Area Forecast Discussion
Issued by NWS Grand Rapids, MI
Issued by NWS Grand Rapids, MI
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730 FXUS63 KGRR 241055 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 655 AM EDT Tue Sep 24 2024 .KEY MESSAGES... - Wet and Gloomy Day Ahead - Dry Wednesday/Thursday, then rain chances increase - Cooler next week && .DISCUSSION... Issued at 321 AM EDT Tue Sep 24 2024 - Wet and Gloomy Day Ahead An upper level trough will amplify as it passes into the Great Lakes Region today. Meanwhile, it`s associated surface low will slowly track through Lower Michigan this morning and afternoon bringing spotty showers through much of the day. As the column gradually saturates further this morning, showers will fill in late morning to afternoon. Some periods of heavier rain and embedded non-severe thunderstorms will be possible as PWATS climb to 1.5" to 1.75", especially across southern Lower Michigan. Showers diminish in coverage late tonight to early Wednesday, but some fog potential exists for early Wednesday morning. - Dry Wednesday/Thursday, then rain chances increase Models continue to show the deep upper low over the MS Valley Thursday shearing off the northern part leaving a cutoff low over the Missouri Valley. Surface high pressure camped out over the western Great Lakes will result in sunny skies Thursday and early Friday. What`s left of the Gulf hurricane is progd to move north into the Ohio Valley, but the high over our region will slow the northward spread of rainfall. We`ll likely see an increase in cloudiness, however, Friday afternoon, before the ridge over us moves east, which will enable the cutoff low to drift north. As the low moves slowly northward, rainfall chances will increase to 30-50 percent Saturday through Tuesday. Thunder chances aren`t high, but not zero either. - Cooler next week The upper low will finally get kicked east from the next upstream wave on Monday. This short wave will push a stronger cold front through the cwa Tuesday dropping h8 temps from 12c to 6c. Highs Tuesday will be a bit below normal in the mid to upper 60s. && .AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/... Issued at 649 AM EDT Tue Sep 24 2024 Light rain is moving through the region and ceilings and visibilities are falling to MVFR/IFR. Ceilings below 1k ft will continue through much of the afternoon before briefly rising to around 1k ft toward sunset. Once the rain ends late in the day, we`ll see fog and IFR/LIFR conditions develop again and continue overnight. && .MARINE... Issued at 321 AM EDT Tue Sep 24 2024 Winds and waves should be fairly low through much of this week. Waves may become choppy Wednesday afternoon but should remain below Small Craft Criteria. Periodic showers, fog, and low clouds may limit visibility over the next 12 to 24 hours. Over lake instability today and tonight will present a low chance for waterspouts across the southern half of Lake Michigan. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ DISCUSSION...04/Thielke AVIATION...04 MARINE...Thielke