695 FXUS63 KMQT 242022 AFDMQT Area Forecast Discussion National Weather Service Marquette MI 322 PM EST Thu Nov 24 2022 .SHORT TERM...(This afternoon through Tonight) Issued at 156 PM EST THU NOV 24 2022 Low-lying clouds are moving through the UP this afternoon as a weak cold front pushes through the area. With PWATs around 0.5" and weak forcing along the front, not much precip is expected with its passage, just maybe some drizzle and light snow showers where it's cold enough; no snowfall accumulations are expected as temps are expected to be above freezing this afternoon into this evening. The far east may see light rain instead of drizzle late this afternoon and early this evening, as forcing improves along the front as it moves eastward. In addition, the Michigamme Highlands and far east could see some patchy fog ahead of the cold front as the low-lying clouds could lower sfc temps to the dewpoint (in addition to some light upslope flow possibly helping out too). Once we get behind the front, clearing looks to occur near the WI border. However, lake-effect cloud cover looks to move over the rest of the area, with the east possibly seeing some lake-effect drizzle as delta-Ts over eastern Lake Superior get to around 13C; some freezing drizzle could be seen in the east late tonight in the east as temps drop to around freezing over there (lows in the 20s are expected in the central and west tonight). While snowfall is plausible tonight over the east, it looks much less likely until late, as inversion heights fail to reach -10C until late. .LONG TERM...(Friday night through Thursday) Issued at 317 PM EST THU NOV 24 2022 The shortwave trough and cold frontal passage today will give way to shortwave ridging and a waa regime for late Friday into Saturday as max temps on Saturday could rise to near record levels for late November. A shortwave trough moving across northern Ontario will send a cold front across Upper Mi Sat night bringing light mixed pcpn to mainly central and eastern portions of the cwa with some light north wind LES behind the front into Sunday. After a quiet period of weather Monday into Monday night under weak mid-level ridging, attention then turns to a shortwave and developing sfc low lifting out of the mid-level western CONUS trough and advancing toward the Great Lakes region for the middle of next week. Forecast confidence is still low on details and potential impacts from this system due to model uncertainty, but at a bare minimum it looks like it will bring widespread pcpn to the region for late Tuesday into Wednesday and probably windy conditions behind the system late Wednesday into early Thursday. Beginning Friday, model soundings showing temps near -8C at the top of a shallow convective layer just marginal enough for light lake effect pcpn into the eastern counties with a nw flow. Could also be some fzdz mixing in at times too in the morning. Any light mixed pcpn should end by afternoon as winds back and waa gets underway in response to shortwave tracking e to northern Manitoba. Look for max temps in the upper 30s to lower 40s. The waa will continue tonight into Sat as a shortwave moves into northern Ontario and a 50+ kt LLJ moves across the area. Pres falls north of the lake ahead of the shortwave along with the tightening gradient will result in gusty southwest winds Fri night into Sat, especially for downsloping areas along Lake Superior. By Sat morning, 850mb temps will surge to 10 to 13C, but low sun angle and inversion will prevent temps from reaching their full potential on Sat. Still, Sat will be a warm day for late November, especially since there will be little in the way of cloud cover, only some high clouds if anything. Expect high temps mostly in the upper 40s F to lower 50s, warmest for downsloping locations along Lake Superior. Coolest conditions (lower 40s F) will be near Lake MI in areas where sw winds are off of the lake. Record high at NWS Marquette on Sat is a weaker one for late Nov at 48F set in 1984. There's a good chance that will be broken. The northern Ontario shortwave will send a cold front across Upper MI Sat night. There may be some -shrasn mainly central and east, then as 850mb temps fall toward -10C on Sun, some light LES may develop and continue into Sun night. Meanwhile, vigorous southern stream wave will head into the Lower Great Lakes. As upper diffluence from right entrance of northern stream upper jet comes into play across Upper MI on Sun, the southern stream system may aid in spreading sufficient moisture to the nw for the upper diffluence to generate some -snra across mainly the se half of the fcst area. Mon/Mon night should be see mostly uneventful weather, then attention will turn w where a shortwave will begin to progress downstream from western CONUS mid-level trough. Consensus of most of the deterministic 12Z model runs and ensemble members appear to be converging on a storm track that takes the developing associated sfc low into central or possibly western Upper Mi Tue night then into northern Quebec Thu morning. There may end up being 2 waves, a northern wave moving along near the U.S./Canada border and the main southern wave that tracks to the Great Lakes, and that could further complicate the system evolution. One notable exception in storm track from the rest of the deterministic model suite is the 12Z UKMET which has the deepening storm tracking across the Mackinac Straits Tue night. This solution, although it appears to be a bit of an outlier at this point, would likely be more favorable for widespread snow and possible lake enhanced snow from the system. As was the case yesterday, the latest round of ensembles still have a number of sfc lows with pres dropping into the 980s mb, particularly with the EPS, with some down into the 970s mb as well. Details of ptype and whether or not this will be significant system for Upper MI won't be known with much confidence for a few more days. For now, it appears pcpn could begin to spread into Upper MI on Tue with Tue night/Wed the main period of pcpn. A brief period of windy conditions and nw flow LES would then most likely follow behind the system late Wed into early Thu. && .AVIATION...(For the 18Z TAFS through 18Z Friday afternoon) Issued at 1249 PM EST THU NOV 24 2022 IFR/MVFR conditions over the TAF sites this afternoon remain until this evening as a weak cold front pushes through the area. Once the cold front passes through by this evening, VFR conditions are expected to return to KIWD, and may return for a short while at KCMX and KSAW early. However, MVFR lake-effect cloud cover is expected to return behind the cold front at KCMX and KSAW tonight. Some borderline low-level wind shear is possible over KSAW tonight, but given the uncertainty decided to leave out of the TAF. The MVFR cigs look to remain over KSAW and KCMX until early Friday afternoon. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 317 PM EST THU NOV 24 2022 A cold front will move across Lake Superior this aftn thru early evening. Ahead of the front, sw winds will gust to around 20kt. Behind the front, expect nw winds gusting to 25-30kt. Winds will diminish some on Fri as they back to the w to sw. SW winds will then increase Fri night into Sat morning. Although warmer air moving across the area at that time will limit mixing, believe that gales will develop given the strength of low-level wind fields not far above the sfc. In addition, pres falls up to 6mb/3hr shifting across northern Ontario will give winds a favorable isallobaric boost. Have thus opted to upgrade the gale watch to a gale warning for LSZ263- 264 Fri night into Sat morning. Elsewhere, expect gusts mainly 25- 30kt. Winds will fall back to mostly under 20kt late Sat into Sat night as a cold front crosses the lake and pres gradient weakens considerably for a time. NW winds on Sun may gust up to 25kt. On Mon, winds should be under 20kt across Lake Superior. South to southeast winds will likely ramp up again on Tuesday ahead of a developing storm system approaching from the Central Plains with gusts of 25 to possibly 30 knots for east half and north central portions of the lake. Confidence is increasing on a high-end west to northwest gale event in the wake of the deepening midweek system late Wednesday into early Thursday. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... Gale Warning from 8 PM Friday to 10 AM EST Saturday for LSZ243- 244-263-264. Lake Michigan... None. && $$ SHORT TERM...TAP LONG TERM...Voss AVIATION...TAP MARINE...Voss