Area Forecast Discussion
Issued by NWS Marquette, MI
Issued by NWS Marquette, MI
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731 FXUS63 KMQT 260525 AFDMQT Area Forecast Discussion National Weather Service Marquette MI 125 AM EDT Wed Jun 26 2024 .KEY MESSAGES... - Gusty winds up to 40 mph across the Keweenaw into early evening. - Pattern remains active, especially from late week into early next week, with yet more rounds of showers and storms && .SHORT TERM /THROUGH TONIGHT/... Issued at 343 PM EDT Tue Jun 25 2024 Water vapor imagery and RAP analysis show that the convectively enhanced shortwave that brought shra/tsra to the area last night is over Georgian Bay. Another shortwave trof extends from James Bay to nw of Lake Superior and a third shortwave is over southern Saskatchewan. At the sfc, a trof extends across eastern Lake Superior and central Upper MI, and a cold front extends from James Bay to just nw of Lake Superior. Rapidly deepening mixed layer to the w of the sfc trof is leading to sharp drying this aftn as sfc dwpts are plummeting into the mid 40s to lwr 50s F across western Upper MI. To the e, sfc trof and lake breeze development off of Lake Superior has led to a few shra developing recently. For the next couple of hrs, expect isold shra over the eastern fcst area ahead of sfc trof/lake breeze. Otherwise, dwpts will continue to fall from w to e in the wake of passing sfc trof, leading to more comfortable conditions under temps in the mid 70s to mid 80s F. Across the Keweenaw, fcst soundings suggest wind gusts to around 40 mph over the next several hrs. Wouldn`t be surprised to see a few gusts to around 45 mph for a couple of hrs based on winds at top of mixed layer. Otherwise, wind gusts of 20-30mph will be fairly common over roughly the w half of Upper MI. Cold front approaching Lake Superior will drop s across the area later this evening/overnight. Other than a wind shift to n to ne, it should pass uneventfully given the drying that is currently underway. Expect clear to partly cloudy skies thru the evening. Late tonight, attention turns to shortwave currently over southern Saskatchewan. This wave will reach nw WI/western Lake Superior around 12z Wed. Given the decent, small cluster of shra currently associated with this feature, models seem on track bringing shra into nw Upper MI in the 10-12z timeframe. Cold front that drops into the area tonight will be aligned from northern MN se thru northern WI early Wed morning, and that should also provide some focusing of forcing as well due to weak waa over the boundary in response to the wave. Temps tonight will fall back to the mid 40s to mid 50s F. && .LONG TERM /WEDNESDAY THROUGH TUESDAY/... Issued at 320 PM EDT Tue Jun 25 2024 An inverted trough along a descending cold front from northern Ontario moving through the U.P. Wednesday looks to bring some light rainfall across mainly the Keweenaw during the morning hours before degrading throughout the day and only bringing slight rain chances to the east and south central later in the day. As high pressure ridging builds in from our west throughout the day, expect the cloud cover to dissolve away with time Wednesday. However, with fairly cool temps aloft moving over us in association with the ridging moving in and the cold air advection behind the front (4-6C), highs Wednesday should be limited to the 60s inland and the mid 50s to around 60 along the Lake Superior shoreline. With ridging continuing to build into the Upper Great Lakes Wednesday night, expect clear skies, allowing temperatures to plummet in the interior areas; some spots could get into the mid to upper 30s or lower. That being said, given the drier air moving in, no frost is expected to form over the interior areas Wednesday night. Calm weather continues Thursday as the high pressure ridging peaks over us during the morning hours. More active weather looks to return late Thursday night/Friday as a low lifts off of the Rockies through the Canadian Prairies/Northern Plains into northern Ontario. Along the cold front moving through Friday through Saturday expect some showers and thunderstorms. In addition, a shortwave low rotating around the low pressure system could bring additional light rain shower activity (that`s possibly upslope enhanced) late Saturday into possibly Sunday morning behind the cold front. With MUCAPE between 500-1500 J/kg ahead and along the cold front and 0-6 km bulk shear around 40 to 50 kts, there is a non-zero chance that we could see some severe weather as the cold front passes. More quiet weather returns early next week as yet another high pressure ridge moves overhead. Behind it, another low pressure lifting through the Canadian Prairies looks to bring more rain showers and thunderstorms to end the extended period. Overall, expect temperatures around normal for the next several days, with showers and thunderstorms coming and going every few days. && .AVIATION /06Z TAFS THROUGH 06Z THURSDAY/... Issued at 124 AM EDT Wed Jun 26 2024 VFR will prevail at IWD/CMX/SAW through tonight. Winds will diminish toward sunset and then veer n to ne. A few shra may also occur at CMX btwn 11-14z. The MVFR cigs at CMX and SAW that form in the morning will scatter out to VFR at CMX/SAW during the aftn. && .MARINE... Issued at 320 PM EDT Tue Jun 25 2024 The last of the patchy fog over the eastern lake ends late this afternoon/early this evening as a cold front descends from northern Ontario this evening into Wednesday. As this happens, the southwest to west winds of 25 to 30 knots across the lake this afternoon die down to 20 knots or less behind the cold front. The light winds look to continue Wednesday to Friday morning as high pressure ridging moves over the region. Once we get into Friday, thunderstorms look possible over the lake again as a low pressure lifting from the Rockies moves towards northern Ontario. Currently, thunderstorms look possible Friday through Saturday; as of right now, there is a non-zero chance of severe weather. In addition to the thunderstorms, winds pick back up to around 20 knots from the southeast Friday as the low`s center approaches. With the surface low looking to move through Lake Superior Friday night/Saturday, we could see winds shift suddenly and sharply near the center of the low. Behind the low, expect winds from the north and northwest to pick to 20 to 25 knots across the lake. That being said, if the cold air advection behind the low is strong enough, we could see gusts up to 30 knots or even gales (see the 12z run of the GFS for an example). These stronger winds look to die down to 20 knots or less again by Saturday night as ridging starts building back in once again over the region. The light winds continue Sunday into next Monday as high pressure ridging dominates the Upper Midwest. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...Rolfson LONG TERM...TAP AVIATION...07 MARINE...TAP