619
FXUS63 KGRB 061133
AFDGRB
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
533 AM CST THU NOV 6 2025
UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE
KEY MESSAGES
- BREEZY WITH SCATTERED SHOWERS TONIGHT. A FEW RAIN AND SNOW
SHOWERS (30-60% CHANCE) NORTH-CENTRAL WI ON FRIDAY.
- COOLER BY SATURDAY WITH SCATTERED MIXED RAIN AND SNOW, CHANGING
TO SNOW SATURDAY NIGHT, WITH MINOR ACCUMULATIONS IN SOME AREAS.
- MUCH COLDER SUNDAY AND MONDAY. ACCUMULATING LAKE EFFECT SNOW
INTO FAR NORTHERN WISCONSIN AT TIMES.
DISCUSSION
ISSUED AT 309 AM CST THU NOV 6 2025
NEXT QUICK MOVING SHORTWAVE TROUGH AND DEVELOPING SFC LOW IN
ONGOING ZONAL FLOW PATTERN IS CROSSING THE NORTHERN ROCKIES THIS
MORNING. WINDS ARE MAIN CONCERN AS THIS MOVES THROUGH TONIGHT.
CONDITIONS ARE COLD AND MOSTLY CLEAR TO START THE DAY, BUT MID
AND HIGH CLOUDS WILL SPREAD IN STEADILY THIS MORNING. PERHAPS ENOUGH
LIFT/SATURATION IN WARM AIR ADVECTION THIS AFTERNOON FOR SPRINKLES
FAR NORTH. OTHERWISE, ANY RAIN HOLDS OFF UNTIL THIS EVENING INTO
THE EARLY OVERNIGHT, VERY DRY MID-LEVELS AHEAD OF THE SYSTEM LEAD
TO QUESTIONS ON WESTWARD EXTENT OF SHOWERS THIS EVENING. MAIN
CHANCES FOR SHOWERS WILL BE OVER EASTERN WI, BUT AMOUNTS WILL BE
LIGHT WITH QPF UNDER 0.10 INCH. LOW-LEVEL JET OF 45-55KT DOWN TO
925MB LEADS TO GUSTY WIND POTENTIAL TONIGHT. SOUNDINGS LOOK STABLE
THOUGH WITH WARM AIR ADVECTION ALOFT AND THERE IS NOW REAL SHALLOW
COLD LAYER. THUS, THINK BULK OF STRONGER WINDS/GUSTS WILL STAY
ALOFT. DECENT PRESSURE FALLS CROSSING NORTHERN WI WILL ALLOW FOR
25-35 MPH GUSTS AT TIMES THIS EVENING. ALSO COULD SEE BRIEF GUSTY
WINDS (40+ GUSTS) WITH ANY STRONGER SHOWERS MOVING THROUGH.
INSTABILITY IS NIL, SO THIS IS NOT A SURE THING, BUT GIVEN DEPTH
AND STRENGTH OF LOW-LEVEL JET, NOT COMPLETELY OFF THE TABLE
EITHER. SHOWERS END AFTER MIDNIGHT OVER EASTERN WI AND WINDS
TAILING OFF AS LOW-LEVEL JET SHIFTS EAST.
NORTHERLY FLOW BEHIND THE SYSTEM ON FRIDAY LOOKS MORE CONVERGENT
AND CYCLONIC INTO NORTHERN WI. EXPECT SCATTERED RAIN SHOWERS MIXED
WITH GRAUPEL OR LIGHT SNOW AT TIMES AFTERNOON INTO EVENING AS
TEMPS ALOFT AND SFC COOL. MARGINAL SFC TEMPS WILL KEEP ANY SNOW
ACCUMULATIONS TO TRACE AMOUNTS.
