960
FXUS63 KMQT 260459
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
1259 AM EDT Sat Jul 26 2025

.KEY MESSAGES...

- Canadian wildfire smoke will lower the air quality to
  Unhealthy for Sensitive Groups (Orange AQI) to occasionally
  Unhealthy (Red AQI) through this evening.

- Warmer than normal temperatures and muggy dew points prevail
  through Monday. Sunday and Monday have a ~10% chance of heat
  indices of 100+ in the interior west.

- Shower and thunderstorms are possible late Saturday through
  Monday. A few storms may be strong to severe Sunday and may be
  accompanied by torrential rainfall.

- Cooler than normal temperatures and drier conditions are
  expected by the middle of next week.

&&

.SHORT TERM /THROUGH SATURDAY/...
Issued at 134 PM EDT Fri Jul 25 2025

Under a RAP-analyzed ~1017mb high pressure that expands across much
of the eastern CONUS, satellite imagery shows mostly clear skies
across the UP save for some fair-weather cu fields. The gradual
warming trend observed the last few days will continue today with
highs expected to be around the 80 degree mark and around the 85
degree mark for Saturday. Despite stubborn high pressure, the
atmosphere still refuses to dry out with dew points expected to
still be around 60 today and in the mid-60s tomorrow, so it will
still be slightly muggy. NAEFS IVT charts show that the Gulf
connection is interrupted and the SW monsoon does not quite make it
either, so with vapor transport appearing to come from the
Dakotas and MN, the likely culprit is agricultural
evapotranspiration.

With no precipitation anticipated until at least 00Z Sunday, the
most impactful weather element today will be Canadian wildfire
smoke. Subsidence from the high pressure is helping keep smoke from
efficiently ventilating, so air quality remains poor at times.
METARs have shown occasional visibility drops to as low as 3 miles
due to the haze. For more information about health risks and
resources related to the air quality, refer to the Air Quality Alert
which remains in effect until midnight Eastern tonight. RAP-Smoke
shows a gradually diminishing trend in near-surface smoke through
Saturday as high pressure weakens slightly and dispersion increases
as a result.

&&

.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
Issued at 340 PM EDT Fri Jul 25 2025

By 00Z Sunday, the upper air pattern consists of a 500mb ridge over
the southeastern US, weak ridging over the Plains, and a pair of
troughs in Canada (one strong cutoff low over Nunavut/NW
Territories and a weakening trough over British Columbia). Flow
will be quasi- zonal across the UP Sunday except for a couple of
shortwaves transiting the periphery of the weak ridging that
will give opportunities for showers and thunderstorms, though a
lot will depend on upstream placement and evolution of mesoscale
systems. Longer-range CAMs such as the NAM Nest and RRFS have
been inconsistent run-to-run about whether the UP takes a direct
hit from a MCS or gets missed entirely, decreasing confidence
in either solution. Should thunderstorms occur, plentiful
instability is expected with the Euro ensemble mean showing over
2500 J/kg of SBCAPE by 00Z Monday. Shear will be time-dependent
as 0-500mb shear increases throughout the day Sunday per the
Euro ensemble. Sunday`s weather is worth monitoring because the
ceiling for impacts is high, with damaging winds the primary
threat, though the ensemble max of the LREF does show potential
for multiple inches of rain in the worst case scenario. However
the floor could be literally nothing happening (10th percentile
of the LREF is 0 inches of rain). The boom-or-bust nature
averages out for SPC and WPC to issue Marginal Risks of severe
weather and excessive rainfall respectively. Chances of rain and
thunder linger through Monday.

In addition to the thunder threat, it will be hot and muggy, with
NBM dew points up to the mid 70s in some spots in the afternoon of
Sunday and Monday. Paired with high temperatures in the 80s to low
90s, heat indices will be approaching 100, though the NBM only
gives around 10 percent chances of triple digit heat index at
this time. Low temperatures in the mid 60s will provide only a
little relief from the heat for those without air conditioning.
Relief from the heat will be coming in the mid to late week
though as the aforementioned Canadian troughs will combine and
deepen over Hudson Bay while ridging builds over the US Plains
and Canadian Rockies. This sets up cooler NW flow aloft over the
UP which will lead to temperatures near or below normal (highs
in the mid to lower 70s, lows around 50) Tuesday through the end
of the week. Being upstream of ridging will lead to dry weather
for the most part, though the cooler temperatures and surface
moisture that just wont quit will keep RHs from falling too far.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 1259 AM EDT Sat Jul 26 2025

Overnight fog/mist and smoke may result in reduced visibilities
overnight, but aside from this, VFR conditions are expected in this
TAF period. Fog may reduce visbilities to IFR or LIFR at times,
mainly at KIWD, but MVFR is generally expected at all sites. Gusty
southwesterly winds may gust to near 20kts by afternoon Saturday.

&&

.MARINE...
Issued at 134 PM EDT Fri Jul 25 2025

Light winds of 20 knots or less dominate the rest of this week
through early next week as high pressure ridging generally remains
over the region for the next several days, save for a shortwave
trough embedded within the ridge passing through the region Sunday.
This shortwave will bring thunderstorms to the lake, and a few may
bring severe weather (5-14 percent chance) and frequent lightning.

&&

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

&&

$$

SHORT TERM...GS
LONG TERM...GS
AVIATION...JTP
MARINE...GS/TAP