128
FXUS63 KMQT 241829
AFDMQT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
229 PM EDT MON AUG 24 2026
KEY MESSAGES
- A BEACH HAZARD STATEMENT IS IN EFFECT THROUGH THIS EVENING FOR THE
SHORELINE OF ALGER COUNTY DUE TO STRONG WINDS AND HIGH WAVES
CREATING DANGEROUS RIP CURRENTS AND SWIMMING CONDITIONS.
- FOG IS POSSIBLE (~20% CHANCE) ACROSS MUCH OF THE CENTRAL AND
EASTERN UP TONIGHT.
- THE NEXT CHANCES FOR WIDESPREAD SHOWERS AND THUNDERSTORMS ARRIVES
IN THE WEST ON TUESDAY, SPREADING EAST OVERNIGHT AND WEDNESDAY
BEFORE ENDING FOR MOST LATE WEDNESDAY.
- GENERALLY SEASONABLE TEMPERATURES ARE EXPECTED THROUGH THE REST OF
THIS WEEK.
DISCUSSION
ISSUED AT 226 PM EDT MON AUG 24 2026
EARLY AFTERNOON GOES-EAST IMAGERY SHOWS MOSTLY CLEAR SKIES OVER THE
UP EXCEPT FOR A FEW FAIR WEATHER CU ALONG THE WESTERN UP HIGHLANDS
AND SINE LOW CLOUDS ALONG THE SHORES OF EASTERN LAKE SUPERIOR WHERE
MOISTURE AND FORCING IS STILL MARGINALLY PRESENT ASSOCIATED WITH A
RAP-ANALYZED 1007MB LOW OVER THE ONTARIO/QUEBEC LINE. A 1018 MB
SURFACE HIGH EXTENDS FROM WESTERN LAKE SUPERIOR TO ILLINOIS WHICH IS
PROVIDING THE CLEAR SKIES ELSEWHERE AND ALLOWING TEMPERATURES TO
CLIMB BACK INTO THE MID 60S AFTER AN AUTUMN-FEELING MORNING. WITH
EFFICIENT RADIATIONAL WARMING EXPECTED TODAY, EXPECT HIGHS TO
REACH INTO THE 70S EXCEPT IMMEDIATELY ALONG THE LAKE SUPERIOR
SHORELINE ALONG THE EAST HALF, WHERE CONTINUED BRISK
NORTHWESTERLIES ARE LEADING TO LAKE SUPERIOR-COOLED AIR TO BE
ADVECTED ONSHORE. THESE WINDS ARE ALSO DRIVING WAVE HEIGHTS OF
3-6 FEET FROM 1-5 MILES FROM SHORE ALONG ALGER AND LUCE COUNTY
SHORELINES TODAY, WHICH WILL DRIVE A HIGH RISK OF DANGEROUS RIP
CURRENTS. THEREFORE, THE BEACH HAZARDS STATEMENT WILL CONTINUE
THROUGH THIS EVENING, THOUGH THE SWIM RISK DROPS SIGNIFICANTLY
TONIGHT AS THE HIGH PRESSURE FULLY ESTABLISHES ITSELF OVER THE
UP AND WIND SPEEDS SIMILARLY DECREASE. ANOTHER MOSTLY CLEAR
NIGHT TONIGHT WILL ALLOW TEMPERATURES TO FALL TO THEIR DEW
POINTS FOR MANY INTERIOR LOCATIONS, WITH THE HREF GIVING POCKETS
OF 20-40% CHANCES OF FOG FORMATION ESPECIALLY IN THE EAST.
TEMPERATURES SHOULD BE TOO HIGH FOR FROST, THOUGH A FEW INTERIOR
LOCATIONS MAY FALL INTO THE UPPER 30S.
BY 12Z TUESDAY, THE UPPER AIR PATTERN CONSISTS OF A MASSIVE RIDGE
OVER THE SOUTH-CENTRAL TO SOUTHWESTERN CONUS FLANKED BY A PAIR OF
DEEP TROUGHS, ONE OVER QUEBEC AND OFF THE PACIFIC NORTHWEST COAST
RESPECTIVELY. ADDITIONALLY, A TROUGH WILL BE OVER SOUTHERN MANITOBA
AND WILL PIVOT AROUND THE RIDGE INTO THE GREAT LAKES REGION FOR THE
MIDWEEK PERIOD, BRINGING A PERIOD OF ACTIVE WEATHER. WITH THE CAMS
NOW BEGINNING TO COVER THIS TIME PERIOD, THE CONSENSUS ON THE
ARRIVAL TIME OF SHOWERS IN THE WEST WITH THE PREFRONTAL ISENTROPIC
ASCENT HAS ACCELERATED, WITH THE HREF MEAN ARRIVAL TIME OF PRECIP
NOW SHOWING SHORTLY AFTER NOON TUESDAY AT IWD AND AROUND 22Z FOR THE
US41/141 CORRIDOR. MOIST SOUTHERLY FLOW AHEAD OF THE COLD FRONT WILL
ALLOW FOR DEW POINTS TO CLIMB INTO THE LOW 60S AND FOR PWATS TO GROW
TO 1.25-1.5 INCHES IN THE WEST, WHICH IS ABOVE THE 85TH PERCENTILE
OF CLIMATOLOGY FOR THIS TIME OF YEAR. THIS WILL PROMOTE AN UNSTABLE
AIRMASS WITH HREF MEAN SBCAPE VALUES IN THE WEST BALLOONING TO
AROUND 750 J/KG BY 23Z TUESDAY. HOWEVER, SHEAR IS RELATIVELY
UNIMPRESSIVE AS SOUNDINGS SHOW FLOW IS SUB-30 KT BELOW 525MB, THOUGH
THE LOW LEVEL HODOGRAPHS DO SHOW GOOD CURVATURE. THEREFORE, WILL
EXPECT MOSTLY SUB-SEVERE THUNDERSTORMS AS BUOYANCY IS SUFFICIENT
WITH WEAK FORCING AND NOT ENOUGH SHEAR TO KEEP STORMS ORGANIZED
ENOUGH.
