591
FXUS63 KMQT 150553
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
153 AM EDT Wed Oct 15 2025

.KEY MESSAGES...

- Seasonable temperatures for midweek followed by a warm start
  to the weekend.

- Chance for light rain showers tonight closer to the WI/MI
  stateline. Rain chances increase late Thursday and continue
  into the weekend.

&&

.DISCUSSION...
Issued at 301 AM EDT Tue Oct 14 2025

Early morning RAP analysis and GOES satellite imagery reveal a deep
trough encompassing much of the western CONUS as a closed upper low
digs south down the California coastline. This is working to
amplify upstream height rises across the Upper Midwest and Great
Lakes where incoming sfc high pressure in the Canadian Prairies is
providing mostly clear skies and chilly NW flow. Temps across the UP
this morning range from the mid 30s in the interior west where light
winds have allowed efficient radiational cooling to around 50 in the
Keweenaw, being somewhat modified by NW flow off of Lake Superior.
Elsewhere, temps have dipped into the 40s. Weak embedded shortwaves
within the broad troughing further S and W is beginning to usher in
high to midlevel cloud cover.


Aforementioned sfc high pressure builds over the Upper Great Lakes on
today, becoming centered overhead on Wednesday as it weakens
slightly. Mid level ridging builds over the central CONUS with a
ridge riding shortwave tonight into Wednesday. Meanwhile, the deep
trough upstream sets up over the Rockies and a series of troughs
moves over eastern Canada. Cooler northerly flow keeps temps
slightly colder than normal with highs only expected in the upper
40s to upper 50s under partly to mostly cloudy skies. Latest
guidance suite is still rather unimpressed with measurable (>0.01")
rain chances late tonight into early Wednesday, with global
ensembles displaying a 10-40% chance along the MI/WI border.
HREF/NBM are a bit more optimistic, suggesting a ~40-70% chance for
measurable rain by Wednesday morning. Regardless, if any rain can be
squeezed out, it will be rather low impact. That said, if a drier
solution pans out, less clouds could help cooler temps resolve.
Quiet and calm weather returns on Wednesday with the high pressure
now centered overhead. Highs will be in the 50s across the UP.
Expect similar lows Wednesday night, but with clouds increasing from
the southwest, coldest temps will be interior east instead.

Attention then turns to the deep trough upstream. The mid level
ridge begins to migrate east as the trough lifts out over the
Northern Plains, developing surface low Wednesday night. The high
pressure quickly gives way to the east on Thursday, allowing for a
warm front to re-introduce PoPs to the forecast as the low to the
west lifts toward the Dakotas. The trough begins to quickly pivot
northeast Thursday night through Friday, deepening the surface low
as it lifts to near Lake Winnipeg. Guidance begins to diverge on the
mid level pattern as the shortwave/surface low pair continue
northeast this weekend, but persistent troughing over the region
keeps rain chances in the forecast this weekend (supported also by
marginally cold enough lake surface-850mb delta-Ts for lake effect
precip Saturday night and Sunday). That said, impactful amounts of
rain are unlikely given probabilities of 0.5" struggle to reach 25%.
Otherwise, temps warm back above normal for the first half of the
weekend with spots possibly reaching back into the low to mid 70s on
Friday.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 153 AM EDT Wed Oct 15 2025

VFR conditions today and tonight as clouds retreat late this morning
and sunny skies return by this afternoon. Expect calm winds this
morning to give way to the Lake Superior lake breeze by the
afternoon before becoming calm again this evening.

&&

.MARINE...
Issued at 248 PM EDT Tue Oct 14 2025

North to northwest winds have been observed settling across Lake
Superior today as high pressure stretches into the Upper Great
Lakes. Winds look to remain light and mostly under 20kts as this
feature transits the region into Thursday. By late Thursday,
increasing southerly flow as a warm front lifts through may result
in winds of 20-25kts from the Keweenaw eastward overnight, then more
widespread 20-25kt southerly winds Friday. The setup with a strong
low level jet advecting in warmer air aloft over the east half
suggests stronger winds may be possible, particularly for higher
reporting platforms and in the downsloping areas closer to the
southern lakeshores. At the moment, gales can`t be ruled out and
this general idea is reflected in the most recent EC ensemble
system, which currently suggests 10-20% for gales Friday afternoon.
The GEFS pairs well with its deterministic counterpart, suggesting
upwards of 50% probabilities. Elevated winds look to remain possible
over the lake through the weekend ahead of and behind a cold front
Saturday, and potentially in response to a surface low lifting north
from lower Michigan on Sunday.

&&

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

&&

$$

DISCUSSION...JTP
AVIATION...BW/TAP
MARINE...JTP