722
FXUS63 KGRB 170859
AFDGRB
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
259 AM CST WED DEC 17 2025
FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE
KEY MESSAGES
- MIX OF RAIN, FREEZING RAIN AND SNOW EXPECTED WEDNESDAY NIGHT
INTO EARLY THURSDAY, THEN RAIN CHANGING TO SNOW THURSDAY
AFTERNOON AND EVENING. FLASH FREEZE POSSIBLE LATE THURSDAY
AFTERNOON AND EVENING. TRAVEL CONCERNS FROM LATE WEDNESDAY
NIGHT THROUGH THURSDAY NIGHT.
- LIGHT SNOW POSSIBLE FRIDAY NIGHT INTO SATURDAY MORNING.
- PERIODIC WINDY CONDITIONS AND A CHANCE OF GALES ON LAKE MICHIGAN
THROUGH THE REST OF THE WORK WEEK.
DISCUSSION
ISSUED AT 259 AM CST WED DEC 17 2025
MAIN FOCUS OF THE FORECAST WILL BE ON THE UPCOMING WINTRY SYSTEM
SET TO ARRIVE LATE TONIGHT INTO THURSDAY. FOLLOWING THIS, ANOTHER
ROUND OF SNOW OR TWO WILL ALSO BE IN THE WORKS FOR THE END OF THE
WEEK INTO THE WEEKEND AS THE NEXT CLIPPER ARRIVES.
ACTIVE WEATHER LATE TONIGHT THRU THURSDAY...
A STRONG LOW PRESSURE SYSTEM WILL TRACK ACROSS THE WESTERN GREAT
LAKES LATE TONIGHT THROUGH THURSDAY. PRECIPITATION TYPE REMAINS
THE MOST CHALLENGING ASPECT OF THE FORECAST, SPECIFICALLY ON THE
WHEN/WHERE TRANSITION OCCURS. INITIAL ONSET OF THE SYSTEM EARLY
THURSDAY MORNING WILL FEATURE A WINTRY MIX WITH SNOW GIVING WAY TO
RAIN AS WARMER AIR INTRUDES IN THE MID LEVELS AND ICE BECOMES
SCARCE. FREEZING RAIN POTENTIAL REMAINS LIMITED MAINLY BY SURFACE
TEMPERATURES AND HOW QUICKLY THESE WARM. SUSPECT THAT PRIOR ROAD
TREATMENTS, STRONG NON-DIURNAL WARMING PUSHING AIR TEMPS INTO THE
30S, AND TIMING DISCREPANCIES FOR PRECIP ONSET WILL LARGELY SPARE
THE FOX VALLEY AND AREAS EASTWARDS FROM A FREEZING RAIN THREAT, SO
REMOVED THESE AREAS FOR THE MORNING PERIOD. HOWEVER, PORTIONS OF
CENTRAL, NORTH- CENTRAL, AND NORTHEASTERN WISCONSIN WILL STILL SEE
A WINDOW FOR FREEZING PRECIPITATION THROUGH THE MID-MORNING BEFORE
THIS CONCERN ENDS. ICE ACCUMULATIONS SHOULD STAY IN THE REALM OF A
COUPLE HUNDRETHS WHICH WILL LIKELY BE TOO MINOR TO POSE AN
INFRASTRUCTURE CONCERN, BUT ANY ICING WILL BE A TRAVEL CONCERN.
RAIN WILL BECOME THE PREDOMINANT PRECIPITATION FOR THE LATE
MORNING TO EARLY AFTERNOON FOR ALL BUT FAR NORTHERN WISCONSIN
BEFORE SNOW WORKS ITS WAY IN WITH THE COLDER AIR. SNOW TOTALS
REMAIN AROUND AN INCH OR LESS FOR MOST OF THE AREA, EXCEPT FAR
NORTHERN WISCONSIN WHERE TOTALS COULD GET UP TO A FEW INCHES FROM
BOTH LAKE ENHANCEMENT AND SNOW BEING THE MORE DOMINANT P-TYPE.
FINALLY, TIMING ON WHEN THE COLDEST AIR RETURNS THURSDAY EVENING
REMAINS UNCERTAIN BUT THERE IS POTENTIAL FOR A RAPID FALL IN
TEMPERATURES WHICH COULD PRODUCE ADDITIONAL ICY SPOTS ON UNTREATED
SURFACES. THIS WILL ALSO BE ANOTHER PERIOD OF STRONGER WIND GUSTS
IN THE REGION. ULTIMATELY, ALL OF THIS WILL MAKE FOR A PERIOD OF
HAZARDOUS TRAVEL, SO MAKE SURE TO BE READY FOR CHANGES IN ROAD
CONDITIONS ESPECIALLY IF TRAVELING VERY EARLY THURSDAY OR LATE
THURSDAY EVENING.
NEXT CLIPPER LATE FRIDAY INTO SATURDAY...
ANOTHER CLIPPER WILL CROSS THE GREAT LAKES REGION OVERNIGHT FRIDAY
INTO SATURDAY, BRINGING WITH IT ANOTHER ROUND OF LIGHT SNOWFALL.
AMOUNTS WILL LIKELY BE HIGHER IN NORTHERN WISCONSIN BUT OVERALL
SHOULD STILL REMAIN RELATIVELY LIGHT.
AVIATION
FOR 06Z TAF ISSUANCE
ISSUED AT 1042 PM CST TUE DEC 16 2025
LATE THIS EVENING, A COLD FRONT WAS MOVING ACROSS NORTHWEST
WISCONSIN. IT REMAINS ON TRACK TO PUSH ACROSS THE REGION OVERNIGHT.
RELATIVELY STRONG WINDS EXIST IN THE LOWEST 3 KM ABOVE GROUND
LEVEL AHEAD OF AND BEHIND THE FRONT. THEREFORE, LOW LEVEL WIND
SHEAR CONDITIONS ARE EXPECTED AT ALL TERMINALS THROUGH
APPROXIMATELY 06Z-09Z. AFTER A BREAK, HIGH CONFIDENCE THAT LOW
LEVEL WIND SHEAR WILL RETURN ON WEDNESDAY EVENING.
MVFR CEILINGS (1400-2800 FT) DEVELOPED OVER NORTH- CENTRAL WI
(RHI) ON TIME (AROUND 03Z). THESE LOWER CLOUDS WILL CONTINUE TO
SPREAD SOUTHEAST ACROSS THE REST OF THE REGION, LIKELY PERSISTING
INTO EARLY WEDNESDAY MORNING BEFORE DEPARTING.
SKIES ARE EXPECTED TO CLEAR ON WEDNESDAY MORNING, RETURNING THE
ENTIRE AREA TO VFR CONDITIONS. CLOUD BASES WILL LOWER AGAIN ON
WEDNESDAY EVENING, BUT SHOULD REMAIN VFR THROUGH THE END OF THE
TAF PERIOD.
GUSTY WINDS WILL VEER TO THE NORTHWEST FOLLOWING THE COLD FRONT'S
PASSAGE OVERNIGHT. THE GUSTINESS SHOULD SUBSIDE SOME ON WEDNESDAY
MORNING. AS WIND DIRECTIONS BECOME SOUTHERLY ON WEDNESDAY
EVENING, GUSTS FROM 20 TO 25 KTS WILL BE POSSIBLE BY THE END OF
THE TAF PERIOD.
GRB WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION.....UHLMANN
AVIATION.......MPC
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