FXUS63 KMQT 091127 AFDMQT Area Forecast Discussion National Weather Service Marquette MI 727 AM EDT Thu Jul 9 2026 .KEY MESSAGES... - Patches of dense fog will linger this morning, potentially impacting the morning commute. - A warming trend is forecast as high temperatures increase daily through at least Monday. Highs around 90 are becoming more likely Sunday into early next week. && .UPDATE... Issued at 259 AM EDT Thu Jul 9 2026 The going forecast remains on track this morning. While remnant showers linger in the southern to southeastern UP this morning, the main weather impact of the morning will be patchy dense fog. Unfortunately, remnant high cloud cover remains over half of the UP, so satellite investigation of fog is limited somewhat. What does show on GOES-East Nighttime Microphysics is a mid-level cloud deck over the far west and patches of low stratus/fog for the Keweenaw Peninsula, with the CMX METAR showing 1/4SM visby to verify the density. Other METAR reports around the UP have shown some fogginess but the consistency has been tough to come by, so will hold off on any headlines for now. Once the morning fog clears, benign weather takes hold of the region as ridging gradually builds over the Upper Midwest Friday through Monday morning. By Monday, LREF 500mb height reaches the 99th percentile of climatology, and the building atmospheric thickness (as well as efficient diurnal heating with high surface pressure leading to clear skies) will allow temperatures to slowly climb. The LREF, which can sometimes run cool on high temp forecasts, is already calling for up to 75% chances of breaking 90 degrees on Monday for much of the interior UP. With LREF mean dew points in the 60s on Monday, heat indices into the triple digits will be in play (NBM mean apparent temperature does reach 100 in a few spots Monday), though there is enough moving parts in the setup to cause confidence in the forecast to be low. Confidence in the forecast deteriorates further for Tuesday and beyond as spread in how ensemble members resolve the strength and placement of a potential kicking trough over the Pacific Northwest. Should the trough not be strong enough or take a suboptimal path, the heat and lack of meaningful precip may last into the midweek period. On the other hand, the kicking trough may shift the ridge into a placement that brings more seasonable temperatures to the UP as well as more precip chances. LREF 10th-90th percentile spread is nearly 20 degrees by Wednesday evening, so confidence in the forecast is too low to deviate from the NBM at this time. && .DISCUSSION... Issued at 117 PM EDT Wed Jul 8 2026 Amended at 259 AM EDT Thu Jul 9 2026 Synoptic-scale subsidence is favored for today/Friday with seasonable temps. This weekend into early next week, anomalous midlevel anticyclone over the Four Corners region will build into the northern Plains by early next week. Impressive 500 mb heights approaching 600 dam are modeled by early next week over the northern Plains, +2 to +3 sigma as we approach the hottest time of the year. 850 mb temps in the low to possibly mid-20s (C) are similarly impressive. The upshot is growing confidence in a period of highs approaching or exceeding 90F Sunday through Tuesday. It does appear that humidity will be less of an additive factor to the apparent temps than the previous heat spell at the end of June/early July, as low-level trajectories will have more of a westerly/downsloping component off the high plains. Given the lack of deep-layer moisture and positioning downstream of the apex of the ridge, convective potential is fairly low until probably Tuesday, when there are indications of a possible backdoor front/ridge rider. && .AVIATION /12Z TAFS THROUGH 12Z FRIDAY/... Issued at 725 AM EDT Thu Jul 9 2026 Dense fog has impacted all 3 terminals to varying degrees this morning. As SAW is in a region of more widespread FG, the 1/4SM vis will prevail until 14Z and then improve through the morning while CMX/IWD are in a more patchy setup, so will only carry TEMPO groups until 14Z. With high pressure building in, VFR conditions are forecast, with chances of FG redevelopment around 30% tonight. Confidence is too low to include FG mention for tonight with this TAF issuance. Expect mostly light winds this period, with the only winds greater than 5 kt expected being northerlies during the daytime hours today. && .MARINE... Issued at 117 PM EDT Wed Jul 8 2026 High pressure building over the lake in the wake of a weak frontal boundary will maintain light winds through at least Saturday. Rain showers may lead to areas of fog through at least Thursday morning. A thunderstorm or two cannot be ruled out this evening, especially closer to the shoreline, but overall potential is low. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... Dense Fog Advisory until 11 AM EDT /10 AM CDT/ this morning for LSZ162-243>251-263>267. Lake Michigan... None. && $$ UPDATE... DISCUSSION...Thompson AVIATION...GS MARINE...Thompson