060  
FXUS63 KGRB 180454  
AFDGRB  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GREEN BAY WI  
1054 PM CST FRI JAN 17 2025  
 
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE  
   
KEY MESSAGES  
 
- AN ARCTIC AIRMASS ARRIVES THIS WEEKEND, BRINGING A PROLONGED  
PERIOD OF WIND CHILLS OF 20 TO 35 BELOW ZERO FROM SATURDAY  
NIGHT THROUGH WEDNESDAY MORNING. WIND CHILLS AS COLD AS 40 BELOW  
ARE POSSIBLE ON TUESDAY MORNING.  
 
 
   
DISCUSSION  
 
ISSUED AT 353 PM CST FRI JAN 17 2025  
 
SHORT TERM...TONIGHT AND SATURDAY  
 
WEAK FORCING AHEAD OF A SURFACE FRONT A MID-LEVEL SHORTWAVE IS  
SHOWING SOME WEAK PRECIP RETURNS ON RADAR FROM SOUTHEAST MN INTO  
NORTH- CENTRAL WI. HOWEVER, LITTLE, IF ANY, OF THIS IS REACHING  
THE GROUND. FLURRIES/SPRINKLES OR A BRIEF, LIGHT SHOWER ARE  
POSSIBLE THROUGHOUT THE AFTERNOON AND EARLY EVENING, BUT MOST  
PLACES WILL REMAIN PRECIP-FREE. WINDS AT 1930Z WERE FROM THE W  
AND SW, BUT CONTINUE TO VEER NW. THIS WILL BRING CHANCES OF ON/OFF  
LAKE EFFECT SNOW SHOWERS TO FAR NORTH-CENTRAL WISCONSIN STARTING  
THIS EVENING. AMOUNTS HERE WILL BE LIGHT, WITH UP TO 1" OF  
ACCUMULATION FROM 00Z/SAT TO 00Z/SUN.  
 
AS THE WINDS TURN NW, THIS ALSO BEGINS THE CHANGE TO A MUCH  
COLDER AIRMASS. TEMPERATURES AT 1930Z WERE IN THE MIDDLE 30S TO  
LOWER 40S, WITH WAUPACA COMING IN AT 45 AND WAUTOMA 46 DEGREES.  
EXPECT TO SEE READINGS ABOUT 25-40 DEGREES COOLER BY SATURDAY  
MORNING. TEMPS WILL REMAIN FAIRLY STEADY THROUGHOUT SATURDAY, BUT  
GUSTY NW WINDS WILL LEAD TO WIND CHILLS BELOW ZERO FOR THE MOST  
PART, AND TEENS BELOW ZERO IN CENTRAL/NORTH-CENTRAL WI. READINGS  
WILL GET MUCH COLDER INTO SATURDAY NIGHT.  
 
LONG TERM...SATURDAY NIGHT THROUGH FRIDAY  
 
MAIN FOCUS FROM THIS FORECAST PERIOD IS THE CONTINUED STRONG SIGNAL  
FOR BITTER COLD TEMPERATURES AND DANGEROUSLY COLD WIND CHILLS  
ASSOCIATED WITH AN ARCTIC AIRMASS. THE COLDEST CONDITIONS WILL OCCUR  
BETWEEN SATURDAY NIGHT THROUGH WEDNESDAY MORNING. IN ADDITION TO THE  
COLD, PERIODS OF LIGHT LAKE-EFFECT SNOW SHOWERS ARE ANTICIPATED IN  
FAR NORTH-CENTRAL WI, BUT IMPACTS WILL BE MINOR.  
 
TEMPERATURES...AN ANOMALOUSLY COLD AIRMASS WILL OVERSPREAD THE  
REGION FROM SATURDAY NIGHT THROUGH WEDNESDAY MORNING. DESPITE THIS  
AIRMASS BEING ABNORMALLY COLD FOR THIS TIME OF YEAR, AIR  
TEMPERATURES WILL NOT BE NEARING/THREATENING RECORDS. HOWEVER, HIGH  
TEMPERATURES WILL BE IN THE SINGLE DIGITS ABOVE AND BELOW ZERO EACH  
DAY FROM SUNDAY THROUGH TUESDAY. LOW TEMPERATURES WILL BE ABOUT 20  
TO 25 DEGREES BELOW NORMAL EACH NIGHT/MORNING FROM SATURDAY NIGHT  
THROUGH TUESDAY NIGHT WITH LOWS RANGING MAINLY FROM -10 TO -25F.  
SLIGHTLY "WARMER" AIR RETURNS TO THE REGION ON WEDNESDAY AS A  
SURFACE RIDGE BUILDS OVER THE AREA.  
 
