983  
FXUS63 KMKX 090109 AAA  
AFDMKX  
 
AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI  
809 PM CDT TUE SEP 8 2026  
   
KEY MESSAGES
 
 
- MODERATE SWIM RISK AT OZAUKEE & SHEBOYGAN COUNTY BEACHES THIS  
EVENING. STAY AWAY FROM BREAKWATERS AND PIERS IF PLANNING TO  
BE IN THE WATER.  
 
- PERIODS OF OFF/ON SHOWERS WITH A CHANCE OF THUNDERSTORMS  
CONTINUE THROUGH TONIGHT. STORMS COULD PRODUCE LOCALLY HEAVY  
RAINFALL.  
 
- WARM TEMPERATURES WITH LOW HUMIDITY THROUGH THE SECOND HALF OF  
THE WORK WEEK. SHOWER AND STORMS RETURN TO THE FORECAST FRIDAY  
NIGHT INTO SATURDAY.  
 

 
   
UPDATE
 
 
ISSUED 809 PM CDT TUE SEP 8 2026  
 
LIGHT RAIN SHOWERS ARE SPREADING INTO SOUTH CENTRAL WI THIS  
EVENING. THESE ARE ELEVATED AND WITHOUT LIGHTNING SINCE THE  
INSTABILITY AXIS IS LAGGING BEHIND IN SOUTH CENTRAL MN AND IOWA  
RIGHT NOW.  
 
THE AREA OF STRONGEST STORMS IS OVER CENTRAL IOWA AND THAT WILL  
CONTINUE TO DIVE SOUTHEASTWARD ALONG THE THETA-E GRADIENT AND  
ALSO THE INSTABILITY GRADIENT. SOUTHERN WI WILL CONTINUE TO BE  
IN THE STRATIFORM RAIN REGION. THERE WILL BE INCREASING  
PRECIPITABLE WATER VALUES WHICH WILL BRING LOWER CLOUD BASES  
AND DEEPER MOISTURE. A SOUTHWEST TO WEST LOW LEVEL JET WILL PUSH  
INTO SOUTH CENTRAL WI ALREADY LATE THIS EVENING BUT THEN SHIFT  
SOUTH (OUT OF WI) AFTER 4 AM. THIS IS ALSO COINCIDENT WITH A  
WEAK 500MB SHORTWAVE TROUGH. THE LLJ WILL HELP TRIGGER MORE  
WIDESPREAD SHOWERS AND GIVE US A LITTLE CHANCE FOR A FEW RUMBLES  
OF THUNDER TONIGHT.  
 
GIVEN THAT WE ARE NOT EXPECTING DEEP CONVECTION TONIGHT, THE  
FLOODING RISK IS PRETTY LOW. HOWEVER, IT STILL LOOKS LIKE ALL  
BUT CENTRAL WI HAS A HIGH CHANCE (80%) OF SEEING A SOAKING RAIN  
WITH AMOUNTS UP TO A HALF INCH. LOCALLY HIGHER AMOUNTS UP TO AN  
INCH WILL BE POSSIBLE, ESPECIALLY TOWARD THE IL BORDER.  
 
SHOWERS WILL END FROM NORTHWEST TO SOUTHEAST THROUGH MID  
WEDNESDAY MORNING.  
 
CRONCE  
 

 
   
SHORT TERM
 
 
ISSUED 150 PM CDT TUE SEP 8 2026  
 
REST OF THIS AFTERNOON THROUGH FRIDAY:  
 
SYNOPSIS/MESOANALYSIS: LOW PRESSURE IS CENTERED OVER CENTRAL  
MANITOBA THIS AFTERNOON, WITH AN ATTENDANT COLD FRONT EXTENDING FROM  
THE MANITOBA-SASKATCHEWAN BORDER SOUTH TOWARD THE SIOUX FALLS, SD  
VICINITY. A MUDDY PREFRONTAL WARM SECTOR IS APPARENT REGIONALLY,  
WITH AREAS OF SHOWERS AND EMBEDDED THUNDERSTORMS ONGOING FROM  
SHEBOYGAN SOUTHWEST TO THE MISSOURI RIVER. ACTIVITY IS ONGOING  
WITHIN STEADY WARM ADVECTION NORTH & EAST OF A WARM FRONT CURRENTLY  
EXTENDING FROM DES MOINES TO NEAR ST LOUIS. BOTH THE WARM & COLD  
FRONTS WILL WORK THEIR WAY TOWARD AND INTO SOUTHERN WISCONSIN THIS  
EVENING INTO WEDNESDAY MORNING, BRINGING CONTINUING CHANCES FOR ON  
AND OFF SHOWERS AND STORMS. SOME STORMS COULD PRODUCE ISOLATED GUSTY  
WINDS AND LOCALLY HEAVY RAINFALL. THE APPROACHING COLD FRONT WILL  
PUSH SOUTHEAST OF THE AREA BY WEDNESDAY AFTERNOON, WITH HIGH  
PRESSURE SETTLING INTO THE WESTERN GREAT LAKES WEDNESDAY NIGHT  
THROUGH THE DAY ON FRIDAY. THE ARRIVING HIGH WILL MAINTAIN PLEASANT  
& WARM CONDITIONS WITH LOW HUMIDITY THROUGH THE END OF THE WORK  
WEEK.  
 
