Area Forecast Discussion
Issued by NWS Grand Rapids, MI
Issued by NWS Grand Rapids, MI
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552 FXUS63 KGRR 160722 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 322 AM EDT Fri Aug 16 2024 .KEY MESSAGES... - Periods of Showers/Storms through Saturday - Showers ending Sunday then fair and cool next week && .DISCUSSION... Issued at 322 AM EDT Fri Aug 16 2024 - Periods of Showers/Storms through Saturday We are currently in a lull in shower activity. However, a thunderstorm complex near Chicago is slowly moving ENE toward Lower MI and may graze the southern cwa early this morning. Additionally, new convective development over central Wisconsin is moving east and if it holds together could impact the western cwa within a few hours. Low pressure over northwest WI is pushing an occluded front across the eastern portion of that state and an upper low is sending minor short waves east toward MI. As a result, mesoanalysis shows in uptick in shear and mid level lapse rates approaching Lake MI. We`ll likely see some storms develop by 09z. Even so, shear isn`t all that high and so svr storms aren`t expected early this morning, but it wouldn`t be out of the question. By mid morning, we`ll be in another lull as the first short wave moves east. The next short wave will approach toward 00z and so we`ll see an uptick in showers/storms by late afternoon. Generally, progd shear values are less than 25 kts this afternoon and so while we`ll likely see storms from late afternoon through this evening, we`re leaning toward them being non severe. The next short wave to rotate through the flow will arrive Saturday morning and we`ll see another uptick in showers/storms then that will carry through much of the day. Once again, limited shear will render the storms non severe. - Showers ending Sunday then fair and cool next week The rain should be ending by Sunday night as the upper trough axis and surface low finally kicks out to the east. Fair weather with below normal temperatures can be expected next week as northwest flow regime brings in surface high pressure of Canadian origin while the heat and humidity remains bottled up across the SW CONUS. Overnight lows will drop into the 40s in rural areas both Monday and Tuesday nights. There is a slight chance of showers by the end of next week as another upper trough approaches from the northwest, but moisture is limited. && .AVIATION /06Z TAFS THROUGH 06Z SATURDAY/... Issued at 132 AM EDT Fri Aug 16 2024 MVFR conditions with some patchy IFR can be expected overnight. Thunderstorms are possible by 12Z across western Lower Michigan with conditions alternating between VFR and MVFR/IFR at times in heavier showers and thunderstorms during Friday. Southeast winds around 10 knots will go southwest Friday afternoon. && .MARINE... Issued at 322 AM EDT Fri Aug 16 2024 Wind and waves will remain below advisory criteria through Saturday as low pressure settles over the region. Isolated to scattered thunderstorms will remain in the forecast, though, and be a marine/beach hazard. Waves will increase a bit by Sunday and a Small Craft Advisory may be needed then. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ DISCUSSION...Ostuno/04 AVIATION...Ostuno MARINE...04