


Area Forecast Discussion
Issued by NWS Marquette, MI
Issued by NWS Marquette, MI
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148 FXUS63 KMQT 071718 AFDMQT Area Forecast Discussion National Weather Service Marquette MI 118 PM EDT Mon Jul 7 2025 .KEY MESSAGES... - Seasonable temperatures return to the Upper Peninsula for the work week. - Rain showers and a few thunderstorms return tonight and Tuesday. && .SHORT TERM /THROUGH TUESDAY/... Issued at 118 PM EDT Mon Jul 7 2025 Quasi-zonal flow is noted across northern CONUS with a notable shortwave upstream in Saskatchewan/Manitoba/Dakotas and a few others in the Central Plains/Middle Mississippi River Valley. At the surface overhead, RAP analysis paints high pressure, which is helping to support mostly clear skies above Upper Michigan. Cooler temperatures than what has been realized the past few days have also been observed thanks to light northerly surface flow and an 850mb airmass of 10-13C, per SPC mesoanalysis. As of noon eastern time, widespread 60s were still observed with mid to upper 50s by Lake Superior. These cooler and dry conditions should persist for the remainder of today, although most locations should warm into the 70s this afternoon. Convection associated with the upstream wave in the Northern Plains will press eastward tonight. CAMS suggest better organization with each run and now suggest a line of showers and storms will hold together as they press into western Upper Michigan after midnight. Given the decreasing instability and deep layer shear as they move closer to our forecast area, thunderstorms should be waning. These will press into central/eastern Upper Michigan through the morning and early afternoon hours Tuesday. Behind this initial wave Tuesday afternoon/evening, dinurally driven destabilization upwards of 1000- 1500 j/kg and deep layer shear near 40 kts ahead of a weak surface front/trough, should be enough for afternoon showers and thunderstorms to develop west and central. Any precip should end in the evening as the front/trough press through the region and forcing dives southeast of the forecast area. Temperatures tonight will fall into the 50s, perhaps with 40s in the interior east. Should warm into the 70s Tuesday before falling back into the 50s Tuesday night, maybe low 60s for southern Menominee County. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... Issued at 343 AM EDT Mon Jul 7 2025 Following this passing shortwave, ensemble and deterministic guidance continue to show another trough digging into the Great Lakes Wednesday out ahead of a ridge extending from the Plains into central Canada. However, soundings are quite dry, so little more than lingering cloud cover is expected from this secondary trough. Afterwards, deterministic and ensemble guidance are in more agreement on the Plains ridge moving over our region Thursday, perhaps flattening some into Friday ahead of our next trough/frontal system moving out of the Canadian Rockies later Friday into the weekend. This would favor dry weather Thursday at least into early Friday before chances for showers/storms move back in next weekend. By Friday afternoon, deterministic and ensemble guidance show a couple of features (a weak shortwave moving out of the Central Plains and a deeper trough moving out of the Canadian Prairies) phasing over the Upper Midwest. PoPs work back into the area Friday with warm advection out ahead of the system, lingering into Saturday as the cold front sweeps through. Severe parameters are also lackluster with this next system, with just a few hundred j/kg of CAPE and around 20-30kts of bulk shear. Guidance diverges after Saturday, with some of the guidance showing the system becoming vertically stacked and meandering over the Great Lakes, and others a little more progressive. This will keep in at least some low-end chances for lingering showers/thunder into the end of the forecast period. Otherwise, look for temperatures to come in more or less seasonal through the coming week with highs ranging generally in the 70s and lows in the 50s. Thursday and Friday are looking like the warmest days of the week as temperatures in the interior peak in the lower 80s. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 118 PM EDT Mon Jul 7 2025 VFR conditions and light winds are expected today and tonight, with an afternoon lake breeze pushing through all terminals. Late tonight, showers and thunderstorms will move into the region, resulting in increasing low level moisture and falling ceilings. Expect precip to press eastward overnight into Tuesday morning. && .MARINE... Issued at 343 AM EDT Mon Jul 7 2025 Winds and waves will remain light, mainly from the north, today as sfc high pressure becomes planted overtop the lake. South winds develop early Tuesday ahead of a weak low pressure before veering NW behind a cold front Tuesday night. However, winds are not expected to top 15 kts. Showers and a few thunderstorms accompany the weak low`s passage Tuesday, which may caused gusty and erratic winds. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...JTP LONG TERM...LC AVIATION...JTP MARINE...BW