OVERNIGHT INTO EARLY WEDNESDAY, SHOWERS AND THUNDERSTORMS OVERSPREAD
THE UP. IF STORMS CAN MAINTAIN ELEVATED FROM THE BOUNDARY LAYER, THE
EURO ENSEMBLE PROJECTS THEY WILL HAVE 500-750 J/KG OF MUCAPE TO WORK
WITH, THOUGH SHEAR REMAINS SUBPAR WITH WEAK FLOW ALOFT, SO OVERNIGHT
THUNDERSTORMS ARE NOT EXPECTED TO BE SEVERE. DIURNAL DESTABILIZATION
WILL REINVIGORATE STORMS DURING THE AFTERNOON WEDNESDAY AS EURO MEAN
MUCAPE WILL CLIMB TO NEAR 1000 J/KG FOR MUCH OF THE EAST HALF. EVEN
IF STORMS REMAIN SUB-SEVERE FOR MOST, A GOOD SOAKING RAIN IS
EXPECTED AS LREF PROBABILITIES OF OVER A HALF INCH OF RAIN ARE 40-
60% FOR MOST.
LINGERING NORTHERLY FLOW BEHIND THE SHORTWAVE WILL ALLOW
TEMPERATURES ALOFT TO FALL TO SIMILAR TEMPERATURES THAT CAUSED LIGHT
LAKE EFFECT RAIN SHOWERS YESTERDAY, SO SOME POPS WILL LINGER INTO
THURSDAY. OVER THE LAST 24 HOURS, CONFIDENCE HAS INCREASED IN HIGH
PRESSURE SETTLING OVER THE GREAT LAKES FRIDAY INTO THE WEEKEND,
LEADING TO DRY WEATHER. WHILE THE MODELS DIFFER IN THE DETAILS, THE
GLOBAL DETERMINISTIC SUITE HAS COME INTO INCREASING AGREEMENT THAT
THE RIDGE ALOFT WILL SHIFT TO THE SOUTHEAST CONUS AND BRING WITH IT
A MORE POTENT TROUGH THROUGH THE GREAT LAKES IN THE EARLY PORTIONS
OF NEXT WEEK, WHICH COULD BRING UNSETTLED WEATHER TO THE UP AS SOON
AS LATE SATURDAY AND SUNDAY.
AVIATION /18Z TAFS THROUGH 18Z TUESDAY/
ISSUED AT 152 PM EDT MON AUG 24 2026
VFR CONDITIONS PREVAIL AT ALL TAF SITES UNDER CLEAR SKIES. BREEZY
NORTHERLIES AT CMX AND SAW PERSIST THROUGH THE AFTERNOON, BUT WILL
FALL OFF BELOW 15 KTS BY THE EVENING. UNDER MOSTLY CLEAR SKIES AND
DECOUPLING, AREAS OF FOG ARE POSSIBLE ACROSS THE UP, HOWEVER,
CONFIDENCE IS LOW REGARDING VISIBILITY IMPACTS AT ANY ONE TERMINAL,
SO HAVE OPTED TO LEAVE MENTION OUT OF THIS TAF CYCLE.
MARINE
ISSUED AT 226 PM EDT MON AUG 24 2026
WIND GUSTS LINGER AROUND 20 KT THIS AFTERNOON BEFORE FALLING BELOW
20 KT THROUGH TUESDAY AFTERNOON WITH HIGH PRESSURE SETTLING OVER THE
REGION. SOUTHERLY TO SOUTHEASTERLY WIND GUSTS OF AROUND 25 KT PICK
UP TUESDAY NIGHT AHEAD OF AN APPROACHING COLD FRONT, WITH WINDS
TURNING NORTHWESTERLY BEHIND THE FRONT BY THURSDAY MORNING. WINDS
QUICKLY RELAX BELOW 20 KT THURSDAY NIGHT INTO FRIDAY AS UNCERTAINTY
IN THE FORECAST GROWS INTO THE WEEKEND. ALONG THE MIDWEEK COLD FRONT
WILL BE 20-40% CHANCES OF THUNDERSTORMS. ONGOING WAVES OF 3-6 FT
FALL BELOW 3 FT THIS EVENING BEFORE INCREASING AGAIN TO 4-7 FT IN
THE SOUTHEAST PART OF THE LAKE THURSDAY MORNING THROUGH THURSDAY
NIGHT.
MQT WATCHES/WARNINGS/ADVISORIES
UPPER MICHIGAN...
BEACH HAZARDS STATEMENT UNTIL 8 PM EDT THIS EVENING FOR MIZ006.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
DISCUSSION...GS
AVIATION...BW
MARINE...GS
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