658
FXUS63 KGRB 221906
AFDGRB
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
206 PM CDT WED OCT 22 2025
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST 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 SHOWER 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. DISPUTE DIFFERENCES IN THE ENSEMBLES IMPACTS
FROM THIS SYSTEM ARE EXPECTED TO BE MINIMAL. INSTABILITY IS
EXPECTED TO BE SHUNTED WELL TO THE SOUTH, LIMITING AND
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 18Z TAF ISSUANCE
ISSUED AT 1209 PM CDT WED OCT 22 2025
BLANKET MVFR CIGS OVER THE REGION EARLY THIS AFTERNOON ALONG WITH
SCATTERED LINGER SHOWERS ACROSS NORTH-CENTRAL AND NORTHEASTERN
WISCONSIN. MVFR CONDITIONS ARE EXPECTED TO PERSIST THROUGH THE
AFTERNOON AS STATUS/STRATOCUMULUS CLOUDS CONTINUE TO MOVE OVER THE
REGION. A SLIGHT UPTICK IN SHOWER ACTIVITY IS ALSO EXPECTED THIS
AFTERNOON AS DAYTIME HEATING SPURS ON A FEW LAKE EFFECT SHOWERS,
MAINLY ACROSS NORTH-CENTRAL AND NORTHEAST WISCONSIN.
MFVR CONDITIONS ARE EXPECTED TO LINGER OVERNIGHT ACROSS CENTRAL AND
NORTHERN WISCONSIN, WITH PERIODS OF IFR CONDITIONS POSSIBLE MAINLY
ACROSS NORTH-CENTRAL WISCONSIN. IN ADDITION TO THE LOWER CIGS A
TRANSITION TO A WINTRY MIX IS POSSIBLE ACROSS FAR NORTHERN
WISCONSIN, MAINLY EFFECTING RHI, OVERNIGHT INTO THURSDAY MORNING.
DON'T EXPECT ANY SNOW TO ACCUMULATION, BUT BRIEF REDUCTIONS IS
VISIBILITY ARE POSSIBLE.
VFR CONDITIONS ARE EXPECTED TO RETURN TO THE FOX VALLEY AND
LAKESHORE AREAS THIS EVENING AND CONTINUE INTO THURSDAY MORNING.
GRB WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION.....GK
AVIATION.......GK
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