304 FXUS63 KGRR 131856 AFDGRRArea Forecast Discussion National Weather Service Grand Rapids MI 256 PM EDT Sat Sep 13 2025
.KEY MESSAGES...
- Dry weather through early next week
- Chance of showers/storms late next week
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.DISCUSSION... Issued at 255 PM EDT Sat Sep 13 2025
- Dry weather through early next week
The trough that brought rainfall this morning will continue to move southward this afternoon with dry air filling in behind it. A Building high will move over the Midwest and dominate the pattern through the upcoming week. Models remain in good agreement as the high will bring fair weather with warm air advection through mid week. The high will remain entrenched over the region with weak flow through that time frame. With 850mb temps increasing as the week progresses, temps at 850 mb should build to upwards of +20C by Wednesday. That will correlate to bringing maximum surface temps from Sunday through Thursday in the mid to upper 80s, with 90 not necessarily out of reach on Wednesday. The Warm and dry weather should linger into Thursday.
- Chance of showers/storms late next week
The high pressure that will dominate the first half of the week will be ejected by an upper level low as it moves along the Canadian border and through the region late Thursday into Saturday. There is some disparity in the models but ensembles bring the front through Friday into Saturday. Some runs move it quicker depending on the cold air and the strength of the high. Given those considerations have a broad period of chance Pops.
Currently, there is good mid to low level forcing with that system. The latest EC shows the presence of an LLJ Friday afternoon. That correlates with increased CAPE through the ensembles. So there is the potential for storms along the frontal boundary Friday into Saturday. Position, timing and strength will vary as that timeframe marches closer.
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.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/... Issued at 201 PM EDT Sat Sep 13 2025
The chance of rain has more or less ended, and all that remain are patchy VFR cloud decks. VFR is likely through tonight with light winds.
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.MARINE... Issued at 240 PM EDT Sat Sep 13 2025
Prevailing winds will be light from east the next few days, though the direction may flop around during afternoons as the lake breeze partially counteracts the prevailing flow. Waves will stay 1 foot or less.
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.GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None.
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DISCUSSION...Ceru AVIATION...CAS MARINE...CAS
NWS GRR Office Area Forecast Discussion