835
FXUS63 KMQT 111104
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
704 AM EDT Thu Sep 11 2025

.KEY MESSAGES...

- Areas of dense fog are possible across the U.P. through this
morning.

- Drier weather persists until Friday night.

- Warmer temperatures reach the 60s and 70s most days for the
forecast period.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 308 AM EDT Thu Sep 11 2025

Morning RAP analysis has a ridge axis broad ridging over the Plains
and Prairie Provinces, supporting sprawling surface high pressure
centered over Ontario. Water vapor imagery shows dry midlevel air
over the Great Lakes, but with plenty of lower-level moisture in
place courtesy of recent rainfall and northeast flow off of
Superior, the UP remains socked in under low stratus. Fog is also
evident in surface observations and available webcams, and it
continues to be dense at times with some spots showing sporadic
drops in visibility well below a mile. Given that this is not very
widespread, and that these lower-end visibilities are more fleeting
under widespread cloud cover, will hold off on any headlines.
Otherwise, temperatures are staying rather mild, hovering in the
mid 50s for most.

High pressure in place will allow for quiet conditions to wrap up
the work week. Fog and low stratus slowly diminish this morning,
with more breaks of sunshine during the afternoon as temperatures
peak in the 60s to near 70. Soundings are supportive for at least
some patchy fog development again tonight into early Friday morning
while temperatures fall back into the 50s and possibly upper 40s.
Expect increasing clouds Friday ahead of another shortwave that will
eventually bring rain chances Friday night. Winds generally out of
the south will help to usher in a warmer airmass, with highs ranging
in the 70s.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
Issued at 308 AM EDT Thu Sep 11 2025

A weak clipper system moving over top of upstream ridge arrives
Friday evening, with a quick round of rain Friday night into the
early morning hours of Saturday. Some thunder is also possible with
ensembles showing several hundred, possibly to near 1000j/kg of
elevated CAPE as well as around 30kts of shear to sustain updrafts.
Still, given the weak nature of forcing and marginal parameters,
severe weather is not expected. Though widespread heavy rain is not
expected, with most of the area looking at rainfall totals blow a
quarter-inch, latest guidance is showing some heavier embedded
totals as high as 0.25-0.50in. This is heaviest nearer the WI border
in the western and south-central UP, where greater instability is
more supporting of thunderstorm development. Showers/storms quickly
move out Saturday morning. The clipper will have a negligible impact
on temperatures as the upper level ridge quickly becomes re-
established overhead, keeping highs in the 70s through the weekend
and into the early part of next week.

Ensemble show good agreement in maintaining upper level ridging over
the region through the first half of next week as the ridge axis
slowly shifts eastward through northern Ontario. The position of the
ridge axis will be critical, as a farther east solution would
potentially allow embedded shortwave disturbances to brush the area
and bring periods of showers or thunderstorms during the first half
of the week. This is reflected by NBM PoPs which keep a 15-30%
chance of precipitation across the area Tuesday into Wednesday.

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 704 AM EDT Thu Sep 11 2025

Low clouds and fog hover overhead much of the UP this morning as
high pressure descends across the Great Lakes region atop a moist
low level airmass. LIFR cigs are present at SAW and IWD, and somehow
CMX has managed to break out to MVFR. These flight rules will
persist through much of the morning and potentially into the early
afternoon, however, guidance suggests ceilings lifting to IFR/MVFR
between 15-18z. This afternoon and evening, periods of VFR return to
all sites. Additionaly chances for fog return tonight into Friday
morning.

&&

.MARINE...
Issued at 308 AM EDT Thu Sep 11 2025

Light winds of generally 10-15 kt or less expected through the
period as high pressure builds over the region. The exception will
be on Sunday, when a tighter pressure gradient over the Upper
Midwest may result in stronger 20+kt gusts over western Lake
Superior. Meanwhile, satellite continues to show plenty of lower
cloud cover over the lake and the Upper Peninsula, where surface
observations show visibility dropping well below a mile at times.
The Dense Fog Advisory thus remains in effect through Thursday
afternoon as conditions will remain conducive to fog formation.
Patchy fog may also expand to the eastern half of the lake and
northern parts of Lake Michigan tonight into Thursday morning. A
weak clipper will bring some light rain and potentially a few
thunderstorms to the area Friday night into Saturday morning.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
  Dense Fog Advisory until 2 PM EDT /1 PM CDT/ this afternoon
     for LSZ162-240>244-263-264.

Lake Michigan...
None.

&&

$$

SHORT TERM...LC
LONG TERM...CB/LC
AVIATION...BW
MARINE...CB/LC