Area Forecast Discussion
Issued by NWS Grand Rapids, MI
Issued by NWS Grand Rapids, MI
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904 FXUS63 KGRR 022324 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 724 PM EDT Sun Jun 2 2024 .KEY MESSAGES... - Chance of rain Monday afternoon and night - Cold front to bring showers and a few storms Wednesday - Cooler and unsettled late week into the weekend && .DISCUSSION... Issued at 242 PM EDT Sun Jun 2 2024 - Chance of rain Monday afternoon and night Cu/stratocu will decrease as heating wanes late in the day, leading to partly cloudy sky overnight. Our next chance of rain is Monday afternoon. A weak short wave is going to move east from the northern Plains in weak zonal flow. A 30 kt low level jet ahead of it will push moisture into the northwest cwa late in the day and evening. Instability will also increase throughout the day as mid level lapse rates climb. As the short wave approaches, we`ll likely see some showers/storms develop; highest PoPs will be across the northwest cwa closer to the better moisture and dynamics. HREF localized probability matched mean (LPMM) suggests a quarter inch to over an inch of rain possible across the northwest cwa with considerably less elsewhere. Precipitation will diminish late Monday night. Highs Monday will be well above normal in the lower to mid 80s. - Cold front to bring showers and a few storms Wednesday Warm and humid conditions are expected Tuesday through early Wednesday out ahead of the cold front in the southerly flow waa pattern. H8 temps should reach 17-18 C Tue afternoon. Guidance has trended warmer and we now expect high temps to reach well into the 80s Tuesday with mild temps in the 60s Tuesday night in the humid airmass. A cold front will bring showers and a few thunderstorms Wednesday. At first glance some parameters would appear favorable for severe wx potential. However cold frontal timing is not favorable as it will be coming through Wednesday morning with lots of clouds and showers in place. Therefore we will have very limited instability for any convection to occur and guidance favors areas well east of our area for the better chance for convection and certainly any svr wx potential. - Cooler and unsettled late week into the weekend An upper trough axis settles in late in the week resulting in much cooler and somewhat unsettled wx and below normal temps by then. Some scattered showers are expected as several upper level disturbances pass through coincident with some instability from daytime heating and cool air aloft. Initially the relatively better chance for mainly diurnally drive pcpn will be north to ne of our area in closer proximity to the upper low center and where mid to upper level dynamics will be stronger. However by the weekend stronger mid to upper level disturbances will move in from the wnw keeping our wx cool and unsettled with below normal temps and some scattered showers. && .AVIATION /00Z TAFS THROUGH 00Z MONDAY/... Issued at 724 PM EDT Sun Jun 2 2024 We continue to see improving conditions this evening, with the low clouds from earlier lifting up and scattering out. Still a decent amount of cumulus development, but it is all VFR at this point and is diminishing. The main impact to aviation interests in this forecast period will be the potential for fog potential tonight. Dew points in the boundary layer remain a bit high. We do not see a significant amount of dry air moving in. Crossover temperatures are in the upper 50s and lower 60s, which we should see exceeded below these values at all sites. The lakeshore (KMKG) has the best chance with the moist flow off of the lake. Also, the models seem to be favoring the East where the limited drier air has not reached quite yet. We foresee plenty of IFR, and even VLIFR along the lakeshore and to the east. Always tough to tell with fog forecasting, but that is the trend we expect. The fog will burn off/mix out quickly by mid Monday morning. && .MARINE... Issued at 242 PM EDT Sun Jun 2 2024 High pressure overhead is producing light winds at the lake and this will continue for the next few days. The pressure gradient and corresponding surface winds may tighten a bit Wednesday when a cold front approaches. Thunderstorms are possible Monday which would pose a threat to boaters. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ DISCUSSION...Laurens/04 AVIATION...NJJ MARINE...04