987
FXUS63 KMQT 171730
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
130 PM EDT Fri Jul 17 2026

.KEY MESSAGES...

- Smoke from upstream wildfires will continue to impact Upper
  Michigan into this weekend. Air Quality Alerts remain in
  effect today. Consider remaining indoors when possible.

- An approaching system is expected to bring scattered rain and
  thunderstorms to the UP today through Saturday morning. A few
  storms could be strong to severe this evening.

- On and off periods of dense smoke should be expected through
  the weekend into early next week.

&&

.DISCUSSION...
Issued at 335 AM EDT Fri Jul 17 2026

Early morning GOES satellite imagery reveals the stubborn broad
ridge parked over the central CONUS. A midlevel perturbation is seen
descending southeast through the top of the ridge, reflecting a
developing surface low pressure across the Dakotas. Ascent ahead of
this feature will aid in the development of scattered showers and
thunderstorms over the area of active wildfires to our northwest and
eventually across much of the UP. However, confidence has managed to
decrease regarding the spatial coverage of WAA driven precipitation
this morning and afternoon prior to the system`s cold frontal
passage tonight, where CAMs are more sold on widespread precip/storm
coverage. Opting to maintain Slight Chance to chance PoPs across the
area, with the greatest coverage over Lake Superior and the northern
tier of the UP. 00z CAM ensembles continue to suggest a 50-80%
chance for rainfall amounts greater than 0.25", least closest to the
WI stateline. As previously mentioned, the greatest confidence in
shower/storm activity will likely be focused ahead of the system`s
cold front, which CAM guidance has trended later into this evening
and overnight hours of early Saturday morning. SPC has maintained a
Marginal Risk for severe hail >1" and damaging winds, as CAMs
suggest healthy instability >1000 j/kg present at the time of
arrival coinciding modest bulk shear near 40 kts. However, given the
dense smoke concentration over the area, there remain questions
surrounding how much diurnally driven surface based instability will
be realized and if dry, smokey air aloft may entrain into developing
updrafts, altogether limiting severe potential. Gusty south to
southwest winds may be able to clear some of the densest smoke out
of the western interior UP, as indicated by the most recent HRRR-
smoke guidance, but heavy near-sfc smoke is still modeled to stick
around much of the area today. Otherwise, a warmer day is expected
across the west half with temps climbing into the mid to upper 80s,
cooling the further east you go as winds off Lake Michigan keep the
eastern third of the UP near 80. Southwest flow will usher in
dewpoints back into the mid to upper 60s today, allowing heat
indices in the west half to poke 90F. The combination of increased
warmth, moisture, and lingering dense smoke may be quite
uncomfortable.

The Michigan Dept of Environment, Great Lakes, and Energy (EGLE)
maintains the statewide Air Quality Alert today given ongoing smoke
concerns over the region.

Modeled smoke concentrations do provide a brief period of clearing
behind the cold front late tonight into early Saturday morning,
largely across the west half of the UP, but this doesn`t last long as
north to northwest flow may bring in unhealthy to hazardous smoke
concentrations to the region the rest of Saturday. Hopefully
scattered showers and thunderstorms provide meaningful rainfall to
the wildfires and lessen additional rounds of smoke.

Aside from the lingering questions about smoke, the forecast
otherwise looks relatively benign through much of next week as the
region settles back into northwesterly flow with temperatures near
seasonal norms. There is increasing confidence in another system
bringing another shot of rainfall to the area Monday.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 129 PM EDT Fri Jul 17 2026

Widespread smoke and scattered -shra/tsra are making for a
challenging aviation forecast. Smoke has generally resulted in IFR
and periodic LIFR vsby so far today at the CMX and SAW. IWD had
improved to MVFR vsby as southwest winds brought in cleaner air.
Guidance suggests the smoke will continue to retreat to the north
with southerly flow, bringing vsby to MVFR and VFR later the
evening. Meanwhile, a few rounds of showers and thunderstorms will
move through the region, mostly handled with PROB30s. A few of the
thunderstorms could be strong to severe, with large hail, damaging
winds and frequent lightning. Late tonight the winds will shift
northwest behind a cold front with a few hour period of MVFR cigs.
The northerly flow will transport smoke back to the south. The
highest confidence in smoke increasing on Saturday is at CMX,
indicated with MVFR vsby through Saturday afternoon.

&&

.MARINE...
Issued at 335 AM EDT Fri Jul 17 2026

Dense Smoke Advisories remain in effect for all of Lake Superior and
northern Lake Michigan/Bay of Green Bay through this evening as
wildfire smoke from Ontario and MN continues to drift over the
region. Expect visibility to continue to fluctuate below 1 nm at
times. Will continue to evaluate whether these headlines need to be
extended in future forecast cycles, but there is potential for at
least some relief from the smoke heading into the weekend as a
system moves through the region today into early Saturday. Gusty
southerlies upwards of 25 kts in the eastern half of the lake
increase this afternoon ahead of a developing low pressure. This
system works just north of the lake tonight, shifting winds to the
NW behind the system`s cold front overnight through daybreak
tomorrow. Showers and thunderstorms are expected to develop along
the cold front, which may be strong to severe. NW winds 15-25 kts
with a few gusts to 30 kts in the east half linger on Saturday
before falling below 15 kts lakewide Saturday night. Peak wave
heights between 3-5 ft are possible along the eastern Superior
shorelines Saturday.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
  Dense Smoke Advisory until 8 PM EDT /7 PM CDT/ this evening
     for LSZ162-240>251-263>267.

Lake Michigan...
  Dense Smoke Advisory until 8 PM EDT this evening for LMZ221-
     248-250.

&&

$$

DISCUSSION...BW
AVIATION...NL
MARINE...BW