Area Forecast Discussion
Issued by NWS Grand Rapids, MI
Issued by NWS Grand Rapids, MI
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174 FXUS63 KGRR 250750 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 350 AM EDT Wed Sep 25 2024 .KEY MESSAGES... - Rain Ends this Morning, Then Dry - Small chances for rain showers over the weekend - Above normal temperatures much of the forecast period && .DISCUSSION... Issued at 350 AM EDT Wed Sep 25 2024 - Rain Ends this Morning, Then Dry The surface low that brought active weather yesterday will continue to pass to the northeast early this morning, then surface ridging will fill into Lower Michigan. Upper level subsidence will build into the day and clouds will push out to the east throughout the afternoon. Temperatures peak in the low 70s. - Small chances for rain showers over the weekend The main chance for precipitation will come this weekend in the form of scattered rain showers. An existing upper low in the mid Mississippi Valley will combine with the remnant low of what will become Hurricane Helene. This two features will become one dominant low over the weekend centered in Kentucky and Tennessee. Lower Michigan will be well north of this feature, but moisture will increase across the area in the Friday night through Sunday time frame. There is a distinct difference in moisture depth from north to south, with profiles across Central Lower almost cloud free and fairly deep moisture near I94. So, we expecting showers to mainly affect areas near and south of I96, especially down towards I94. That said, this will certainly not be a washout with only isolated to scattered activity, Friday night through Sunday. Ridging builds in for Monday bringing dry weather again, followed by a cold front that will move through the area on Tuesday. Small chances for rain showers will be possible Tuesday morning as the front quickly moves through. - Above normal temperatures much of the forecast period 850mb temperatures will be in the lower to middle teens C much of the forecast period which will provide above normal temperatures. Highs look to be in the 70s most days. The Tuesday cold front will change the game with 850mb temperatures plunging towards zero C. Highs will quickly move back to normal or even below normal next Tuesday and Wednesday with highs in the lower to middle 60s. && .AVIATION /06Z TAFS THROUGH 06Z THURSDAY/... Issued at 206 AM EDT Wed Sep 25 2024 Low pressure is centered over Central Lower Michigan at 06z. The low will gradually pull away from the area overnight and during the day on Wednesday. A varied mix of conditions are occurring at the TAF sites at 06z with LIFR to MVFR conditions in place. A gradual improvement will be noted as the low moves away, but poor aviation conditions are expected through daybreak with areas of IFR And LIFR continuing. A stronger wind just off the deck at 1,000 and 2,000 feet though should keep things in check from bottoming out to widespread VLIFR conditions. We should turn VFR as we work into the afternoon hours of Wednesday. && .MARINE... Issued at 350 AM EDT Wed Sep 25 2024 Waves will remain low through the end of the week, but conditons may turn choppy this afternoon as northerly winds build waves to 2 feet across the southern half of Lake Michigan. Easterly winds will build into Friday resulting in high wave heights for the Indiana, Illinois, and Wisconsin shorelines with wave heights along the West Michigan lakeshore staying generally around 1 to 2 feet through Saturday. An SCA may be needed late in the week across the southern marine zones mainly for hazardous wind gusts. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ DISCUSSION...Duke/Thielke AVIATION...Duke MARINE...Thielke