710  
FXUS63 KGRB 190551  
AFDGRB  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GREEN BAY WI  
1251 AM CDT TUE MAY 19 2026  
 
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE  
   
KEY MESSAGES  
 
- ISOLATED SEVERE STORMS POSSIBLE THROUGH TONIGHT. GREATEST  
COVERAGE OF STORMS NORTHWEST PART OF THE AREA LATE THIS EVENING  
AND OVERNIGHT.  
 
- DRIER AND COOLER MID TO LATE WEEK. FROST OR FREEZE HEADLINES MAY  
BE NEEDED TUESDAY NIGHT AND WEDNESDAY NIGHT.  
 
- WARMER BY NEXT WEEKEND WITH RETURN OF RAIN CHANCES.  
 
 
   
DISCUSSION  
 
ISSUED AT 142 PM CDT MON MAY 18 2026  
 
MAIN CONCERN IS CHANCE OF SEVERE STORMS THROUGH TONIGHT AHEAD OF  
AN APPROACHING COLD FRONT. MODIFIED WARM FRONT IS WORKING THROUGH  
THE AREA FROM THE SOUTH. IT IS RUNNING INTO AFFECTS FROM EARLIER  
STORMS TO SOUTH AND SOUTHEAST. SUBSIDENCE TO WEST OF STORMS OVER  
MICHIGAN IS RESULTING IN MINIMAL RE-DEVELOPMENT OF SHOWERS AND  
STORMS THUS FAR. DECENT CU FIELD IS BLOSSOMING OVER WESTERN WI  
INTO CENTRAL WI, BUT CAPPING IS NOTED ON FORECAST SOUNDINGS IN  
THESE AREAS REST OF THE DAY. LOWERED POPS TO SLIGHT CHANCE ALL  
AREAS THROUGH 5P. AN WARM AND CERTAINLY MORE HUMID DAY BY RECENT  
STANDARDS.  
 
PRIMARY CONVECTIVE DEVELOPMENT THIS AFTERNOON INTO EARLY EVENING  
WILL BE WELL TO THE SOUTH OVER THE CENTRAL PLAINS. AS THE WARM  
FRONT LIFTS NORTH, IT COULD BE ENOUGH TO OVERCOME THE CAPPING FOR  
A FEW STORMS TO DEVELOP, ESPECIALLY NORTHERN WI. ISOLATED STRONG  
STORM IS POSSIBLE WITH MUCAPE UP TO 1000J/KG AND EFFECTIVE SHEAR  
OF 30-40 KTS. SEVERE THREAT WILL BE HIGHER IF A STORM COULD  
BECOME TRULY SURFACED BASED AND OCCUR NEAR THE FRONT. WAVE TO  
NORTH OF THIS CONVECTION OVER THE PLAINS ALONG WITH APPROACHING  
SFC LOW LOOKS TO BRING BEST CHANCE OF A LINE OF STORMS LATE THIS  
EVENING INTO THE OVERNIGHT HOURS FOR CENTRAL AND NORTH-CENTRAL WI.  
MAIN HAZARD WITH THESE STORMS WILL BE GUSTY WINDS AND HEAVY RAIN.  
ISOLATED DAMAGING WIND GUST COULD OCCUR IF LINE REMAINS MORE  
ORGANIZED AS IT MOVES INTO THE AREA. OVERALL THE CHANCE FOR SEVERE  
WEATHER THIS AFTERNOON THROUGH TONIGHT HAS TRENDED DOWNWARD AS SPC  
HAS TRIMMED THE SLIGHT RISK OUT OF ALL OUR FORECAST AREA.  
 
LEFTOVERS OF THIS OVERNIGHT LINE OF STORMS SHIFT BY LATE TONIGHT.  
A FEW SHOWERS OR STORMS MAY LINGER THROUGH THE MORNING OVER EASTERN  
WI, JUST AHEAD OF COLD FRONT. THE FRONT SWEEPS THROUGH BY EARLY  
AFTERNOON, SHIFTING SOUTHWEST WINDS TO NORTHWEST. WINDS WILL BE  
GUSTY UP TO 30 MPH. HIGHS COULD TOUCH 70 OVER EASTERN WI, BUT WILL  
BE IN THE 60S FOR MOST, WITH EVEN SOME 50S OVER NORTH-CENTRAL WI.  
 
BEYOND TUESDAY, REST OF THE WEEK LOOKS GENERALLY DRY. CANADIAN  
HIGH SHIFTS ACROSS LATE TUESDAY THROUGH WEDNESDAY NIGHT. FROST OR  
FREEZE HEADLINES MAY BE NEEDED TUESDAY NIGHT AND WEDNESDAY NIGHT,  
ESPECIALLY NORTHERN WI. GREATEST RISK IS WEDNESDAY NIGHT WITH  
HIGH OVERHEAD AND PWATS LESS THAN 0.5 INCH. MIN RH WILL BE LOW WED  
THROUGH FRI AFTERNOON'S. RETURN FLOW KICKS IN LATE THIS WEEK INTO  
NEXT WEEKEND WITH HIGHS STEADILY RETURNING TO AT OR ABOVE NORMAL.  
CHANCES FOR RAIN AND PERHAPS SOME THUNDER INCREASE BY NEXT WEEKEND.  
 
 
   
AVIATION  
FOR 06Z TAF ISSUANCE  
ISSUED AT 1251 AM CDT TUE MAY 19 2026  
 
ONGOING LINE OF RAIN AND THUNDERSTORMS IS MOVING EAST ACROSS  
CENTRAL AND INTO NORTHEAST WI AS OF 0530Z. THE MAIN LINE HAS  
EXITED KAUW, KCWA, AND KRHI, BUT A SMALL THUNDER THREAT REMAINS  
FOR THE NEXT COUPLE HOURS FROM ADDITIONAL DEVELOPMENT TO THE SOUTH.  
 
MAIN HAZARD ALONG AND EAST OF THE MAIN LINE OVER THE NEXT 3 TO 4  
HOURS WILL BE STRONG WIND GUSTS TO 40 KNOTS AND HEAVY RAIN. THERE  
REMAINS A SMALL POTENTIAL FOR ISOLATED SEVERE WIND GUSTS TO 50  
KNOTS, BUT EXPECT THIS POTENTIAL TO DIMINISH AS THE STORMS MOVE  
EAST.  
 
WIDELY SCATTERED SHOWERS REMAIN THROUGHOUT TUESDAY MORNING, WITH  
CONDITIONS AREA-WIDE DRYING OUT AFTER ~18Z. MOST LOCATION ARE  
STILL VFR, BUT EXPECT CIGS TO DROP TO IFR/MVFR OVERNIGHT, WITH  
IMPROVEMENTS TO MVFR/VFR THIS AFTERNOON. ADDITIONALLY, FOG OFF  
LAKE MICHIGAN WILL DROP VSBY AT KMTW AT TIMES THROUGH TUESDAY  
MORNING.  
 
SOUTH WINDS VEER SOUTHWEST OVERNIGHT, AND THEN VEER TO THE WEST-  
NORTHWEST TUESDAY BEHIND THE COLD FRONT, ALONG WITH WIND GUSTS TO  
25 KTS.  
 
 
   
GRB WATCHES/WARNINGS/ADVISORIES  
 
NONE.  
 
 
 
 
 
DISCUSSION.....JLA  
AVIATION.......KLJ  
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