928
FXUS63 KGRB 211812
AFDGRB
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
112 PM CDT SAT MAR 21 2026
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
KEY MESSAGES
- SNOWMELT WILL CAUSE INCREASED FLOWS AND RISING LEVELS ON RIVERS
AND STREAMS. SEVERAL RIVERS MAY REACH BANKFULL OR EVEN MINOR
FLOOD STAGE BEGINNING THIS WEEKEND.
- RAIN (30-50% CHANCE) TONIGHT INTO SUNDAY MORNING. RAIN MAY
BRIEFLY MIX WITH SNOW OR SLEET BEFORE ENDING, BUT LITTLE OR NO
ACCUMULATION IS EXPECTED.
- WELL ABOVE NORMAL TEMPERATURES EXPECTED TODAY, ESPECIALLY IN
CENTRAL WISCONSIN, WHERE HIGHS COULD REACH WELL INTO THE 60S AND
POSSIBLY 70 (20-40% CHANCE). MILD READINGS INTO THE 50S ARE
ALSO ANTICIPATED NEXT TUESDAY AND THURSDAY.
- A WINTRY MIX OF PRECIPITATION POSSIBLE DURING THE MIDDLE OF
NEXT WEEK, ESPECIALLY WEDNESDAY INTO THURSDAY.
DISCUSSION
ISSUED AT 1255 AM CDT SAT MAR 21 2026
SOME PATCHY FOG AND STRATUS WILL IMPACT THE REGION THIS MORNING
WITH LIGHT WINDS AND LOW-LEVEL MOISTURE FROM MELTING SNOW. ONCE
THE FOG DISSIPATES, THERE WILL BE A SMALL (10-30%) CHANCE FOR
RAIN OR FREEZING RAIN THIS MORNING IN RESPONSE TO ISENTROPIC LIFT
IN A MOISTURE STARVED AIR MASS.
TODAY WILL LIKELY BE THE WARMEST DAY OF THE WEEK AS AN
APPROACHING LOW PRESSURE SYSTEM FROM THE NORTHERN PLAINS BRINGS A
WARM FRONT AND ASSOCIATED SURGE OF VERY MILD AIR INTO THE FORECAST
AREA. THIS WARMTH WILL PRIMARILY BE FELT IN CENTRAL WISCONSIN,
WHERE THERE IS A 60-80% CHANCE OF HIGHS GREATER THAN 65 DEGREES
AND A 20-40% CHANCE OF HIGHS HITTING 70 DEGREES ACROSS THE FAR
SOUTHWEST CORNER OF THE REGION. FARTHER NORTH AND EAST, A
COMBINATION OF LOW CLOUDS (NORTH OF THE WARM FRONT) AND SE-S WINDS
OFF LAKE MICHIGAN WILL KEEP READINGS IN THE 40S AND 50S.
AS THE LOW SHIFTS EAST, A COLD FRONT WILL SWEEP THROUGH THE
FORECAST AREA DURING THE LATE AFTERNOON/EVENING. MODELS SHOW
STRONG MID-LEVEL FGEN FORCING WITH THIS SYSTEM, WHICH SHOULD
BRING A BAND OF LIGHT RAIN THROUGH THE AREA TONIGHT INTO EARLY
SUNDAY. THIS BAND SHOULD SAG SOUTHEAST WITH TIME, WITH THE LAGGING
INFLUX OF COLDER AIR ONLY LEADING TO A BRIEF PERIOD OF MIXED
PRECIPITATION (MAINLY SLEET/SNOW) ON THE NORTHWEST PERIPHERY OF
THE PRECIPITATION BAND. THEREFORE, NOT EXPECTING MUCH (IF ANY)
SNOW ACCUMULATION. MOST OF THE PRECIPITATION SHOULD BE GONE BY
SUNDAY AFTERNOON.
