945
FXUS63 KMQT 040500
AFDMQT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
100 AM EDT THU SEP 4 2025
KEY MESSAGES
- A COOL AIRMASS WILL BUILD OVER THE UPPER GREAT LAKES THE REST
OF THIS WEEK, PROVIDING THE REGION BELOW NORMAL TEMPERATURES
ALL THE WAY TO THE WEEK'S END.
- THERE IS A 30-50% CHANCE FOR GALES ON LAKE SUPERIOR FRIDAY
EVENING BEHIND A REINFORCING COLD FRONT, MAINLY ALONG THE WEST
SIDE OF THE KEWEENAW.
- WIDESPREAD RAIN IS POSSIBLE THURSDAY NIGHT INTO FRIDAY WITH A
CLIPPER-LIKE LOW MOVING THROUGH THE REGION.
SHORT TERM /THROUGH TONIGHT/
ISSUED AT 350 PM EDT WED SEP 3 2025
FALL LIKE WEATHER WAS BEING OBSERVED OVER THE AREA THIS AFTERNOON.
SATELLITE AND MODEL ANALYSIS SHOWED AN UPPER LEVEL LOW PRESSURE OVER
WESTERN LAKE SUPERIOR AND ONTARIO. THE COLD FRONT THAT BROUGHT RAIN
TO MUCH OF THE U.P OVERNIGHT INTO TODAY WAS NOW EAST OF THE U.P.
BEHIND THE FRONT TEMPERATURES HAD DROPPED INTO THE 40S OVER THE WEST
AND 50S CENTRAL AND EAST. LAKE EFFECT RAIN SHOWERS HAD DEVELOPED
OVER THE WEST AND CENTRAL IN THE NORTHWEST WIND BELTS. MOST OF THE
SHOWERS WERE LIGHT BUT OVER THE KEWEENAW MODERATE SHOWERS WERE
MOVING ONSHORE. WINDS WERE BREEZY ACROSS THE AREA AND OVER THE
KEWEENAW WINDS WERE GUSTING 30-40 MPH.
THE UPPER LEVEL LOW PRESSURE WILL MOVE OVER LAKE SUPERIOR TONIGHT
AND BEGIN TO LIFT NORTH ON THURSDAY, THEN BEGIN TO STALL/RETROGRADE
OVER CENTRAL ONTARIO. COLD AIR ADVECTION WILL CONTINUE OVER THE AREA
WITH SUFFICIENT INSTABILITY FOR LAKE EFFECT RAIN SHOWERS THROUGH
THURSDAY BUT EXPECTING THE SHOWERS TO SHIFT INTO THE WEST WIND BELTS
EARLY THURSDAY AND MOVE OFFSHORE BY THURSDAY AFTERNOON. DRIER AIR
WILL ALSO MOVE INTO THE AREA OVERNIGHT LIMITING SHOWER ACTIVITY IN
THE FAR WEST. THE DRIER AIR WILL ALSO HELP TO DIMINISH LAKE EFFECT
SHOWERS OVER THE KEWEENAW BY THURSDAY AFTERNOON.
LOWS TONIGHT WILL BE IN THE MID TO UPPER 30S OVER THE INTERIOR AND
40S ELSEWHERE. THE THREAT FOR FROST APPEARS TO BE LOW DUE TO CLOUD
COVER AND WINDS. HIGHS ON THURSDAY WILL BE IN THE 50S.
LONG TERM /THURSDAY THROUGH WEDNESDAY/
ISSUED AT 350 PM EDT WED SEP 3 2025
IT WILL CONTINUE TO FEEL MUCH LIKE FALL INTO AT LEAST THE EARLY
WEEKEND WITH COOL, BREEZY CONDITIONS ALONG WITH LAKE AFFECT RAIN
SHOWERS AT TIMES. A STRONGER CLIPER-LIKE LOW COULD BRING A ROUND OF
WIDESPREAD RAIN TO THE U.P THURSDAY NIGHT INTO FRIDAY AS IT MOVES
THROUGH THE AREA.
THURSDAY NIGHT INTO FRIDAY A CLIPPER-LIKE LOW WILL SWIFTLY MOVE
SOUTHEAST OUT OF ALBERTA INTO THE THE UPPER MIDWEST AND GREAT LAKES
REGION. MOST OF THE GUIDANCE HAS THIS LOW TRACKING THROUGH THE
CENTRAL AND EASTERN U.P WITH A SHIELD OF MODERATE RAIN ACCOMPANYING
IT. RAINFALL AMOUNTS COULD APPROACH AN INCH, ESPECIALLY IN THE
CENTRAL AND WEST.
