Area Forecast Discussion
Issued by NWS Marquette, MI
Issued by NWS Marquette, MI
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582 FXUS63 KMQT 091754 AFDMQT Area Forecast Discussion National Weather Service Marquette MI 154 PM EDT Thu May 9 2024 .KEY MESSAGES... - Clipper system brings chances for thunderstorms to the far western areas of Upper Michigan Friday afternoon and Friday evening. - Chances for thunderstorms return on Sunday for the west and central portions of the Upper Peninsula. - Multiple passing low pressure systems will keep rain and thunder chances in the forecast next week, but uncertainty on timing and track remains. && .SHORT TERM /THROUGH THIS AFTERNOON/... Issued at 510 AM EDT Thu May 9 2024 The last remaining rain showers near the WI/MI border are tapering off at this time as high pressure overspreads Upper Michigan. Latest water vapor imagery shows a sharp cutoff in cloud cover over the southern portions of the forecast area and clearing to the north due to a system traversing the Lower Midwest/Ohio Valley. Skies over the southern counties should become partly cloudy as well though through the course of the morning with plenty of sunshine today. Temperatures will be closer to normal today with most of the interior topping off in the 50s with some low 60s to the south. Coolest temperatures will be near Lake Superior, which will struggle to get into the upper 40s. Currently, temperatures across the area are holding steady in the upper 40s across the south where that cloud cover is lingering, but ground-based obs elsewhere are generally reporting upper 30s/low 40s. Expect north-northeast winds in the 5 to 15 mph range today. && .LONG TERM /TONIGHT THROUGH WEDNESDAY/... Issued at 447 AM EDT Thu May 9 2024 Starting tonight, a trough will be settling south while ever so brief ridging and sfc high pressure builds in over the UP from the northwest. While this trough settles south, some shortwave energy passing over the eastern UP may give some additional forcing for clouds. That said, q-vector divergence and dry model soundings indicate dry weather will persist under mostly clear skies are expected. With good radiational cooling, temps below normal are forecast with lows in the upper 20s to 30s, coolest in the interior west. Dry weather ends Friday afternoon as shortwave over the Manitoba/Ontario province line dives southeast into Upper MI and WI. Mixing ahead of the shortwave is expected to result in lower RHs into the upper 20s to 30s. That being said, there are no major fire weather concerns as highs for the day are expected in the mid 50s to mid 60s (cooler near the lakeshores), winds are expected to remain light below 15 mph, and precip is on the way. Some lake breezes are also likely late morning/early afternoon off both lakes which should help RHs recover some and result in some variable winds. PVA kicks off showers mainly after 2 PM EDT over the far west. As the cold front moves east over the UP then, showers move east with it. With mid level lapse rates ~7C/km and the 5/9 0z HREF mean MUCAPE around 100j/kg (individual models plotting up to 200-400j/kg) there is a slight chance for thunderstorms over the far western UP. That said, bulk shear is lacking (mainly below 25 kts) and the forcing mechanisms do not appear as strong later in the day. Severe weather is not expected. Chances for showers continue east across the UP Friday night as temps fall into the mid 30s to mid 40s. As the trough moves southeast toward New England on Saturday, additional shortwave energy advects over the UP suppling enough forcing for some slight chances of showers, mainly over the east on Saturday. Chances for showers and thunderstorms return again on Sunday as a sfc low over northern Ontario moves east, tracking a cold front across the UP. As we move into next week, there are discrepancies on precip timing and track and thus confidence diminishes. The GFS has a weak shortwave for later in the day Monday forcing some showers and potentially thunderstorms while the ECMWF stays dry with sfc ridging extending over the UP through Tuesday. The next best chances for showers and thunderstorms arrive mid to late next week when a shortwave riding east along the U.S./Canada border earlier in the week arrives at the Great Lakes. With current spread in the guidance, opted to leave NBM chance PoPs as is. && .AVIATION /18Z TAFS THROUGH 18Z FRIDAY/... Issued at 153 PM EDT Thu May 9 2024 VFR conditions are expected to prevail throughout the TAF period. A patch of SCT/BKN stratocu around 3.5kft will likely linger through the evening, but clear skies will return overnight. Northerly to northeasterly winds will continue to gust around 20 kt for the remainder of the daylight hours before becoming light and variable overnight. && .MARINE... Issued at 447 AM EDT Thu May 9 2024 Northeast winds of 15-25 kts will diminish this morning, falling back below 20 kts across the lake as high pressure builds over the lake and stability increases. With this weak high pressure maintaining over the lake through tonight, winds likely will remain below 15 kts into the weekend as the stability remains. The exception to this is Friday night behind the cold front when the combination of cold air advection and downsloping off the northwestern shores of the lake may result in some gusts nearing 20 kts along the lakeshore areas. Some thunderstorms over the far western portions of the lake are also possible with the passing cold front. Winds increase to around 15-20 kts on Sunday as another cold front passes over the lake; some thunderstorms over the west half of the lake are possible with this cold front as well. Winds otherwise hold around 10-20 kts into the early parts of next week. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... Small Craft Advisory until 2 PM EDT /1 PM CDT/ this afternoon for LSZ240-241. Lake Michigan... None. && $$ SHORT TERM...TDUD LONG TERM...Jablonski AVIATION...Thompson MARINE...Jablonski