667  
FXUS63 KMKX 310019  
AFDMKX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI  
719 PM CDT THU JUL 30 2026  
   
KEY MESSAGES  
 
- INCREASING CHANCES FOR SHOWERS AND WEAK THUNDERSTORMS AT  
TIMES FROM FRIDAY MORNING THROUGH FRIDAY NIGHT (80-95%  
CHANCES). CHANCES GRADUALLY TAPER DOWN THROUGH SATURDAY.  
 
- BREEZY ONSHORE WINDS WILL LEAD TO HIGH WAVES AND DANGEROUS  
CURRENTS AT LAKE MICHIGAN BEACHES THIS WEEKEND, WITH MODERATE  
TO HIGH SWIM RISK CONDITIONS POSSIBLE SATURDAY AND SUNDAY.  
 
 
   
UPDATE  
 
ISSUED 720 PM CDT THU JUL 30 2026  
 
QUIET AND CALM CONDITIONS THROUGH TONIGHT. AN ISOLATED SHOWER  
ACROSS FAR SOUTHWESTERN WISCONSIN CANNOT BE RULED OUT, BUT  
CHANCES ARE VERY LOW (10-15%). OTHERWISE, EXPECTING INCREASING  
CLOUD COVER AND LIGHT WINDS.  
 
MH  
 
 
   
SHORT TERM  
 
ISSUED 200 PM CDT THU JUL 30 2026  
 
TONIGHT THROUGH SATURDAY:  
 
DRY WEATHER CONTINUES FOR THE REST OF TODAY THROUGH TONIGHT, WITH  
HIGH PRESSURE OVERHEAD SHIFTING SOUTHEAST INTO THE OHIO RIVER  
VALLEY. SIMULTANEOUSLY, A POSITIVELY-TILTED 500MB TROUGH SWINGS  
SOUTHEASTWARD ACROSS THE UPPER MIDWEST. CORRESPONDING SURFACE LOW  
PRESSURE DEEPENS OVER IA ON FRIDAY AND CONTINUES EAST THROUGH  
IL ON SATURDAY. THE SLOW-MOVING NATURE OF THIS LOW COUPLED WITH  
STEADY ISENTROPIC UPGLIDE THROUGH ITS PRECIP SHIELD AND ~2" PWAT  
VALUES WILL MAKE IT A VERY EFFICIENT RAIN-MAKER FOR PORTIONS OF  
THE MIDWEST. THE EXACT TRACK OF THE SYSTEM (FURTHER NORTH/SOUTH IN  
IA AND IL) WILL HEAVILY INFLUENCE THE AMOUNT OF RAINFALL WE GET  
HERE IN SOUTHERN WI, AND A SHARP CUTOFF BETWEEN A FEW LIGHT  
SHOWERS (FURTHER NORTH) AND A DROUGHT-BUSTING LONG-DURATION  
RAINFALL (FURTHER SOUTH AND WEST) COULD EASILY SET UP NEAR OR  
WITHIN OUR CWA. THAT SAID, MODEL GUIDANCE IS BEGINNING TO  
CONVERGE ON THE SYSTEM TRACK.  
 
REGARDLESS OF THE TRACK OF THE LOW, WE DON'T EXPECT STRONG TO  
SEVERE THUNDERSTORMS IN SOUTHERN WI GIVEN THE LACK RETURN FLOW  
AND LIMITED MUCAPE (MOST GUIDANCE 500 JOULES OR LESS). THE ONLY  
CONCERNS WOULD BE THE POTENTIAL FOR LOCALIZED HEAVY RAINFALL  
(LEVEL 2 OUT OF 4 RISK ALONG AND WEST OF THE I-90 CORRIDOR) AND  
A CHANCE FOR LIGHTNING.  
 
A GRADUAL SOUTHWEST TO NORTHEAST ARRIVAL OF RAIN CHANCES UNFOLDS  
THROUGH THE DAYTIME HOURS ON FRIDAY. ACTIVITY WOULD THEN PEAK  
IN INTENSITY / COVERAGE LATER FRIDAY THROUGH FRIDAY NIGHT, AND  
SLOWLY DIMINISH THROUGH SATURDAY.  
 
BREEZY ONSHORE WINDS ASSOCIATED WITH THE LOW WILL LEAD TO  
MODERATE OR HIGH SWIM RISK CONDITIONS ON LAKE MICHIGAN BEACHES  
LATE FRIDAY NIGHT THROUGH THIS WEEKEND, ESPECIALLY FROM  
MILWAUKEE COUNTY SOUTHWARD.  
 
