953  
FXUS63 KGRB 302140  
AFDGRB  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GREEN BAY WI  
440 PM CDT SUN MAR 30 2025  
 
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE  
   
KEY MESSAGES  
 
- RAIN/FREEZING RAIN WILL TRANSITION TO SNOW FROM NORTHWEST TO  
SOUTHEAST THIS AFTERNOON INTO TONIGHT. ADDITIONAL ICE  
ACCUMULATIONS UP TO 0.25 INCHES IS ANTICIPATED ACROSS THE  
NORTHWOODS THROUGH EARLY THIS EVENING BEFORE TRANSITIONING TO  
SNOW. SNOW ACCUMULATIONS OF 1 TO 4 INCHES IS FORECAST FOR  
LOCATIONS NORTH AND WEST OF THE FOX VALLEY. UP TO 1 INCH OF SNOW  
AND A LIGHT GLAZE OF ICE IS FORECAST FOR LOCATIONS IN THE FOX  
VALLEY AND LAKESHORE AREAS. ADDITIONAL POWER OUTAGES AND TREE  
LIMB DAMAGE IS ANTICIPATED FOR LOCATIONS MAINLY ACROSS THE  
NORTHWOODS DUE TO THE RECENT ICING, WET SNOW, AND GUSTY WINDS  
EXPECTED THROUGH TONIGHT.  
 
- THE RECENT, ONGOING, AND ANY ADDITIONAL WIDESPREAD  
RAINFALL/PRECIPITATION THIS WEEK WILL LEAD TO RISING RIVER AND  
STREAM LEVELS AND MINOR FLOODING FOR SOME LOCATIONS.  
 
- ANOTHER IMPACTFUL PERIOD OF PRECIPITATION IS LIKELY TUESDAY INTO  
WEDNESDAY WITH POTENTIAL FOR ACCUMULATING SNOWFALL, RAINFALL,  
AND THUNDERSTORMS.  
 
 
   
DISCUSSION  
 
ISSUED AT 440 PM CDT SUN MAR 30 2025  
 
SHORT TERM...TONIGHT AND MONDAY  
 
THE ONGOING WINTRY PRECIPITATION ASSOCIATED WITH A LOW PRESSURE  
SYSTEM MOVING ACROSS THE MIDWEST REMAINS TO BE THE MAIN FOCUS FROM  
THIS FORECAST PERIOD.  
 
THIS EVENING THROUGH MONDAY MORNING...AS OF THIS AFTERNOON, THE  
SURFACE LOW PRESSURE SYSTEM WAS LOCATED OVER SOUTHERN LAKE MI AND  
SLOWLY TRACKING NORTHEAST. MEANWHILE, THE DEFORMATION ZONE AND AREAS  
OF F-GEN WERE BEGINNING TO SET UP OVER NORTHERN WI. THIS COINCIDED  
WITH A LARGE BAND OF PRECIPITATION OVER THE NORTHWOODS PRODUCING  
RAIN, FREEZING RAIN, SLEET, AND SNOW. ANOTHER BAND OF BROKEN RAIN  
AND FREEZING RAIN WAS LIFTING ACROSS EAST-CENTRAL WI THIS AFTERNOON.  
AS THE SURFACE LOW CONTINUES TO TRACK NORTHEASTWARD THIS EVENING AND  
OVERNIGHT, THE ELEVATED WARM LAYER PRODUCING THE WINTRY MIX WILL  
ALSO MOVE EASTWARD ACROSS THE AREA. THIS WILL LEAD TO A GRADUAL  
TRANSITION TO A BRIEF PERIOD OF A WINTRY MIX TO ALL SNOW FROM WEST  
TO EAST THROUGH EARLY THIS EVENING. THE SNOW WILL THEN COME TO AN  
END BY EARLY MONDAY MORNING.  
 
ADDITIONAL ICE ACCUMULATIONS OF 0.05 TO 0.25 INCHES WILL BE MAINLY  
FOCUSED ACROSS THE NORTHWOODS AND WILL MAINLY FALL THROUGH EARLY  
THIS EVENING BEFORE SWITCHING OVER TO SNOW. THEREFORE, KEPT THE ICE  
STORM WARNING AS IS WITH AN END TIME OF 7 PM THIS EVENING. MINOR ICE  
ACCUMULATIONS OR A LIGHT GLAZE ARE POSSIBLE ELSEWHERE AS THE BRIEF  
PERIOD OF THE WINTRY MIX MOVES OVER OTHER LOCATIONS.  
 
SNOW ACCUMULATIONS HAVE INCREASED FROM THE PREVIOUS FORECAST AS THE  
SURFACE LOW WILL DEEPEN AS IT MOVES FURTHER NORTHEAST THIS EVENING,  
ALLOWING FOR A BETTER ORGANIZED DEFORMATION ZONE TO DEVELOP OVER THE  
AREA. SNOW ACCUMULATIONS OF 1 TO 4 INCHES IS FORECAST BY EARLY  
MONDAY MORNING FOR LOCATIONS NORTH AND WEST OF THE FOX VALLEY WITH  
UP TO AN INCH IN THE FOX VALLEY AND LAKESHORE AREAS. IN ADDITION TO  
THE SNOWFALL, GUSTY NORTHERLY WINDS OF 25 TO 30 MPH ARE EXPECTED  
OVERNIGHT. THE COMBINATION OF THE ONGOING ICE IMPACTS (SEVERAL  
THOUSANDS WITHOUT POWER ACROSS THE NORTHWOODS), WET SNOW, AND GUSTY  
WINDS WILL LIKELY LEAD TO ADDITIONAL IMPACTS WITH MORE POWER OUTAGES  
AND TREE LIMB DAMAGE. THEREFORE, AFTER COLLABORATING WITH  
SURROUNDING OFFICES, DECIDED TO ISSUE A WINTER STORM WARNING INTO  
THIS EVENING/NIGHT FOR THE AREAS WHERE THE ICE STORM WARNING REMAINS  
IN EFFECT UNTIL 7 PM. THE WINTER STORM WARNINGS WILL THEN EXPIRE  
FROM NORTHWEST TO SOUTHEAST AS THE SNOW COMES TO AN END TONIGHT.  
 
