015 FXUS63 KMQT 141923 AFDMQTArea Forecast Discussion National Weather Service Marquette MI 323 PM EDT Sun Sep 14 2025
.KEY MESSAGES...
- Warm and humid weather through early next week.
- Areas of fog expected early this morning and potentially again tonight; fog could be dense.
- Cooler air moves back in for the late week.
&&
.SHORT TERM /THROUGH TONIGHT/... Issued at 322 PM EDT Sun Sep 14 2025
The upper level ridge, omega block, continues to get squeezed as it slowly pushes east, with the axis now extending from the lower Mississippi Valley to the U.P and into Ontario. The closed low over the west was starting to open up as it merged with an approaching trough along the Pacific Northwest. Over the east a trough extended through eastern Canada down into New England with weak troughing all the way down into Florida. The ridge was keeping the U.P dry though ample low level moisture, light winds and favorable radiational cooling conditions resulted in a foggy start to the day for most across the U.P. It was warm this afternoon with highs reaching into the 70s.
The main forecast challenge through tonight will be the possibility for fog redevelopment. Low level moisture, light winds and radiation cooling will be conducive for fog development. Expect fog, possibly dense, to form late tonight into early tomorrow morning. A light southerly downslope wind could limit fog development in the lower elevation near Lake Superior, especially in the west.
Through Monday night the upper level ridge will continue to slowly migrate east as a broader trough develops in the west with multiple short waves ejecting from the Rockies north through the northern Plains. Most of the forcing from these systems will stay west of the U.P continuing the dry weather. Temperatures will remain warm with highs in the 70s today and 70s to lower 80s Monday.
&&
.LONG TERM /MONDAY THROUGH SUNDAY/... Issued at 322 PM EDT Sun Sep 14 2025
The upper level ridge will hold on through Tuesday and begin to break down as a trough moves through the Upper Great Lakes on Wednesday. The chance for showers and thunderstorms will come back for midweek with the passage of the trough and a cold front. Models are coming into better agreement that a low will cut off from the trough as it pushes from the Rockies into the Midwest late this week and take its time tracking through the Great Lakes through the weekend. Temperatures Tuesday and Wednesday will be 10 to 15 degrees above average with highs in the 70s and 80s. Cooler weather will arrive for Thursday through the weekend with highs falling back into the low to mid 60s, just a bit below average for this time of year. For Friday through the weekend models keep a majority of the precipitation south of the U.P through at least a slight chance for showers is maintained through the weekend.
&&
.AVIATION /18Z TAFS THROUGH 18Z MONDAY/... Issued at 122 PM EDT Sun Sep 14 2025
Dense fog continues to lead to LIFR and VLIFR restrictions at CMX and SAW over the next couple of hours, with a gradual improvement to VFR expected mid to late morning. Meanwhile, IWD is returning to VFR already. VFR prevails at all terminals through the afternoon and evening, but then fog development is expected again tonight. This may lead to another night of IFR-or-worse restrictions, most likely at CMX and SAW. Otherwise, winds increase out of the E to SE around 8 kts for the afternoon.
&&
.MARINE... Issued at 322 PM EDT Sun Sep 14 2025
Mainly light winds, less than 20 knots, are expected through mid- week for most of the lake. However, northeast flow over the far west will result in winds up to 25 knots through tonight. Expecting fog to become dense and more widespread again tonight over the far west where a dense fog advisory has been hoisted. Over the remainder of the lake there is some indications that developing southeasterly flow could bring slightly drier air out over the lake and limit the fog potential. Monday through Wednesday winds will be mainly below 20 knots. Northeast winds to 25 knots are expected for late Thursday into Friday as the area will be between a strong high pressure moving south into Quebec and low pressure over the midwest. NBM continues to maintain low probabilities for for gales, 25%, for the late week period.
&&
.MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... Dense Fog Advisory until 11 AM EDT /10 AM CDT/ Monday for LSZ162.
Lake Michigan... None.
&&
$$
SHORT TERM...NL LONG TERM...NL AVIATION...GS MARINE...NL
NWS MQT Office Area Forecast Discussion