635
FXUS63 KMQT 140827
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
427 AM EDT Mon Jul 14 2025

.KEY MESSAGES...

- Wildfire smoke from Canada continues to reside over the area,
resulting in air quality concerns and reduced visibility. See the
Air Quality Alert for more information.

- A few showers and thunderstorms are possible (20-35% chance)
across the south-central UP this afternoon.

- Periods of rain and thunderstorms are expected overnight tonight
into Tuesday (20-50% chance; highest north/west) and Wednesday (50-
80% chance).

- Seasonably warm through Tuesday, then sharply cooler Wednesday
into Thursday.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 426 AM EDT Mon Jul 14 2025

KMQT radar returns show shower coverage and intensity decreasing
through the early morning hours as a weak surface trough moves
through the western UP and eastern Lake Superior. A reinforcing cold
front following that trough is expected to move through the area
through the morning, though it is weak enough that it will need the
assistance of the Lake Michigan lake breeze to kick off any showers
and thunderstorms this afternoon. 00Z CAMs are split on the
potential for that to occur with significant timing, placement, and
intensity differences of convection this afternoon, though the most
likely locations seem to be along the Bay of Green Bay in Menominee
and Delta counties. Severe weather is not expected with this
convection as a low to mid level inversion will limit instability
somewhat and flow in the bottom 200 or so mb of the atmosphere is
fairly weak. Still, enough instability is present such that any
updrafts that can establish free convection will be vigorous enough
to produce lightning, so outdoor industry and recreation in the
south-central today should keep an eye on the weather this
afternoon. Otherwise, expect high temperatures to once again reach
the 80s for the interior UP (NBM probabilities of exceeding 90
degrees around 30 percent for some pockets of the interior west) and
highs in the upper 70s next to the Great Lakes where the lake breeze
will keep temperatures slightly cooler. The other hazard of the day
continues to be the air quality as wildfire smoke from Canadian
fires continues to be trapped near the surface, with both the HRRR-
Smoke and the RAP-Smoke showing concentrations of near-surface smoke
exceeding thresholds that are unhealthy for sensitive groups. An Air
Quality alert from MI EGLE remains in effect today as a result.

Tonight, with NAEFS moisture content showing over the 90th
percentile of climatology and ongoing 850mb warm advection,
temperatures will struggle to fall below the mid 60s. Attention then
turns upstream to a shortwave impulse approaching the region from
the west. Pre-frontal warm advection showers are currently only
expected to impact Isle Royale, western Lake Superior (up to 50
percent PoPs each), and potentially the Keweenaw Peninsula (~20%
chance) prior to 12Z. Thunderstorms will be possible, but severe
weather is not prior to the arrival of better forcing and diurnal
destabilization.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Issued at 245 PM EDT Sun Jul 13 2025

Flat zonal flow over the northern tier of the CONUS to start the
week will amplify with time as a shortwave trough, as an extension
of a deep Hudson Bay low, will shift eastward across the northern
Plains midweek and into the Great Lakes by the end of the week. At
lower levels, a warm front will extend northeast from a low in the
central High Plains, sagging southward with time as high pressure
builds in behind it. The placement of this front in the vicinity of
the local area will be the main driver of impactful weather
through the midweek period.

Tuesday, model consensus suggests we will be mainly on the warm side
of the front, and with 850 mb temps averaging around 16C (+1 to +2
sigma), this will be the warmest day of the week. Highs are expected
to be in the mid to upper 80s (except perhaps for the Keweenaw which
will be cooler in closer proximity to the front and possible
rainfall), and with dewpoints approaching 70F, this could result in
heat indices in the lower 90s. Instability will likely be quite
healthy in this warm airmass, with the 06Z REFS mean indicating 1-2
kJ/kg by 18Z Tue. Thunderstorm potential will be maximized north of
the area in closer proximity to the front and lower midlevel
heights, but it`s possible that the front sags south far enough to
touch off some convective activity in the afternoon, especially over
the north/west. There likely exists some severe potential if this
occurs given the instability, although model consensus suggests deep-
layer shear may be on the weak side at less than 30 kt.

The low-level front continues to linger in the area Wednesday into
Thursday, with consensus supporting the surface portion of it
sagging mainly south of the area. This will result in sharply cooler
temperatures by Wednesday, with highs stuck in the 60s (and maybe
even 50s closer to the still below-normal temperatures of Lake
Superior) over most of the northern half. Additional rounds of
showers and perhaps thunderstorms are expected along the front,
especially Tuesday night into Wednesday. Some areas could see heavy
rainfall if repeated rounds develop. The pattern largely supports
this, with mid/upper level winds largely parallel to the slowly-
moving lower-level boundary, and PWATs around 1.5 (+1 to +2 sigma).

Gradual drying trend for the end of the week as high pressure builds
in the wake of this front, with temps likely rebounding closer to
normal Friday into Saturday.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 147 AM EDT Mon Jul 14 2025

VFR cigs are expected the full duration of the 6Z TAF period. The
current reprieve from HZ/FU vis restrictions is anticipated to hold
through early this morning. -SHRA and a few rumbles of thunder are
currently passing the far W, but this wave likely weakens and dries
out before reaching SAW. MVFR vis restrictions from HZ/FU are
anticipated to return by mid morning as another plume of Canadian
wildfire smoke surges in from the NW. Improvement is expected late
in the day, likely occuring first at IWD/SAW, then a few hours later
at CMX.

&&

.MARINE...
Issued at 903 AM EDT Sun Jul 13 2025

Visibility will continue to be reduced in areas of fog and wildfire
smoke into Monday. Winds will increase with west-southwesterly gusts
around 20 kt through today, mainly over the western half. A
weakening band of showers and thunderstorms is possible over the
western lake this evening (40% chance). Winds diminish early in the
week, but could increase to near 20 kt from the north late in the
week behind a frontal boundary. Unsettled weather returns
Tuesday/Wednesday with additional rounds of showers and
thunderstorms possible, plus the potential for fog where rainfall
occurs.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
  Air Quality Alert until midnight EDT /11 PM CDT/ tonight for
     MIZ001>007-009>014-084-085.

Lake Superior...
None.
Lake Michigan...
None.

&&

$$

SHORT TERM...GS
LONG TERM...Thompson
AVIATION...Jablonski
MARINE...Thompson