ATTENTION ON SATURDAY TURNS TO SHARP CLIPPER SHORTWAVE THAT CRASHES
ASHORE THE PACIFIC NORTHWEST LATE TONIGHT. THERE ARE DIFFERENCES
ON HOW FAR NORTH THIS SYSTEM TRACKS, RIDING THE PERIPHERY OF
STRONG UPPER TROUGH STEADILY DROPPING SOUTH FROM VICINITY OF
HUDSON BAY. ONE CAMP (GFS, CANADIAN) KEEP PRIMARY BAROCLINIC ZONE,
FRONTOGENESIS FARTHER SOUTH, WHILE THE OTHER CAMP (ECMWF AND
ESPECIALLY THE NAM) FAVOR EXPANSION OF RAIN/SNOW LATER SATURDAY
INTO EASTERN WI. NAM LOOKS TOO WOUND UP AND TOO FAR NORTH WITH
850MB LOW, SO NOT LEANING ON THAT TOO MUCH, YET. CURRENT FORECAST
HAS LOW-END LIKELY POPS EAST-CENTRAL WI AND FAR NORTH-CENTRAL ON
SATURDAY EVENING. TEMPS IN THE MID-UPPER 30S ARE MARGINAL
INITIALLY FOR ONLY SNOW, UNLESS RATES KICK UP AS THE NAM SHOWS.
NBM/LREF PROBABILITIES CURRENTLY SHOW 25-55% OF SEEING OVER 0.5
INCH OF SNOW, BUT NOT EVEN 30% OF SEEING OVER AN INCH. DETAILS
COULD CHANGE, SO STAY TUNED. LOOKS LIKE THERE IS GOOD AGREEMENT
THAT ANY RAIN/SNOW OR SNOW TAPERS OFF AFTER MIDNIGHT, EXCEPT OVER
NORTH-CENTRAL WI AS LAKE EFFECT BEGINS TO START UP IN EARNEST.
STILL APPEARS BETTER CHANCE FOR ACCUMULATING SNOW OF AT LEAST A
FEW INCHES LATER IN THE WEEKEND INTO EARLY MONDAY WILL BE IN THE
LAKE EFFECT BELT OF FAR NORTH-CENTRAL WI, MAINLY VILAS COUNTY.
POPS CONTINUE TO INCREASE WITH FAVORABLE SETUP AS THE DEEP TROUGH
SETTLES OVERHEAD AND COLD CYCLONIC NORTH-NORTHWEST FLOW RAMPS UP.
PEAK OF THIS EVENT WILL BE SUNDAY AND SUNDAY NIGHT AS LAKE EQLS
RISE OVER 10KFT AND FLOW IS FAVORABLE. BY MONDAY, FLOW BACKS MORE
NW AND INVERSIONS BEGIN TO FALL TO LESS THAN 5KFT, ALLOWING THE
LAKE EFFECT TO START TO WANE. PROBABILITIES FROM NBM POINT TO OVER
50% CHANCE OF SEEING 3+ INCHES OF SNOW DURING THIS TIME OVER FAR
NORTHERN VILAS (NORTH OF MANITOWISH WATERS AND BOULDER JUNCTION),
DROPPING TO AROUND 10% OVER NORTHERN ONEIDA, WELL TO THE NORTH OF
RHINELANDER. EVEN USING THE NBM 75TH PERCENTILE TO GAUGE HIGHER
"CEILING" FOR THIS EVENT, MAJORITY OF 5+ INCH AMOUNTS REMAIN
CLOSER TO LAKE SUPERIOR. AWAY FROM THE LAKE EFFECT IN NORTH-
CENTRAL, DOES STILL LOOK LIKE A COUPLE INCHES OF SNOW COULD ALSO
OCCUR LOCALLY IN NORTHERN DOOR COUNTY TOWARD WASHINGTON ISLAND,
WITH SUNDAY BEING THE MAIN TIME FRAME TO SEE THE SNOW THERE. NOW
APPEARS FLOW IS TOO WEST OF NORTH TO BRING MUCH IN WAY OF LAKE
EFFECT TO THE REST OF THE LAKE MICHIGAN SHORELINE. ELSEWHERE ON
SUNDAY, SPOTTY SNOW SHOWERS AND FLURRIES WILL OCCUR AT TIMES.
