492
FXUS63 KMQT 250858
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
458 AM EDT Wed Sep 25 2024

.KEY MESSAGES...

- Patchy fog ends within an hour or two after sunrise. Some
  areas of fog may be dense at times, reducing visibilities to
  1/2 mile or less.

- Dry weather is expected this week into the weekend.

- Temperatures trend well above normal into next week.

&&

.SHORT TERM /THROUGH THIS AFTERNOON/...
Issued at 414 AM EDT Wed Sep 25 2024

Current RAP analysis shows the 1006mb low centered over Lower MI
underneath a shortwave. This is currently lighting up the radar
returns over northern Lower MI and the far eastern UP as light
showers lift through Luce County. The stronger mid level features
include mid level trough over northwestern Ontario, an additional
trough over the Mid Mississippi Valley, and a strong ridge over the
Rockies. The showers over the east will continue to lift north
through Sunrise as the low moves toward Lake Huron. These showers
alongside the low cloud deck are keeping temps warmer in the east in
the mid to upper 50s. In contrast, a drier airmass to the west has
limited mid level clouds ahead of the trough to the northwest. Thus,
radiative cooling under these clear skies has allowed for temps to
fall into the low 40s. With the strong inversion in place and light
winds, this set up has resulted in patchy fog development across the
west half. Some of this fog has been dense at times, particularly
along the WI/MI state line where visibilities have periodically
dropped down to 1/2 miles or less. While a few spots may dip into
the mid to upper 30s ahead of sunrise, fog may limit cooling. Patchy
fog is likely to prevail through a hour or two of sunrise.

As the low pressure lifts north over Lake Huron to northern Ontario
this morning and low level winds turn northwest, showers diminish
and are forced east out of the CWA. Some scattered low level clouds
may accompany the eastward progressing trough to the north, but
mostly sunny skies and dry weather is expected today as the mid
level ridge progresses east toward the Great Lakes. Temps warm above
normal today, peaking in the mid 60s to mid 70. Also, mixing this
afternoon may result in some west winds gusting up to 20 mph in the
Keweenaw.

&&

.LONG TERM /TONIGHT THROUGH TUESDAY/...
Issued at 432 AM EDT Wed Sep 25 2024

Synoptic setup across the CONUS early in the extended period
consists of strong ridging shifting from the Rockies into the Plains
and mid-level troughing extending into the Great Lakes Region.
Farther south, a closed low is centered over the western Tennessee
Valley, while Tropical Storm Helene spins in the Gulf of Mexico.
Elsewhere, broad troughing is influencing the west coast.  So,
essentially, this omega block pattern will keep the forecast dry
across Upper Michigan for the majority of the long term period.
Therefore, the main focus through the weekend and into next week
will be the above normal temperatures and the fluctuation between
summer and fall that comes around this time of year.  Daily high
temperatures will generally be in the 70s and even near the 80
degree mark from Thursday through Saturday in the southerly surface
flow.  Meanwhile, overnight lows will elude any freezing marks with
widespread 40s/low 50s through Monday night.  By Tuesday, however,
long range ensemble models trend toward the shift back to Fall and
normal high temperatures in the 60s and overnight lows dipping back
into the upper 30s.

Outside of the dry weather and above normal temperatures, there will
be a few drawbacks.  First, with the mostly clear skies and light
winds, radiational fog will pretty much be a nightly possibility
throughout the extended period.  Then further out, the pattern will
finally shift as the ridge axis shifts and is replaced by the next
low pressure system over northern Manitoba on Monday.  This will
likely be the UP`s next chance at rain showers, but ensembles do
seem to be overdoing the precipitation chances a bit with
probabilities up to 50%.  Due to it still being days 5 and 6 though,
will not deviate from Pops at this time until confidence increases
with evolution of the associated cold front.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 141 AM EDT Wed Sep 25 2024

VFR is expected to prevail thru this fcst period at CMX. At SAW,
radiational fog should develop under mostly clear skies and little
to no wind. IWD is already seeing patchy fog down to LIFR/IFR
levels, which likely will persist until around sunrise. As with
previous fcst, kept a mention of MVFR at SAW overnight. While there
is some potential for IFR or even LIFR, light northwesterly low-
level flow is not typically favorable for such development. If fog
does develop, it will dissipate within 2 hrs after sunrise. Light
winds under 5kt overnight will become W to NW to around 10kt today,
but wind will become NNE at SAW in the aftn.

&&

.MARINE...
Issued at 457 AM EDT Wed Sep 25 2024

Upper Michigan will remain under high pressure for the duration
of the forecast period. Therefore, winds will remain at or
below 20 knots through Sunday. The next chance for 20 to 25 knot
winds will not be until Monday when the next system enters the
region.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.

&&

$$

SHORT TERM...Jablonski
LONG TERM...TDUD
AVIATION...Jablonski/Rolfson
MARINE...TDUD