Area Forecast Discussion
Issued by NWS Grand Rapids, MI
Issued by NWS Grand Rapids, MI
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865 FXUS63 KGRR 081700 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 100 PM EDT Wed May 8 2024 .KEY MESSAGES... - Dry and mostly sunny today - Rain and chance thunderstorm tonight through Thursday - Showers on Saturday && .UPDATE... Issued at 1033 AM EDT Wed May 8 2024 No updates planned for today. Looks like quite a bit of sunshine and highs in the mid 60s near US-10 to mid 70s near I-94. && .DISCUSSION... Issued at 350 AM EDT Wed May 8 2024 - Dry and mostly sunny today The upper-level shortwave trough and surface low associated with yesterday`s thunderstorms is scooting east toward New England today, while its former parent low over the Dakotas begins to fill and shear out. There will be a narrow zone of ridging with 500 mb height rises over our area along with drier air moving through, keeping us mostly sunny until clouds increase late in the evening. There should be only a moderate breeze from the west becoming northwest. - Rain and chance thunderstorm tonight through Thursday Remnants of the Dakota low phasing with a southward-moving positively tilted trough from northern Ontario are expected to develop a surface low across Illinois-Indiana-Ohio tonight. To its north will be a period of likely rain for much of the day Thursday across southern to central Lower Michigan. Some MUCAPE may be present in southern Michigan which could be enough for some rumbles of thunder. Some questions remain as to the northward extent of a soaking rainfall, and also rainfall totals. HREF member model mean rain totals suggest 0.5 to 1.0 inch rain totals are most likely (though much less near/north of US-10), however, 1.5 inch totals are possible in some spots. - Showers on Saturday Shortwave ridging should bring fair weather for Friday into Friday night but clouds will be moving in after midnight as a shortwave trough approaches, with rain moving back in for Saturday. This trough is less amplified than previous runs but some diurnal enhancement of the showers Saturday afternoon is still possible given the steep lapse rates. Isolated thunderstorms are possible and even some small hail with any deeper updrafts. Cool air in northerly flow on the back side of the sfc low results in low temperatures in the upper 30s to lower 40s Saturday night with scattered frost potential in the colder outlying areas. The trough moves east on Sunday but there is low confidence with forecast details next week, although there is model agreement on a longwave trough forming across the central/eastern CONUS by late in the week. && .AVIATION /18Z TAFS THROUGH 18Z THURSDAY/... Issued at 100 PM EDT Wed May 8 2024 VFR expected through the TAF window. Clear skies are expected through the evening before mid to high clouds move in tonight. Rain showers move in from south to north tonight and continue through the end of the TAF window. However showers will be light enough that reductions to visibility are not expected. West- northwest winds today become northeasterly tonight at 7-12 mph. && .MARINE... Issued at 350 AM EDT Wed May 8 2024 West winds becoming north later today are not expected to pose a hazard on Lake Michigan. East-northeast winds Thursday morning may gust over 20 knots Thursday morning. As winds become north later on Thursday, some larger waves may peel toward the shore from the stronger midlake wind field. Essentially, could be marginally hazardous for small craft on Thursday, not to mention the chance of lightning. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ UPDATE...04 DISCUSSION...Ostuno/CAS AVIATION...Thomas MARINE...CAS