871
FXUS63 KGRB 280934
AFDGRB
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
434 AM CDT FRI MAR 28 2025
FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE
KEY MESSAGES
- FREEZING DRIZZLE OR LIGHT FREEZING RAIN COULD BRING ICY TRAVEL
TO NORTH-CENTRAL AND FAR NORTHEAST WISCONSIN THROUGH MID-MORNING.
- THERE IS A 20% CHANCE OF THUNDERSTORMS SOUTH OF TWO RIVERS THIS
MORNING, FOLLOWED BY A 25-50% CHANCE OF THUNDERSTORMS ACROSS THE
FORECAST AREA LATE THIS AFTERNOON AND EVENING. SOME OF THE
STRONGER STORMS COULD PRODUCE SMALL HAIL, ALTHOUGH A FEW REPORTS
OF LARGE HAIL ONE INCH OR GREATER CANNOT BE RULED OUT.
- A SIGNIFICANT ICE ACCUMULATION IS POSSIBLE ACROSS NORTH- CENTRAL
AND FAR NORTHEAST WISCONSIN SATURDAY NIGHT AND SUNDAY. THE
FREEZING RAIN COULD CREATE SIGNIFICANT DISRUPTIONS IN TRAVEL,
ALONG WITH DAMAGE TO TREES AND POWER OUTAGES. A WINTER STORM
WATCH HAS BEEN ISSUED WHERE ICE ACCUMULATIONS ARE LIKELY BE THE
GREATEST. THERE IS A 40-60% CHANCE THAT THE AREA BETWEEN WAUSAU
AND IRON MOUNTAIN WILL SEE AT LEAST 0.25" OF ICE ACCUMULATION
FROM SATURDAY NIGHT TO SUNDAY.
- PRECIPITATION TOTALS (QPF) ARE LIKELY (40-70%) TO BE GREATER
THAN 1 INCH THROUGHOUT THE EVENT, WHICH COULD LEAD TO FAST
FLOWS AND MINOR FLOODING ALONG THE SHORELINES OF AREA RIVERS AND
STREAMS NEXT WEEK.
DISCUSSION
ISSUED AT 434 AM CDT FRI MAR 28 2025
SHORT TERM...TODAY THROUGH SUNDAY NIGHT
A CLASSIC SETUP FOR A SIGNIFICANT ICE ACCUMULATION EVENT ACROSS
NORTH-CENTRAL AND FAR NORTHEAST WISCONSIN IS POSSIBLE SATURDAY
NIGHT AND SUNDAY. A 1030MB HIGH OVER HUDSON BAY WILL BE THE SOURCE
OF COLD DRY AIR FILTERING SOUTHWEST INTO THE WESTERN GREAT LAKES,
COMBINED WITH WARM AT ABOVE 0C AT 850MB WITH STRONG LOW LEVEL JET
OVERRUNNING THE SURFACE WARM FRONT. HISTORICALLY, SOME OF THE
MORE SIGNIFICANT ICE EVENTS ACROSS NORTHERN WISCONSIN HAVE
OCCURRED FROM MID MARCH TO EARLY APRIL.
WELL, THERE IS A LOT TO TALK ABOUT THIS MORNING. WILL START OUT
WITH SCATTERED THUNDERSTORMS THAT DEVELOPED ACROSS SOUTHWEST
WISCONSIN EARLY THIS MORNING. SOME OF THE STORMS COULD CLIP EAST-
CENTRAL WISCONSIN, MORE LIKELY SOUTH OF HIGHWAY 10. LOW WETBULB
ZERO HEIGHTS AROUND 8,000 FEET AND SURFACE TEMPERATURES AROUND 40
DEGREES WOULD SUPPORT SOME OF THE STORMS PRODUCING SMALL HAIL.
THE STORMS SHOULD EXIT THE AREA AROUND 15Z TODAY. OVER THE NORTH,
LOW CLOUDS HAVE DEVELOPED. ENOUGH LIFT IN THE ATMOSPHERE, COMBINED
WITH SHALLOW MOISTURE STILL SUPPORTS FREEZING DRIZZLE ACROSS THE
FAR NORTH FOR SEVERAL HOURS THIS MORNING THROUGH 15Z. SINCE
PRECIPITATION TOTALS WILL BE ON THE LIGHT SIDE, AND FORECAST ROAD
TEMPERATURES ONLY DROPPING TO NEAR FREEZING, IT WAS ELECTED TO
COVER THIS SCENARIO WITH A SPECIAL WEATHER STATEMENT SINCE THE
IMPACTS ARE NOT EXPECTED TO BE SIGNIFICANT.
