462
FXUS63 KMQT 180018
AFDMQT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
818 PM EDT WED SEP 17 2025
KEY MESSAGES
- ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED THIS
AFTERNOON ACROSS CENTRAL AND EASTERN UPPER MICHIGAN.
- MORE SEASONABLE TEMPERATURES THURSDAY AND THROUGH THE WEEKEND.
- THEIR WILL BE CHANCES FOR SHOWERS AND POSSIBLY A THUNDERSTORM
THROUGH EARLY NEXT WEEK
DISCUSSION
ISSUED AT 327 PM EDT WED SEP 17 2025
THIS AFTERNOON THE UPPER LEVEL RIDGE OF HIGH PRESSURE CONTINUES TO
BREAK DOWN OVER THE GREAT LAKES AS TROUGHING APPROACHES FROM THE
WEST. THE UPPER LEVEL TROUGH EXTENDED FROM THE HUDSON BAY SOUTH INTO
THE CENTRAL ROCKIES WITH TWO UPPER LEVEL LOW PRESSURES, ONE IN THE
BASE OF THE TROUGH OVER WYOMING AND ANOTHER OVER SOUTHERN
MOVING SOUTH, DOWNSTREAM OF AN UPPER LEVEL RIDGE THAT
EXTENDED FROM THE WEST COAST TO ALBERTA. AT THE SURFACE LOW PRESSURE
WAS DEVELOPING OVER THE CENTRAL PLAINS WHILE A LARGE AREA OF HIGH
PRESSURE OVER CANADA APPROACHED FROM THE NORTH, WITH A COLD FRONT
PUSHING SOUTH THROUGH THE U.P. TEMPERATURES HAD CLIMBED INTO THE 70S
AND LOWER 80S WITH ABUNDANT SUNSHINE THIS AFTERNOON. SCATTERED
THUNDERSTORMS AFFECTED PORTIONS OF MENOMINEE AND DELTA COUNTIES
THIS MORNING BUT DIMINISHED BY MID-MORNING. ADDITIONAL THUNDERSTORMS
HAD DEVELOPED ALONG THE COLD FRONT, WHERE IT WAS INTERSECTING A LAKE
BREEZE BOUNDARY OVER CENTRAL AND EASTERN MARQUETTE COUNTY. SOME OF
THE STORMS WERE STRONG WITH HEAVY RAINFALL AND FREQUENT LIGHTNING,
LIGHTNING STRIKES UP TO 20 MILES AWAY FROM THE STORMS HAS BEEN
OCCURING UNDER THE ANVILS.
THE REST OF TODAY INTO TONIGHT EXPECT THE COLD FRONT TO PUSH SOUTH
TROUGH THE U.P WITH NORTHERLY WINDS DEVELOPING BEHIND IT. WHILE THE
AIRMASS ISN'T UNUSUALLY COLD FOR THIS TIME OF YEAR IT WILL BRING
NOTABLY COOLER TEMPERATURES FOR TONIGHT THROUGH THE SATURDAY (50S
FOR LOWS AND 60S FOR HIGHS), CLOSER TO SEASONAL AVERAGES. SCATTERED
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP AND TRACK SOUTH
INTO DICKINSON, ALGER, DELTA AND MENOMINEE COUNTIES. THERE IS PLENTY
OF INSTABILITY BEING ANALYZED IN THIS AREA, UP TO 2K J/KG CAPE BUT
LITTLE IN THE WAY OF SHEAR. THIS WILL KEEP THE INDIVIDUAL UPDRAFTS
SHORT LIVED AS THE FRONT SAGS SOUTH AND LIMIT THE SEVERE POTENTIAL.
THE MAIN THREAT WILL BE FREQUENT LIGHTNING, SMALL HAIL AND HEAVY
RAINFALL. EXPECTING SHOWERS AND THUNDERSTORMS TO DIMINISH BY LATE
EVENING. A PERIOD OF FOG COULD DEVELOP OVER THE EASTERN HALF OF THE
U.P, ESPECIALLY IN THE NORTH WIND UPSLOPE AREAS LATE TONIGHT AS
COOLER, MOIST AIR MOVES INTO THE AREA.
