529
FXUS63 KGRB 011733
AFDGRB
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
1133 AM CST SUN FEB 1 2026
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
UPDATE
ISSUED AT 927 AM CST SUN FEB 1 2026
LIGHT SNOW ACROSS WESTERN WI CONTINUES TO STRUGGLE ADVANCING EAST DUE
TO THE PRESENTS OF MUCH DRIER AIR. THIS IS EVIDENT ON UPSTREAM RADARS
AND MID-LEVEL WATER VAPOR IMAGERY. SO HAVE DELAYED THE ONSET OF ANY
PRECIP IN CENTRAL WI BY A FEW HOURS.
THE OTHER CHANGE TO THE FORECAST THIS MORNING HAS BEEN TO INTRODUCE
A ~15% CHANCE FOR FREEZING DRIZZLE ALONG THE LEADING EDGE OF THE
SNOW ARRIVING THIS AFTERNOON. SURFACE OBS FROM EAST-CENTRAL MN HAVE
PERIODICALLY BEEN REPORTING UNKNOWN PRECIP WHICH WITH TEMPERATURES
BELOW FREEZING THROUGH THE LOW AND MID LEVELS (EVIDENT ON MPX 12Z
RAOB) SUGGESTS THE PRESENTS OF FREEZING DRIZZLE. THIS ALSO ALIGNS
WITH MESOANALYSIS DATA SHOWING A POCKET DRY MIDDLE AIR CURRENTLY
ACROSS NW WI AND NE MN. DURATION OF ANY FREEZING DRIZZLE SHOULD BE
BRIEF AS DEEPER MOISTURE WILL ARRIVE JUST AHEAD OF THE COLD FRONT
AND STRONGER SHORT-WAVE FORCING. WHILE THIS IS A SUBTLE SIGNAL FOR
FREEZING DRIZZLE ANY ICING ON ROADS IS ALWAYS A CONCERN. IF YOU WILL
BE ON THE ROAD OUT IN CENTRAL AND NORTH-CENTRAL WI THIS AFTERNOON
DRIVE WILL EXTRA CAUTION AS ICE MAY BE DIFFICULT TO SEE ON ANY
UNTREATED ROADS.
KEY MESSAGES
- LIGHT SNOW IS FORECAST TO MOVE ACROSS THE REGION THIS AFTERNOON
AND TONIGHT. ACCUMULATIONS OF A HALF INCH (60-80% CHANCE) TO ONE
INCH (10-30% CHANCE) ARE EXPECTED. SLIPPERY TRAVEL CONDITIONS
WILL LIKELY DEVELOP, AND MAY EXTEND INTO THE MONDAY MORNING
COMMUTE.
- A POTENT CLIPPER SYSTEM MAY IMPACT THE AREA NEXT THURSDAY AND
FRIDAY. WHILE SIGNIFICANT TIMING AND TRACK UNCERTAINTIES
REMAIN, THIS SYSTEM HAS THE POTENTIAL TO BRING ACCUMULATING SNOW
AND GUSTY WINDS.
- HIGHS IN THE 20S WILL BE COMMON FOR MUCH OF NEXT WEEK, POSSIBLY
EXCEEDING 30 DEGREES AT A FEW LOCATIONS THURSDAY AND FRIDAY.
DISCUSSION
ISSUED AT 252 AM CST SUN FEB 1 2026
MOSTLY CLEAR SKIES AND LIGHT S-SW WINDS WERE OBSERVED ACROSS THE
REGION EARLY THIS MORNING AS SURFACE HIGH PRESSURE GRADUALLY
SHIFTED EAST. TEMPERATURES WERE GENERALLY IN THE SINGLE DIGITS
ABOVE AND BELOW ZERO. A CLIPPER LOW PRESSURE SYSTEM WAS MOVING
THROUGH SOUTHERN MANITOBA, WITH A COLD FRONT EXTENDING SOUTH
ALONG THE DAKOTAS/MN BORDER. WIDESPREAD LIGHT SNOW WITH THIS
SYSTEM WAS OVERSPREADING MN.
CAMS SHOW THE LEADING EDGE OF LIGHT SNOW REACHING NC/C WI LATER
THIS MORNING, BUT ERODING AS IT ENCOUNTERS DRIER AIR. THIS OCCURS
FOR SEVERAL HOURS UNTIL FORCING WITH THE COLD FRONT AND SHORT-
WAVE TROUGH PUSH A BAND OF STEADY LIGHT SNOW (VSBYS MOSTLY 1 1/2
TO 4 MILES) THROUGH THE FORECAST AREA LATER THIS AFTERNOON AND
TONIGHT. HAVE MAINTAINED HIGH POPS (AROUND 80 PERCENT) WITHIN THE
MAIN SNOW BAND, BUT DID SLOW THE ARRIVAL TIME DOWN BY AN HOUR OR
TWO. MOST LOCATIONS SHOULD RECEIVE A HALF INCH TO AN INCH OF SNOW,
AND ROADS WILL LIKELY BECOME SLIPPERY IN SPOTS. THE SNOW SHOULD
END BY MONDAY MORNING; WITH THE EXCEPTION OF SCATTERED LAKE-
EFFECT SNOW SHOWERS IN FAR NC WI, THOUGH SLIPPERY STRETCHES COULD
LINGER INTO THE MORNING COMMUTE.
