592
FXUS63 KGRR 270759
AFDGRR
Area Forecast Discussion
National Weather Service Grand Rapids MI
359 AM EDT Sun Sep 27 2026
.KEY MESSAGES...
- Quiet weather regime continues through Tuesday
- Rain chances Tuesday night through Thursday night
- Fair weather again for Friday and Saturday
&&
.DISCUSSION...
Issued at 358 AM EDT Sun Sep 27 2026
- Quiet weather regime continues through Tuesday
Dry weather continues through Tuesday as ridging hangs on through
that time. It is not until during the day on Tuesday that the
surface high finally begins to slip away to the east in response
to a system moving across Canada. It is this system that will push
the east coast low out to sea. High confidence in dry weather
through Tuesday and maybe even Tuesday night as the new GFS and
ECMWF ensembles that just came in show all 80 members dry at least
through Tuesday evening.
Main focus in the this period is to watch for the threat of
morning fog and stratus in a moist flow off of Lake Huron. Just
beginning to see some stratus now towards Saginaw Bay in the
nighttime microphysics imagery. Sites along U.S. 127 are
definitely showing fog and we will be monitoring visibilities. A
similar setup presents itself tonight into Monday morning.
- Rain chances Tuesday night through Thursday night
Not a significant amount of change in the models during the mid
week time frame. We are still expecting rain associated with
moisture transport on Wednesday. A cold front is forecast to
press in from the northwest on Thursday. The surge in moisture
from the southwest with tropical origins still tries to press in,
but the models look less impressive tonight. 7 day totals of
rainfall may push to around an inch in our south and especially
southwest, but this is not overly concerning.
- Fair weather again for Friday and Saturday
High pressure quickly returns for Friday and Saturday with dry
weather returning after a couple days of rain. In terms of
temperatures through the entire 7 day period we will be above
normal much of the time, but cooling off into Friday and Saturday
as northwest flow advects in colder air. Highs back into the 60s
after many days in the 70s.
&&
.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 211 AM EDT Sun Sep 27 2026
Main concern with this set of TAFs is the threat of fog and
stratus between mainly 09z and 13z this morning. Fog is already
occurring however and that may mean that the fog may be a bit more
widespread than anticipated. A moist northeast flow off of Lake
Huron, especially in the lowest 1k to 2k feet will spread moisture
into a cool airmass leading to fog formation. As of 06z, little to
no low clouds are seen, so the fog at this point is very local and
raditional. Again, we anticipate an increase in the fog as we head
through the night with some LIFR or VLIFR ceilings as well. We may
not have gone pessimistic enough and will amend as necessary this
morning. After any fog lifts this morning VFR weather should
prevail the rest of the TAF period with little in the way of cloud
cover. Winds will be northeast to north in most areas today at
5-10 knots. A lake breeze will back the winds at MKG to northwest
this afternoon.
&&
.MARINE...
Issued at 358 AM EDT Sun Sep 27 2026
We remain in a light wind regime today through Tuesday. A bit of a
north flow increase occurs today, but it should not exceed 10-15
knots. A south flow on Tuesday does the same increasing to around
10-15 knots. The result is a quiet forecast on Lake Michigan with
winds largely staying below 15 knots through Tuesday which results
in waves of 2 feet or less the next 3 days.
Tuesday night into Thursday looks to be a more active period on
the big lake with chances for rain as well as an increasing
southerly flow. South winds of 10 to 20 knots with higher gusts
will likely push conditions to advisory levels on Wednesday
especially north of Grand Haven.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.
&&
$$
DISCUSSION...Duke
AVIATION...Duke
MARINE...Duke
NWS GRR Office Area Forecast Discussion