HIGH PRESSURE WILL THEN PROVIDE MAINLY DRY WEATHER AND MORE
SEASONABLE TEMPERATURES FROM SUNDAY AFTERNOON THROUGH MONDAY
NIGHT. ANOTHER CLIPPER SYSTEM WILL MOVE THROUGH DURING THE MIDDLE
OF NEXT WEEK. THIS SYSTEM LOOKS FAIRLY SIMILAR TO THIS WEEKEND'S
SYSTEM, WITH POTENTIAL FOR A LIGHT MIX OF RAIN/SNOW, ESPECIALLY
WEDNESDAY INTO THURSDAY. MILD DAYS OCCUR AHEAD OF THE CLIPPER ON
TUESDAY, AND WITHIN A DRY SLOT ON THURSDAY, WITH POTENTIAL FOR
50S BOTH DAYS.
AVIATION
FOR 18Z TAF ISSUANCE
ISSUED AT 1258 PM CDT SAT MAR 21 2026
SHOWERS WERE ENDING IN FAR NE WI AND MID-LEVEL CLOUDS WERE
RAPIDLY ERODING FROM WEST TO EAST EARLY THIS AFTERNOON.
LOW STRATUS STILL COVERED PARTS OF FAR NE WI, BUT THIS SHOULD
MIX OUT DUE TO DAYTIME HEATING AND WIND WITHIN A COUPLE HOURS.
GUSTY S-SW WINDS WILL INCREASE THIS AFTERNOON, THEN DIMINISH BY
SUNSET. AREAS OF LLWS WILL OCCUR IN SPOTS, ESPECIALLY AT RHI, GRB,
ATW AND MTW, THEN DIMINISH BY EARLY EVENING.
QUIET WEATHER WILL PREVAIL THIS AFTERNOON AND EARLY EVENING. A
COLD FRONT WILL SINK SOUTH TONIGHT, BRINGING MVFR/IFR STRATUS.
A BAND OF LIGHT RAIN MIXED WITH SLEET WILL DEVELOP BEHIND THE
FRONT AND SHIFT SOUTH THROUGH EARLY SUNDAY. THE PRECIPITATION
SHOULD START SHORTLY BEFORE MIDNIGHT IN THE FAR NORTH, AND EXIT
THE FAR SOUTH BY MID-MORNING SUNDAY. BRISK NORTH WINDS WILL ALSO
DEVELOP IN THE WAKE OF THE FRONT, WITH GUSTS REACHING 20 TO 25 KTS
LATE TONIGHT INTO SUNDAY MORNING.
EXPECT CEILINGS TO GRADUALLY RISE SUNDAY MORNING, THOUGH MOST
PLACES SHOULD REMAIN IN THE MVFR CATEGORY THROUGH 18Z.
HYDROLOGY
ISSUED AT 1255 AM CDT SAT MAR 21 2026
AS TEMPERATURES WARM ACROSS THE REGION, THE SNOWMELT WILL RESULT
IN INCREASING FLOWS AND RISING RIVER LEVELS. SOME RIVERS COULD
REACH BANKFULL OR EVEN MINOR FLOOD STAGE STARTING THIS WEEKEND.
THE LACK OF A PROLONGED SIGNIFICANT WARMUP POINTS TO A MORE
GRADUAL RISE IN AREA RIVERS AS OPPOSED TO WIDESPREAD RAPID RISE
FLOODING. THAT BEING SAID, THE FLOODING SITUATION WILL BE
MONITORED CLOSELY GIVEN HOW MUCH WATER IS LOCKED UP IN THE
CURRENT SNOWPACK ACROSS THE REGION. MODELED SNOWPACK TEMPERATURE
FROM THE NOHRSC SITE POINTS TO WIDESPREAD RIPENING OF THE
SNOWPACK (AND HIGHER SUSCEPTIBILITY OF MELTING/RUNOFF) OVER THE
AREA TODAY.
GRB WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION.....KURIMSKI
AVIATION.......KIECKBUSCH
HYDROLOGY......KURIMSKI
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