710  
FXUS63 KGRB 220354  
AFDGRB  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GREEN BAY WI  
1054 PM CDT SUN JUL 21 2024  
 
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE  
   
KEY MESSAGES
 
 
- NEXT CHANCE OF SHOWERS/STORMS WILL BE MONDAY AFTERNOON INTO  
MONDAY NIGHT OVER NORTH CENTRAL AND CENTRAL WI. MORE WIDESPREAD  
STORMS EXPECTED ON TUESDAY. LOCALLY HEAVY RAINFALL WILL BE  
POSSIBLE.  
 
- HAZY CONDITIONS FROM ELEVATED SMOKE AT TIMES EARLY THIS WEEK.  
 
- SEASONAL TEMPERATURES WILL BRIEFLY DROP BELOW NORMAL ON  
WEDNESDAY, THEN CLIMB BACK ABOVE NORMAL AT THE END OF THE WEEK.  
 

 
   
DISCUSSION
 
 
ISSUED AT 322 PM CDT SUN JUL 21 2024  
 
SHOWER/STORM CHANCES & HEAVY RAIN POTENTIAL:  
 
MOST OF THE AREA WILL STAY DRY THIS AFTERNOON/EVENING AS NORTHEAST  
FLOW HAS PROVIDED FOR DRIER AND MORE STABLE CONDITIONS. BUT WITH A  
LITTLE MORE MOISTURE IN CENTRAL WI, SBCAPE HAS BUILT TO 600-1000  
J/KG NEAR WOOD COUNTY, SO A FEW POP UP SHOWERS OR STORMS WILL BE  
POSSIBLE MAINLY WEST OF A MOSINEE TO WAUTOMA LINE LATE THIS  
AFTERNOON. THE THREAT FOR THE SHOWERS/STORMS WILL END BY EARLY  
EVENING AS THE ACTIVITY/INSTABILITY SHIFTS TO THE SOUTHWEST AWAY  
FROM THE AREA. LOCALLY HEAVY RAIN WILL BE POSSIBLE WHERE/IF ANY  
STORMS OCCUR AS THEY WILL BE SLOW MOVERS. WEAK HIGH PRESSURE AND  
A DRIER CANADIAN AIR MASS WILL BRING DRY DRY CONDITIONS TONIGHT.  
 
MONDAY WILL START OFF DRY, THEN CHANCES FOR SHOWERS AND STORMS  
WILL INCREASE ACROSS CENTRAL AND NORTHERN WI IN THE LATE MORNING  
AND AFTERNOON AS A WEAK BOUNDARY DROPS INTO NORTHERN WI AND AN  
UPPER TROUGH/SHORTWAVE APPROACHES. INSTABILITY IS FORECAST TO  
BUILD TO 700-1500 J/KG, BUT SHEAR WILL REMAIN UNDER 15 KTS.  
SHOWERS/STORMS LOOK MORE WIDESPREAD ON TUESDAY AS LITTLE BETTER  
SHEAR ARRIVES AND POSSIBLY A LITTLE MORE CAPE IF WE GET ENOUGH  
SUN, AS THE FRONT AND SHORTWAVE DROP DOWN ACROSS THE AREA. HEAVY  
RAIN STILL APPEARS TO BE THE MAIN THREAT FROM THE STORMS (TALL,  
SKINNY CAPE), WITH SOME SMALL HAIL AND WIND GUSTS TO 40 MPH IN THE  
STRONGEST STORMS POSSIBLE IF THE BETTER INSTABILITY MATERIALIZES.  
THE SHOWER/STORM ACTIVITY WILL LINGER INTO TUESDAY NIGHT, BUT  
INSTABILITY WILL DECREASE THROUGH THE EVENING.  
 
SOME LAKE EFFECT SHOWER ACTIVITY MAY MOVE INTO FAR NORTH CENTRAL  
WI LATE TUESDAY AND WEDNESDAY AS CAA PUSHES ACROSS THE WARM GREAT  
LAKES. IN ADDITION, SOME INSTABILITY SHOWERS OR PERHAPS A STORM  
(CAPE UP TO ~500 J/KG) WILL BE POSSIBLE UNDER THE UPPER TROUGH,  
ESPECIALLY ACROSS EASTERN WI. DRY CONDITIONS ARE EXPECTED  
WEDNESDAY NIGHT INTO SATURDAY AS HIGH PRESSURE AND MID-UPPER LEVEL  
RIDGING BUILDS ACROSS THE GREAT LAKES. NEXT CHANCE FOR SHOWERS  
AND STORMS ARRIVE LATE IN THE WEEKEND AS THE RIDGE BREAKS DOWN AND  
A BOUNDARY APPROACHES FROM THE NORTHWEST.  
 
SMOKE & FOG TRENDS:  
 
AFTERNOON GOES IMAGERY SHOWING A THICKER BATCH OF ELEVATED SMOKE  
SLOWLY SHIFTING TO OUR WEST/SOUTH, WITH MUCH THINNER/PATCHIER  
SMOKE OVER LAKE SUPERIOR, THE U.P., AND NORTHEAST WI. MUCH THICKER  
SMOKE, INCLUDING SOME REACHING THE SURFACE, REMAINED WELL TO OUR  
WEST IN MN, SD AND ND. HRRR/RAP SHOWING A THIN LAYER OF SMOKE  
REMAINING OVER THE REGION AT TIMES TONIGHT INTO MONDAY, BUT  
CONTINUES TO SHOW THE THICKER SMOKE TO OUR WEST. THIS THICKER  
BATCH LOOKS TO REMAIN TO OUR NORTHWEST THROUGH MONDAY NIGHT AND IT  
DOESN'T APPEAR THERE WILL BE ANY SIGNIFICANT IMPACTS AT THE  
SURFACE.  
 