A BRIEF PERIOD OF HIGH PRESSURE WILL BRING DRY CONDITIONS LATE
MONDAY THROUGH WEDNESDAY AS THE UPPER-LEVEL PATTERN RE-AMPLIFIES.
AN UPPER RIDGE WILL THEN STRENGTHEN OVER THE WESTERN U.S. WHILE A
MEAN TROUGH REINFORCES ITSELF OVER THE EAST. THIS SET-UP WILL
PAVE THE WAY FOR A POTENTIALLY MORE SIGNIFICANT CLIPPER SYSTEM
THURSDAY INTO FRIDAY. MODEL GUIDANCE INDICATES AN INTENSIFYING
LOW PRESSURE SYSTEM CROSSING THE GREAT LAKES, THOUGH DIFFERENCES
IN TIMING AND TRACK PERSIST AT THIS POINT. GIVEN THE POTENTIAL FOR
STRONG DYNAMICS, THIS SYSTEM WILL NEED TO BE MONITORED FOR BOTH
ACCUMULATING SNOW AND STRONG WIND IMPACTS. CURRENT PROBABILITIES
FOR SNOWFALL GREATER THAN 1 INCH ARE HIGHEST (50-70%) ACROSS THE
NORTHEAST THIRD OF THE CWA, WITH A 30-50% CHANCE OF 2+ INCHES
OVER VILAS COUNTY AND FAR NORTHEAST WI, INCLUDING DOOR COUNTY. IF
THIS SYSTEM TRACKS FAR ENOUGH NORTH, THERE MAY BE ENOUGH WARM AIR
PULLED INTO THE REGION TO SUPPORT A RAIN/SNOW MIX IN THE SOUTH.
THERE IS POTENTIAL (30-50% CHANCE) OF GALE FORCE GUSTS NEAR
DEATHS DOOR AS THE SYSTEM DEPARTS FRIDAY AND FRIDAY EVENING.
TEMPERATURES REMAIN ON THE MILDER SIDE THROUGH MOST OF THE PERIOD,
WITH HIGHS MAINLY IN THE 20S, AND EVEN SOME LOW TO MID 30S IN
C/EC WI THURSDAY INTO FRIDAY. A BRIEF SHOT OF COLDER AIR ARRIVES
IN THE WAKE OF THE LATE WEEK CLIPPER SYSTEM, AS 850 MB
TEMPERATURES DROP TO -20 TO -25 C. BELOW NORMAL TEMPERATURES ARE
LIKELY ON SATURDAY, BUT SHOULD REBOUND A BIT BY THE END OF THE
WEEKEND.
AVIATION
FOR 18Z TAF ISSUANCE
ISSUED AT 1133 AM CST SUN FEB 1 2026
MVFR STATUS DECK IS JUST STARTING TO PUSH INTO C/NC WI EARLY LATE
THIS MORNING. CIGS HAVE BEEN VFR THROUGH THE MORNING BUT WILL LOWER
AS THIS STATUS DECK PUSHES EAST THIS AFTERNOON. ALONG AND JUST AHEAD
OF A COLD FRONT DRAPED ACROSS NE/C MN LIGHT SNOW IS IS CREATED
PERIODS OF MVFR/IFR VSBYS (1-3SM). AS THE FRONT SWEEPS ACROSS WI
THIS AFTERNOON EXPECT THESE VSBYS RESTRICTIONS WILL IMPACT ALL TAF
SITES AT TIMES. HAVE FRAMED OUT THE PERIODS WITH IFR VSBYS IN TEMPO
GROUPS AT ALL SITES. FOR AUW, CWA, AND RHI EXPECT THE GREATEST
IMPACTS BETWEEN 22-02Z. FOR THE EASTERN WI SITES ATW, GRB, AND MTW
THESE IMPACTS ARE EXPECTED BETWEEN 03-09Z. FOR GROUND OPERATIONS
DON'T EXPECT MUCH IN THE WAY OF ACCUMULATING SNOW AT ANY TERMINALS
WITH MOST SEEING A FEW TENTHS UP TO AROUND 1".
DOWNSLOPING NORTHWEST WINDS BEHIND THE FRONT SHOULD HELP SCATTER OUT
THE MVFR STATUS MONDAY MORNING ACROSS EASTERN WI, WHILE THE LOW
CLOUDS MAY LINGER LONGER ACROSS NORTHERN WI AS STRATUS CONTINUES TO
STREAM OFF LAKE SUPERIOR.
SOUTHERLY WINDS THIS AFTERNOON AHEAD OF THE FRONT WILL GUSTS 15-
20KTS AT TIMES. BEHINDS THE FRONT WINDS SHOULD START TO DIMINISH
TONIGHT WITH LIGHT WINDS EXPECTED MONDAY.
GRB WATCHES/WARNINGS/ADVISORIES
NONE.
UPDATE.........GK
DISCUSSION.....KIECKBUSCH
AVIATION.......GK
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