504  
FXUS63 KGRB 091151  
AFDGRB  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GREEN BAY WI  
651 AM CDT THU APR 9 2026  
 
UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE  
   
KEY MESSAGES  
 
- ASIDE FROM LIGHT RAIN ACROSS THE THE SOUTH HALF OF THE FORECAST  
AREA TONIGHT, GENERALLY DRY CONDITIONS ARE ANTICIPATED THROUGH  
SATURDAY.  
 
- PERIODS OF HEAVY RAINFALL AND THUNDERSTORMS EXPECTED LATE THIS  
WEEKEND THROUGH THE MIDDLE OF NEXT WEEK. 1.5 TO 2" OF RAINFALL  
EXPECTED, WITH LOCALLY HIGHER AMOUNTS POSSIBLE. STRONG OR SEVERE  
THUNDERSTORMS POSSIBLE MONDAY AFTERNOON AND EVENING.  
 
- MINOR FLOODING CONTINUES ALONG THE WOLF RIVER, THOUGH RUNOFF  
FROM MELTING SNOW IN THE UPPER PENINSULA PAIRED WITH HEAVY RAIN  
MAY RESULT IN MORE WIDESPREAD AND SIGNIFICANT FLOODING LATE THIS  
WEEKEND INTO NEXT WEEK.  
 
 
   
DISCUSSION  
 
ISSUED AT 249 AM CDT THU APR 9 2026  
 
THE LAST REMNANTS OF THE FRONTAL BAND OF RAIN WAS EXITING EAST  
CENTRAL WI EARLY THIS MORNING, FOLLOWED BY CLEARING SKIES OVER  
MOST OF THE REGION. AN UPPER LOW WAS MOVING THROUGH SOUTHERN  
ONTARIO, AND CAA AND SUBSIDENCE ON THE SOUTH FLANK OF THIS SYSTEM  
WAS GENERATING GUSTY WEST WINDS OVER NORTHERN MN AND NORTHWEST  
WI.  
 
WEST WINDS GUSTING TO 25 TO 30 MPH CAN BE EXPECTED TODAY DUE TO  
SUBSIDENCE AND DAYTIME MIXING. LOW CLOUDS WILL MOVE INTO THE  
NORTHWEST PART OF THE FORECAST AREA, BUT THE REST OF THE AREA  
SHOULD SEE PERIODS OF SUNSHINE. HIGHS WILL BE IN THE 40S  
NORTHWEST AND OVER DOOR COUNTY, AND 50S ELSEWHERE.  
 
LOW PRESSURE TRACKS SOUTH OF THE REGION TONIGHT, BUT STRONG  
MID-LEVEL FGEN BRINGS LIGHT RAIN TO MAINLY CENTRAL AND EAST  
CENTRAL WI. SOME MODELS SHOW MEASURABLE PRECIPITATION AS FAR NORTH  
AS NORTHERN WI, BUT DRIER AIR SHOULD LIMIT THIS TO SPRINKLES OR  
FLURRIES. LOWS RANGE FROM THE MIDDLE TO UPPER 20S NORTHWEST TO THE  
MIDDLE TO UPPER 30S SOUTHEAST.  
 
HIGH PRESSURE BRINGS DRY WEATHER FRIDAY INTO SATURDAY MORNING,  
WITH A SMALL CHANCE OF SHOWERS ARRIVING IN NC/C WI LATER SATURDAY  
AFTERNOON.  
 
A PROLONGED PERIOD OF ACTIVE WEATHER ARRIVES SATURDAY NIGHT INTO  
SUNDAY AND CONTINUES THROUGH THE MIDDLE OF NEXT WEEK. PERIODIC  
SHOWERS AND THUNDERSTORMS, AND POTENTIAL FOR HEAVY RAINFALL, CAN  
BE EXPECTED THROUGH THE PERIOD. THE RAIN WILL BE FOCUSED ALONG A  
FRONTAL BOUNDARY THAT LIFTS NORTH AS A WARM FRONT LATE SATURDAY  
NIGHT INTO SUNDAY, SHIFTS BACK SOUTH AND STALLS ACROSS THE AREA  
MONDAY INTO TUESDAY, AND POTENTIALLY LIFTS BACK TO THE NORTH AS A  
STRONG LOW PRESSURE SYSTEM APPROACHES TUESDAY NIGHT INTO WEDNESDAY.  
THIS FRONT WILL INTERACT WITH A PERSISTENT FLOW OF GULF MOISTURE  
AND MARGINAL TO MODERATE INSTABILITY. INSTABILITY PEAKS ACROSS  
THE SOUTHWEST HALF OF THE FORECAST AREA MONDAY AFTERNOON AND  
EVENING, AS CAPE INCREASES TO 1-2K J/KG. THIS MODERATE  
INSTABILITY, COMBINED WITH THE FRONTAL BOUNDARY AND DEEP LAYER  
SHEAR OF 35-50 KNOTS, COULD LEAD TO A PERIOD OF STRONG TO SEVERE  
STORMS. ADDITIONAL SEVERE POTENTIAL COULD OCCUR ON WEDNESDAY,  
DEPENDING ON THE TRACK OF THE SURFACE LOW. SEE THE HYDROLOGY  
SECTION FOR POSSIBLE FLOODING IMPACTS.  
 