EXPECTING LINGERING LAKE EFFECT SHOWERS TO DIMINISH THOUGH THE DAY
ON SATURDAY WITH DRY AND COOL WEATHER FOR SUNDAY. SUNDAY NIGHT LOOKS
TO BE THE BEST CHANCE FOR SEEING FROST OVER THE INTERIOR AS SKIES
CLEAR AND WINDS BECOME LIGHT. MONDAY WILL BE SEE TEMPERATURES
MODERATING INTO THE 60S FOR MOST OF THE U.P.
AVIATION /00Z TAFS THROUGH 00Z FRIDAY/
ISSUED AT 1259 AM EDT THU SEP 4 2025
OFF AND ON LAKE EFFECT RAIN SHOWERS ARE EXPECTED IN THIS TAF PERIOD,
MAINLY AT KCMX TONIGHT, AND AGAIN THURSDAY AFTERNOON. MVFR
CONDITIONS ARE EXPECTED IN THESE SHOWERS. GUSTY WINDS NEAR 20KTS ARE
POSSIBLE TONIGHT AT KCMX. INCREASED MIXING THURSDAY WILL SUPPORT
GUSTY WINDS NEAR 20KTS AT KIWD/KSAW AND NEAR 30KTS AT KCMX.
MARINE
ISSUED AT 350 PM EDT WED SEP 3 2025
A STORM SYSTEM IS BRINING WINDY CONDITIONS, LAKE EFFECT RAIN SHOWERS
AND THE THREAT FOR WATERSPOUTS OVER LAKE SUPERIOR TONIGHT INTO
THURSDAY. ANOTHER PERIOD OF WINDY CONDITIONS WILL BE POSSIBLE ON
FRIDAY. THEREAFTER EXPECTING LIGHTER WINDS FOR SATURDAY NIGHT INTO
EARLY NEXT WEEK.
A TIGHT PRESSURE GRADIENT WILL REMAIN OVER LAKE SUPERIOR TONIGHT
RESULTING IN NEAR-GALE FORCE NORTHWEST WINDS OVER THE CENTRAL
PORTION OF THE LAKE WITH GALES LIKELY ALONG AND NORTH OF THE
KEWEENAW THROUGH EARLY EVENING. ON THURSDAY WINDS WILL SLOWLY SHIFT
TO THE WEST AND SLACKEN SOME, FALLING BELOW 25KTS BY LATE THURSDAY
EVENING. EXPECTING THE WATERSPOUT THREAT TO DIMINISH THURSDAY
MORNING AS THE LOW PRESSURE PUSHES NORTH AWAY FROM THE LAKE.
BY FRIDAY MORNING ANOTHER LOW PRESSURE WILL APPROACH THE AREA
BRINGING A REINFORCING COLD FRONT AND WINDY CONDITIONS BACK TO THE
LAKE. EXPECTING NORTHWEST WINDS TO GUST UP TO 30 KTS FRIDAY TROUGH
FRIDAY EVENING OVER MUCH OF THE LAKE. THE STRONGEST WINDS AGAIN
APPEAR TO BE ALONG AND NORTH OF THE KEWEENAW WHERE THE NBM HAS 40-
60% CHANCE FOR WINDS EXCEEDING GALE FORCE.
THE PRESSURE GRADIENT WILL BEGIN TO WEAKEN TOWARD SATURDAY MORNING
WITH MOST OF THE LAKE FALLING BELOW 20 KTS EXCEPT NEAR THE KEWEENAW
WHERE GUSTS TO 25 KTS WILL HOLD ON THROUGH THE DAY. FOR SATURDAY
NIGHT THROUGH EARLY NEXT WEEK EXPECTING THE WINDS TO BE LIGHTER,
BELOW 20 KNOTS.
MQT WATCHES/WARNINGS/ADVISORIES
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
GALE WATCH FROM LATE TONIGHT THROUGH FRIDAY AFTERNOON FOR
LMZ248-250.
SHORT TERM...NL
LONG TERM...NL
AVIATION...JTP
MARINE...NL
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