Area Forecast Discussion
Issued by NWS Marquette, MI
Issued by NWS Marquette, MI
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503 FXUS63 KMQT 101100 AFDMQT Area Forecast Discussion National Weather Service Marquette MI 700 AM EDT Wed Jul 10 2024 .KEY MESSAGES... - Isolated showers and storms possible in the interior west and far east this afternoon. - Showers and thunderstorms enter the picture again over the weekend. Severe storm risk will need to be monitored for Sunday and Monday, maybe Tuesday as well. - Very warm and humid over the weekend with high temperatures well into the mid and upper 80s F. About a 10% chance of widespread high temperatures at or above 90F. Cooling trend begins Monday. && .SHORT TERM /THROUGH THIS AFTERNOON/... Issued at 226 AM EDT Wed Jul 10 2024 Some areas of fog are looking to develop over the north central and east in the pre-dawn hours this morning as marine fog over Lake Superior advects onto shore. Indeed, webcams show that a patch of fog has already developed up the hill from Munising in Wetmore, and M-28 near I-75 has also developed some fog as well. With upslope flow continuing through the pre-dawn hours, we could see patchy fog develop well inland into the interior west, as well as the Keweenaw. Conditions will continue to be monitored this morning on whether dense fog occurs; if it does, then an SPS or a Dense Fog Advisory could be forthcoming. Once we get past dawn, expect the fog to burn off, but a little bit slower this morning over the north central and east as high-level clouds from Beryl`s remnants remain over the area. These higher-level clouds will help the central and east to be a little cooler today than yesterday, in addition to the high pressure over Lake Superior strengthening and creating a stronger lake breeze. Overall, expect highs in the 70s inland with maybe a few spots hitting 80 in the interior west, whereas near Lake Superior highs will probably be around 70. In the afternoon hours, as the remnants of Beryl move through Detroit into southern Ontario, we could see enough forcing from the former hurricane to create some isolated showers and storms over the far east (Newberry and eastward) this afternoon, with a secondary shortwave digging from the Northern Plains towards the Ohio Valley possibly bringing some isolated showers and storms to the interior west by mid afternoon. Any rainfall we do see today looks to rather light, and no severe weather is expected. && .LONG TERM /TONIGHT THROUGH TUESDAY/... Issued at 354 AM EDT Wed Jul 10 2024 Last 24hrs of medium range model runs have maintained consistency on the large scale evolution of the flow across N America over the next 7 to 10 days, and if anything, agreement has improved a little. There has been slight progression of western N America mid-level ridging and central N America troffing over the last 24hrs. This progression will continue over the next few days as a shortwave moving off of the ne Pacific into Canada flattens the ridge and forces height rises/positive height anomalies to spread downstream across southern Canada. A second wave will quickly follow off of the ne Pacific Fri/Sat. As ridging then rebuilds over western N America, that wave will be forced se, leading to modest trof amplification over eastern Canada and the ne U.S. during the mid week period next week. For Upper MI, this evolution of the pattern will support a drier pattern for the next few days. There are still indications for a shortwave to pass early weekend, supporting the potential of shra/tsra later Sat/Sat night. The next potential of greater coverage pcpn events as well as possible svr storms will be late weekend/early next week in advance of and in association with the onset of eastern troffing. As for temps, the spreading of positive height anomalies downstream across southern Canada will herald a warming trend beginning Thu, leading to a very warm/humid weekend with highs well into the 80s to 90F. Cooler weather will follow once eastern troffing develops early next week. Still looks like there will be a couple of pleasant U.P. summer days in the midweek period next week as Canadian high pres settles over the Great Lakes region. Beginning tonight, any shra from this aftn over the interior w and far eastern fcst area will move out of the area or dissipate before sunset. Some fog/stratus may continue to persist e near Lake Superior. Otherwise, a quiet night with little/no wind may support some radiation fog development, especially w where lower level winds will be lightest. Min temps should range from the upper 40s to 60F, coolest at traditional interior cold spots across the w. Models have definitely trended toward a more hostile environment for any potential aftn isold convection on Thu and Fri. Compared to 24hrs ago, fcst soundings now show a notably drier column both days, especially on Thu, and that also includes a somewhat drier look in the boundary layer. Not only does the much drier air aloft thru a much deeper layer make convection less likely, but the drying in the boundary layer also results in parcels not being able to get passed weak capping. Thus, expect dry weather across the board Thu thru Fri. High temps in the mid 70s to lwr 80s on Thu will rise to mostly the 80s on Fri. Expect locally cooler conditions along Lake Superior and Lake MI on Thu and mainly just near Lake MI on Fri as a s to sw gradient wind takes over. Over the weekend, warming under sw flow will send high temps well into the mid and upper 80s F. NBM probabilities of exceeding 90F have slipped slightly from 24hrs ago. Potential of widespread high temps aoa 90F is now down to around 10pct, but probabilities are higher locally near Lake Superior in areas that see downsloping under s to sw winds. Arrival of a shortwave supports the potential of sct shra/tsra Sat aftn/Sat night. Then late weekend/early next week, timing of main shortwave that brings cooling to the area is still fairly uncertain. However, ahead of that wave, models continue to show other subtle waves that will be progressing thru wnw flow into the Upper Great Lakes. Given the substantial instability that will build due to the very warm/humid conditions over the Upper Mississippi Valley/Upper Great Lakes and the climatologically favored wnw flow regime for summer svr storms in Upper MI, there will be a risk of svr storm complexes with these waves. Of course, at this time range, timing of these subtle waves and the resulting convection, including where convection develops, is highly uncertain. Will certainly be something to monitor Sun/Mon, maybe Tue as well. Fcst reflects a broad brushing of chc pops, generally 30-40pct, Sun thru Tue. Cooling should get underway Mon or Tue, more likely Tue, leading to what should be pleasant U.P. summer weather Wed/Thu as Canadian high pres settles over the Great Lakes. && .AVIATION /06Z TAFS THROUGH 06Z THURSDAY/... Issued at 659 AM EDT Wed Jul 10 2024 VFR conditions are expected throughout the daylight and evening hours today as high pressure over Lake Superior strengthens ever so slightly. This will cause the north to northeasterly winds to speed up just a little bit in comparison to yesterday. Patchy fog looks to move into the western two terminals late tonight, and could drop conditions down to as low as LIFR. && .MARINE... Issued at 354 AM EDT Wed Jul 10 2024 A weak pres gradient will dominate over and in the vcnty of Lake Superior for the next several days. Result will be winds across Lake Superior under 20kt and often under 15kt. Some increase in winds may occur over the weekend with high pres to the se and low pres troffing to the w and nw. Areas of fog, locally dense, currently over portions of eastern Lake Superior will become confined to southern portions of the lake to the east of the Keweenaw today due to northerly winds. Difficult to say how long this fog will persist, but it would seem that advection of drier air across the lake should lead to the fog clearing out later today and this evening. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... Dense Fog Advisory until 11 AM EDT this morning for LSZ249>251- 266-267. Lake Michigan... None. && $$ SHORT TERM...TAP LONG TERM...Rolfson AVIATION...TAP MARINE...Rolfson