ON THURSDAY INTO FRIDAY THE TWO UPPER LEVEL LOWS OVER THE CENTRAL
AND WESTERN U.S WILL PIVOT THROUGH THE BASE OF THE TROUGH AND MERGE
INTO A SINGLE LOW PRESSURE OVER THE DAKOTAS. AS THIS HAPPENS
MULTIPLE SHORTWAVES WILL ROTATE THROUGH THE MIDWEST KEEPING THE
THREAT FOR SHOWERS AND THUNDERSTORMS IN THE FORECAST. THE FIRST WAVE
WILL ARRIVE THURSDAY MORNING WITH SHOWERS AND POSSIBLY A
THUNDERSTORM ALONG THE MI/WI BORDER. THE SHORTWAVE WILL WEAKEN AS IT
MOVES INTO THE U.P WHICH WILL LIMIT THE THREAT FOR THUNDER. WITH
PWATS REMAINING HIGH, >1.25", ANY SHOWERS OR THUNDERSTORMS THAT FORM
COULD PUT OUT BRIEF HEAVY RAIN. THE MAIN ENERGY WITH FRIDAY'S
SHORTWAVE LOOKS TO PASS WEST OF THE AREA AND THE NBM MAINTAINS LOW
POPS OVER THE WEST. SOME GUIDANCE HAS SHOWERS FURTHER EAST INTO THE
CENTRAL U.P WHICH ALSO SEEMS LIKE A REASONABLE SOLUTION AS WARM,
MOIST SOUTHERLY FLOW OVERRIDES A FRONTAL BOUNDARY THAT WILL BE
STALLED OVER THE U.P. DIDN'T DEVIATE FROM THE NBM AT THIS TIME BUT
WORTH NOTING.
FOR THE WEEKEND THE MODELS DIVERGE ON THE EXACT TRACK OF THE UPPER
LEVEL LOW BUT OVERALL IT IS EXPECTED TO SLOWLY MOVE THROUGH THE
NORTHERN U.S AND INTO SOUTHERN ONTARIO THROUGH THE WEEKEND. THIS
WILL KEEP THE CHANCE FOR PRECIPITATION IN THE FORECAST AS MULTIPLE
SHORTWAVES MOVE THROUGH THE AREA. THIS SYSTEM WILL EXIT THE AREA ON
MONDAY. TEMPERATURES WILL BEGIN TO MODERATE FOR SUNDAY INTO EARLY
NEXT WEEK WITH HIGHS IN THE 70S.
EARLY NEXT WEEK, ANOTHER TROUGH LOOKS TO MOVE THROUGH CENTRAL NORTH
AMERICA. THIS MAY TAKE ON A NEGATIVE TILT THEN STALL OVERHEAD,
RESULTING IN A DEEPENING LOW PRESSURE OVER THE UPPER GREAT LAKES
TUESDAY/WEDNESDAY. THIS WILL KEEP THE CHANCE FOR PRECIPITATION IN
THE FORECAST.
AVIATION /00Z TAFS THROUGH 00Z FRIDAY/
ISSUED AT 818 PM EDT WED SEP 17 2025
VFR CONDITIONS WILL PREVAIL INTO TONIGHT AT ALL TAF SITES WITH ANY
LINGERING SHOWERS/STORMS LOCATED ALONG THE FRONTAL BOUNDARY SOUTH OF
THE TAF SITES THIS EVENING. HOWEVER, WILL INCLUDE IFR/LIFR FOG
MENTION AGAIN TONIGHT FOR SAW AS WELL AS PROB30 GROUPS TO ACCOUNT
FOR ANY MVFR CONDITIONS AGAIN TOMORROW MORNING AT IWD WITH ANOTHER
ROUND OF POSSIBLE RAIN SHOWERS. MEANWHILE, WINDS WILL GENERALLY BE
IN THE 5 TO 10 KT RANGE OUT OF THE NORTHEAST.
MARINE
ISSUED AT 327 PM EDT WED SEP 17 2025
NORTHEASTERLY WINDS WILL DEVELOP OVERNIGHT AS HIGH PRESSURE BUILDS
INTO NORTHERN ONTARIO AND LOW PRESSURE DEVELOPS OVER WESTERN MN AND
THE DAKOTAS. OVER THE WEST HALF OF THE LAKE NORTHEAST WINDS WILL
STRENGTHEN TO 20-25 KNOTS THROUGH THURSDAY AND UP TO 30 KNOTS ON
FRIDAY OVER THE FAR WESTERN PART OF THE LAKE. OVER THE EAST HALF
WINDS WILL GENERALLY BE BELOW 20 KNOTS. PATCHY FOG WILL ALSO BE
POSSIBLE OVER THE FAR EASTERN PART OF THE LAKE TONIGHT AS THE
COOLER, MOIST AIR MOVES INTO THE AREA. SOUTHERLY WINDS RETURN FOR
SATURDAY INTO EARLY NEXT WEEK AND ARE EXPECTED TO MAINLY BE BELOW 20
KNOTS.
MQT WATCHES/WARNINGS/ADVISORIES
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
DISCUSSION...JTP/NL
AVIATION...TDUD
MARINE...NL
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page