WIDESPREAD FOG POTENTIAL LOOKS ON THE LOW SIDE TONIGHT AS DRIER  
AIR FILTERS INTO THE AREA (DEWPOINTS IN THE 40S AND 50S). BUT WITH  
RECENT RAINS IN CENTRAL AND NORTH CENTRAL WI, LIGHT WINDS, A LOW-  
LEVEL INVERSION AND AT LEAST SOME PARTIAL CLEARING, SOME GROUND  
FOG WILL BE POSSIBLE, ESPECIALLY IN THE WI RIVER VALLEY (CENTRAL  
AND NORTH CENTRAL WI). WILL CONTINUE WITH THE PATCHY FOG IN THE  
FORECAST WEST OF THE FOX VALLEY. CLOUDS ARE FORECAST TO INCREASE  
MONDAY NIGHT, WHICH SHOULD LIMIT FOG POTENTIAL, BUT IF SKIES CAN  
STAY CLEAR, PATCHY FOG WOULD BE POSSIBLE ONCE AGAIN.  
 
TEMPS & HUMIDITY:  
 
IT WILL BE ANOTHER COOL NIGHT ACROSS NORTH-CENTRAL WI WITH SOME OF  
THE COOLER SPOTS LIKELY DROPPING INTO THE UPPER 40S. LOWS MAINLY  
IN THE 50S TO AROUND 60 ARE EXPECTED ACROSS CENTRAL AND EAST  
CENTRAL WI. HIGH ON MONDAY LOOK TO MAINLY BE IN THE UPPER 70S TO  
LOW 80S, WITH SLIGHTLY COOLER READINGS NEAR LAKE MICHIGAN AS WINDS  
TURN ONSHORE. SLIGHTLY COOLER TEMPS ARRIVE ON TUESDAY THEN  
STRONGER CAA ARRIVES ON WEDNESDAY WITH SLIGHTLY BELOW NORMAL HIGHS  
EXPECTED, MAINLY IN THE 70S. TEMPS WILL REBOUND AT THE END OF THE  
WEEK, RETURNING TO ABOVE NORMAL.  
 
IT WILL BE A PRETTY COMFORTABLE DAY ON MONDAY WITH DEWPOINTS  
MAINLY IN THE UPPER 50S TO LOW 60S. DEWPOINTS TICK UPWARD ON  
TUESDAY, WITH SOME MID 60S LIKELY ACROSS PARTS OF CENTRAL AND  
EASTERN WI. HUMIDITY LEVELS WILL DROP OFF LATE IN THE WEEK WITH  
COMFORTABLE LATE JULY CONDITIONS EXPECTED.  
 

 
   
AVIATION
 
FOR 06Z TAF ISSUANCE  
ISSUED AT 1054 PM CDT SUN JUL 21 2024  
 
ANY VFR CU DISSIPATES EARLY LEAVING PATCHY HIGH CLOUDS AND AN  
ELEVATED LAYER OF SMOKE FOR THE OVERNIGHT. COULD SEE SOME FOG  
LATE TONIGHT WITH LOCALIZED IFR VISIBILITY AT CWA AND AUW AND  
POSSIBLY RHI.  
 
ON MONDAY, EXPECT VFR CONDITIONS TO PREVAIL. SCATTERED TO BROKEN  
CU WILL DEVELOP MIDDAY INTO THE AFTERNOON WITH BEST CHANCE OF  
PERSISTENT CIGS CENTRAL TO NORTH-CENTRAL WI. ELEVATED SMOKE WILL  
CONTINUE TO IMPACT THE AREA. AN APPROACHING COLD FRONT AND UPPER  
DISTURBANCE WILL BRING THE CHANCE FOR A SHOWER OR STORM AT RHI ON  
MONDAY EVENING.  
   
OSH
 
A FEW LINGERING CU (040-050) AROUND INTO THE EARLY OVERNIGHT.  
OTHERWISE, PATCHY HIGH CLOUDS AND ELEVATED SMOKE LAYER PREVAILS  
THROUGH MONDAY MORNING. FEW TO SCATTERED CU (BASES 050-060)  
DEVELOP MIDDAY MONDAY THROUGH MONDAY AFTERNOON WITH ELEVATED SMOKE  
LAYER PERSISTING. LIGHT AND VARIABLE WINDS EXPECTED REST OF  
TONIGHT WITH LIGHT N-NE WINDS ON MONDAY EVENTUALLY SHIFTING MORE  
SW BY LATE IN THE DAY. LOOKING AHEAD, THE NEXT CHANCES FOR SHOWERS  
AND STORMS WILL BEGIN TO IMPACT OSH VERY LATE MONDAY NIGHT.  
BETTER CHANCES FOR SHOWERS AND STORMS WILL BE DURING THE AFTERNOON  
AND EVENING HOURS ON TUESDAY.  
 

 
   
GRB WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  
 

 
 

 
 
DISCUSSION.....BERSCH  
AVIATION.......JLA  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab WI Page Main Text Page