596
FXUS63 KMQT 111906
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
306 PM EDT Sun Aug 11 2024

.KEY MESSAGES...

- Warm and dry weather is expected for the first half of the week.

- Chances for showers and maybe some thunderstorms increase late
  next week, but confidence in timing and track is low.

&&

.SHORT TERM /THROUGH THIS AFTERNOON/...
Issued at 319 AM EDT Sun Aug 11 2024

Water vapor imagery and RAP analysis show an elongating mid-level
low over southern Quebec and the Great Lakes region. Rather vigorous
shortwave wrapping around the circulation crossed Lake
Superior/Upper MI last evening, bringing increased coverage of shra
to the area. That wave is now departing to the se. In its wake,
850mb thermal trof of 3 to 5C across eastern Lake Superior per
latest RAP analysis overtop 14-19C sfc waters is supporting some
lake aided -shra into the eastern fcst area under nw low-level flow.
To the n and ne, a much weaker shortwave is dropping toward eastern
Lake Superior. Current temps are in the upper 40s F over portions of
interior western Upper MI where clouds have thinned out. Otherwise,
mostly low/mid 50s are the rule, though Copper Harbor is 62F.

Aforementioned weak shortwave that will be dropping across eastern
Lake Superior this morning should bring a little uptick in -shra
activity across the eastern fcst area. Expect those -shra to depart
around noon, if not sooner. To the w, most of the CAMS indicate
isold shra developing during the aftn due to sufficient column
moisture and MLCAPE building to 200-400j/kg. With the axis of the
instability running from ne MN se into WI, the CAMS show the shra
developing mostly to the w and s of Upper MI this aftn. For now,
opted to keep western and southern Upper MI dry today. With Lake
Superior waters approaching the annual max temp, some of the shra
developing in ne MN may survive the trip across the lake to produce
some sprinkles toward 00z in Gogebic/Ontonagon counties. Mention was
not included in fcst given low probability. After the fall-like day
yesterday, temps today will rebound to generally the upper 60s to
mid 70s F. Finally, lingering wave action from the stronger winds
across the lake yesterday will result in a high swim risk along the
Lake Superior beaches of Marquette County to the e of Marquette this
morning and at the beaches of Alger County into early aftn.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Issued at 305 PM EDT Sun Aug 11 2024

Warm and dry weather will prevail for our forecast area Monday
through at least Wednesday thanks to high pressure and mid level
ridging holding fast over the area. Daytime temps each day are
expected to climb into the upper 70s to low 80s and overnight lows
in the 60s by the lakeshores and 50s interior. Winds should be
mostly light with afternoon lake breezes. Skies each day are
expected be partly cloudy to mostly clear, save for diurnal cumulus
development in the afternoon hours.

Toward the end of the week, elongated mid-level trough will push
through central North America. Within this, surface low may develop
ahead of a shortwave pressing through the central US, which then
would gradually spread through the Great Lakes region Friday and
through the weekend. Depending on the speed of this evolution,
shower and thunderstorm activity could begin as early as Thursday,
and then linger into Sunday or Sunday night. There`s a good bit of
uncertainty when it comes to how persistent precip activity will be
and much of this will be dictated by the track of the system.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 130 PM EDT Sun Aug 11 2024

VFR will prevail thru this fcst period at IWD/CMX/SAW. NW winds
(IWD/CMX) and NE winds (SAW) at around 10kt will be the rule
until near sunset.

&&

.MARINE...
Issued at 305 PM EDT Sun Aug 11 2024

Winds of 20kts or less are expected through the first half of the
coming week thanks to high pressure over the region. Toward the end
of the week, a system ejecting out of the Plains will support
surface low development. The low will track into the Great Lakes,
but there`s low confidence in where it will track. If it takes on a
northern route, its possible winds could increase to 20kts or higher
Thursday and into the weekend. This contrasts with the southern
option, which keeps conditions below 20kts. Additionally, depending
on the evolution of the system, some thunderstorm activity may be
possible as early as Wednesday night/Thursday.

&&

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

&&

$$

SHORT TERM...Rolfson
LONG TERM...JTP
AVIATION...Voss
MARINE...JTP