771
FXUS63 KGRB 211020
AFDGRB
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
520 AM CDT SAT MAR 21 2026
UPDATED AVIATION PORTION FOR 12Z 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 12Z TAF ISSUANCE
ISSUED AT 520 AM CDT SAT MAR 21 2026
HIGH CLOUDS STREAMING IN ACROSS THE REGION PREVENTED MUCH IN THE
WAY OF FOG FROM FORMING ACROSS THE TAF SITES EARLY THIS MORNING,
WITH ONLY A SMATTERING OF MVFR VSBYS NOTED. THERE IS A SLIGHT
CHANCE FOR RAIN OR SNOW ACROSS THE FAR NORTH THIS MORNING;
HOWEVER, THIS SHOULD REMAIN WELL NORTH OF KRHI. OTHERWISE, VFR
CONDITIONS ARE EXPECTED FOR THE REST OF TODAY.
A COLD FRONT WILL SINK SOUTH TONIGHT, BRINGING A SWATH OF LIGHT
RAIN AND MVFR/IFR CONDITIONS TO THE TAF SITES FROM NORTH TO
SOUTH. AS COLDER AIR FILTERS IN BEHIND THE COLD FRONT
PRECIPITATION MAY TRANSITION TO SNOW AT KRHI; HOWEVER, ANY
SNOWFALL AMOUNTS WOULD BE DE MINIMIS.
WINDS WILL GRADUALLY VEER TO SOUTH/SOUTHWESTERLY THROUGHOUT THE
DAY, PICKING UP SLIGHTLY THIS AFTERNOON. GUSTS BETWEEN 15 AND 20
KNOTS WILL BE POSSIBLE. LLWS WILL BECOME A CONCERN LATE THIS
MORNING AND AFTERNOON AS WINDS JUST OFF THE SURFACE INCREASE TO
AROUND 40 KNOTS OUT OF THE SOUTHWEST.
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.......KURIMSKI
HYDROLOGY......KURIMSKI
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