273
FXUS63 KMQT 141852
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
252 PM EDT Mon Sep 14 2026

.KEY MESSAGES...

- Widespread rain showers move into the UP from west to east
  tonight through Tuesday morning. There is a general 25-75%
  chance for rainfall amounts >0.5", with the highest chances
  across the southern half of the UP.

- A Wind Advisory has been issued for Northern Houghton and
  Keweenaw Counties on Tuesday. Strong westerly winds with
  frequent gusts of 45+ mph are likely (60-90% chance).

- Gale Warnings remain in effect for the Upper Great Lakes
  tonight through Tuesday. Southerly gales 35-40 kts turn
  westerly by early Tuesday afternoon. Westerly gusts 40-45 kts
  will be common with a few Storm force gusts to 50 kts possible
  (up to 50% chance) near the Keweenaw Peninsula.

- Strong winds over the Upper Great Lakes tonight through
  Tuesday are expected to create dangerous swimming conditions
  along the Schoolcraft and Alger County shorelines on Tuesday.

&&

.DISCUSSION...
Issued at 250 PM EDT Mon Sep 14 2026

Afternoon GOES water vapor imagery reveals a sharp trough digging
across eastern Montana that is supporting a ~998 mb surface low
along the Canada/MT/ND border. A strong 45-60 kt 850 mb jet
stretches from northern MO all the way to southern Manitoba,
transporting warm moisture air northward and isentropically forcing
an area of showers and thunderstorms from Iowa through Minnesota.
Closer to home, departing high pressure has kept the UP dry thus
far. This region of precipitation is slated to lift from west to east
across the UP this evening through Tuesday morning as the trough and
surface low work northward through northern Ontario. CAM ensembles
largely agree upon the southern half of the UP receiving a health
0.25-0.75" of rain, with the greatest probability for >0.5"
concentrated in Menominee and Delta counties (60-90% chance).
Elsewhere, 0.25-0.50" is expected. Apart from the rain, gusty winds
are the other main concern of the short term forecast period.
Southerly wind gusts 25-35 mph will be common tonight with
potentially stronger gusts near 40 mph in the downsloping areas of
the central UP. Tomorrow, the attendant surface low pressure system
cold front will press through the region during the late morning to
early afternoon hours, veering winds to the west. Strong pressure
rises upwards of 1-2 mb/hour and modest upper level cold air
advection will work to increase wind gusts on Lake Superior and in
the Keweenaw between 40-50 mph with occasional gusts to 55 mph
should mixing be able to tap into higher gusts aloft. A Windy
Advisory has been issued for N Houghton and Keweenaw Counties from
15-00z Tuesday (10a-8p local).

Moving into the rest of the week, expect generally quieter weather
as zonal flow in the upper levels and shortwave ridges moving
through the U.P. generally keep active weather away. While this
should keep temperatures fairly seasonable for the rest of the week,
this does also support dry weather continuing until the end of the
forecast period, provided we don`t get grazed by a nearby shortwave.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 226 PM EDT Mon Sep 14 2026

Current VFR conditions deteriorate to MVFR/IFR through tonight
before improving back to VFR beginning tomorrow late morning. An
incoming low pressure system brings elevated southerly winds today
and rain chances tonight, followed by strong westerlies and LLWS
tomorrow morning. Impacts will largely be felt west to east;
confidence is high on precipitation chances and ceiling trends, but
less so on visibility. LLWS included for speed shear at all three
sites between in the early morning hours tomorrow (spanning 02-11Z
together) due to a strong SSW`ly  LLJ. Current model soundings show
45 kts reaching to just below 2kft for several hours at all three
sites. Though not included in this TAF, tomorrow brings strong
westerly gusts, particularly at KCMX. For this site, the period of
highest winds looks to be 15Z-22Z tomorrow with sustained winds at
25-30 kts and gusts to 45 kts possible during this time. A Wind
Advisory has been issued for Keweenaw County starting at 15Z
tomorrow.

&&

.MARINE...
Issued at 250 PM EDT Mon Sep 14 2026

Lake Superior: Increasing southerly winds are being observed this
afternoon as a deepening surface low continues northeast towards
northern Ontario and surface high pressure departs the Great Lakes.
This evening and into the overnight hours, southerly gusts 35-40 kts
will be common in the eastern half of the lake. By the late morning
to early afternoon, the system`s cold front will traverse the lake,
veering winds to the west. Given strong pressure rises and increase
cold air advection, westerly winds are expected to increase between
35-45 kts for much of the lake. There is a 50-60% chance for a few
Storm force gusts to 50 kts around the Keweenaw. Have maintained Gale
Warnings for dual directional gales tonight through tomorrow
evening. Westerlies fall below 35 kts tomorrow evening and continue
diminishing overnight through Wednesday.

Northern Green Bay and northwestern Lake Michigan: Southerly winds
are on the rise this afternoon eventually reaching gales to 35 kts
by around midnight tonight. As winds turn westerly behind a cold
front Tuesday morning/early afternoon, winds fall below 25 kts and
continue diminishing to 15 kts or less through the evening.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
  Wind Advisory from 11 AM to 8 PM EDT Tuesday for MIZ001-003.

Lake Superior...
  Gale Warning from 11 PM this evening to 8 AM EDT Tuesday for
     LSZ249.

  Gale Warning from 7 AM EDT /6 AM CDT/ to 4 PM EDT /3 PM CDT/
     Tuesday for LSZ162.

  Gale Warning from 8 AM EDT /7 AM CDT/ to 5 PM EDT /4 PM CDT/
     Tuesday for LSZ240.

  Gale Warning from 8 AM EDT /7 AM CDT/ to 8 PM EDT /7 PM CDT/
     Tuesday for LSZ241>243.

  Gale Warning from 8 PM this evening to 8 PM EDT Tuesday for
     LSZ244-245-248-265-266.

  Gale Warning from 10 AM to 8 PM EDT Tuesday for LSZ246-247.

  Gale Warning from 2 AM to 8 PM EDT Tuesday for LSZ250.

  Gale Warning from 3 AM to 9 AM EDT Tuesday for LSZ251-267.

  Gale Warning from midnight tonight to 8 PM EDT Tuesday for
     LSZ263-264.

Lake Michigan...
  Gale Warning from 11 PM this evening to 8 AM EDT Tuesday for
     LMZ221-248-250.

&&

$$

DISCUSSION...BW
AVIATION...RE
MARINE...BW