503
FXUS63 KMQT 031123
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
723 AM EDT Thu Apr 3 2025

.KEY MESSAGES...

- As low pressure departs, expect showers and fog to clear up
  throughout the day today. Gusty westerly winds to 30 mph
  expected with a few gusts to 45 mph possible (30%) along the
  shores of the Great Lakes.

- Warming temperatures and the high April sun angle will lead to
  melting snow and ice during the daylight hours late this week.
  Travel on any remaining frozen lakes and rivers is not advised.

&&

.SHORT TERM /THROUGH THIS AFTERNOON/...
Issued at 223 AM EDT Thu Apr 3 2025

RAP Analysis shows a stacked low over western Lake Superior and
Isle Royale at 06Z with a surface pressure of 991mb. GOES East
low level water vapor imagery shows significant dry slot over
the UP and upstream which is at least mostly to blame for lack
of precipitation over much of the UP right now. However, that
does not mean there`s a lack of boundary-layer moisture, as 32+
F dewpoints advected over a ripe snowpack have contributed to
foggy conditions across the UP currently with a number of UP
METAR locations showing sub-1 mile vis. As winds ramp back up in
the wake of the passing cold front, this fog bank is expected
to advect to the northeast and out of the area throughout the
morning. Speaking of the winds, pressure rises as much as
15mb/6hr in the wake of the low`s passage along with 850mb cold
advection to the rate of as much as -25 C/12hr will combine for
a bit of a windy day, with widespread gusts to 30 mph expected
and HREF probabilities of a few gusts to 45 mph along the shores
of the Great Lakes at around 30%. Given widespread frequent 45
mph gusts are not expected, will not elect to issue any land
hazards, but still, expect a breezy day today. Expect any
lingering light showers to end by the early afternoon hours with
even some clearing expected by 00Z as surface high pressure
encroaches on the area, with high temperatures today climbing to
around the 40 degree mark.

&&

.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
Issued at 232 AM EDT Thu Apr 3 2025

Much calmer weather is expected for the extended period as high
pressure moves in tonight behind the low and generally remains
across Lake Superior and Upper Michigan through the last part of
this week. Because of this, expect temperatures across the area to
be around normal as two shortwaves, one missing us to the south and
another weaker one missing us just to the northwest, bring some
cloudier skies back across the area Friday afternoon through
Saturday. Nevertheless, expect high temperatures Friday and Saturday
to get into the 40s to possibly low 50s, and for lows tonight
through Saturday night to drop into lower 30s to the the 20s. The
warm daytime temperatures and the high April sun angle will work
together late this week to melt the remaining snowfall and ice
across the area for the rest of this week; this will make traveling
out onto the remaining frozen lakes and rivers risky,
potentially even dangerous. Therefore, in order to not fall into
any near-freezing water by accident, it`s best to avoid
stepping foot on any of the remaining frozen lakes and rivers.

While there is a slight chance (~20%) that we could get a glancing
blow of precipitation from the two shortwaves missing us Saturday,
our next best chance for precipitation occurs late this weekend into
early next week as a cold front descending from Ontario brings 850mb
temps of around -15 C over Lake Superior, creating lake effect snow
showers across the northwest to north wind snow belts Sunday through
Monday. While delta-Ts look to be in the mid to upper teens, with
high pressure quickly trying to push in from the west early next
week and the high April sun angle significantly eating snowfall
during the daytime, snowfall accumulations will be very light, with
any accumulations more than likely being limited to the nighttime
hours. While we can expect well below average temperatures behind
the cold front Sunday night, Monday, and Monday night (highs in the
upper 20s to mid 30s and lows in the mid-teens to lower 20s), more
normal temperatures look to return by the middle of next week as the
high pressure descending from the Northern Plains/Canadian Prairies
into the Ohio River Valley pushes the polar air out of our area and
replaces it with air from the Desert Southwest.

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 1203 AM EDT Thu Apr 3 2025

Abundant low level moisture will continue LIFR ceilings at all sites
overnight. Some improvement is expected by morning, with further
improvement to MVFR and then VFR through the day Thursday. Models
are handling fog at KSAW and KCMX poorly, but signals are present
for LIFR fog to develop and then continue at least through 8z when
the wind shift to the southwest. Westerly gusty winds will develop
later tonight and persist Thursday. Highest, upwards of 35 kts, are
expected at KCMX while 20-25kts are mostly expected at KSAW/KIWD.

&&

.MARINE...
Issued at 232 AM EDT Thu Apr 3 2025

As the center of the low moves through western Lake Superior early
this morning, expect the winds to pick up from the west and west-
northwest later this morning once the low pressure begins lifting
out of the lake into Ontario. Expect the west to west-northwesterly
winds to reach gales of 35 to 40 knots across the central and
eastern portions of the lake by the mid-morning, remaining until the
late afternoon when high pressure moving in from the west quickly
reduces the winds to 20 knots or less again by this evening. The
light winds remain across Lake Superior the rest of this week as
high pressure ridging dominates the region. As a cold front descends
from northern Ontario over us late Sunday into Monday, expect the
winds to increase from the north at 20 to 25 knots behind it. As
high pressure behind the front descends from the Canadian Prairies
and Northern Plains into the Ohio River Valley from early to mid
next week, expect the winds to become 20 knots or less again by
Monday night, looking to continue through the rest of next week as a
general stable pattern looks to settle over us.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
  Gale Warning until 2 PM EDT /1 PM CDT/ this afternoon for
     LSZ241>244-263-264.

  Gale Warning until 2 PM EDT this afternoon for LSZ245-247-248-
     265.

  Gale Warning until 5 PM EDT this afternoon for LSZ250-251-266-
     267.

Lake Michigan...
  Gale Warning until 2 PM EDT this afternoon for LMZ221-248-250.

&&

$$

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