REST OF THIS AFTERNOON: ON AND OFF SHOWERS AND THUNDERSTORMS WILL  
CONTINUE AREAWIDE. STORMS COULD PRODUCE A FEW FLASHES OF LIGHTNING &  
BRIEF HEAVY DOWNPOURS, ALTHOUGH SCATTERED COVERAGE & LIMITED  
RESIDENCE TIME WILL KEEP LOCALLY HEAVY RAINFALL CONCERNS LOW. WITH  
BETTER INSTABILITY STILL LAGGING TO THE WEST OF THE REGION, NOT  
EXPECTING ANY SEVERE WEATHER HAZARDS IN STORMS. KEEP AN EYE ON THE  
RADAR IF PLANNING TO BE OUTSIDE. INCREASING WAVE HEIGHTS WILL LEAD  
TO A MODERATE SWIM RISK AT SHEBOYGAN AND OZAUKEE COUNTY BEACHES.  
EXERCISE EXTREME CAUTION IF HEADING LAKESIDE IN THESE LOCATIONS.  
 
TONIGHT INTO WEDNESDAY MORNING: MODERATE SWIMMING RISK CONTINUES  
THROUGH MID-EVENING (~9 PM) AT SHEBOYGAN AND OZAUKEE COUNTY BEACHES.  
ANTICIPATING A STEADY SOUTHWEST-NORTHEAST UPTICK IN SHOWERS AND  
STORMS NEAR & AFTER 12 AM AS COLD FRONTAL AND LOW LEVEL JET-  
AFFILIATED FORCING SPREAD INTO SOUTHERN WISCONSIN. INCREASING STORM  
COVERAGE COULD BEGIN A TOUCH EARLIER (~9 PM-MIDNIGHT) WEST OF I-39 &  
A TOUCH LATER (MIDNIGHT-3 AM) FURTHER EAST. MODESTLY HIGHER  
INSTABILITY WILL BE ARRIVING INTO SOUTHERN WISCONSIN DURING THIS  
TIME FRAME, SO GREATER EMBEDDED THUNDERSTORM COVERAGE IS ANTICIPATED  
RELATIVE TO THIS AFTERNOON'S SHOWERY ACTIVITY. AS EVIDENCED BY  
UPSTREAM 12Z SOUNDINGS FROM MPX & SGF, AN UNSEASONABLY MOIST AIR  
MASS CHARACTERIZED BY 1.75"+ PRECIPITABLE WATER VALUES WILL ALSO BE  
ARRIVING, WHICH WILL HELP TO SUPPORT BRIEF PERIODS OF ENHANCED  
RAINFALL RATES WITHIN STORMS. THUS EXPECTING A GENERAL 0.1-0.5"  
RAINFALL AREAWIDE, WITH AREAS TO THE WEST OF I-39 MOST LIKELY TO SEE  
THE HIGHER ACCUMULATIONS. FRONT-PARALLEL STEERING FLOW POINTS TOWARD  
SOME POTENTIAL FOR BRIEF PERIODS OF TRAINING & AFFILIATED LOCALLY  
HIGHER TOTALS IN THE 1-2"+ RANGE. BEST POTENTIAL FOR THESE LOCALLY  
HIGHER TOTALS WILL BE OVER THE SOUTHERN HALF OF THE AREA. COULD SEE  
SOME MINOR HYDRO IMPACTS (PONDING OF WATER, URBAN & SMALL STREAM  
FLOODING) IN AREAS OF LOCALIZED TRAINING, THOUGH WIDESPREAD FLASH  
FLOODING POTENTIAL IS LOW. AN ISOLATED STRONGER STORM WITH GUSTY  
WINDS CAN'T BE RULED OUT, THOUGH MORE WIDESPREAD SEVERE WEATHER  
POTENTIAL IS EXPECTED TO REMAIN WELL SOUTHWEST OF THE AREA.  
 
