820  
FXUS63 KGRB 032330  
AFDGRB  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GREEN BAY WI  
630 PM CDT FRI JUL 3 2026  
 
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE  
   
KEY MESSAGES  
 
- ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED AT  
TIMES THIS AFTERNOON INTO THIS EVENING, MAINLY ACROSS NORTHERN  
WI.  
 
- ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS ARE EXPECTED  
THROUGHOUT THE HOLIDAY WEEKEND.  
 
- SEASONAL SUMMER TEMPERATURES ARE EXPECTED FOR THE HOLIDAY  
WEEKEND.  
 
 
   
DISCUSSION  
 
ISSUED AT 126 PM CDT FRI JUL 3 2026  
 
REST OF TODAY...A SUBTLE SHORT-WAVE PASSING OVER THE REGION ALONG  
WITH REMNANT OUTFLOW BOUNDARIES FLOATING AROUND HAS LEAD TO AN AREA  
OF SCATTERED SHOWERS ACROSS CENTRAL AND EAST-CENTRAL WI THAT WILL  
CONTINUE THROUGH THIS AFTERNOON. RAP ANALYSIS DOES SHOW ENOUGH WEAK  
ELEVATED INSTABILITY FOR THESE SHOWERS TO PRODUCE ISOLATED LIGHTNING,  
HOWEVER, RADAR AND SATELLITE TRENDS OVER THE PAST HOUR HAVE SHOWN NO  
IMMINENT SIGNS OF LIGHTNING. ANOTHER AREA OF SHOWERS AND STORMS IS  
POSSIBLE ACROSS NORTHERN WI THIS AFTERNOON AND EVENING AS A LAKE  
BREEZE MOVES SOUTH OF LAKE SUPERIOR. AGAIN, THERE IS ENOUGH  
INSTABILITY TO SUPPORT LIGHTNING, HOWEVER, WITH A LACK STRONGER DEEP  
LAYER SHEAR DON'T EXPECT ANY STRONGER MORE ORGANIZED STORMS TO  
DEVELOP.  
 
SHOWER AND STORM CHANCES THIS WEEKEND...LINGERING BOUNDARY  
(LAKE/OUTFLOW) SCATTERED ACROSS THE FORECAST AREA SATURDAY MORNING  
MAY PROVIDE THE FOCUS FOR SCATTERED SHOWERS WITH EMBEDDED  
THUNDERSTORMS. HOWEVER, CONFIDENCE IN SHOWERS AT ANY GIVEN LOCATION  
IS LOW SO HAVE LIMITED POPS THROUGH THE MORNING TO 20-40%.  
PRECIPITATION CHANCES DO INCREASE INTO THE AFTERNOON AND EVENING AS A  
MIDDLE LEVEL SHORT-WAVE, TRACKS OVER THE REGION. HIGHEST  
PRECIPITATION CHANCES (50-70%) ARE ACROSS CENTRAL WI SATURDAY  
AFTERNOON WITH LOWER CHANCES (30-50%) CLOSER TO THE LAKESHORE AND  
INTO NORTH AND NORTHEAST WI. MUCAPE VALUES OF 800-1200 J/KG WILL  
MAKE ISOLATED THUNDERSTORMS POSSIBLE DURING THE AFTERNOON AND  
EVENING, HOWEVER, WITH WEAK DEEP LAYER SHEAR THE CHANCE FOR STRONGER  
ORGANIZED STORMS IS LOW (~10%). CAM ENSEMBLES POINT TOWARDS A SECOND  
TRAILING SHOWER-WAVE PASS OVER THE REGION SATURDAY NIGHT INTO SUNDAY  
LEADING TO LINGERING SHOWER AND THUNDERSTORM CHANCES (20-40%)  
THROUGH SUNDAY MORNING BEFORE PRECIP CHANCE DRY UP SUNDAY AFTERNOON.  
 
DRY TO START NEXT WEEK...GLOBAL ENSEMBLES AND LONGER RANGER ML  
MODELS ARE IN GENERALLY GOOD AGREEMENT THAN AN UPPER RIDGE WILL BE  
BUILDING OVER THE UPPER MIDWEST DURING THE BEGINNING OF NEXT WEEK.  
THIS WILL BRING LARGELY DRY CONDITIONS TO THE FORECAST AREA MONDAY  
AND TUESDAY. AS THE AFOREMENTIONED RIDGE PUSHES EAST DURING THE  
MIDDLE OF NEXT WEEK LARGE SCALE TROUGHING IS EXPECTED TO DEVELOP.  
THIS WILL LEAD TO INCREASING CHANCES FOR SHOWERS AND THUNDERSTORM  
WEDNESDAY INTO THURSDAY. LONG RANGE GLOBAL ENSEMBLES DO SHOW  
INSTABILITY TYPICAL OF EARLY JULY DURING THIS TIME MAKING STRONGER  
STORMS POSSIBLE, HOWEVER, THERE IS NO SIGNAL OF A HIGHER END SEVERE  
EVENT WITHIN THE STATISTICAL SUITE OF GUIDANCE.  
 
TEMPERATURE TRENDS...THIS WEEKEND TEMPERATURES ARE FORECAST TO TREND  
NEAR SEASONAL AVERAGES WITH HIGHS IN THE UPPER 70S TO LOW 80S  
SATURDAY AND SUNDAY.  
 
 
   
AVIATION  
FOR 00Z TAF ISSUANCE  
ISSUED AT 311 PM CDT FRI JUL 3 2026  
 
MVFR CU FIELD CONTINUES TO SCATTER OUT THIS EVENING, LEAVING MID  
CLOUDS IN ITS WAKE. SCT SHOWERS AND STORMS ARE ALREADY DEVELOPING  
ALONG A LAKE BREEZE SINKING SOUTH OFF OF LAKE SUPERIOR THIS  
EVENING AND ARE EXPECTED TO CONTINUE INTO TONIGHT; HAVE THUS  
OPTED TO INCLUDE A PROB30 MENTION FOR -TSRA IN THE RHI TAF WHERE  
THUNDER IS MOST LIKELY. SHOWERS WILL CONTINUE TO DIMINISH IN  
COVERAGE OVERNIGHT, THOUGH MAY LINGER INTO SATURDAY MORNING. BRIEF  
LOWERING OF CIGS TO MVFR WILL BE POSSIBLE IF A SHOWER OR STORM  
MOVES DIRECTLY OVER A TERMINAL. REMNANT MOISTURE NEAR THE SURFACE  
MAY THEN RESULT IN PATCHY FOG DEVELOPMENT ACROSS THE FORECAST  
AREA LATE TONIGHT INTO SATURDAY MORNING, THOUGH CONFIDENCE  
REMAINS LOW IN FOG COVERAGE AND DENSITY. WILL LIMIT ANY REDUCTIONS  
IN VSBYS TO MVFR.  
 
WINDS WILL START OUT OF THE SOUTH/SOUTHWEST, EVENTUALLY VEERING TO  
EAST/NORTHEAST BEHIND THE LAKE BREEZE SATURDAY MORNING. WINDS MAY  
GUST TO 15 KNOTS NEAR MTW SATURDAY AFTERNOON.  
 
 
   
GRB WATCHES/WARNINGS/ADVISORIES  
 
NONE.  
 
 
 
 
 
DISCUSSION.....GK  
AVIATION.......GOODIN  
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