FOR TODAY, A WARM FRONT IS GOING TO MOVE INTO OUR FAR SOUTHERN
COUNTIES LATER THIS AFTERNOON INTO THIS EVENING, BEFORE PUSHING
SOUTHWARD AS A COLD FRONT AFTER MIDNIGHT. HIGH TEMPERATURES WILL
BE IN THE MIDDLE TO UPPER 30S OVER FAR NORTHEAST WISCONSIN TO THE
LOWER TO MIDDLE 60S IN CENTRAL AND EAST-CENTRAL WISCONSIN. IT WILL
BE IN THE 70S TO AROUND 80 ACROSS SOUTHERN WISCONSIN, SO CLOSE!
CONFIDENCE IN THE 60S IS LOW AS WARM FRONTS HAVE A TENDENCY TO NOT
MOVE AS FAR NORTH AS THE MODELS WOULD INDICATE THIS TIME OF YEAR.
FOR LATE THIS AFTERNOON INTO THIS EVENING, THERE IS A CHANCE OF
THUNDERSTORMS. COOL AIR MASS AT THE SURFACE COMBINED WITH LOW
WETBULB ZERO HEIGHTS WOULD SUPPORT SOME STORMS PRODUCING SMALL
HAIL, EVEN A FEW ONE INCH HAIL STONES CAN'T BE RULED OUT.
LATER TONIGHT, ONGOING PRECIPITATION COULD CHANGE OVER TO FREEZING
RAIN ACROSS THE FAR NORTH, GENERALLY BETWEEN 08Z-14Z. SINCE THERE
WAS DIFFERENCES IN THE MODEL QPF, AND HOW MUCH QPF WOULD REMAIN
ONCE THE COLDER TEMPERATURES ARRIVES, DECIDED TO HOLD OFF ON A
WINTER WEATHER ADVISORY FOR NOW. IF THERE IS ENOUGH QPF ONCE
THE AIR TEMPERATURES HIT FREEZING, THERE MAY BE A NEED FOR A
SHORT FUSED WINTER WEATHER ADVISORY. LATER SATURDAY MORNING, THERE
WILL BE A BREAK IN THE PRECIPITATION ACROSS THE NORTH UNTIL THE
MAIN SYSTEM ARRIVES LATE SATURDAY AFTERNOON OR EARLY SATURDAY
EVENING.
ATTENTION THEN TURNS TO THE POTENTIAL FOR A SIGNIFICANT ICE
ACCUMULATION EVENING. THE HIGHEST CONFIDENCE IN REACHING 0.25
INCHES IS BETWEEN WAUSAU AND SHAWANO TO NEAR IRON MOUNTAIN. OVER
FAR NORTH-CENTRAL WISCONSIN, A LITTLE BIT LOWER CONFIDENCE IN ICE
ACCUMULATIONS AS ONCE THE HEAVIER PRECIPITATION ARRIVES IT COULD
CHANGE OVER TO ALL SNOW (CONCRETE TYPE) FOR SEVERAL HOURS. FOR THE
MOMENT, ICE ACCUMULATIONS BETWEEN 0.10 TO 0.40 INCHES IS
EXPECTED. WITH INCREASING NORTHEAST WINDS USHERING THE COLDER DRY
AIR SHOULD CAUSE TEMPERATURES TO STRUGGLE ON SUNDAY. DID LOWER
HOURLY TEMPERATURES SATURDAY NIGHT AND SUNDAY, WHICH RESULTED IN
THE HIGHER ICE ACCUMULATIONS. FOR CENTRAL WISCONSIN INTO THE FOX
VALLEY, TEMPERATURES MAY ONLY BE A FEW DEGREES ABOVE FREEZING
SUNDAY MORNING, THUS WILL NEED TO LOOK AT LATER MODEL RUNS TO SEE
IF WINTER HEADLINES NEED TO BE EXPANDED SOUTH AND EAST. BUFKIT
SOUNDINGS INDICATED SEVERAL HOURS OF SLEET AND FREEZING RAIN
SUNDAY EVENING TO SUPPORT THE EXPANSION OF HEADLINES DOWN THE
ROAD.
THE LATEST PROBABILITIES:
THERE IS A 20 PERCENT CHANCE OF THUNDERSTORMS SOUTH OF TWO RIVERS
THIS MORNING. THERE IS A 25-50% CHANCE OF THUNDERSTORMS ACROSS
THE REGION FROM LATE THIS AFTERNOON AND EVENING. SOME OF THE
STRONGER STORMS COULD PRODUCE SMALL HAIL, ALTHOUGH A FEW REPORTS
OF LARGE HAIL ONE INCH OR GREATER CAN NOT BE RULED OUT. THERE IS
A 40-70% CHANCE OF PRECIPITATION TOTALS OVER AN INCH, AND 10-30%
CHANCE OVER TWO INCHES ACROSS NORTHEAST WISCONSIN THROUGH SUNDAY
NIGHT. THE WIDESPREAD PRECIPITATION COULD LEAD TO FAST FLOWS AND
MINOR FLOODING ALONG THE SHORELINES OF AREA RIVERS AND STREAMS
NEXT WEEK.