QUIGLEY  
 

 
   
LONG TERM
 
 
ISSUED 150 PM CDT TUE SEP 8 2026  
 
FRIDAY NIGHT THROUGH TUESDAY:  
 
SYNOPSIS: NEAR OR SLIGHTLY ABOVE NORMAL TEMPERATURES ARE EXPECTED  
THROUGH THE DURATION OF THE LONG TERM PERIOD. A PAIR OF UPPER  
DISTURBANCES ARE PROGGED TO MOVE THROUGH THE WESTERN GREAT LAKES  
SATURDAY-SATURDAY NIGHT & MONDAY-MONDAY NIGHT, PROVIDING LARGER  
SCALE FORCING FOR PERIODS OF SHOWERS & EMBEDDED THUNDERSTORMS. EACH  
DISTURBANCE WILL BE ACCOMPANIED BY AN AFFILIATED PAIRING OF SURFACE  
WARM & COLD FRONTS, WITH SEASONABLY MUGGY CONDITIONS ANTICIPATED IN  
THE WARM SECTORS BUILDING IN BETWEEN THE BOUNDARIES. CURRENTLY  
LOOKING AT THE HIGHEST HUMIDITIES BEING ON SATURDAY  
AFTERNOON/EVENING & MONDAY AFTERNOON/EVENING, WHEN SOUTHERN  
WISCONSIN IS FORECAST TO BE EACH IN EACH RESPECTIVE WARM SECTOR. NOT  
ANTICIPATING HUMIDITY REACHING HEAT HEADLINE-LEVEL THRESHOLDS DURING  
EITHER PERIOD.  
 
FRIDAY NIGHT THROUGH SATURDAY NIGHT: FIRST OF TWO UPPER DISTURBANCES  
WILL CROSS SOUTHERN WISCONSIN, BRINGING PERIODS OF SHOWERS AND  
THUNDERSTORMS. EXPECTING AN INITIAL WAVE OF ACTIVITY FRIDAY NIGHT  
INTO EARLY SATURDAY MORNING AS A WARM FRONT & AFFILIATED WARM/MOIST  
ADVECTION OVERSPREAD THE AREA, WITH MORE PRECIP DEVELOPMENT POSSIBLE  
SATURDAY AFTERNOON/EVENING ALONG THE TRAILING COLD FRONT. SATURDAY  
AFTERNOON/EVENING STORM DEVELOPMENT WILL BE CONTINGENT ON SUFFICIENT  
SUNSHINE & THERMODYNAMIC RECOVERY IN THE WAKE OF OVERNIGHT/EARLY  
MORNING ACTIVITY, WITH MORE DETAILS BECOMING APPARENT AS FINER SCALE  
MODEL GUIDANCE ARRIVES LATER IN THE WEEK. RAW SHEAR AND PRECIPITABLE  
WATER VALUES POINT TOWARD SOME POTENTIAL FOR ORGANIZED STORMS WITH  
HEAVY DOWNPOURS IN ANY DEVELOPMENT, THOUGH WHETHER OR NOT FAVORABLE  
PARAMETERS WILL BE REALIZED REMAINS TO BE SEEN. WILL BE WATCHING  
TRENDS THROUGH THE END OF THE WEEK AND PROVIDING UPDATES.  
 
SUNDAY NIGHT THROUGH MONDAY NIGHT: NEXT WINDOW OF SHOWER AND STORM  
POTENTIAL ARRIVES AHEAD OF THE NEXT UPPER DISTURBANCE. EXPECTING  
SIMILAR SYSTEM EVOLUTION TO FRIDAY NIGHT-SATURDAY NIGHT, WITH AN  
INITIAL BATCH OF WARM ADVECTION SHOWERS & STORMS SUNDAY NIGHT/EARLY  
MONDAY MORNING & COLD FRONTAL REDEVELOPMENT MONDAY  
AFTERNOON/EVENING. LIKE THE WEEKEND SYSTEM, GLOBAL ENSEMBLES POINT  
TOWARD SUFFICIENT DEEP LAYER SHEAR & PRECIPITABLE WATER VALUES FOR  
MORE ORGANIZED STORMS WITH HEAVY DOWNPOURS, WITH THE REALIZATION OF  
FAVORABLE ENVIRONMENTAL CONDITIONS BEING DEPENDENT ON STILL  
UNCERTAIN THERMODYNAMICS. WILL BE PROVIDING UPDATES AS TRENDS  
CLARIFY.  
 
