832  
FXUS63 KMKX 171923  
AFDMKX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI  
223 PM CDT MON AUG 17 2026  
   
KEY MESSAGES  
 
- SHOWERS AND STORMS RETURN TUESDAY. CURRENTLY FAVORED WINDOW  
FOR PRECIP IS 1-9 PM. AN ISOLATED SEVERE STORM WITH HAIL AND  
GUSTY WINDS CAN'T BE RULED OUT.  
 
- DRY AND PLEASANT CONDITIONS WEDNESDAY THROUGH THURSDAY. RAIN CHANCES  
RETURN FRIDAY.  
 
- NICE WEATHER EXPECTED THIS WEEKEND.  
 
 
   
SHORT TERM  
 
ISSUED 225 PM CDT MON AUG 17 2026  
 
THIS AFTERNOON THROUGH TUESDAY NIGHT:  
 
SYNOPSIS/MESOANALYSIS: A RIDGE OF SURFACE HIGH PRESSURE IS MOVING  
INTO WISCONSIN THIS AFTERNOON, RESULTING IN MAINLY WEST-NORTHWEST  
WINDS ACROSS THE REGION. LONE EXCEPTION TO THE BROADER PATTERN IS  
NEAR LAKE MICHIGAN, WHERE A LAKE BREEZE IS ATTEMPTING TO MIX INLAND.  
EXPECT THE LAKE BREEZE TO CONTINUE NUDGING WEST INTO THE AFTERNOON,  
WITH AN EASTERLY WIND SHIFT AND SLIGHTLY COOLER TEMPERATURES  
MATERIALIZING IN ITS WAKE. FURTHER WEST, SURFACE OBSERVATIONS SHOW A  
COLD FRONT EXTENDING FROM GRAND FORKS, NORTH DAKOTA SOUTHWEST INTO  
THE SOUTH DAKOTA BLACK HILLS. THE BOUNDARY WILL WORK TOWARD THE  
UPPER MISSISSIPPI VALLEY TONIGHT, AND IS FORECAST TO PULL THROUGH  
SOUTHERN WISCONSIN TUESDAY AFTERNOON & EVENING. SHOWER AND  
THUNDERSTORM CHANCES RETURN ALONG/AHEAD OF THE BOUNDARY, WITH PEAK  
POTENTIAL BETWEEN ~1-9 PM TUESDAY. WHILE NOT EXPECTED TO BE  
WIDESPREAD, A FEW STRONG-SEVERE THUNDERSTORMS WITH GUSTY WINDS AND  
DAMAGING WINDS CAN'T BE RULED OUT. HEAVY DOWNPOURS WILL ALSO  
ACCOMPANY THUNDERSTORMS, WITH WIDESPREAD FLOODING POTENTIAL  
APPEARING LOW AT THIS TIME. CONDITIONS WILL DRY OUT TUESDAY NIGHT AS  
THE COLD FRONT DEPARTS & DRIER AIR BEGINS TO WORK INTO THE AREA.  
 
TONIGHT-TUESDAY MORNING: WITH HIGH PRESSURE INFLUENCES LINGERING,  
CAN'T RULE OUT SOME FOG IN THE WISCONSIN VALLEY. NOT ANTICIPATING  
ANY DENSE FOG, BUT WILL BE MONITORING VISIBILITIES. WILL ALSO BE  
WATCHING RADAR TRENDS FROM THE NORTHERN PLAINS INTO THE UPPER  
MISSISSIPPI VALLEY. EXPECTING AREAS OF THUNDERSTORM DEVELOPMENT  
ACROSS THIS REGION AS WARM/MOIST ADVECTION COMMENCES AHEAD OF THE  
ENCROACHING COLD FRONT. RELATIVELY SOLID CONSENSUS AMONGST HIGH-RES  
GUIDANCE POINTS TO THIS ACTIVITY REMAINING WEST OF THE REGION  
THROUGH THE OVERNIGHT HOURS, THOUGH INDIVIDUAL SOLUTIONS BEGIN TO  
DIVERGE REGARDING THE EASTWARD CONTINUATION OF ACTIVITY BEYOND  
DAYBREAK. THIS DIVERGENCE LEADS TO SEVERAL POSSIBLE SCENARIOS  
REGARDING SHOWER/STORM POTENTIAL OVER THE AREA ON TUESDAY MORNING,  
WITH POSSIBILITIES RANGING FROM ENTIRELY DRY CONDITIONS TO AREAS OF  
SHOWERS/STORMS MOVING IN FROM THE WEST. WITH RESIDUAL DRIER AIR  
STILL IN PLACE ON THE BACK SIDE OF DEPARTING HIGH PRESSURE/THE BULK  
OF MOISTURE RECOVERY HAVING YET TO OCCUR LOCALLY, HAVE TRENDED THE  
FORECAST TOWARD THE QUIETER/LESS PRECIP SCENARIO IN THE AFTERNOON  
UPDATE, BUT WILL NEED TO CLOSELY MONITOR FOR POSSIBLE INCREASES IN  
PRECIP PROBS INTO TONIGHT. NOT EXPECTING ANY SEVERE WEATHER HAZARDS  
IN THE EVENT SHOWERS/STORMS MAKE IT INTO THE REGION TUESDAY MORNING  
GIVEN LITTLE OR WEAK INSTABILITY.  
 
