283  
FXUS63 KMQT 170716  
AFDMQT  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MARQUETTE MI  
316 AM EDT THU SEP 17 2026  
   
KEY MESSAGES  
 
- ONGOING RAIN SHOWERS EARLY THIS MORNING END BY NOON, RAIN TOTALS  
GENERALLY LESS THAN A TENTH OF AN INCH.  
 
- RAIN BECOMES LIKELY (>50% CHANCE) FOR THE SOUTH HALF OF THE UP  
FRIDAY AFTERNOON INTO AT LEAST SATURDAY MORNING. THERE IS A SLIGHT  
CHANCE (~20-40%) OF AMOUNTS EXCEEDING AN INCH, MOSTLY LIMITED TO  
MENOMINEE COUNTY SOUTH OF US-2. THERE IS UNCERTAINTY IN HOW FAR  
NORTH THE PRECIPITATION WILL REACH.  
 
 
   
DISCUSSION  
 
ISSUED AT 316 AM EDT THU SEP 17 2026  
 
KMQT RADAR RETURNS AT 05Z SHOW A BIT MORE WIDESPREAD RAIN SHOWER  
COVERAGE OVER THE WESTERN UP THAN FORECAST 24 HOURS AGO AS THE  
SHORTWAVE LOW OVER NORTHERN MANITOBA HAS MORE PRONOUNCED TROUGHING  
ALONG ITS SOUTHERN PERIPHERY. DESPITE THIS TREND UPWARDS IN SHOWER  
COVERAGE, INTENSITY REMAINS LOW AS THE SHOWERS ARE HAVING TO FIGHT  
SUBSIDENCE FROM A SURFACE HIGH OF 1026-1028 MB THAT REMAINS OVER THE  
REGION, THOUGH IS NOW CENTERED AROUND SOUTHERN JAMES BAY. 00Z HREF  
75TH PERCENTILE QPF BY THE TIME SHOWERS END AROUND 12Z IS STILL LESS  
THAN A TENTH OF AN INCH FOR ALL EXCEPT FOR THE WATERSMEET AREA.  
CONFIDENCE IN ANY MEASURABLE RAINFALL THIS MORNING DECREASES SHARPLY  
OVER THE EAST HALF OF THE UP, WITH THE HREF POPS EAST OF THE M-94  
CORRIDOR MOSTLY SUB-15%. THE ADDITIONAL LOW LEVEL MOISTURE FROM  
THESE SHOWERS MAY LEAD TO A FEW PATCHES OF FOG, BUT WIDESPREAD DENSE  
FOG IS NOT EXPECTED AS HREF CHANCES OF VISIBILITY LESS THAN 1 MILE  
IS ONLY 10-20% THIS MORNING.  
 
ELSEWHERE, THE 500MB PATTERN CONSISTS OF 600 DAM RIDGING OVER  
MEMPHIS BOUNDED BY DEEP TROUGHS CENTERED OVER NORTHERN CALIFORNIA  
AND THE BAHAMAS IN ADDITION TO THE AFOREMENTIONED NORTHERN MANITOBA  
TROUGH. THE FIRST KEY FEATURE TO WATCH WILL BE A RIDGE-RIDING  
SHORTWAVE CURRENTLY OVER THE UT/CO/WY TRIPLE POINT THAT WILL TRACK A  
SURFACE LOW SOUTH OF THE UP THIS WEEKEND AND BRING CHANCES OF RAIN  
TO THE UP FRIDAY AND SATURDAY. THE NBM CONTINUES TO TREND THE CORE  
OF HEAVY RAINFALL SOUTH, THOUGH THE LREF HAS WAVERED BACK AND FORTH  
SOME OVER THE PAST FEW RUNS. THE 00Z RRFS DOESN'T EVEN GUARANTEE  
PRECIP FOR THE VAST MAJORITY OF THE UP, ONLY SHOWING MEASURABLE  
PRECIP FOR SOUTHERN MENOMINEE COUNTY AND POCKETS OF THE INTERIOR  
WEST. WHILE THAT SOLUTION IS ON THE DRY SIDE OF THE DISTRIBUTION, IT  
IS WITHIN THE REALM OF POSSIBILITIES. CURRENT CHANCES OF A TENTH OF  
AN INCH OF PRECIP OR HIGHER IN THE LREF ARE AROUND 50% OR HIGHER FOR  
THE US-2 CORRIDOR AND SOUTH. THE 25TH-75TH PERCENTILE PRECIPITATION  
ACCUMULATION REMAINS HIGH AS THE 25TH PERCENTILE SHOWS VERY LITTLE  
PRECIP FOR ALL EXCEPT FOR MENOMINEE COUNTY, THOUGH THE 75TH  
PERCENTILE SHOWS UP TO HALF AN INCH FOR IRON RIVER/ESCANABA AND OVER  
AN INCH FOR THE SOUTHERN HALF OF MENOMINEE COUNTY, SO SOME HEAVY  
RAINFALL REMAINS POSSIBLE BUT IS FAR FROM GUARANTEED.  
 
