Area Forecast Discussion
Issued by NWS Grand Rapids, MI
Issued by NWS Grand Rapids, MI
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895 FXUS63 KGRR 141941 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 341 PM EDT Tue May 14 2024 .KEY MESSAGES... - Drying out tonight; sunny/dry for Wednesday - Scattered showers return late Thursday and continue into Friday - Warm with low chances for showers this weekend into early next week && .DISCUSSION... Issued at 340 PM EDT Tue May 14 2024 - Drying out tonight; sunny/dry for Wednesday Low level convergence zone has set up near the Michigan/Indiana border and SB Capes of 500-1000 J/KG related to earlier sunshine has resulted in scattered thunderstorms. The storms are currently tracking west and should remain south of the I-94 corridor based on current radar trends. However would not totally rule out additional development farther north especially if any outflows from those push/fan out northward. Also the convection currently in Lenawee County could clip the JXN area based on current movement. Meanwhile the band of showers farther north near GRR related to mid level deformation have mostly faded with only a few lighter showers/sprinkles remaining. Once the diurnal convection in far srn Lwr MI dissipates after sunset we should be largely dry overnight with only 20 pops lingering into early Wednesday mainly near/south of I-94. Drier air pours in from the north/northeast on Wednesday with decreasing clouds occurring from north to south. Should be a very pleasant day with plenty of sunshine, highs near 70, dew pts in the 40s, and a fresh northeast breeze. - Scattered showers return late Thursday and continue into Friday Pleasant weather will persist early Thursday, with short range models in good agreement that surface ridge will be overhead early in the day. WAA will then increase later on Thursday as the aforementioned ridge migrates east, and a 500 mb short wave trough moves from northern Plains into Upper MS valley. This will set the stage for scattered showers and thunderstorms late Thursday, Thursday Night, and into Friday. Surface forcing weakens considerably by Friday, in response to dampening upper trough. However, still expect scattered /diurnally enhanced/ showers and storms Friday with broad/weak trough aloft, daytime heating, and lake breezes. Low temperatures Thursday morning in the 40s will rebound into the mid 70s Thursday afternoon. Highs on Friday will again reach the 70s. High temps both Thursday and Friday will be several degrees above normal. - Warm with low chances for showers this weekend into early next week Temperatures are expected to remain above normal this weekend into early next week. Though differences exist in the ensemble output, the general trend is for the relatively zonal/progressive flow pattern aloft to become slightly more amplified by early next week, with troughing over the Pacific NW and downstream ridging over Upper MS Valley and Great Lakes. This will support continued warm temperatures, with highs in the 70s to around 80 /again, several degrees above normal/. Current ensemble output provides mixed signals on whether weak short wave energy can still advance into the Great Lakes, even as upper heights slowly build. As a result, the forecast will reflect low chances /20-30%/ for showers Saturday, and again Monday/Tuesday. All in all, expect a decent stretch of weather this weekend and into next week - especially for the mid-late May timeframe - with above normal temperatures and occasional wetting showers. && .AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/... Issued at 134 PM EDT Tue May 14 2024 Occasional MVFR ceilings /1.5kt to 2.5 kt/ and scattered showers will impact parts of West and Southwest Lower Michigan through the late afternoon and early evening. This risk will continue a bit later /00-01Z/ along the AZO-BTL-JXN corridor, where sunshine and weak instability may also yield a rumble of thunder or two by 20-21Z. From 00Z onward, VFR conditions are generally expected. However, there is some uncertainty in the low level moisture and MVFR cloud potential overnight... also along the AZO-BTL-JXN corridor. Otherwise, mid clouds will gradually erode from the north overnight and into the early daytime hours of Wednesday, as generally light northeast breezes bring dryer air into the region. && .MARINE... Issued at 340 PM EDT Tue May 14 2024 The Big Sable Point observation indicates that the stronger northerly winds of 15-20 kts has developed near the Points as anticipated. There may be a further increase in winds north of Whitehall through sunset before falling off and turning more northeasterly after dark. Since the duration of these increased conditions should be brief will not have a Small Craft Advisory. A similar situation is shown for Wednesday afternoon, with northerly flow strengthening over the entire nearshore by mid afternoon and continuing through sunset. Otherwise little support for hazardous marine conditions through the rest of the week. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ DISCUSSION...Meade/Smith AVIATION...Smith MARINE...Meade