332
FXUS63 KGRR 142334
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
734 PM EDT SUN SEP 14 2025
KEY MESSAGES
- AREAS OF FOG TONIGHT NORTH OF I96 AND EAST OF US131
- DRY WITH SUMMER-LIKE CONDITIONS THIS WEEK
- RAIN CHANCES RETURN LATE FRIDAY INTO THE WEEKEND
DISCUSSION
ISSUED AT 222 PM EDT SUN SEP 14 2025
- AREAS OF FOG TONIGHT NORTH OF I96 AND EAST OF US131
CLEAR SKIES ARE ONGOING ACROSS WEST MICHIGAN THIS AFTERNOON WITH THE
ONLY CONCERN OVER THE NEXT 24 HOURS BEING SOME FOG TONIGHT. EASTERLY
FLOW OFF OF LAKE HURON/SAGINAW BAY WILL BRING IN SOME ENHANCED LOW-
LEVEL MOISTURE WITH FAVORABLE RADIATIONAL COOLING CONDITIONS. THIS
WILL LEAD TO AREAS OF FOG DEVELOPING, MAINLY NORTH OF I96 AND EAST
OF US131. ANY FOG SHOULD BURN AWAY SHORTLY AFTER SUNRISE.
- DRY WITH SUMMER-LIKE CONDITIONS THIS WEEK
THE OVERALL LARGE SCALE PATTERN FOR MUCH OF THE WEEK WILL BE A REX
BLOCK ACROSS THE EASTERN CONUS. WITH US UNDER THE UPPER-LEVEL
RIDGING PORTION THIS WILL BRING SEVERAL DAYS OF DECENT SUNSHINE
AND DRY CONDITIONS. THIS PATTERN DRIVES THE FORECAST THROUGH
THURSDAY BEFORE BREAKING DOWN AND MOVING OFF TO THE EAST. 850 MB
TEMPERATURES IN THE MID TEENS WILL TRANSLATE INTO HIGHS WELL INTO
THE 80S, WITH A LOW (~10 PERCENT) CHANCE OF HIGHS REACHING 90
WEDNESDAY/THURSDAY ACROSS SOUTHERN MICHIGAN.
- RAIN CHANCES RETURN LATE FRIDAY INTO THE WEEKEND
ONCE THE REX BLOCK BREAKS DOWN, THE APPROACH OF UPPER-LEVEL TROFING
WILL BRING RAIN CHANCES, AND POSSIBLY A FEW THUNDERSTORMS, BACK INTO
THE FORECAST FOR THIS WEEKEND. HOWEVER, UNCERTAINTY REMAINS ELEVATED
AS TO WHEN AND HOW MUCH PRECIPITATION FALLS. QUESTIONS AS TO THE
STRENGTH/POSITION OF UPPER-LEVEL WAVES AND THE EXTENT A STRONG
HIGH OVER ONTARIO AFFECTING MOISTURE QUALITY HAVE THE OUTGOING
FORECAST WITH SEVERAL PERIODS OF LOW (15-30 PERCENT) RAIN CHANCES.
HOWEVER, THE OUTCOME IS LIKELY TO BE PERIODS OF SPOTTY SHOWERS
WITH VERY LIGHT ACCUMULATION WITHIN THIS TIMEFRAME.
AVIATION /00Z TAFS THROUGH 00Z TUESDAY/
ISSUED AT 734 PM EDT SUN SEP 14 2025
SKIES ARE EXPECTED TO BE MAINLY CLEAR FOR THE MOST PART WITH VFR
WEATHER PREVAILING THROUGH THE TAF PERIOD. THE ONE EXCEPTION IS
THE THREAT OF SOME FOG AND STRATUS ACROSS CENTRAL LOWER MICHIGAN
LATE TONIGHT AND EARLY MONDAY MORNING. HIGH RESOLUTION MODELS HAVE
BEEN CONSISTENT IN SHOWING THE FOG/STRATUS FROM NEAR LANSING AND
AREAS OFF TO THE NORTH. AT THIS POINT HAVE BROUGHT IN SOME LIGHT
(MVFR) VISIBILITY FOG BETWEEN 10Z AND 14Z AT LAN, OTHERWISE ALL
OTHER TAFS AND TIME FRAMES ARE VFR THROUGH 00Z ON TUESDAY.
MARINE
ISSUED AT 222 PM EDT SUN SEP 14 2025
LIGHT WINDS AND LITTLE WAVE ACTION WILL BE THE DOMINANT MODE FOR
MUCH OF THE UPCOMING WEEK. HIGH PRESSURE WILL REMAIN OVER THE GREAT
LAKES FOR THE EARLY PORTION OF THE WORK WEEK WITH A WEAK FRONT AND
SLACK GRADIENT MID WEEK. THE NEXT STRONGER WIND DOES NOT LOOK LIKE
IT APPEARS UNTIL THE END OF THE WEEK AND THAT WIND WILL BE OFF
SHORE. SO, WE ARE LIKELY LOOKING AT WAVES OF LESS THAN 2 FEET RIGHT
THROUGH THE WORK WEEK.
GRR WATCHES/WARNINGS/ADVISORIES
MI...NONE.
MARINE...NONE.
DISCUSSION...THOMAS
AVIATION...DUKE
MARINE...DUKE
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