307
FXUS63 KMQT 051916
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
316 PM EDT Thu Jun 5 2025

.KEY MESSAGES...

- Smoke and haze from upstream wildfires continues to impact air
quality today across eastern Upper Michigan.

- A round of scattered showers and a few thunderstorms is expected
Friday.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 316 PM EDT Thu Jun 5 2025

Afternoon water vapor imagery and RAP analyses show weakly zonal
flow over the Great Lakes, along with dry midlevel air. Broad mid-
and upper-level troughing is extending from the Canadian Prairie to
the Northern Plains, with an embedded shortwave moving through the
Dakotas at this time. At the surface, high pressure remains sprawled
out over the region. Fair-weather cumulus is popping up over much of
the Upper Peninsula, at least ahead of the lake breezes, and some
more agitated cu is apparent along the Superior lake breeze. Would
not be surprised to see some showers finally develop over the next
couple of hours, though dry air and weak forcing should limit both
coverage, intensity, and accumulations.

Otherwise, temperatures are climbing generally into the mid 70s
inland, and the upper 60s near the Great Lakes. Dewpoints falling
through the 30s in the interior-western UP and along the WI border,
yielding RH below 30%, would present a limited fire weather concern.
Light winds continue to temper this threat, but will note that the
developing lake breeze is expected to lead to rapid changes in wind
direction as it presses further inland.

Tonight, shower activity should wane in the evening, followed by dry
conditions for most under increasing cloud cover as the shortwave
over the Northern Plains moves eastward. Weak isentropic ascent
courtesy of rising 850mb temperatures may support rain showers
across the west half by day break, before becoming more widespread
through the day Friday across the forecast area as the trough swings
through. Weak instability per model soundings indicates a limited
threat for any thunder. Meanwhile, temperatures should come in
cooler than today, peaking in the lower/mid 60s in the western UP
and the upper 60s to near 70F to the east.

Finally, will note the lingering potential for poor air quality
through the evening due to patchy near-surface smoke across the
eastern UP. Michigan`s Department of Environment, Great Lakes, and
Energy (EGLE) has continued the Air Quality Alert for elevated
levels of fine particulate (PM2.5) for these areas. It is
recommended that, when possible, you avoid strenuous outdoor
activities, especially those with heart disease and respiratory
diseases such as asthma.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
Issued at 316 PM EDT Thu Jun 5 2025

Weak midlevel ridging and surface high pressure over the Great Lakes
Saturday will support a brief period of dry weather. A rather
pleasant summer day is expected with temperatures starting off in
the 40s and increasing to more seasonal values in the 70s (60s in
the Keweenaw and near the Great Lakes) with sunny skies.

Active weather returns Sunday into early next week. Deterministic
and ensemble guidance have a vigorous shortwave trough diving
through the Prairies provinces through Saturday, reaching the Upper
Midwest by early Sunday while an embedded midlevel low closes off. A
cold front sweeps through the Great Lakes Sunday with some shortwave
energy out ahead of this main feature, bringing our next batch of
widespread rain and thunderstorms. PWATs in excess of an inch,
deeply saturated soundings, and several hundred to 1000 j/kg of
MUCAPE (depending on your model/member of choice) indicate a
potential for some healthy amounts of precipitation - highest in any
thunderstorms. NBM has widespread rain totals of a quarter to half-
inch with the cold front, and around a 30-40% chance for totals in
excess of an inch (mainly across the central UP). After perhaps a
brief break in shower activity behind the front into early Monday
morning, additional rain chances develop early next week as the
stacked low meanders over the Great Lakes with associated wraparound
moisture behind the front as well as a cooler airmass. Ridging into
midweek will allow for a return to dry weather while a warming trend
kicks off.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 126 PM EDT Thu Jun 5 2025

VFR conditions are expected throughout this TAF period with
afternoon lake breezes today. Showers may develop near KIWD, aided
by the lake breeze, but better potential is just inland of the
terminal. Late tonight, showers begin pressing into Upper Michigan`s
west, potentially bringing rain to KIWD/KCMX that should linger into
the morning. Showers hold off at KSAW until Friday afternoon.

&&

.MARINE...
Issued at 316 PM EDT Thu Jun 5 2025

Shifting winds continue to come in below 15kts the rest of today
through Friday. Then, a period of gustier winds is forecast this
weekend, with south/southwest winds gusting to around 20-25 kts late
Saturday into Sunday as a low pressure system approaches the Great
Lakes. Winds shift to the northwest behind the low pressure system
early next week, falling back below 20kts.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
  Air Quality Alert until 1 AM EDT Friday for MIZ006-007-013-014-
     085.

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

&&

$$

SHORT TERM...LC
LONG TERM...LC
AVIATION...LC
MARINE...LC