TUESDAY AFTERNOON-EVENING: THE CURRENTLY FAVORED WINDOW FOR SHOWERS  
AND STORMS OPENS AS THE COLD FRONT MOVES THROUGH. ~1-9 PM BEING THE  
PREFERRED WINDOW FOR STORMS WILL BE HEAVILY CONTINGENT ON SUFFICIENT  
MOISTURE & INSTABILITY RECOVERY IN SOUTHERN WISCONSIN DURING THE  
MORNING HOURS, WITH ANY COMBINATION OF STORMS TO THE WEST/OVER THE  
AREA OR AFFILIATED CLOUD DEBRIS ACTING TO DISRUPT THE  
DESTABILIZATION PROCESS. GIVEN CURRENT THINKING (NAMELY THAT  
CONDITIONS WILL STAY DRIER DURING THE MORNING & THAT SOME  
DESTABILIZATION WILL BE ABLE TO OCCUR), HAVE THUS BROUGHT  
~60%/LIKELY PRECIP PROBABILITIES INTO THE FORECAST DURING THIS TIME  
FRAME, WITH THE UNDERSTANDING THAT CHANGES COULD OCCUR IN THE EVENT  
THAT THE MORNING PLAYS OUT DIFFERENTLY. GIVEN THAT SOME  
MOISTURE/INSTABILITY RECOVERY WOULD HAVE OCCURRED IN THIS SCENARIO,  
OVERLAPPING WIND SHEAR WOULD BE SUFFICIENT FOR A FEW ORGANIZED  
STORMS CAPABLE OF GUSTY WINDS & ISOLATED LARGE HAIL. LEVEL 1/5  
SEVERE WEATHER RISK THUS CONTINUES ACROSS MOST OF SOUTHERN WISCONSIN  
IN THE LATEST SEVERE OUTLOOK FROM THE STORM PREDICTION CENTER. STAY  
WEATHER-AWARE IF PLANNING TO BE OUTDOORS TUESDAY AFTERNOON/EVENING.  
 
QUIGLEY  
 
 
   
LONG TERM  
 
ISSUED 225 PM CDT MON AUG 17 2026  
 
WEDNESDAY THROUGH MONDAY:  
 
SYNOPSIS: THE COLD FRONT RESPONSIBLE FOR TUESDAYS STORM POTENTIAL IS  
FORECAST TO BE SOUTH OF THE WISCONSIN-ILLINOIS BORDER BY WEDNESDAY  
MORNING, WITH DRIER NORTHERLY FLOW & PASSING HIGH PRESSURE LEADING  
TO PLEASANT & PRECIP-FREE CONDITIONS WEDNESDAY AFTERNOON THROUGH  
THURSDAY. WINDS WILL TREND SOUTHWESTERLY ON FRIDAY, BRINGING MILDER  
AND MODESTLY MORE HUMID AIR TO THE REGION. THE NEXT COLD FRONT IS  
FORECAST TO MOVE THROUGH THE WESTERN GREAT LAKES FRIDAY EVENING,  
WHEN SOME SCATTERED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE.  
PLEASANT CONDITIONS WILL RETURN BY THE SATURDAY-SUNDAY TIME FRAME  
BEHIND THE DEPARTED FRONT. HIGH PRESSURE WILL SLIDE THROUGH THE  
WESTERN GREAT LAKES SUNDAY INTO MONDAY, MAINTAINING PLEASANT  
CONDITIONS THROUGH THE CONCLUSION OF THE LONG TERM PERIOD.  
 
FRIDAY AFTERNOON-EVENING: APPEARS THAT THE NEXT WINDOW FOR SHOWERS &  
THUNDERSTORMS WILL OPEN ALONG THE NEXT COLD FRONT. SIMILAR TO  
TUESDAYS SETUP, A COMBINATION OF ABUNDANT SYNOPTIC FORCING +  
SUFFICIENT WIND SHEAR POINTS TOWARD GENERAL FAVORABILITY FOR MORE  
ORGANIZED THUNDERSTORMS, WITH PRE-FRONTAL MOISTURE RETURN &  
INSTABILITY BEING THE LIMITING FACTOR ON MORE PRECISE STORM  
COVERAGE, LOCATION, AND INTENSITY. WILL BE MONITORING TRENDS  
REGARDING THESE FACTORS OVER COMING FORECASTS & PROVIDING ADDITIONAL  
UPDATES AS DETAILS CLARIFY.  
 
