAIN WITH THIS SYSTEM.
BEHIND THE FRONT, QUIET WEATHER WITH LOWER DEWPOINTS EXPECTED
FROM SUNDAY EVENING THROUGH MONDAY NIGHT.
THE NEXT PERIOD OF ACTIVE WEATHER IS EXPECTED LATE TUESDAY THROUGH
WEDNESDAY, WITH A SHORTWAVE TROUGH ROTATING AROUND THE LONGWAVE
TROUGH OVER HUDSON BAY. SUFFICIENT MOISTURE AND INSTABILITY ARE
EXPECTED TO BE IN PLACE, YIELDING A HIGH CHANCE OF SHOWERS AND
THUNDERSTORMS. SOME HINT OF JET COUPLING OVER WISCONSIN SO WE
WILL NEED TO WATCH FOR THE POTENTIAL FOR HEAVY RAINFALL AMOUNTS.
AVIATION
FOR 06Z TAF ISSUANCE
ISSUED AT 1036 PM CDT FRI AUG 14 2026
CLOUD COVER WILL GRADUALLY INCREASE OVERNIGHT AS A SURFACE BOUNDARY
CURRENTLY PARKED ALONG THE I-94 CORRIDOR BEGINS TO LIFT NORTH. CIGS
SHOULD REMAIN VFR THROUGH THE MORNING, BUT A FEW POCKETS OF MVFR
CIGS ARE POSSIBLE ACROSS THE FOX VALLEY SATURDAY MORNING. THERE IS
ALSO A SMALL CHANCE (20-30%) FOR SOME SCATTERED SHOWERS TO DEVELOP
ACROSS CENTRAL INTO EAST-CENTRAL WI EARLY SATURDAY MORNING, HOWEVER,
WITH LIMITED INSTABILITY AND WEAK FORCING THE RISK FOR ANY LIGHTNING
IS LOW. LOW END VFR CIGS ARE EXPECTED TO OVERTAKE MUCH OF THE REGION
BY SATURDAY AFTERNOON. A COLD FRONT SWEEPING ACROSS THE REGION
SATURDAY WILL BRING ANOTHER (40-60%) FOR SCATTERED SHOWERS FROM WEST
TO EAST AFTER 03Z. CONFIDENCE THAT ANY SHOWERS WOULD IMPACT A
TERMINAL BEFORE THE END OF THE TAF PERIOD WAS TOO LOW TO INCLUDE IN
THE TAFS AS THIS POINT BUT WILL LIKELY NEED TO INTRODUCE AT LEAST
SHRA WITH FUTURE ISSUANCES.
LIGHT EAST TO SOUTHEAST WINDS ARE EXPECTED TONIGHT. A SLIGHT
INCREASE IN THE SOUTHEAST WINDS IS EXPECTED SATURDAY WITH OCCASIONAL
GUSTS UP TO 15 KTS DURING THE DAY. BEHIND THE PASSING FRONT SATURDAY
NIGHT WINDS WILL VEER AROUND TO THE WEST NORTHWEST.
MARINE
ISSUED AT 223 PM CDT FRI AUG 14 2026
SOUTHEAST WINDS WILL INCREASE SATURDAY ACROSS THE NEARSHORE
LAKE MICHIGAN WATERS AS A COLD FRONT APPROACHES THE AREA. THIS
WILL BRING SMALL CRAFT ADVISORY CONDITIONS WITH GUSTS UP TO 25
KTS AND WAVES UP TO 5 FEET, PARTICULARLY FROM KEWAUNEE
SOUTHWARD.
GRB WATCHES/WARNINGS/ADVISORIES
BEACH HAZARDS STATEMENT FROM 8 AM CDT SATURDAY THROUGH SATURDAY
EVENING FOR WIZ040-050.
DISCUSSION.....KS
AVIATION.......GK
MARINE.........KS
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