IN THE WAKE OF THE DISTURBANCE, THE WESTERN CONUS TROUGH WILL SHIFT  
INTO THE NORTHERN PLAINS, WEAKENING SLIGHTLY. AT THE SAME TIME,  
RIDGING TO THE NORTH OF THE TROUGH AMPLIFIES, CAUSING SPLIT FLOW. AT  
THIS TIME, THE FAVORED SOLUTION IS FOR THE UP TO BE AFFECTED BY THE  
NORTHERN BRANCH OF THIS SPLIT FLOW WHICH WILL LEAD TO PERSISTENT  
HIGH PRESSURE AND DRY WEATHER AND NEAR-NORMAL TO SLIGHTLY BELOW  
NORMAL TEMPERATURES FOR SUNDAY THROUGH AT LEAST THE FIRST FEW DAYS  
OF NEXT WEEK UNTIL ENSEMBLE SPREAD INCREASES FOR THE MIDWEEK AND  
BEYOND.  
 
 
   
AVIATION /06Z TAFS THROUGH 06Z FRIDAY/  
 
ISSUED AT 123 AM EDT THU SEP 17 2026  
 
VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE TAF PERIOD. A  
WEAK SHORTWAVE WILL MOVE ACROSS THE AREA THROUGH EARLY MORNING  
BRINGING MID-LEVEL CLOUDINESS ALONG WITH A BAND OF LIGHT SHOWERS.  
CONFIDENCE WAS HIGH ENOUGH TO INCLUDE A TEMPO GROUP EARLY IN THE TAF  
PERIOD AT THE SITES. OVERALL, SHOWERS ARE NOT EXPECTED TO IMPACT  
FLIGHT CATEGORIES. WINDS WILL BE LIGHT THOUGH THE PERIOD.  
 
 
   
MARINE  
 
ISSUED AT 316 AM EDT THU SEP 17 2026  
 
HIGH PRESSURE KEEPS WINDS BELOW 20 KT THROUGH TONIGHT. FRIDAY AND  
SATURDAY, LOW PRESSURE PASSING BY TO THE SOUTH COMBINED WITH A HIGH  
TO THE NORTH WILL RESULT IN PROLONGED NORTHEASTERLY FLOW INTO THE  
WESTERN ARM OF LAKE SUPERIOR, WITH WINDS INCREASING LOCALLY TO 20-30  
KT AND WAVES OF 2-3 FEET. A STRONGER HIGH BUILDING TO THE NORTH ON  
SUNDAY LOOKS TO EXPAND COVERAGE OF 20-30 KT WINDS TO MUCH OF THE  
SOUTHERN HALF OF LAKE SUPERIOR. MODELS DISAGREE ABOUT GALE  
POTENTIAL, WITH THE EURO ENSEMBLE PROBABILITIES OF GALES ONLY AROUND  
10% OVER THE WESTERN ARM WHILE THE NBM PROJECTS GALE CHANCES OF  
AROUND 40%. WAVES INCREASE TO NEAR 3 FEET OVER NORTHERN LAKE  
MICHIGAN AND GREEN BAY ON SATURDAY AS WELL DUE TO PROLONGED  
EASTERLY FLOW APPROACHING 20 KT.  
 
 
   
MQT WATCHES/WARNINGS/ADVISORIES  
 
UPPER MICHIGAN...  
NONE.  
LAKE SUPERIOR...  
NONE.  
LAKE MICHIGAN...  
NONE.  
 
 
 
 
 
DISCUSSION...GS  
AVIATION...NL  
MARINE...GS/THOMPSON  
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