Area Forecast Discussion
Issued by NWS Grand Rapids, MI
Issued by NWS Grand Rapids, MI
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817 FXUS63 KGRR 041900 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 300 PM EDT Sat May 4 2024 .KEY MESSAGES... - A few showers,maybe some thunder this evening, quiet Sunday - Dry Monday, then chances for showers/storms && .DISCUSSION... Issued at 255 PM EDT Sat May 4 2024 - A few showers,maybe some thunder this evening, quiet Sunday Showers/thunderstorms will try to get their act together this afternoon in Illinois and Wisconsin will move across Lake Michigan and western Indiana early this evening along with a weak cold front. Models are indicating this line will struggle to remain organized as it moves east and considering decreasing elevated instability overnight - it is looking more like a broken weakening line of showers/thunderstorms that may result in quite a bit of the area seeing no rain at all. If any storms do hold together, not out of the question that some small hail will be possible though this doesnt look that likely at this time. Any lingering light showers should be off to the east by daybreak Sunday. High pressure begins to build in Sunday with stubborn cloud cover lingering through much of the day. This could result in cooler temperatures than Saturday but dry weather should result regardless. - Dry Monday, then chances for showers/storms Transient high pressure over Lower MI Monday will produce sunny skies and mild temperatures with highs around 60. An upper low over the northern Plains will influence our wx the rest of the week as pieces of energy will rotate through the flow and move across the region. Clouds will increase Monday night with storms likely Tuesday when a warm front lifts north late in the day. Moderately strong dynamics look to be develop late Tuesday as a LLJ moves over the region and a mid level speed max aims at Lower MI from the southwest. H85-h5 lapse rates also climb to around 7c/km during this time frame. Given the warm frontal interaction, strong shear and decent helicity, all forms of severe wx look to be possible from late Tuesday afternoon through Tuesday evening; SPC has highlighted the southwest cwa for a severe wx risk. Once the warm front moves through late Tuesday night there may be a lull in precipitation until the next wave over the central Plains moves toward the region late Wednesday through Thursday night. More showers/storms are expected then. The upper low isn`t progd to move through the state until late Saturday, so unsettle conditions will continue through the first half of the weekend. && .AVIATION /18Z TAFS THROUGH 18Z SUNDAY/... Issued at 124 PM EDT Sat May 4 2024 Pesky MVFR cigs continue across some of the terminals. Latest visible imagery shows some decrease in the cu field which should lead to a decrease in MVFR cigs this afternoon. An approaching cold front will fire off a line of showers/storms over IL late this afternoon which will then move east. However, it`s going to encounter more atmospheric stability which will weaken the line. We included a VCSH comment in the TAFs and any precipitation that does develop should be in weakening mode as it moves through. Models indicate more IFR/LIFR tonight along the frontal boundary. Once the front clears the region Sunday morning, cigs will lift. && .MARINE... Issued at 300 PM EDT Sat May 4 2024 Winds this evening still expected to nudge up this evening as a cold front works across Lake Michigan. A few showers and some thunder possible but showers/storms should be weakening as they approach the shoreline. Behind the front north/northwest flow should increase a little but at this time looks like it should peak out 15-20kts and will continue to hold off on an advisory. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ DISCUSSION...Maczko/04 AVIATION...04 MARINE...Maczko