SHEPPARD  
 
 
   
LONG TERM  
 
ISSUED 200 PM CDT THU JUL 30 2026  
 
SATURDAY NIGHT THROUGH THURSDAY:  
 
DRY WEATHER EXPECTED SUNDAY INTO MONDAY AS HIGH PRESSURE SETTLES  
OVER THE UPPER GREAT LAKES. TEMPERATURES BEGIN A GRADUAL UPTREND  
EARLY NEXT WEEK AS A RIDGE IN THE UPPER JET BUILDS EAST INTO THE  
REGION. THE WARMTH WOULD LIKELY PEAK ON TUESDAY AS THE UPPER RIDGE  
AXIS PASSES, WITH HIGH TEMPERATURES IN THE MID TO UPPER 80S  
POSSIBLE, WITH DEWPOINTS IN THE UPPER 60S TO AROUND 70. AN  
APPROACHING LONGWAVE TROUGH WILL ALLOW SOME DIFFLUENT FLOW TO  
OVERSPREAD THE REGION TUESDAY PM (10-20% SHOWER/STORM CHANCES),  
INTENSIFYING TUESDAY NIGHT INTO WEDNESDAY AS THE RIGHT ENTRANCE  
OF AN ASSOCIATED JET STREAK PASSES BY (25-35% SHOWER/STORM  
CHANCES). THE SURFACE PRESSURE RESPONSE TO THESE FEATURES IS  
CERTAINLY NOT LOOKING ORGANIZED ON MODEL GUIDANCE, HENCE OUR  
CONFIDENCE IN RAINFALL WITH IT REMAINS LOW. THE LONGWAVE PATTERN  
IN THE JET LOOKS TO REMAIN PREDOMINANTLY ZONAL THROUGH NEXT  
WEEK, SUGGESTING MOSTLY DRY WEATHER AND NEAR NORMAL TO SLIGHTLY  
ABOVE NORMAL TEMPERATURES (HIGHS IN THE LOW TO MID 80S) FOR  
LATE NEXT WEEK. THAT SAID, THE PROXIMITY OF THE JET AND SMALLER  
PERTURBATIONS WITHIN IT MERIT SOME CONTINUED ~25% PRECIP CHANCES  
INTO THURSDAY.  
 
SHEPPARD  
 
 
   
AVIATION  
 
ISSUED 720 PM CDT THU JUL 30 2026  
 
VFR CONDITIONS EXPECTED THROUGHOUT TONIGHT AND INTO FRIDAY, WITH  
RAINFALL DEVELOPING AND PROGRESSING EASTWARD THROUGH THE DAY  
FRIDAY. CEILINGS ARE EXPECTED TO REMAIN VFR, BUT DROPS IN  
VISIBILITY TO MVFR ARE EXPECTED. BY FRIDAY EVENING, EXPECT  
STEADY RAINFALL ACROSS ALL OF SOUTHERN WISCONSIN, WITH ISOLATED  
EMBEDDED LIGHTNING.  
 
LIGHT AND VARIABLE WINDS ARE EXPECTED TONIGHT, BECOMING  
SOUTHEASTERLY AND INCREASING TO AROUND 10 KT INTO FRIDAY. WINDS  
WILL CONTINUE TO INCREASE INTO FRIDAY EVENING.  
 
MH  
 
 
   
MARINE  
 
ISSUED 200 PM CDT THU JUL 30 2026  
 
LIGHT AND VARIABLE WINDS WILL TAKE ON A SOUTHERLY COMPONENT THIS  
AFTERNOON AS HIGH PRESSURE AROUND 30.0 INCHES STARTS TO DRIFT  
TOWARD THE LOWER GREAT LAKES. LOW PRESSURE AROUND 29.7 INCHES WILL  
TRACK ACROSS IOWA FRIDAY AND THROUGH ILLINOIS SATURDAY. THE  
APPROACHING AREA OF LOW PRESSURE WILL BRING CHANCES FOR SHOWERS  
AND A FEW THUNDERSTORMS FRIDAY INTO SATURDAY. SEVERE WEATHER IS  
NOT EXPECTED IN ANY OF THIS ACTIVITY. BREEZY NORTHEAST WINDS  
WILL DEVELOP SATURDAY AND SHOULD CONTINUE THROUGH SUNDAY  
AS HIGH PRESSURE OF 30.0 INCHES BUILDS OVER LAKE SUPERIOR. A  
FEW GUSTS UPWARDS OF 30 KT WILL BE POSSIBLE OVER THE SOUTHERN  
HALF OF THE LAKE.  
 
FOR NEARSHORE ZONES FROM SHEBOYGAN TO WINTHROP HARBOR, THE GUSTY  
NORTHEAST WINDS AND BUILDING WAVES ARE LIKELY TO REACH SMALL  
CRAFT ADVISORY LEVELS AT TIMES SATURDAY THROUGH SUNDAY NIGHT.  
 
SHEPPARD  
 
 
   
MKX WATCHES/WARNINGS/ADVISORIES  
 
WI...NONE.  
LM...NONE.  
 
 
 
 
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