291
FXUS63 KGRB 131133
AFDGRB
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
633 AM CDT WED MAY 13 2026
UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE
KEY MESSAGES
- WINDY CONDITIONS EXPECTED TODAY, WITH HAZARDOUS CONDITIONS FOR
SMALL CRAFT ON THE LAKE AND BAY.
- NEXT CHANCE OF MAINLY LIGHT RAIN OCCURS THURSDAY NIGHT INTO
FRIDAY.
- GUSTY NORTHWEST WINDS AND LOW RELATIVE HUMIDITY TODAY, LOW
RELATIVE HUMIDITY ON THURSDAY, AND GUSTY WEST WINDS AND LOW
RELATIVE HUMIDITY ON SATURDAY WILL RESULT IN PERIODS OF ELEVATED
FIRE WEATHER CONDITIONS THIS WEEK.
- PERIODS OF HEAVY RAINFALL POSSIBLE LATE SATURDAY NIGHT THROUGH
MONDAY NIGHT. POTENTIAL FOR SEVERE STORMS AT TIMES FROM SUNDAY
NIGHT THROUGH MONDAY EVENING.
DISCUSSION
ISSUED AT 237 AM CDT WED MAY 13 2026
CYCLONIC NORTHWEST FLOW, CAA AND AND A PRONOUNCED THERMAL TROUGH
WERE SUPPORTING WIDESPREAD LOW CLOUD COVER ACROSS THE REGION
EARLY THIS MORNING. MANY LOCATIONS WERE REPORTING WINDS GUSTING
TO 20 TO 30 MPH, WITH OCCASIONAL HIGHER GUSTS. TEMPERATURES
HAD DROPPED INTO THE MIDDLE TO UPPER 30S IN NORTH CENTRAL WI, BUT
WERE STILL IN THE 40S AND LOWER 50S ELSEWHERE.
DEEP MIXING WILL BRING STRONGER WINDS ALOFT TO THE SURFACE FOR
MOST OF TODAY, WITH WIDESPREAD GUSTS OF 25 TO 35 MPH EXPECTED,
AND LOCAL HIGHER GUSTS TO 35 TO 40 MPH ACROSS DOOR COUNTY.
OVERCAST SKIES SHOULD GRADUALLY GIVE WAY TO PARTIAL SUNSHINE IN
THE EARLY TO MID AFTERNOON, WHICH SHOULD HELP BOOST HIGH
TEMPERATURES INTO THE UPPER 50S TO MIDDLE 60S. WINDS WILL
GRADUALLY SUBSIDE LATER THIS AFTERNOON AS HIGH PRESSURE BUILDS
INTO THE REGION.
THE HIGH WILL KEEP DRY WEATHER IN PLACE TONIGHT THROUGH THURSDAY.
A COOL NIGHT IS ANTICIPATED, WITH FROST POTENTIAL IN NORTH
CENTRAL AND PARTS OF CENTRAL AND FAR NORTHEAST WI. HOWEVER,
TEMPERATURES WILL REBOUND INTO THE 60S AND LOWER 70S ON THURSDAY,
EXCEPT NEAR LAKE MICHIGAN, WHERE A LAKE/BAY BREEZE WILL KEEP
READINGS IN THE MIDDLE 50S TO LOWER 60S.
ANOTHER FRONTAL SYSTEM ARRIVES THURSDAY NIGHT INTO FRIDAY, WITH
LIGHT SHOWERS AND ISOLATED THUNDERSTORMS EXPECTED. MOST OF THE
RAIN WILL SHIFT EAST FRIDAY MORNING, BUT PARTIAL CLEARING AND
DAYTIME HEATING SHOULD ALLOW A FEW SHOWERS AND ISOLATED STORMS TO
REDEVELOP AS A WEAK BOUNDARY MOVES THROUGH IN THE AFTERNOON.
