582
FXUS63 KGRB 300619
AFDGRB
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
119 AM CDT THU APR 30 2026
FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE
KEY MESSAGES
- ANOTHER ROUND OF RAIN SHOWERS TODAY, MIXED WITH SNOW NORTH.
SMALL CHANCE OF SHOWERS ON FRIDAY. DRY SATURDAY, THEN CHANCES
FOR MORE SHOWERS SUNDAY INTO NEXT WEEK.
- FROST ADVISORY FOR CENTRAL WI TO THE WESTERN FOX VALLEY EARLY
THIS MORNING. ADDITIONAL FROST AND FREEZE HEADLINES EXPECTED
OVER CENTRAL AND EAST CENTRAL WI TONIGHT. FREEZE LOOKING LIKELY
FOR MUCH OF THE AREA FRIDAY NIGHT.
- MINOR FLOODING LINGERS ON THE WOLF RIVER AND WINNEBAGO SYSTEM.
WATER LEVELS WILL SLOWLY RECEDE GIVEN LACK OF SIGNIFICANT
RAINFALL.
- BELOW NORMAL TEMPERATURES EXPECTED THROUGH MOST OF THE PERIOD.
DISCUSSION
ISSUED AT 116 AM CDT THU APR 30 2026
NEAR TERM THROUGH TONIGHT...SHOWERS HAVE EXITED EARLY THIS
MORNING. PATCHES OF STRATOCU CLOUDS WILL LEAD TO VARIABLE TEMPS
EARLY THIS MORNING, BUT WITH TEMPS IN THE MID TO UPPER 30S, SOME
FROST IS EXPECTED WHERE SKIES CAN CLEAR. ATTENTION IS ON SHORTWAVE
NORTH OF LAKE SUPERIOR IN GENERAL TROUGHING. EXPECT THIS WAVE TO
DIP OVER WESTERN GREAT LAKES BY THIS AFTERNOON, RESULTING IN
ANOTHER ROUND OF SHOWERS FROM MID MORNING THROUGH EARLY EVENING.
COLDER ALOFT THIS TIME AROUND, WITH H85 TEMPS OVER NORTHERN WI
BOTTOMING OUT AROUND -5C. SOUNDINGS THERE LOOK TO SUPPORT SNOW
AND/OR GRAUPEL MORE THAN RAIN. A SMATTERING OF RAIN/SNOW OR JUST
SNOW SHOWERS SEEN IN MUCH OF THE HIGH-RES GUIDANCE ESPECIALLY
NORTH. SFC TEMPS, GROUND TEMPS APPEAR TOO WARM AND SNOWFALL RATES
TOO LOW TO LEAD TO ANY ACCUMULATION ON THE GROUND, BUT SNOW IN THE
AIR IS LIKELY FROM RHINELANDER NORTHWARD.
ONCE SHOWERS END THIS EVENING, ANOTHER CHILLY NIGHT IS IN STORE,
BUT SIMILAR TO EARLY THIS MORNING, BASED ON UPSTREAM OBS AND HREF
GUIDANCE, THERE WILL BE A FAIR AMOUNT OF STRATOCU TO MODULATE
TEMPS. NEVERTHELESS, FROST/FREEZE HEADLINES WILL BE NEEDED IN SOME
SHAPE OR FORM AGAIN. WITH CURRENT HEADLINES OUT FOR EARLY THIS
MORNING, WILL LET DAYSHIFT ISSUE THE NEW SET OF HEADLINES.
PRECIPITATION CHANCES BEYOND TODAY: ONE LAST SHORTWAVE SET TO DROP
ACROSS ON FRIDAY. WITH A NOD TO PERSISTENCE AND SINCE SOME MODELS
ARE SHOWING AT LEAST LIGHT QPF, OPTED TO ADD SOME SLIGHT CHANCES
FOR SHOWERS. PTYPE LOOKING MAINLY LIKE RAIN AS COLDER AIR ALOFT
DOES EASE. DECENT SIGNAL WE SNEAK IN AT LEAST ONE DRY DAY SATURDAY
WITH WEAK RIDGING ALOFT AND SINCE THE AREA WILL BE WELL DOWNSTREAM
OF STRONGER SHORTWAVE/SFC TROUGH WORKING ACROSS SOUTH CENTRAL
CANADA AND NORTHERN PLAINS. AS THAT SYSTEM ARRIVES FOR SUNDAY,
EXPECT RENEWED CHANCE FOR SHOWERS. MUCAPES UP TO 300-400J/KG WITH
PLUME OF MID-LEVEL LAPSE RATES OVER 7C/KM SUPPORT SLIGHT CHANCE
OF THUNDER. STRONGER TROUGH CROSSES MONDAY SO CHANCES FOR SHOWERS
CONTINUE. BETTER THUNDER CHANCES MAY BE SOUTH AND EAST OF THE AREA
BY THAT TIME FOLLOWING THE PLUME OF STEEPER MID-LEVEL LAPSE
RATES. STILL SOME UNCERTAINTY ON THOSE DETAILS THOUGH. UNSETTLED
WEATHER TO CLOSE OUT THE REST OF THE FORECAST AS WE RETURN TO A
REGIME SIMILAR TO WHAT WE ARE SEEING AT PRESENT WITH NORTHWEST
FLOW ALOFT AND SHORTWAVES RIDING ACROSS THE AREA.
