601  
FXUS63 KGRB 021700  
AFDGRB  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GREEN BAY WI  
1200 PM CDT SAT MAY 2 2026  
 
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE  
   
KEY MESSAGES  
 
- RAIN CHANCES WILL INCREASE LATE TONIGHT INTO SUNDAY MORNING. THE  
HIGHEST PROBABILITIES FOR PRECIPITATION ARE CURRENTLY FOCUSED  
OVER NORTH-CENTRAL WISCONSIN (60-80% CHANCE).  
 
- A STRONGER COLD FRONT WILL MOVE THROUGH THE REGION ON MONDAY.  
THIS SYSTEM WILL BRING A HIGH CHANCE FOR RAIN, ALONG WITH A FEW  
THUNDERSTORMS, MONDAY AFTERNOON (50-70% CHANCE).  
 
- OTHER THAN SUNDAY AND MONDAY, BELOW NORMAL TEMPERATURES WILL  
WILL RETURN MID TO LATE NEXT WEEK, WITH SEVERAL OPPORTUNITIES  
FOR FROST AND FREEZE CONDITIONS.  
 
 
   
DISCUSSION  
 
ISSUED AT 1234 AM CDT SAT MAY 2 2026  
 
THE HIGH PRESSURE SYSTEM WILL SLIDE SOUTHEAST OF THE AREA TODAY,  
ALLOWING SOUTHERLY RETURN FLOW TO DEVELOP. THIS WILL LEAD TO A  
MODEST WARMING TREND WITH HIGHS REACHING THE MID TO UPPER 50S.  
TROUGHING ALOFT WILL LIKELY SUPPORT THE DEVELOPMENT OF FAIR-  
WEATHER CUMULUS CLOUDS BY LATE MORNING, SIMILAR TO THE COVERAGE OF  
MINNESOTA YESTERDAY.  
 
ATTENTION THEN TURNS TO A CLIPPER SYSTEM PROGGED TO APPROACH  
TONIGHT. LOW-LEVEL CONVERGENCE AND A SURGE OF MOISTURE WILL  
INCREASE PRECIPITATION CHANCES, PARTICULARLY FOR AREAS NORTH OF  
HIGHWAY 29. RAIN CHANCES HAVE STEADILY INCREASED OVER THE PAST 24  
HOURS, AND HAVE INCREASED AGAIN TONIGHT (NOW UP TO 60-80%). AS  
SUCH, HAVE OPTED TO BOOST NBM POPS FOR THE LATE TONIGHT INTO  
SUNDAY TIMEFRAME. MOST OF THIS ACTIVITY SHOULD EXIT THE REGION BY  
MIDDAY SUNDAY, LEADING TO DECREASING CLOUDS AND HIGH TEMPERATURES  
RETURNING TO THE 60S FOR INLAND LOCATIONS ON SUNDAY AFTERNOON.  
 
FOR THE EARLY TO MIDDLE PART OF NEXT WEEK, THE PATTERN WILL BE  
DOMINATED BY AN ANOMALOUS CLOSED UPPER LOW SPINNING OVER NORTHERN  
ONTARIO AND THE HUDSON BAY. A MORE ROBUST COLD FRONT ASSOCIATED  
WITH THIS FEATURE IS FORECAST TO SWEEP ACROSS WISCONSIN ON MONDAY.  
PROBABILITY OF PRECIPITATION HAS INCREASED TO 70-80 PERCENT WITH  
THIS FRONT. WHILE OVERALL MOISTURE REMAINS SOMEWHAT LIMITED, WEAK  
INSTABILITY UP TO 100 J/KG DURING THE AFTERNOON HOURS MAY BE  
SUFFICIENT TO SUPPORT A FEW ISOLATED THUNDERSTORMS. PRECIP AMOUNTS  
WILL GENERALLY BE LIGHT AS THERE IS A LESS THAN 20% CHANCE OF  
1/4" OF RAIN. BUT WITH THUNDERSTORMS, HIGH END AMOUNTS (95  
PERCENTILE) UP TO 1/2 INCH ARE POSSIBLE.  
 
BEHIND THIS FRONT, ANOTHER SURGE OF COLD AIR WILL DROP  
TEMPERATURES BACK BELOW SEASONAL NORMALS FROM TUESDAY THROUGH  
FRIDAY. UNDER THE COLD POOL OF THE UPPER TROUGH, SCATTERED  
DIURNALLY ENHANCED SHOWERS ARE POSSIBLE DURING THE AFTERNOONS FROM  
WEDNESDAY THROUGH FRIDAY THOUGH CONFIDENCE IN COVERAGE IS LOW.  
FROST AND FREEZE POTENTIAL WILL PEAK AGAIN DURING THE EARLY  
MORNING HOURS OF WEDNESDAY THROUGH FRIDAY.  
 
 
   
AVIATION  
FOR 18Z TAF ISSUANCE  
ISSUED AT 1200 PM CDT SAT MAY 2 2026  
 
VFR CONDITIONS ARE EXPECTED THIS AFTERNOON WITH SCT-BKN FAIR  
WEATHER CU WITH BASES AT 6-7K FT. MID CLOUDS THEN INCREASE IN  
COVERAGE THIS EVENING AND TONIGHT AHEAD OF AN APPROACHING LOW  
PRESSURE AND ACCOMPANYING SHOWER CHANCES. THE CHANCE FOR SHOWERS  
LOOKS A BIT LOWER THIS RUN; THEREFORE, WILL HANDLE THE SHOWERS  
WITH PROB30 GROUPS THIS RUN. NO DETERIORATION OF FLIGHT CATEGORY  
IS EXPECTED FOR CIGS OR VSBYS.  
 
SURFACE WINDS WILL MAINLY BE FROM THE WEST TODAY, BACKING  
SOUTHWEST TONIGHT AHEAD OF THE COLD FRONT, THEN VEERING TO THE  
WEST SUNDAY AS THE COLD FRONT MOVES THROUGH THE REGION. WIND  
SPEEDS WILL GENERALLY BE 5 TO 10 KNOTS, GUSTING TO 15-20 KNOTS  
LATE TONIGHT INTO SUNDAY.  
 
 
   
GRB WATCHES/WARNINGS/ADVISORIES  
 
NONE.  
 
 
 
 
 
DISCUSSION.....MPC/GOODIN  
AVIATION.......KURIMSKI  
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