AFTER A BRIEF DRY PERIOD FRIDAY NIGHT INTO SATURDAY EVENING, A
PATTERN CHANGE TO SOUTHWEST FLOW ALOFT WILL BRING AN INCREASINGLY
MOIST AND UNSTABLE AIR MASS TO THE REGION. THE LEADING SURGE OF
MOIST AND MARGINALLY UNSTABLE AIR WILL ARRIVE LATER SATURDAY
NIGHT, BRINGING A CHANCE OF SHOWERS AND ISOLATED STORMS TO MAINLY
CENTRAL AND EAST CENTRAL WI. LOW PRESSURE DEVELOPING IN THE
CENTRAL PLAINS ON SUNDAY WILL LIFT NORTHEAST ALONG A SLOW MOVING
COLD FRONT SUNDAY NIGHT THROUGH MONDAY NIGHT. THIS SYSTEM WILL
GENERATE PERIODS OF SHOWERS AND STORMS, AND LOCALLY HEAVY
RAINFALL, IN AN INCREASINGLY MOIST (PWATS OF 1.2 TO 1.7 INCHES)
AND UNSTABLE AIR MASS. PROBABILISTIC FORECASTS SHOW A 40-60%
CHANCE OF 1+ INCH OF RAIN FROM SUNDAY THROUGH MONDAY NIGHT, WITH
A 20-30% CHANCE OF 2+ INCHES. POTENTIAL FOR SEVERE THUNDERSTORMS
INCREASES SUNDAY NIGHT, AS INCREASING ELEVATED INSTABILITY AND
STEEP MID-LEVEL LAPSE RATES (7-8 C/KM) SUPPORT A THREAT OF LARGE
HAIL. SURFACE BASED INSTABILITY INCREASES TO 1-3K J/KG MONDAY
AFTERNOON AND EARLY EVENING, LEADING TO POTENTIAL FOR SURFACE-
BASED SEVERE CONVECTION, ESPECIALLY AS THE SURFACE LOW, A SHORT-
WAVE TROUGH AND A 50 KT LOW-LEVEL JET MOVE INTO THE REGION IN THE
LATE AFTERNOON/EVENING. THE SURFACE LOW AND COLD FRONT WILL PULL
OUT OF THE REGION LATER MONDAY NIGHT, WITH DRIER CONDITIONS
ARRIVING TUESDAY INTO WEDNESDAY.
TEMPERATURES WILL REMAIN BELOW NORMAL TODAY, CLIMB TO ABOVE
NORMAL LATE THIS WEEK INTO EARLY NEXT WEEK, THEN RETURN TO NEAR
NORMAL FOR THE MIDDLE OF NEXT WEEK.
AVIATION
FOR 12Z TAF ISSUANCE
ISSUED AT 624 AM CDT WED MAY 13 2026
WIDESPREAD MVFR STRATUS COVERED MOST OF THE FORECAST AREA, THOUGH
LOCALIZED IFR CEILINGS WERE REPORTED IN VILAS COUNTY AND PARTLY
CLOUDY SKIES (VFR) WERE OBSERVED IN PARTS OF C/EC WI. THOUGH
NORTHWEST WINDS HAD SUBSIDED A BIT OVERNIGHT, THEY WERE STILL
GUSTING TO 15 TO 25 KNOTS AT TIMES.
THE LOW CEILINGS ARE EXPECTED TO GRADUALLY RISE FROM MVFR TO VFR
BY LATE MORNING, WITH PARTIAL CLEARING OCCURRING DURING THE
MID TO LATE AFTERNOON. DEEP MIXING WILL SUPPORT BRISK NORTHWEST
WINDS, WITH FREQUENT GUSTS TO 20 TO 30 KTS EXPECTED UNTIL LATER
IN THE AFTERNOON.
WINDS QUICKLY SUBSIDE AND SKIES CLEAR THIS EVENING, WITH GOOD
FLIGHT CONDITIONS ANTICIPATED THROUGH THE NIGHT.
FIRE WEATHER
ISSUED AT 237 AM CDT WED MAY 13 2026
PINE FUELS HAVE REACHED THEIR PEAK VOLATILITY AND FINE FUELS HAVE
STILL NOT GREENED UP OVER NORTHERN WI, SO UPCOMING DRY AND WINDY
WEATHER TODAY AND SATURDAY, AND LOW RELATIVE HUMIDITY (RHS
20-30%) ON THURSDAY, WILL RESULT IN ELEVATED FIRE WEATHER
CONDITIONS AT TIMES THIS WEEK.
GRB WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION.....KIECKBUSCH
AVIATION.......KIECKBUSCH
FIRE WEATHER...KIECKBUSCH
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