LONG TERM...MONDAY THROUGH THURSDAY
WEATHER CONDITIONS ACROSS CENTRAL AND NORTHEAST WISCONSIN QUIET
DOWN FOR THE SECOND HALF OF MONDAY AS THE WEEKEND SYSTEM DEPARTS.
HIGH PRESSURE RIDGE ALLOWS FOR QUIET WEATHER FOR MOST OF TUESDAY,
FOLLOWED BY ANOTHER SYSTEM APPROACHING TUESDAY NIGHT.
TIMING AND TRACK DIFFERENCES ARISE WHICH IMPACT THE MORE SPECIFIC
PRECIP TYPES AND TIMING FOR THE LOCAL AREA. GENERAL CONSENSUS
SHOWS LEADING WARM ADVECTION COULD INITIATE PRECIP TUESDAY NIGHT,
FOLLOWED BY UPPER TROUGH, SHORTWAVE, AND SURFACE LOW WHICH WILL
ALL ACT TO SUSTAIN LIFT/PRECIP THROUGHOUT WEDNESDAY. PTYPES ONCE
AGAIN LOOK COMPLEX AND THERE WILL LIKELY BE MULTIPLE TRANSITIONS
BETWEEN PTYPES. SOME THUNDERSTORMS WOULDN'T BE OUT OF THE QUESTION
WEDNESDAY, WITH SNOW ALSO IN THE MIX, ESPECIALLY DURING THE
NIGHTS. EVENT TOTAL SNOW PROBABILITIES RANGE FROM 30-75% FOR AT
LEAST 3" OF SNOW ACROSS THE FORECAST AREA; AND 20-45% FOR AT LEAST
6" OF SNOW, MAKING IMPACTFUL WINTRY ROAD CONDITIONS POSSIBLE.
ALTHOUGH SIMILAR TO THE MODELS, HAVE LOWER CONFIDENCE IN
PROBABILITY DATA THIS FAR OUT.
TEMPERATURES WILL BE BELOW NORMAL MONDAY AND TUESDAY, AND AT AT OR
SLIGHT ABOVE NORMAL FROM WEDNESDAY THROUGH FRIDAY.
AVIATION
FOR 06Z TAF ISSUANCE
ISSUED AT 1008 PM CDT THU MAR 27 2025
AS A WARM FRONT LIFTS NORTH INTO THE SOUTHERN GREAT LAKES LATE
TONIGHT AND FRIDAY MORNING, EXPECT CEILINGS TO DETERIORATE FROM
SOUTH TO NORTH INTO IFR/LIFR RANGE. AS SATURATION DEEPENS BELOW
7000 FT, THE CHANCE OF DRIZZLE AND LIGHT SHOWERS WILL INCREASE
GENERALLY TOWARD 12Z. WITH DRIZZLE CHANCES INCREASING, THE
PROBABILITY OF VISIBILITIES LOWERING TO MVFR WILL INCREASE TOWARD
12Z.
AS DRIZZLE BECOMES MORE WIDESPREAD, TEMPERATURES WILL BE NEAR OR
BELOW FREEZING OVER NORTH-CENTRAL AND FAR NORTHEAST WISCONSIN.
LIGHT ICING WILL BE POSSIBLE PRIOR TO 14-15Z AS PAVEMENT
TEMPERATURES WARM ABOVE 40 DEGREES AND AIR TEMPERATURES APPROACH
THE FREEZING MARK. THEREAFTER, TEMPERATURES SHOULD WARM SLIGHTLY
ABOVE FREEZING LIMITING POTENTIAL ICING. THERE SEEMS TO BE
INCREASING CHANCE (20-30 PERCENT) THAT THUNDER COULD IMPACT THE
AREA FROM SOUTHWEST TO NORTHEAST ON FRIDAY MORNING, MAINLY 12-15Z.
GREATEST RISK FOR THIS IS ACROSS THE FOX VALLEY TO EAST-CENTRAL
WI (ATW, GRB AND MTW). HAVE INCLUDED A PROB30 GROUP AT THESE SITES
TO COVER THE POTENTIAL.
LITTLE TO NO IMPROVEMENTS IN CEILINGS ARE LIKELY THROUGH FRIDAY
MORNING, BUT SLIGHT IMPROVEMENTS SHOULD OCCUR BY LATE AFTERNOON
INTO EARLY EVENING OVER CENTRAL AND EAST-CENTRAL WI AS THE WARM
FRONT LIFTS NORTH. LIGHT RAIN OVER THE NORTH WILL TRANSITION TO
SHOWERS CLOSER TO THE WARM FRONT BY FRIDAY EVENING. GREATEST RISK
OF ADDITIONAL THUNDERSTORMS FRIDAY EVENING WILL BE ACROSS THE FAR
NORTH.
GRB WATCHES/WARNINGS/ADVISORIES
WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING
FOR WIZ005-010>013-018>021-030-031-073.
DISCUSSION.....ECKBERG/KLJ
AVIATION.......JLA
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