QUIGLEY  
 

 
   
AVIATION
 
 
ISSUED 809 PM CDT TUE SEP 8 2026  
 
SEE THE MAIN AREA FORECAST DISCUSSION FOR PRECIP DETAILS. THE  
MAIN WINDOW OF SHOWERS WILL BE BETWEEN 04Z (11PM) AND 09Z (4AM),  
BUT LIGHTER RAIN SHOULD SPREAD IN A LITTLE EARLIER AND THERE IS  
A CHANCE OF A FEW TRAILING SHOWERS IN THE MORNING. A PERIOD OF  
MVFR CEILINGS WITH BASES AROUND 2500 FEET (DOWN TO 1500 FT  
POSSIBLE) IS LIKELY EARLY WEDNESDAY MORNING. LOOK FOR PRECIP AND  
LOW CLOUDS TO END FROM WEST TO EAST LATE WED MORNING AND  
POTENTIALLY INTO EARLY WED AFTERNOON.  
 
CRONCE  
 

 
   
MARINE
 
 
ISSUED 150 PM CDT TUE SEP 8 2026  
 
SOUTHERLY WINDS WILL INCREASE INTO TONIGHT OVER LAKE MICHIGAN AS 998  
MB LOW PRESSURE SHIFTS TOWARD THE HUDSON BAY FROM THE CANADIAN GREAT  
PLAINS. A COLD FRONT WILL MOVE ACROSS LAKE MICHIGAN ON WEDNESDAY,  
BRINGING A GENERALLY WESTERLY WIND SHIFT ACROSS THE LAKE. PERIODS OF  
SHOWERS AND OCCASIONAL THUNDERSTORMS WILL ACCOMPANY THE  
APPROACHING/PASSING SURFACE FRONT THIS AFTERNOON THROUGH WEDNESDAY  
MORNING. SEVERE WEATHER ISN'T EXPECTED.  
 
A NEW AREA OF 1020 MB HIGH PRESSURE WILL MOVE FROM THE NORTHERN  
GREAT PLAINS ACROSS LAKE MICHIGAN WEDNESDAY NIGHT THROUGH THURSDAY  
NIGHT, BRINGING A PERIOD OF LIGHT AND VARIABLE WINDS TO THE WATERS.  
THE NEXT AREA OF 992 MB LOW PRESSURE WILL SHIFT FROM THE CANADIAN  
GREAT PLAINS ACROSS THE HUDSON BAY FRIDAY AFTERNOON THROUGH SATURDAY  
NIGHT, BRINGING INCREASING SOUTHWEST WINDS. A FEW GALE FORCE GUSTS  
ARE POSSIBLE DURING THIS TIME FRAME, PARTICULARLY OVER THE NORTHERN  
THIRD OF LAKE MICHIGAN. WILL BE MONITORING TRENDS THROUGH LATE WEEK  
FOR POSSIBLE HEADLINES. A COLD FRONT WILL MOVE OVER LAKE MICHIGAN  
SUNDAY MORNING, BRINGING A NORTHWEST WIND SHIFT TO THE WATERS.  
 
OCCASIONAL WIND GUSTS APPROACHING SMALL CRAFT ADVISORY THRESHOLDS  
ARE POSSIBLE THROUGH THIS EVENING TO THE NORTH OF PORT WASHINGTON.  
HAVE HELD OFF ON ANY HEADLINES IN THE AFTERNOON UPDATE GIVEN AN  
EXPECTED BRIEF & ISOLATED NATURE TO ANY SUCH CONDITIONS, BUT WILL  
NEVERTHELESS CONTINUE TO WATCH TRENDS. SCATTERED SHOWER AND  
THUNDERSTORM CHANCES WILL CONTINUE THROUGH EARLY WEDNESDAY MORNING  
IN ADVANCE OF AN APPROACHING COLD FRONT, WITH SEVERE WEATHER NOT  
ANTICIPATED. PERIODS OF SMALL CRAFT ADVISORY CONDITIONS ARE POSSIBLE  
FRIDAY INTO SATURDAY & EARLY NEXT WEEK, WITH TRENDS BEING MONITORED  
FOR HEADLINES OVER COMING FORECASTS.  
 
QUIGLEY  
 

 
   
MKX WATCHES/WARNINGS/ADVISORIES
 
 
WI...NONE.  
LM...NONE.  

 
 

 
 
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