QUIGLEY  
 
 
   
AVIATION  
 
ISSUED 225 PM CDT MON AUG 17 2026  
 
VFR FLIGHT CATEGORIES PREVAIL THROUGH THE PERIOD. FAIR WEATHER  
CUMULUS CLOUDS BASED BETWEEN FL040 AND FL060 WILL CONTINUE INTO THIS  
AFTERNOON. AN ISOLATED SPRINKLE IS POSSIBLE ALONG THE LAKE BREEZE,  
WITH COVERAGE REMAINING TOO ISOLATED TO JUSTIFY MENTIONS IN ANY  
FORECASTS AT THIS TIME. WILL BE MONITORING TRENDS FOR POSSIBLE  
ADJUSTMENTS. WINDS WILL REMAIN LIGHT THROUGH THIS EVENING AS AN AREA  
OF HIGH PRESSURE SHIFTS FROM THE UPPER MISSISSIPPI VALLEY ACROSS  
WISCONSIN. FOG DEVELOPMENT IS POSSIBLE IN THE WISCONSIN RIVER VALLEY  
OVERNIGHT, THOUGH ANY IMPACTS ARE EXPECTED TO REMAIN WELL WEST OF  
MSN AND JVL. WILL BE MONITORING TRENDS FOR ANY CHANGES TO THESE  
EXPECTATIONS. WINDS WILL TREND SOUTH-SOUTHWESTERLY AS HIGH PRESSURE  
PUSHES EAST OF THE REGION TUESDAY. A COLD FRONT WILL MOVE INTO  
SOUTHERN WISCONSIN TUESDAY AFTERNOON/EVENING, BRINGING CHANCES FOR  
SCATTERED SHRA AND TSRA. CAN'T RULE OUT SOME ACTIVITY DURING THE  
MORNING, THOUGH CONFIDENCE IN STORM DEVELOPMENT IS GREATEST DURING  
THE AFTERNOON. HAVE ADDRESSED THIS POTENTIAL WITH A PROB30 GROUP  
NEAR THE END OF THE 30 HOUR PERIOD AT MKE, WITH PROB30 GROUPS  
BECOMING NECESSARY IN THE 00Z UPDATE AT 24 HOUR TERMINALS.  
 
QUIGLEY  
 
 
   
MARINE  
 
ISSUED 225 PM CDT MON AUG 17 2026  
 
1018 MB LOW PRESSURE IS APPROACHING LAKE MICHIGAN THIS AFTERNOON,  
BRINGING LIGHT TO VARIABLE WINDS TO THE OPEN WATERS. THE LIGHTER  
WINDS WILL CONTINUE INTO THIS EVENING AS THE HIGH CONTINUES EAST. A  
SLOW-MOVING COLD FRONT WILL APPROACH FROM THE NORTHERN GREAT PLAINS  
TUESDAY INTO WEDNESDAY, BRINGING INCREASING SOUTHWEST WINDS AND  
CHANCES FOR THUNDERSTORMS. TUESDAY EVENING AND NIGHT APPEARS MOST  
FAVORED FOR STORM POTENTIAL, WITH STORM CHANCES EXPECTED TO MOVE  
WELL SOUTH OF THE WATERS ON WEDNESDAY. AN ISOLATED STRONGER STORM  
WITH GUSTY WINDS CANT BE RULED OUT IN THIS ACTIVITY, THOUGH  
WIDESPREAD SEVERE WEATHER POTENTIAL APPEARS LOW AT THIS TIME. WILL  
CONTINUE TO MONITOR TRENDS THROUGH TOMORROW. 1016 MB HIGH PRESSURE  
WILL MOVE THROUGH THE WESTERN GREAT LAKES WEDNESDAY THROUGH  
THURSDAY, WITH LIGHT AND VARIABLE WINDS PREVAILING ACROSS THE  
WATERS. THE NEXT THUNDERSTORM CHANCES ARRIVE FRIDAY AFTERNOON AND  
EVENING, WHEN THE NEXT COLD FRONT IS EXPECTED TO MOVE ACROSS LAKE  
MICHIGAN.  
 
SMALL CRAFT ADVISORY CONDITIONS AREN'T EXPECTED THROUGH THIS WEEK IN  
NEARSHORE ZONES. SHOWERS AND THUNDERSTORMS ARE POSSIBLE TUESDAY  
EVENING AND FRIDAY AFTERNOON ALONG A PAIR OF COLD FRONTS. WIDESPREAD  
SEVERE WEATHER ISN'T EXPECTED IN EITHER WINDOW OF ACTIVITY, THOUGH  
AN ISOLATED STRONGER STORM WITH GUSTY WINDS CAN'T BE RULED OUT ON  
TUESDAY EVENING. WILL CONTINUE TO MONITOR TRENDS AND PROVIDE  
ADDITIONAL UPDATES THROUGH TOMORROW.  
 
QUIGLEY  
 
 
   
MKX WATCHES/WARNINGS/ADVISORIES  
 
WI...NONE.  
LM...NONE.  
 
 
 
 
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