175 FXUS63 KGRR 070730 AFDGRRArea Forecast Discussion National Weather Service Grand Rapids MI 330 AM EDT Sun Sep 7 2025
.KEY MESSAGES...
- Little to no chance of appreciable rain through next Saturday
- Gradually warming temperatures through Friday
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.DISCUSSION... Issued at 330 AM EDT Sun Sep 7 2025
- Little to no chance of appreciable rain through next Saturday
The short waves that have been driving through the area the last couple of days have underperformed a bit with regards to rain shower activity. The short wave coming through tonight is no different, only producing a couple of isolated showers down toward South Haven.
We will see a fair amount of self-destruct sunshine again today, building clouds again this afternoon with the heating of the day and the cold pool aloft remaining over the State. It may not be quite as extensive as Saturday, and a clearing trend is expected this afternoon as the cold pool and upper trough move ENE of the area.
Ridging at the sfc and aloft will dominate the weather for Monday in the wake of the upper trough moving out. The ridge will move east of the area by Tuesday, setting the area up for an increased flow from the south ahead of a frontal system leaning in from the west. Rain chances remain almost zero Tuesday as the low level jet and upper dynamics all remain far enough away to keep the area dry.
The front will drop in on Wednesday, but rain chances will remain fairly low for multiple reasons. The moisture flow ahead of the front will be quite weak as the air will be coming off from the Appalachians. In addition, the front weakens considerably as the stronger jet energy lifts north into Canada, and just leaves the sfc front and weakening upper wave to sink south over the area with little to no fanfare. This all said, Wednesday looks to have the best chance of rain in the next seven days, with only a slight chance.
We will see the Upper Ridge axis over the Plains States nudge toward the area then by Thursday. The sfc will see Canadian ridging building in over the area with the cooler and dry flow from the NE that will become established by Thursday. This will hold stronger general subsidence over the area into Saturday. Some uncertainty develops as a upper low over Canada will be trying to drop SE into the Eastern Great Lakes. Ensemble means keep most of the area fairly dry through next Saturday, with various tracks showing up next Sunday.
- Gradually warming temperatures through Friday
It looks like the coldest temperatures of this cooldown were yesterday with the heart of the cold pool over the area at that time with 850 mb temps around 2-4C. We will see temperatures gradually warm through Tuesday ahead of the next incoming front for Wednesday. It looks like we peak around +12C at 850 mb on Wednesday. These temps aloft would support highs at the sfc up around 80F.
A slight cooldown can be expected behind the front for late next week, but nothing as significant as this weekend has seen. We expect temps to go from around 80F mid week, to come down into the mid 70s F by next weekend.
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.AVIATION /06Z TAFS THROUGH 06Z MONDAY/... Issued at 125 AM EDT Sun Sep 7 2025
The area is under a mainly scattered mid level cloud deck at the beginning of this forecast period. There are a few sprinkles out there, but not nearly enough to have any confidence they will hit one of the terminals.
We will likely see another boost in cloud cover by afternoon as the cold pool remains overhead. These clouds should be VFR up around 5-6k ft agl. The clouds will dissipate quickly toward and after sunset, and eventually become clear by mid evening.
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.MARINE... Issued at 330 AM EDT Sun Sep 7 2025
As mentioned with the late evening update last night, thresholds for meeting SCA and Beach Hazards criteria will be hard to meet today. We will have a decent gradient lingering into the afternoon hours, but it looks like it will be a notch below criteria. Moderate beach hazards are expected with waves a solid 2-4 ft.
Once today`s moderate conditions end, we are looking at an extended period of sub-headline conditions. Winds may be up around 15 knots or so through Tuesday, but could be below 15 knots potentially into next weekend.
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.GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None.
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DISCUSSION...NJJ AVIATION...NJJ MARINE...NJJ
NWS GRR Office Area Forecast Discussion