FROST/FREEZE HEADLINES: SFC RIDGE OVERHEAD WITH LESS TROUGHING
ALOFT WILL PROMOTE BETTER CHANCE OF CLEARING AND LIGHT WINDS
FRIDAY NIGHT. EXPECT WIDESPREAD TEMPS AT OR BELOW FREEZING. THUS,
A WIDESPREAD FREEZE IS LOOKING LIKELY. RECENT LREF RUNS POINT TO
OVER 90% CHANCE OF SEEING TEMPS LESS THAN 32, EVEN INTO THE FOX
VALLEY, WITH A 50-80% CHANCE OF SEEING TEMPS LESS THAN 28 FOR
PORTIONS OF CENTRAL WI. BEYOND FRIDAY NIGHT, CHANCES OF TEMPS LESS
THAN 32 DECREASE MARKEDLY AS WE GET BACK INTO A RETURN FLOW
PATTERN REST OF THE WEEKEND INTO EARLY NEXT WEEK.
TEMPERATURES: NORTHWEST FLOW OF CANADIAN AIR KEEPS TEMPERATURES
BELOW NORMAL THROUGH SATURDAY. FOR REFERENCE, NORMAL HIGHS ARE NOW
IN THE UPPER 50S TO AROUND 60. SOME MODERATION IN TEMPERATURES (TO
NEAR NORMAL) SHOULD OCCUR SUNDAY AND/OR MONDAY AHEAD OF COLD
FRONTS THAT MOVE THROUGH, BUT REINFORCING SHOTS OF CANADIAN AIR
WILL FOLLOW, LEADING TO COOLER THAN NORMAL TEMPS MUCH OF NEXT
WEEK. PER CPC DAYS 6-10/8-14 DAY OUTLOOKS, APPEARS THIS COOLER
PATTERN WILL PERSIST THROUGH AT LEAST MID MAY.
AVIATION
FOR 06Z TAF ISSUANCE
ISSUED AT 949 PM CDT WED APR 29 2026
LIGHT RAIN WILL CONTINUE TO LINGER OVER FAR EASTERN WI THROUGH ABOUT
4Z BEFORE MOVING OUT OVER LAKE MICHIGAN. BRIEF DROPS TO MVFR VSBYS
ARE POSSIBLE AT GRB AND MTW, BUT GENERALLY VFR CONDITIONS WILL
PREVAIL TONIGHT. WEST OF A OSH TO IMT LINE CLOUDS ARE RISING AND
SCATTERING OUT AS DRIER AIR FILLS IN BEHIND THE DEPARTING SHORT-
WAVE. BKN TO OVC CIGS BASED AROUND 4-6KFT WILL REDEVELOP OVER THE
REGION TONIGHT. THURSDAY ANOTHER SHORT- WAVE WILL SWING THROUGH
THE REGION BRINGING ANOTHER ROUND OF LIGHT SHOWERS TO MUCH OF
REGION DURING THE LATE MORNING THROUGH THE EARLY EVENING. AT TIMES
SNOW MAY MIX IN WITH THE RAIN ACROSS NORTHER WI, MAINLY IMPACTING
RHI. SIMILAR TO TODAY CIGS/VSBYS SHOULD REMAIN VFR MUCH OF THE
DAY, HOWEVER, PERIODS OF MVFR CONDITIONS ARE POSSIBLE AS SHOWERS
MOVE OVER ANY TERMINAL.
GRB WATCHES/WARNINGS/ADVISORIES
FROST ADVISORY UNTIL 8 AM CDT THIS MORNING FOR WIZ030-031-
035>038-045-048.
DISCUSSION.....JLA
AVIATION.......GK
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