835
FXUS63 KGRR 141742
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
142 PM EDT SUN SEP 14 2025
KEY MESSAGES
- DRY WEATHER MOST OF THIS WEEK
- CHANCE OF SHOWERS AND THUNDERSTORMS STARTING FRIDAY
DISCUSSION
ISSUED AT 304 AM EDT SUN SEP 14 2025
- DRY WEATHER MOST OF THIS WEEK
FLOW OVER THE EASTERN CONUS WILL RESEMBLE A REX BLOCK PATTERN (RIDGING
WITH THE POLAR JET AND TROUGHING WITH THE SUBTROPICAL JET) BEGINNING
EARLY THIS WORK WEEK. BEING A BLOCKY PATTERN, IT SHOULD PERSIST
FOR SEVERAL DAYS. AND, GIVEN RATHER SHARP RIDGING ALOFT IN OUR
VICINITY, WE CAN EXPECT DRY AND ABNORMALLY WARM MAXIMUM TEMPERATURES.
WE ARE NOW LOOKING AT UPPER 80S WEDNESDAY/THURSDAY, AND THIS
COULD EASILY BE EXCEEDED ON THURSDAY ESPECIALLY.
- CHANCE OF SHOWERS AND THUNDERSTORMS STARTING FRIDAY
MODEL GUIDANCE HAS BEEN FAIRLY CONSISTENT WITH BRINGING AN UPPER
SHORTWAVE TROUGH TO THE WESTERN GREAT LAKES, WHICH WILL BRING MORE
SEASONAL TEMPERATURES ALONG WITH A CHANCE FOR SHOWERS AND THUNDERSTORMS.
PREDICTABILITY IS LIMITED GIVEN WEAK AND POORLY PHASED FLOW ALOFT,
ESPECIALLY REGARDING PRECIPITATION CHANCES. QPF IS BROAD-BRUSHED
AREALLY AND TEMPORALLY (ACROSS MULTIPLE DAYS INCLUDING THE WEEKEND)
TO ILLUSTRATE THE UNCERTAINTY. BUT IN REALITY, PRECIPITATION MAY
BE QUITE EPISODIC AND SPOTTY WITH ANY ACCUMULATIONS NOT EXPECTED
TO MAKE MUCH OF A DENT IN OUR RECENT PRECIPITATION DEFICITS.
AVIATION /18Z TAFS THROUGH 18Z MONDAY/
ISSUED AT 142 PM EDT SUN SEP 14 2025
LITTLE TO NO AVIATION CONCERNS ARE EXPECTED THE NEXT 24 HOURS.
SKIES ARE EXPECTED TO BE MAINLY CLEAR OUTSIDE OF SOME FEW-SCT
CUMULUS DEVELOPMENT OUT OF THE EAST THIS AFTERNOON AND EARLY
EVENING. OVERNIGHT WE ARE EXPECTING SOME FOG AND STRATUS TO FORM
WITH A PUSH OF MOISTURE OFF OF LAKE HURON IN EASTERLY FLOW. THE
BULK IF NOT ALL OF THE FOG SHOULD BE NORTH OF THE TAF SITES ACROSS
CENTRAL LOWER MICHIGAN. WE DID BRING 4 MILES AND FOG INTO THE LAN
TAF IN THE 10Z TO 14Z TIME FRAME AS THAT AIRPORT WILL BE CLOSEST
TO THE FOG BANK. THE FOG WILL BURN OFF RATHER QUICKLY MONDAY
MORNING. BOTTOM LINE, MAINLY VFR WEATHER EXPECTED ACROSS THE TAF
SITES THROUGH 18Z MONDAY. WINDS WILL BE LIGHT EASTERLY THE NEXT 24
HOURS.
MARINE
ISSUED AT 304 AM EDT SUN SEP 14 2025
WINDS AND WAVES ARE EXPECTED TO REMAIN BELOW HAZARDOUS LEVELS. AS
NOTED PREVIOUSLY, THE LARGER SCALE FLOW WILL GENERALLY BE LIGHT
AND OFFSHORE. HOWEVER, LARGE DIURNAL TEMPERATURE SWINGS ARE
EXPECTED OVER LOWER MICHIGAN AND THIS WILL PROMOTE AN ACTIVE
LAKE/LAND BREEZE DIURNAL CYCLE.
GRR WATCHES/WARNINGS/ADVISORIES
MI...NONE.
MARINE...NONE.
DISCUSSION...TJT
AVIATION...DUKE
MARINE...TJT
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