219
FXUS63 KMQT 151745
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
145 PM EDT Tue Sep 15 2026

.KEY MESSAGES...

- Widespread rain showers continue across the eastern half of the UP
this morning. Additional rainfall amounts of 0.10-0.25in are most
likely, but there is a 30% chance for higher amounts up to a half an
inch.

- A Wind Advisory is in effect for Northern Houghton and Keweenaw
Counties this afternoon. Strong westerly winds with frequent gusts
of 45+ mph are likely (60-90% chance).

- Gale Warnings remain in effect for the Upper Great Lakes through
the early evening. 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 create dangerous swimming conditions along the
Schoolcraft and Alger County shorelines through this evening.

&&

.DISCUSSION...
Issued at 158 AM EDT Tue Sep 15 2026

Latest water vapor imagery shows quite nicely the midlevel low
currently moving over Manitoba, with deep 994mb low pressure
analyzed at the surface and a trailing occluded front draped over
the Dakotas. RAP analysis places the UP beneath a strong 40-60kt
southerly LLJ, and resulting isentropic ascent has been able to kick
off a batch of widespread showers (with some embedded thunder).
Showers have moved out of the western half of the UP, and are
currently moving through the eastern UP. MRMS shows a widespread
0.10-0.25in over the past six hours over the western UP, with some
higher embedded amounts around 0.50-0.75. This is corroborated by
available surface observations, and similar amounts are expected
over the eastern UP before showers largely wrap up around 12Z.

Apart from the rain, gusty winds are the other main concern of the
short term forecast period. So far tonight, under southerly flow, we
aren`t quite tapping into the strongest winds aloft. Still, some 20-
30mph gusts have been realized tonight, particularly over the
eastern UP and in the downsloping areas over the higher terrain and
downsloping areas over the north-central UP. Breezy conditions
continue the rest of the night. As we head into the daytime hours,
the surface low moves towards Hudson Bay and the attendant frontal
boundary 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. Elsewhere
throughout the UP, expect wind gusts of 20-35mph to be more common.
A Wind Advisory continues 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 through at least midweek.
Wednesday night, latest guidance brings some weak shortwave action
to the area, with some low-end rain chances. As the ridge begins to
shift eastward towards the weekend and another system moves out of
the Plains, better rain chances finally work in by Friday night, and
this could be accompanied by another period of elevated wind speeds.
That said, there is some disagreement on the precise track and
timing of this next system.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 145 PM EDT Tue Sep 15 2026

Surface observations show flight conditions improving to VFR at UP
terminals this afternoon as a cold front departs to the east. Strong
west winds remain in place behind the front through this evening,
gusting to 25-35 kt at KIWD and KSAW and as high as 40-45 kt KCMX.
Winds will trend down and eventually diminish below 10 kt 00-03z
this evening as high pressure builds in from the west, yielding
clearing skies and VFR conditions through the end of the TAF period.

&&

.MARINE...
Issued at 158 AM EDT Tue Sep 15 2026

Lake Superior: Strong southerly winds persist tonight as a deepening
surface low currently over Manitoba continues northeast towards
northern Ontario. Southerly wind gusts up to 35-40kts are becoming
more common over 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 through Tuesday evening.
Westerlies fall below 35 kts after 00Z and continue diminishing
overnight through Wednesday.

Northern Green Bay and northwestern Lake Michigan: Strong southerly
flow persists the rest of tonight into Tuesday morning, with gales
to 35kts. As winds turn westerly behind a cold front from mid
morning to 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 until 8 PM EDT this evening for MIZ001-003.

  Beach Hazards Statement until 10 PM EDT this evening for
     MIZ006.

  Beach Hazards Statement until 10 PM EDT this evening for
     MIZ014.

Lake Superior...
  Gale Warning until 5 PM EDT /4 PM CDT/ this afternoon for
     LSZ162-240.

  Gale Warning until 8 PM EDT /7 PM CDT/ this evening for
     LSZ241>248-250-263>266.

  Gale Warning until 8 PM EDT this evening for LSZ251-267.

Lake Michigan...
None.

&&

$$

DISCUSSION...BW/LC
AVIATION...CB
MARINE...BW/LC