Area Forecast Discussion
Issued by NWS Grand Rapids, MI
Issued by NWS Grand Rapids, MI
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798 FXUS63 KGRR 020234 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 1034 PM EDT Sat Jun 1 2024 .KEY MESSAGES... - Showers Through Late Tonight, Some Patchy Fog Also Possible - Cool and Cloudy Sunday Morning, Then Partial Clearing/Milder - Above normal temps early next week - Cooler and unsettled mid to late week && .UPDATE... Issued at 1033 PM EDT Sat Jun 1 2024 Areas of light rain and some fog continue across the area at 1030pm. The rain is associated with weak low pressure at the surface moving through the area beneath a dampening out shortwave trough up in the mid levels. Both the trough aloft and the weak surface low will move east of the area Sunday morning. Rain will gradually taper from west to east late tonight as the features driving the precipitation move east. With a weak pressure gradient and low level moisture in place areas of patchy fog can be expected tonight. Low temperatures tonight will be slightly above normal in the middle 50s to around 60 degrees. && .DISCUSSION... Issued at 258 PM EDT Sat Jun 1 2024 - Showers Through Late Tonight, Some Patchy Fog Also Possible MRMS imagery across the region shows a large batch of showers moving over Lake Michigan and into our lakeshore area. SPC mesoanalysis shows no instability present throughout the atmosphere, and this really isn`t expected to change into tonight. There is a possibility for some scant elevated instability to approach I-94 where a rogue lightning strike is possible, but otherwise only showers or a steady light to moderate rain is expected. This precipitation is being supported by the right entrance region of an upper jet, and lower down there is a 500 mb shortwave trough as well as a south to north oriented low level jet of about 30-35 kts nosing into Lower Michigan. The 12z HREF LPMM 24 hour precipitation supports potential for 0.25"-0.50" across our region through early Sunday, with some localized areas of 0.50"-1.00". Patchy fog development is possible tonight with an increase in surface dew points and very light winds as showers traverse the region, though HREF probabilities for < 1/2 mile are only 20-40% mainly near and west of US 131. What is more likely is low stratus, rather than fog. - Cool and Cloudy Sunday Morning, Then Partial Clearing/Milder The 12z HREF favors a cool and cloudy start to Sunday with a slow decrease in low level moisture. Expect temperatures to be stuck in the low to mid 60s Sunday morning before some partial clearing gets underway starting with the lakeshore region, then progressing east. For areas east of US 131, breaks in clouds may not occur until after 18z or so. Have adjusted highs down a bit from previous guidance, mainly featuring 70-73 across the eastern half of our forecast area and 73-76 west. There is a low probability for an isolated shower to pop up mainly east of I-69 Sunday afternoon. Areal coverage looks minimal enough to largely keep that out of the forecast at this time. - Above normal temps early next week It will be quite warm and increasingly more humid early next week in a southerly flow waa pattern and as a ridge builds over the eastern CONUS. H8 temps will reach 15-16 C and with some sun high temps will reach the low to perhaps middle 80s Mon/Tue. A few showers and storms are possible as well but we expect dry wx to prevail the majority of the time on both days. - Cooler and unsettled mid to late week A cold front will bring scattered showers and thunderstorms on Wednesday. After fropa a cooler and drier airmass will advect in as an upper level trough also moves over the Great Lakes region late in the week. This will result in a cool and somewhat unsettled wx pattern with below normal temps by late week into the weekend. Some scattered showers are expected as well as several upper level disturbances move through in conjunction with some instability from daytime heating and with relatively cool air aloft tied to the upper trough axis. By Friday high temps will struggle to reach the middle to upper 60s. && .AVIATION /00Z TAFS THROUGH 00Z MONDAY/... Issued at 741 PM EDT Sat Jun 1 2024 Rain has moved over all of the terminals in our area, however limited impacts are occuring so far. KMKG has had lower visibilities, and lower ceilings are lurking there near the lakeshore. We do expect that ceilings and visibilities will deteriorate overnight even as rainfall tapers off. The initial dry air that was in place is keeping conditions from tanking. We will see better low level moisture move in, and conditions will likely drop into the LIFR and possibly VLIFR category at all sites due to low clouds and fog. Rain will likely end toward 06z or so. The beginning of the daylight hours will see low clouds and fog hold on for much of the morning. Conditions will slowly improve as the system moves away, and drier air starts to make its way over the area. We will see VFR return to all sites by 00z Mon. && .MARINE... Issued at 258 PM EDT Sat Jun 1 2024 Some patchy fog is possible this evening through early Sunday morning. Probabilities look low for any dense fog formation. Otherwise, expect wave action to be 1-2 ft for the majority of the next several days and winds generally 5-15 kts. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ UPDATE...Duke DISCUSSION...Laurens/Hoving AVIATION...NJJ MARINE...Hoving