143
FXUS63 KGRB 222341
AFDGRB
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
641 PM CDT WED OCT 22 2025
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
KEY MESSAGES
- ON AND OFF RAIN SHOWERS REMAIN THROUGH TONIGHT. LAKE EFFECT
SHOWERS LATE TONIGHT INTO THURSDAY MORNING POTENTIALLY MIXING
WITH THE SEASONS FIRST SNOWFLAKES OVER FAR NORTH-CENTRAL
WISCONSIN.
- A FROST OR FREEZE IS EXPECTED OVER THE FOX VALLEY AND LAKESHORE
AREAS ON THURSDAY NIGHT, LIKELY ENDING THE GROWING SEASON.
- BELOW NORMAL TEMPERATURES ARE EXPECTED THROUGH THURSDAY FOLLOWED
BY A SLOW WARMING TREND INTO THE WEEKEND.
DISCUSSION
ISSUED AT 203 PM CDT WED OCT 22 2025
TONIGHT THROUGH FRIDAY...
CYCLONIC FLOW ALONG WITH DAYTIME HEATING HAS INCREASED RAIN SHOWER
ACTIVITY ACROSS THE REGION THIS AFTERNOON. EXPECT THIS ACTIVITY TO
BEGINNING WANING THIS EVENING, EXCEPT ACROSS NORTH-CENTRAL WISCONSIN
WHERE NORTHWEST WINDS OFF WESTERN LAKE SUPERIOR WILL CONTINUE TO
PRODUCE SCATTERED LAKE EFFECT SHOWERS THROUGH THE EVENING. THE
PROBABILITY FOR A FEW SNOWFLAKES TO MIX IN WITH THE RAIN HAS
INCREASED ACROSS FAR NORTH-CENTRAL WI TONIGHT TO AROUND 30-35%.
FAVORABLE WIND TRAJECTORIES, DELTA-TS OF 15-17C, AND HIGH MID-LEVEL
RELATIVE HUMIDITIES WITH LAKE INDUCED EQUILIBRIUM LEVELS UP TO
12,000FT ALL SUPPORT AREAS IN NORTH-CENTRAL WI SEEING THE FIRST
SNOW OF THE SEASON. HOWEVER, WITH GROUND TEMPERATURES ABOVE
FREEZING AND LOW TEMPERATURES HOVERING AT OR JUST ABOVE FREEZING
EXPECT MINIMAL IF ANY ACCUMULATIONS. AS THE SURFACE LOW PULLS
FURTHER TO THE EAST THURSDAY ANY LINGERING PRECIPITATION SHOULD
COME TO AN END DURING THE AFTERNOON.
AS SKIES CLEAR OUT BEHIND THE DEPARTING LOW THURSDAY NIGHT
TEMPERATURES ARE EXPECTED TO FALL NEAR OR BELOW FREEZING ACROSS MOST
OF THE REGION. CONFIDENCE IS LOWEST IN A FREEZE ACROSS EAST-CENTRAL
WISCONSIN WHERE WINDS MAY NOT DECOUPLE ENTIRELY. THIS MAY KEEP LOWS
JUST ABOVE FREEZING FOR PARTS OF THOSE AREAS.
SATURDAY INTO MID NEXT WEEK...
GENERALLY LOW IMPACT WEATHER IS EXPECTED THIS WEEKEND THROUGH THE
MIDDLE OF NEXT WEEK. A RIDGE DEVELOPING OVER THE CENTRAL CONUS WILL
BRING MOSTLY DRY CONDITIONS TO THE REGION THROUGH THIS WEEKEND.
HOWEVER, A SMALL NUMBER (~10%) OF LREF ENSEMBLE MEMBERS DO SHOW A
TRANSIENT SHORT-WAVE SWINGING ACROSS THE REGION EARLY SATURDAY,
WHICH COULD SPUR ON A FEW SHOWERS, BUT EVEN IF A FEW SCATTERED
SHOWERS DO DEVELOP ONLY EXPECT MINIMAL RAINFALL AMOUNTS. THE NEXT
CHANCE FOR AREA WIDE PRECIPITATION IS EXPECTED EARLY NEXT WEEK AS
A BROAD NEGATIVELY TILTED TROUGH DEVELOPS OVER THE WESTERN CONUS
CREATING FAVORABLE CONDITIONS FOR CYCLOGENESIS ACROSS THE WESTERN
GREAT LAKES. THERE IS CONSIDERABLE UNCERTAINTY WITH THE TIMING AND
INTENSITY OF PRECIPITATION WITH THIS SYSTEM AS RECENT RUNS OF THE
GFS/GEFS ARE FAR MORE PROGRESSIVE AND WETTER THAN THE ENS AND
CANADIAN ENSEMBLES. DESPITE DIFFERENCES IN THE ENSEMBLES, IMPACTS
FROM THIS SYSTEM ARE EXPECTED TO BE MINIMAL. INSTABILITY IS
EXPECTED TO BE SHUNTED WELL TO THE SOUTH, LIMITING THE THUNDERSTORM
POTENTIAL. 540 THICKNESSES ARE ALSO EXPECTED TO REMAIN WELL
NORTH, LIMITING THE POTENTIAL FOR ANY FREEZING PRECIPITATION.
TEMPERATURES WILL BEGIN A SLIGHT WARMING TRENDING THIS WEEKEND WITH
HIGHS NEAR TO JUST ABOVE NORMAL. TEMPERATURES THEN LOOK TO REMAIN
STEADILY NEAR NORMAL THROUGH THE SECOND HALF OF NEXT WEEK.
AVIATION
FOR 00Z TAF ISSUANCE
ISSUED AT 639 PM CDT WED OCT 22 2025
MIX OF MVFR TO VFR CIGS STARTS OFF THE EVENING. BY LATE EVENING
AND INTO THE OVERNIGHT HOURS, MFVR CONDITIONS ARE EXPECTED TO
LINGER ACROSS CENTRAL AND NORTHERN WISCONSIN, WITH PERIODS OF IFR
CONDITIONS ACROSS NORTH-CENTRAL WISCONSIN. IN ADDITION TO THE
LOWER CIGS, LAKE EFFECT RAIN SHOWERS OVER THE NORTH (RHI) MAY
TRANSITION TO A WINTRY MIX LATE TONIGHT INTO THURSDAY MORNING.
AS GROUND TEMPS STAY WARM AND PRECIP RATES WILL BE LIGHT, SNOW
SHOULD NOT ACCUMULATE, BUT BRIEF REDUCTIONS TO VISIBILITY (1-3 SM)
CERTAINLY COULD OCCUR IF PRECIP CHANGES TO ALL SNOW.
FOR THE FOX VALLEY TO THE LAKESHORE, VFR CONDITIONS ARE EXPECTED
TO DEVELOP LATER THIS EVENING THROUGH THE REST OF THE NIGHT. THESE
MORE FAVORABLE FLYING CONDITIONS WILL CONTINUE THROUGH THE REST
OF THE TAF PERIOD OVER EAST-CENTRAL WI. MEANWHILE, MVFR CONDITIONS
WILL ONLY SLOWLY IMPROVE TO VFR BY LATE THURSDAY OVER CENTRAL AND
NORTH-CENTRAL WI.
NORTHWEST WILL BE GUSTY TO AROUND 15 KTS AT TIMES INTO THURSDAY,
BUT OVERALL THE WINDS HAVE TRENDED DOWN FROM WHAT WAS OBSERVED
OVER THE LAST 24-36 HRS.
GRB WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION.....GK
AVIATION.......JLA
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page