460
FXUS63 KMQT 311927
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
327 PM EDT Thu Jul 31 2025

.KEY MESSAGES...

- Dry weather persists the rest of the week. Cooler-than-normal
temperatures turn warmer into the weekend.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 121 PM EDT Thu Jul 31 2025

GOES-East imagery shows fair weather cu fields developing over the
central and far eastern UP but otherwise mostly clear skies. RAP
Analysis shows a 1029mb high pressure centered over the northern
MN/Canada border expanding across much of the Upper Midwest. Aloft,
ridging over the Rockies opposes deep troughs/cutoff lows over the
Gulf of Alaska and Atlantic Canada. This sets up cool northwesterly
flow over the UP, with below-normal high temperatures expected today
(upper 60s compared to mid 70s at WFO MQT, for instance).
Diminishing northeasterly flow over Lake Michigan has allowed for
the only marine hazard from this morning, a Small Craft Advisory, to
expire, so summertime recreation will be somewhat safer. However,
the prevailing northwest flow aloft combined with subsidence from
the surface high is keeping smoke from Canadian wildfires near the
surface. As a result, the State of Michigan EGLE has extended the
Air Quality Alert through the day Saturday due to elevated levels of
PM2.5 causing hazardous conditions, especially for people with
sensitivities to respiratory conditions. See the AQA for more
information about the hazard and for more resources.

Tonight, efficient radiational cooling (in addition to the
aforementioned northwesterly flow cutting off the Corn Belt
connection that gave us elevated dew points recently) will allow for
temperatures to fall into the 40s for most away from the shores of
the Great Lakes. Light winds and temperatures falling near the dew
point in the east will allow for chances of patchy fog to climb to
around 30 percent according to the HREF. Despite smoke remaining in
the forecast for Friday, efficient radiational heating will allow
temperatures to climb back to normal and a lake breeze to push off
of Lake Michigan.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
Issued at 326 PM EDT Thu Jul 31 2025

Through the weekend, the global deterministic 500mb charts show
cutoff highs over northwest Mexico and Saskatchewan leading to split
flow between and upstream of those features. The troughing portion
of that split flow will stay too far south to bring precip to the UP
prior to Monday afternoon as the ridging portion keeps high pressure
over the Upper Great Lakes (LREF mean around 1028mb). With the
cooler NW flow aloft being interrupted somewhat, temperatures climb
to around the 80 degree mark, slightly above normal. This may bring
some relief to the smoke but the details of smoke dispersion timing
are still difficult to pin down.

Moving into next week, ensembles diverge significantly about how the
pattern breaks down and how embedded shortwaves track through the
region. This makes the precipitation forecast challenging, though
with less certainty in stifling high pressure, a diurnal
precipitation pattern emerges in the interior west in the NBM as
even in weakly forced atmospheres, the chances of the summertime
airmass over the interior western UP acquiring 1000+ J/kg of SBCAPE
climbs above 50 percent by the midweek period per the LREF. Part of
this increasing trend in instability is due to the increasing trend
in surface moisture as connection to Gulf or Corn Belt moisture
becomes more likely. The LREF shows chances of surface dew points
exceeding 65 degrees climbing over 50 percent by Wednesday. Should
the models start to coalesce around any particular shortwave trough,
severe weather potential will be in play, but no particular day`s
setup stands out at this time. While high temperatures are still
expected to hover around the 80 degree mark throughout the
week, the increased moisture will make for a slight warming
trend in low temperatures, from the 50s Saturday morning to well
into the 60s by the end of the week.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 121 PM EDT Thu Jul 31 2025

Near surface wildfire smoke from Canada will continue to result in
MVFR to temporary IFR visibilities through this TAF period.
Otherwise, SCT or less cloud cover and primarily light winds in the
forecast under high pressure. SAW will have about a 30 percent
chance to see some patchy FG down to IFR conditions overnight, but
will wait to include until better model agreement occurs.

&&

.MARINE...
Issued at 326 PM EDT Thu Jul 31 2025

Under primarily high pressure, winds will remain below 20 kt for
most of this forecast period. The only exception at this time looks
to be Saturday evening, where funneling southwest winds between
Thunder Bay and Isle Royale will cause some localized wind
gusts to around 25 knots. Otherwise, expect wildfire smoke to
cause poor air quality at least through Saturday. There will be
some chances of thunder next week, though model guidance is
widely spread in the timing and location details at this time.

&&

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

&&

$$

SHORT TERM...GS
LONG TERM...GS
AVIATION...GS
MARINE...GS