REST OF THE FORECAST INTO MIDDLE OF THE WEEK HAS SOME LOW-END
POPS, BUT MAIN FOCUS FOR PRECIPITATION WILL BE FARTHER NORTH OF
THE AREA, ALONG PRIMARY STORM TRACK.
TEMPERATURES...THE COLD IS COMING, BUT NOT UNTIL THIS WEEKEND.
WE'LL ENJOY ANOTHER COUPLE DAYS OF NEAR TO SLIGHTLY ABOVE NORMAL
TEMPS THROUGH FRIDAY. BOTTOM DROPS OUT THIS WEEKEND WITH HIGHS
MOST LOCATIONS ON SATURDAY STAYING BELOW 40 AND READINGS SUNDAY
AND MONDAY STAYING IN THE 30S, AND REMAINING BELOW FREEZING
NORTH. NIGHTS WILL BE COLD, WITH MINS IN THE TEENS CENTRAL AND
NORTH-CENTRAL WI STARTING ON SATURDAY NIGHT. TEMPS REBOUND
SLIGHTLY STARTING ON TUESDAY.
AVIATION
FOR 12Z TAF ISSUANCE
ISSUED AT 532 AM CST THU NOV 6 2025
VFR CONDITIONS ARE EXPECTED THROUGH EARLY THIS EVENING. MID-
LEVEL CLOUDS INCREASE THROUGH THE DAY, WITH STRATOCUMULUS DEVELOPING
AS SCATTERED SHOWERS ARRIVE IN THE EVENING. A BRIEF INTERLUDE OF
MVFR CEILINGS MAY OCCUR AT RHI/AUW/CWA LATE THIS EVENING INTO THE
EARLY OVERNIGHT.
LIGHT AND VARIABLE WINDS WILL BECOME SOUTHERLY THIS MORNING, WITH
GUSTY CONDITIONS THIS AFTERNOON AND EVENING. STRONG LLWS, DOWN TO
015 AGL, IS EXPECTED TO DEVELOP REGIONWIDE THIS EVENING (01Z-03Z)
INTO THE OVERNIGHT AS SOUTHWEST WINDS ALOFT INCREASE TO 45 TO 55
KNOTS. PLAN ON THE LLWS TO END 09Z-12Z AS SFC WINDS TURN WEST-
SOUTHWEST AHEAD OF COLD FRONT THAT SWEEPS THROUGH ON FRIDAY.
MARINE
ISSUED AT 309 AM CST THU NOV 6 2025
ANOTHER DAY, ANOTHER SMALL CRAFT ADVISORY. SOUTH WINDS INCREASE
LATE THIS AFTERNOON, REACHING TOWARD 25-30 KTS THIS EVENING. A
FEW GALE GUSTS MAY OCCUR, BUT MOSTLY THIS WILL BE OVER THE OPEN
WATERS. THIS IS SUPPORTED BY LOCAL STUDY THAT LOOKED AT MODEL
GUIDANCE DURING SOUTH WIND GALE EVENTS. THE STRONG SOUTHERLY WINDS
WILL BUILD WAVES TO 7 TO 10 FEET FOR MUCH OF THE LAKE MICHIGAN
NEARSHORE WATERS TONIGHT INTO FRIDAY MORNING. WINDS SHIFT TO THE
NORTHWEST ON FRIDAY AND WILL ONLY SLOWLY EASE THROUGH THE DAY.
NEXT PERIOD OF SMALL CRAFT ADVISORY CONDITIONS OCCURS SATURDAY
NIGHT INTO SUNDAY AS COLD AIR CHARGES SOUTH ACROSS LAKE MICHIGAN.
AT THIS TIME, GREATEST RISK OF GALES LOOKS TO SET UP OVER SOUTHERN
PORTION OF THE LAKE.
GRB WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION.....JLA
AVIATION.......JLA
MARINE.........JLA
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