940
FXUS63 KMQT 102012
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
412 PM EDT Sun Aug 10 2025

.KEY MESSAGES...

- Chances of showers and thunderstorms linger through Tuesday.

- Poor air quality is expected Monday and Tuesday. See the
  latest Air Quality Alert, issued by Michigan`s Department of
  Environmental Quality for additional information.

- High temperatures remain above-normal to near-normal
  throughout the next week.

&&

.SHORT TERM /THROUGH MONDAY NIGHT/...
Issued at 411 PM EDT Sun Aug 10 2025

Afternoon WV and RAP analysis show a deep trough over the much of
the Plains with embedded shortwaves lifting NE toward the Upper
Great Lakes. Another trough over far N Ontario has an associated sfc
low around 1002mb beneath it with a cold front draped S into the
Midwest, currently just W of the CWA. Right now radar is fairly
quiet with returns mostly confined to WI where an embedded shortwave
is located. For the remainder of today, expect iso/sct shra/tsra to
drift over the UP as this shortwave lifts overhead. The latest SPC
mesoanalysis indicates plenty of instability in the UP with SBCAPE up
to 1500-2000j/kg. That said, wind shear is lacking ~25-30 kts and
lapse rates are struggling to reach 6.5C/km, so strong to severe
storms are not likely. The area which storms could produce some
small hail/gusty sub-severe winds is over the west late this
afternoon/evening ahead of a cold front. Otherwise, muggy conditions
continue with Tds in the upper 60s to mid 70s and temps in the 70s
to low 80s.

Tonight, the LLJ strengthens to 35-45 kts over the E supporting
increased coverage of shra/tsra. CAMs are not in the greatest
agreement on exact placement of the LLJ max, but areas underneath
could get up to ~1" given the limited elevated instability (few
hundred j/kg of MUCAPE) and favorable warm cloud layer ~13kft with
PWATS of 1.5-2" over the E. Will want to monitor areas N of M-28 and
E of Munising for minor flooding concerns highlighted in the WPC
Marginal outlook as higher soil moisture is noted in that region.
Otherwise widespread QPF is light, ~0.25" or less. Temps settle into
the 60s.

Monday brings additional chances for shra/tsra over the E thanks to
afternoon lake breezes and embedded shortwaves moving overhead.
Lapse rates will be better in the lowest 3km compared to today, but
the mid level remains unfavorable and instability will be lacking
(the NAM struggles to reach 500j/kg of MUCAPE). This leaves strong
to severe storms unlikely once again. Precip amounts up to ~0.1" are
fcst. Otherwise expect another day in the upper 70s to mid 80s.
Another concern for the start of the work week is Canadian wildfire
smoke returning to the region. As a result, the Michigan Department
of Environmental Quality has issued an Air Quality Advisory for Mon
August 11th through noon EDT on August 12th (Tue), for elevated
levels of fine particulates (PM2.5). Pollutants are expected to be
in the Unhealthy for Sensitive Groups range. See the latest Air
Quality Alert for additional information.

Dry weather looks to briefly return Mon night with the loss of
diurnal heating. Lows will be in the upper 50s to mid 60s.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Issued at 411 PM EDT Sun Aug 10 2025

Precip returns to the forecast on Tue as a deeper trough extending
from MN up along the Manitoba/Ontario province line will be at the W
flank of the CWA by 12Z Tue. This trough shifts over Ontario,
bringing a ~996mb sfc low across far N Ontario and pivoting the
southern end of the trough and attendant cold front over the UP
during the day. This system brings better instability, bulk shear,
and forcing for convection, but is lacking in deep available
moisture. Will want to watch this round regardless as it does
present some potential for strong to severe storms.

From there a dry period sets up for mid week as a mid level ridge
over the N Plains moves over the Great lakes and high pressure
tracks over E Canada, extending ridging down into the Great Lakes.
Slightly cooler temps are expected in the wake of the cold front on
Tue with highs Wed/Thu in the 70s and lows Wed night in the 40s to
mid 50s, coldest interior. This rebounds back above normal for the
end of the work week into the weekend as low level S flow returns.
Quazi-zonal flow aloft returns into the weekend which lowers
predictability, but passing shortwaves keep chance PoPs in the fcst.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 200 PM EDT Sun Aug 10 2025

Lingering IFR/MVFR cigs this afternoon at IWD/SAW will lift to VFR
by this evening with VFR conditions then persisting the remainder of
the period, save for BR/FG at SAW tonight. CMX likely will remain
VFR the entire duration of the 18Z TAF period. Scattered SHRA/TSRA
are expected across the UP this afternoon and evening, but
confidence in timing and coverage impacting sites is not high.
Removed TSRA altogether from SAW and refined PROB30 groups at
IWD/CMX. Otherwise S winds around 10-12 kts this afternoon gradually
taper off into tonight.

&&

.MARINE...
Issued at 411 PM EDT Sun Aug 10 2025

Southerly flow will largely prevail through mid-Tuesday across Lake
Superior thanks to the persistent broad troughing positioned just
upstream in the Northern Plains. Surface troughs will press through
tonight and again Tuesday, which will support a period of westerly
winds afterwards. Northwesterly winds establish themselves Tuesday
night after the cold front finally swings through. Winds will
largely fall in the 15-25 kt range in this period save for gusty
winds associated with passing thunderstorms. Thunderstorm potential
mostly focuses this evening through tonight across the east half of
Lake Superior and then a slow moving, west to east line of showers
and storms late Monday night into Tuesday. Hazards with any of these
storms will be lightning and visibility reductions from potential
heavy rain and post-rain fog that may develop.

&&

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

&&

$$

SHORT TERM...Jablonski
LONG TERM...Jablonski
AVIATION...Jablonski
MARINE...JTP