MONDAY...SURFACE HIGH PRESSURE WILL REIGN OVER THE AREA FOR MONDAY,  
BRINGING THE RETURN OF SUNSHINE. HOWEVER, TEMPERATURES WILL REMAIN  
BELOW NORMAL DUE TO THE COLDER AIR FILTERING DOWN WITH THE HIGH  
PRESSURE. HIGHS TO RANGE FROM THE LOW 30S TO LOW 40S.  
 
LONG TERM...MONDAY NIGHT THROUGH SUNDAY  
 
ANOTHER MESSY SYSTEM IS TAKING SHAPE FOR THE MIDDLE OF THIS WEEK,  
WHICH MAY BRING POTENTIAL IMPACTS TO THE REGION. P-TYPE APPEARS TO  
BE ANOTHER CHALLENGE WITH THIS SYSTEM AS MODELS HAVE THE SURFACE LOW  
PASSING SOMEWHERE OVER THE UPPER MISSISSIPPI VALLEY. DEPENDING ON  
WHERE THE LOW TRACK SETS UP, THERE IS ALSO POTENTIAL FOR THE AREA TO  
BE IN THE WARM SECTOR, WHICH COULD PRESENT THE POTENTIAL FOR  
THUNDERSTORMS. THERE IS ALSO POTENTIAL FOR THE AREA TO SEE  
ACCUMULATING SNOW AS WELL. WITH MANY IMPORTANT DETAILS TO STILL BE  
WORKED OUT, BE SURE TO MONITOR THE FORECAST FOR CHANGES. A LESS  
ACTIVE PATTERN WITH DRY CONDITIONS IS THEN ANTICIPATED THROUGH THE  
END OF THIS WEEK.  
 
 
   
AVIATION  
FOR 18Z TAF ISSUANCE  
ISSUED AT 103 PM CDT SUN MAR 30 2025  
 
VERY POOR FLYING CONDITIONS WILL CONTINUE FOR THE REMAINDER OF THE  
DAY AND INTO TONIGHT WITH MAINLY IFR CIGS. WHILE PERIODS OF RAIN  
WILL REMAIN OVER THE EAST-CENTRAL WI TAF SITES THROUGH LATE THIS  
AFTERNOON, A WINTRY MIX OF RAIN, FREEZING RAIN, SLEET, AND SNOW IS  
EXPECTED OVER THE CENTRAL AND NORTH-CENTRAL WI TAF SITES. THESE  
WINTRY MIX CONDITIONS WILL GRADUALLY MOVE EASTWARD AND ARRIVE AT  
THE EAST-CENTRAL WI TAF SITES AROUND 00Z MON. AS THIS IS  
HAPPENING, A CHANGE OVER TO ALL SNOW WILL OCCUR AT THE CENTRAL AND  
NORTH-CENTRAL WI TAF SITES. ALL PRECIPITATION WILL EXIT THE REGION  
FROM WEST TO EAST BY EARLY MONDAY MORNING. GUSTY NE WINDS WILL  
SHIFT NORTHERLY TONIGHT, WITH GUSTS TO 20 TO 25 KTS.  
 
VFR CONDITIONS WILL RETURN FROM WEST TO EAST MONDAY MORNING AS  
HIGH PRESSURE BUILDS OVER THE AREA.  
 
 
   
HYDROLOGY  
 
ISSUED AT 440 PM CDT SUN MAR 30 2025  
 
RECENT RAINFALL HAS LED TO SATURATED GROUND ACROSS MUCH OF THE  
AREA WITH RISES ON AREA RIVERS/STREAMS, INCLUDING NEAR BANKFULL  
OR MINOR FLOODING AT A FEW LOCATIONS, ESPECIALLY IN THE WISCONSIN  
AND OCONTO AREAS. WITH ADDITIONAL PRECIPITATION CONTINUING THROUGH  
TONIGHT AND ANOTHER BOUT OF IMPACTFUL RAIN/SNOW LIKELY FOR MID-  
WEEK, ADDITIONAL RIVER RISES AND ELEVATED RIVER LEVELS ARE LIKELY  
INTO THE COMING WEEK.  
 
 
   
GRB WATCHES/WARNINGS/ADVISORIES  
 
WINTER STORM WARNING UNTIL 10 PM CDT THIS EVENING FOR WIZ005.  
 
ICE STORM WARNING UNTIL 7 PM CDT THIS EVENING FOR WIZ010>013-  
018>022-030-031-035>037-073-074.  
 
WINTER STORM WARNING UNTIL 1 AM CDT MONDAY FOR WIZ010>012-018-  
019-030-035.  
 
WINTER STORM WARNING UNTIL 4 AM CDT MONDAY FOR WIZ013-020>022-  
031-036-037-073-074.  
 
 
 
 
DISCUSSION.....KRUK/KRUK  
AVIATION.......KRUK  
HYDROLOGY......KRUK  
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