MILDER TEMPERATURES ARE EXPECTED THROUGH THE PERIOD, WITH HIGHS  
REACHING INTO THE 70S IN PARTS OF THE AREA SUNDAY AND MONDAY.  
 
 
   
AVIATION  
FOR 12Z TAF ISSUANCE  
ISSUED AT 645 AM CDT THU APR 9 2026  
 
BKN STRATOCUMULUS CLOUDS WILL IMPACT MAINLY THE WESTERN TAF SITES  
WITH CEILINGS BETWEEN 2500-4000 FT AGL THROUGH LATE MORNING, THEN  
CEILINGS SHOULD RISE TO VFR ONLY. CLOUDS WILL INCREASE REGIONWIDE  
LATER THIS AFTERNOON AND EVENING, WITH FRONTOGENETIC FORCING  
AIDING IN LIGHT PRECIPITATION DEVELOPMENT DURING THE LATER EVENING  
AND OVERNIGHT HOURS. MOST OF THE PRECIPITATION WILL FALL AS RAIN  
ACROSS CENTRAL AND EAST CENTRAL WI, BUT SOME SPRINKLES AND  
FLURRIES MAY MOVE THROUGH PARTS OF NORTHERN WI FOR A FEW HOURS.  
 
GUSTY WEST WINDS WILL IMPACT THE AREA THIS MORNING, THEN GRADUALLY  
DIMINISH LATER TODAY INTO TONIGHT.  
 
   
HYDROLOGY  
 
ISSUED AT 249 AM CDT THU APR 9 2026  
 
MINOR FLOODING CONTINUES ON THE WOLF RIVER EARLY THIS MORNING.  
A MAINLY DRY PERIOD IS ANTICIPATED THROUGH SATURDAY, WITH THE  
EXCEPTION OF LIGHT RAIN OVER PARTS OF CENTRAL AND EAST CENTRAL WI  
TONIGHT. PERIODS OF HEAVY RAIN AND THUNDERSTORMS ARRIVE LATER IN  
THE WEEKEND AND CONTINUE THROUGH THE MIDDLE OF NEXT WEEK.  
DURING THIS UPCOMING PERIOD, PROBABILITIES FOR RAINFALL IN EXCESS  
OF 1 INCH ARE 80-90%, WITH A 30-50% CHANCE OF AMOUNTS IN EXCESS  
OF 2 INCHES AND A 5-15% CHANCE OF 3 INCHES OR MORE. CURRENT  
FORECASTS CALL FOR 1.5 TO 2 INCHES IN MOST AREAS. RUNOFF FROM  
THIS RAINFALL, COMBINED WITH RAPID SNOWMELT IN THE UPPER  
PENINSULA AND FAR NORTHERN WI, IS EXPECTED TO BRING POTENTIAL FOR  
MORE WIDESPREAD AND SIGNIFICANT FLOODING HEADING INTO THE EARLY  
TO MIDDLE PART OF NEXT WEEK. RIGHT NOW, IT APPEARS THE MOST  
SIGNIFICANT FLOODING IMPACTS MAY OCCUR ON THE MENOMINEE RIVER AND  
ITS TRIBUTARIES.  
 
 
   
GRB WATCHES/WARNINGS/ADVISORIES  
 
NONE.  
 
 
 
 
 
DISCUSSION.....KIECKBUSCH  
AVIATION.......KIECKBUSCH  
HYDROLOGY......KIECKBUSCH  
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