WIND CHILLS...A PREVAILING NORTHWEST WIND WILL COMBINE WITH THE  
BITTER COLD TEMPERATURES AND GENERATE DANGEROUSLY COLD WIND CHILLS.  
THE COLDEST WIND CHILLS ARE EXPECTED DURING THE OVERNIGHT INTO  
MORNING HOURS EACH DAY. DUE TO TEMPERATURES DECREASING SLIGHTLY AND  
SURFACE WINDS INCREASING SLIGHTLY, WIND CHILL VALUES HAVE DECREASED  
FOR SATURDAY NIGHT INTO SUNDAY. THEREFORE, DECIDED TO MOVE FORWARD  
WITH ISSUING A COLD WEATHER ADVISORY STARTING SATURDAY EVENING. SEE  
THE NEXT SECTION FOR MORE DETAILS ON HEADLINES. WILL CONTINUE TO  
MONITOR THE NEED FOR AN EXTREME COLD WARNING FOR EARLY NEXT WEEK AS  
THE PROBABILITY OF WIND CHILLS OF -30 OR COLDER IS GREATEST MONDAY  
MORNING (ROUGHLY 40-80%) AND TUESDAY MORNING (70-100%).  
 
COLD WEATHER HEADLINES...AFTER COLLABORATION WITH SURROUNDING  
OFFICES, HAVE ISSUED A COLD WEATHER ADVISORY FROM SATURDAY EVENING  
THROUGH MONDAY EVENING. DECIDED TO HAVE THE ADVISORY CONTINUE DURING  
THE AFTERNOON HOURS, DESPITE THE POSSIBLE BRIEF WINDOW OF WIND  
CHILLS RISING ABOVE CRITERIA. AN EXTREME COLD WARNING WILL LIKELY BE  
NEEDED FROM MONDAY EVENING THROUGH TUESDAY MORNING, BUT WILL ALLOW  
SUBSEQUENT SHIFTS TO ANALYZE THE FORECAST CLOSER. AN ADDITIONAL COLD  
WEATHER ADVISORY MAY BE NEEDED FOR TUESDAY AFTERNOON THROUGH  
WEDNESDAY MORNING.  
 
 
   
AVIATION  
FOR 06Z TAF ISSUANCE  
ISSUED AT 1045 PM CST FRI JAN 17 2025  
 
A COLD FRONT HAD MOVED THROUGH THE FORECAST AREA BY LATE EVENING,  
AND LOW CLOUDS BETWEEN 2500-5000 FT AGL HAD OVERSPREAD ALL BUT  
THE FAR SOUTHEAST PORTION. SNOW SHOWERS WERE ONGOING OVER FAR NC  
WI, AND FLURRIES WERE REPORTED ELSEWHERE. NORTHWEST WINDS WERE  
GUSTING TO 20-30 KTS.  
 
LOW CLOUDS, WITH MVFR CEILINGS IN PARTS OF NC/C WI, WILL CONTINUE  
ACROSS THE REGION UNTIL CLEARING ARRIVES SATURDAY MORNING/EARLY  
AFTERNOON. THE LOW CLOUDS WILL PERSIST LONGER NORTH OF RHI, AND  
LAKE-EFFECT SNOW SHOWERS WILL LIKELY CONTINUE IN NORTHERN VILAS  
COUNTY THROUGH SATURDAY EVENING. GUSTY NORTHWEST WINDS WILL  
CONTINUE THROUGH SATURDAY MORNING THEN DIMINISH A BIT DURING THE  
AFTERNOON AND EVENING.  
 
 
   
GRB WATCHES/WARNINGS/ADVISORIES  
 
COLD WEATHER ADVISORY FROM 9 PM SATURDAY TO 9 PM CST MONDAY FOR  
WIZ005-010>013-018>022-030-031-035>040-045-048>050-073-074.  
 
 
 
 
DISCUSSION.....KLJ/KRUK  
AVIATION.......KIECKBUSCH  
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