Expires:No;;874132 FXUS63 KGRR 061758 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 158 PM EDT Sun Apr 6 2025 .KEY MESSAGES... - Clearing with mild weather today - Snow possible Monday morning; Cold through Tuesday - Chances for Rain through second half of week && .DISCUSSION... Issued at 349 AM EDT Sun Apr 6 2025 - Clearing with mild weather today A pattern shift is in store today. Models remain in good agreement with a strong low slowly moving eastward across northern Canada. That low will bring a strong gradient over the region which will fuel cold air advection across Michigan. Dry air along with a mid level ridge will allow for clearing skies and fair weather today, albeit slightly cooler than normal. That ridge will be short lived as a short wave making its way around the previously mentioned upper level low will couple with mid and low level lows to drop down through Lower Michigan tonight into Monday. - Snow possible Monday morning; Cold through Tuesday Bottom Line up front: Snow is possible for the Monday commute which could cause some slick spots to the roads, especially bridges and overpasses. However, given the variability stated above will hold off on any headlines. 500 mb PV anomalies will aid a clipper as it treks across Lower Michigan tonight through Monday morning. Not much has changed overall in the forecast, though there remains some variation on snow amounts. Model soundings show a strong low level jet moving over the area after 06Z Monday. Soundings also show a strong DGZ, or dendritic growth zone, which will allow for snow generation between 06Z to 15Z Monday morning. QPF is fairly limited, plus given the wet ground and marginal temperatures, snow will have a tough time accumulating. Looking at the latest HRRR, the 10:1 ratio snow total has very little accumulation, where the Kuchera method shows snow totals potentially in the 1 to 3 inch range, especially along the US 10 corridor. Using the Cobb snow tool in conjunction with different models has Big Rapids northward with a half an inch. Thus for snow to accumulate rates would need to be fairly intense and given the ingredients listed above, there is the possibility for that for a short period. The snow bands would arrive just before sunrise. Best chance for snow would be between 10Z to 15Z with light amounts before and after. Have adjusted the forecast with more widespread snow, up to half an inch along the I-96 corridor, with slightly lower amounts up north, with 1 to 2 inches possible. Colder air behind the clipper will sink the region into the doldrums of winter once more. A pause on spring will bring a bitter beginning to April. Lows Tuesday morning will be in the low 20s to upper teens. Highs will attempt to get into the upper 30s Tuesday with lows again in the teens and 20s into Wednesday morning. - Chances for Rain through second half of week Thankfully the blast of cold air will be short lived. More zonal flow, along with a mid level level low will bring warm air back into the region through the latter half of the week. However, coupled with this Warm air, will be precipitation. There remains some variance on timing, location and QPF amounts. Best QPF should be south of Lower Michigan, with the NAEFS anomalies being below normal. So while rain is possible late Wednesday into Thursday it doesn't seem impactful at this time. && .AVIATION /18Z TAFS THROUGH 18Z MONDAY/... Issued at 158 PM EDT Sun Apr 6 2025 VFR is likely through most of tonight. A cold front with a wind shift will move across the area from northwest to southeast Monday morning. It will be near Ludington (LDM) around 09 Z and Jackson (JXN) around 15 Z. Accompanying it will be a quick burst of IFR visibility snow showers, lasting for an hour or two. Short-term models differ on the arrival time by about an hour. && .MARINE... Issued at 349 AM EDT Sun Apr 6 2025 The strong gradient and low level jet that is discussed above will bring strong north flow that could bring 35 gales to the near shore waters south of Manistee. There remains some question on strength and how sporadic the gales would be. Best chance so far will be between 15Z Monday to 00Z Tuesday. Thus have issued a gale watch for that timeframe. && .HYDROLOGY... Issued at 1043 AM EDT Sat Apr 5 2025 Latest hydro forecasts coming in for the rivers enabled us to cancel flood warnings for Sycamore Creek at Holt and the Portage River near Vicksburg. Last night's rainfall didn't overperform and so no additional flooding is expected, other than what's ongoing, which is the Red Cedar at East Lansing. That flood warning remains in effect until early Monday morning. The good news there is that the current river trace reveals that the crest has arrived in East Lansing and the Red Cedar will begin to slowly fall this afternoon. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...Gale Watch from Monday morning through Monday evening for LMZ844>849. && $$ DISCUSSION...Ceru AVIATION...CAS MARINE...Ceru HYDROLOGY...04