Area Forecast Discussion
Issued by NWS Marquette, MI
Issued by NWS Marquette, MI
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938 FXUS63 KMQT 171733 AFDMQT Area Forecast Discussion National Weather Service Marquette MI 133 PM EDT Wed Jul 17 2024 .KEY MESSAGES... - Scattered light showers are expected today. - Cooler and drier for midweek with the arrival of high pressure. - Next chances...albeit low...for showers and maybe some thunder return on Saturday and again daily from Monday through Wednesday. && .SHORT TERM /THROUGH THIS AFTERNOON/... Issued at 516 AM EDT Wed Jul 17 2024 Current WV and RAP analysis highlights the mid level trough axis across western Lake Superior and Upper Michigan. At the sfc, observations are showing a cool front out just ahead of the mid level ridge axis over the western UP and central Lake Superior. As the trough axis continues pivoting over the Upper Great Lakes today, the cool front pushes southeast out of our CWA through this morning. As a result, cool northwest flow dominates the short term forecast. 850mb temps are expected to drop to around 5-6C over Lake Superior, which currently has water temps ranging 15-20C in the open waters; the nearshores are warmer in the low 20s. With some lake enhancement, upslope northwest flow, and PVA, scattered light showers or sprinkles are expected across the UP today. Satellite imagery is already showing the stratocumulus deck developing over the west and radar is showing some isolated showers developing. Although CMX is the only sfc ob showing any rain making it to the ground so far, the showers and clouds are progged to expand south and west across the UP through this morning. Given the low available moisture (PWATs ~0.7-0.9"), not much of any accumulations are expected. With the cool northwest flow and cloud cover, highs will be below normal in the 60s to maybe low 70s in the southcentral UP. While today won`t feel like a beach day, the combination of gusty northwest winds up to 20-25 mph and waves will create a high swim risk this morning through Sunset, especially from Marquette eastward through Alger County. As forcing diminishes in the afternoon and high pressure with a drier airmass begins to build in from the west, precip and cloud cover diminishes from west to east; dry weather expected by this evening. Winds are also expected to begin tapering off in the late afternoon and evening hours. && .LONG TERM /THURSDAY THROUGH TUESDAY/... Issued at 509 AM EDT Wed Jul 17 2024 Surface ridge axis will continue to overspread Upper Michigan Wednesday evening as an upper trough axis pushes farther eastward. Time cross sections indicate a dry air column through Thursday and Friday, which will be conducive to ample sunshine and seasonable temperatures. Daytime highs Thursday will return to the 70s with mostly 80s returning by Friday through the majority of the extended period. Meanwhile, with little cloud cover, the nights will be able to cool into the 50s for much of the period. Wednesday night, especially, will be the chilliest under clear skies and light winds as low temperatures dip into the 40s and even some upper 30s across the areas of the interior west that are prone to cold spots. Outside of the dry weather, there are a few exceptions. The first will arrive on Saturday as an upper low drops southeast from the Hudson Bay into Quebec, while its associated cold front moves southward across Lake Superior/Upper Michigan. With limited moisture, widespread convective activity is not expected. However, some isolated showers/thunderstorms cannot be ruled out Saturday afternoon across the south-central U.P. Further out, the second exception to the dry forecast will be another weak cold front that will dip into the region on Monday and Tuesday, eventually stalling over southern WI/MI on Wednesday. This will be the source of daily (20-30%) chance showers from Monday through Wednesday. && .AVIATION /18Z TAFS THROUGH 18Z THURSDAY/... Issued at 133 PM EDT Wed Jul 17 2024 TAFs look to improve to VFR over the next few hours as the lake- effect cloud deck gives way to high pressure ridging to our west. The northwest to northerly gusty winds this afternoon will slowly die down as the high pressure builds in. Expect fairly light winds and calm/SKC conditions across the TAF sites tonight through Thursday morning. && .MARINE... Issued at 537 AM EDT Wed Jul 17 2024 Northwest winds of 20-25 knots will prevail today, especially across eastern Lake Superior as a trough axis moves across the lake. After light winds on Thursday with high pressure overhead, southwest winds will gust to 25 knots on Friday, mainly between Isle Royale and the Keweenaw. By Saturday winds will shift to the north with frontal passage and eventually become variable, but they will remain below 20 knots through the weekend into early next week. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... Beach Hazards Statement until 11 PM EDT this evening for MIZ005-006. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...Jablonski LONG TERM...TDUD AVIATION...TAP MARINE...TDUD