786
FXUS63 KMQT 022319
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
719 PM EDT Wed Apr 2 2025

.KEY MESSAGES...

- Winter Weather Advisories remain in effect for the Keweenaw and
portions of the eastern UP for snow and a wintry mix into the
evening.

- Wind Advisories remain in effect for portions of the eastern UP
for afternoon wind gusts in excess of 45 mph.

- West gales 35 to 40 kts expected across central and eastern Lake
Superior early Thursday morning, diminishing through the evening as
high pressure builds in.

- Warming temperatures and high April sun angle will lead to rapidly
melting snow and ice during the daylight hours late this week into
early this weekend.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 315 PM EDT Wed Apr 2 2025

Afternoon RAP analysis has deep 990mb low pressure centered over IA,
with a surface warm front extending into WI. Aloft, robust 850mb WAA
persists across the Great Lakes, with a strong 50-60kt
south/southeast LLJ directed over the region. Much of the widespread
wintry precipitation has tapered off over the UP with a dry slot
nosing into the central and eastern portions of the area, but light
to occasionally moderate precipitation persist in the far western UP
and the Keweenaw. Additionally, another round of precipitation is
moving through NW WI and should track through the UP the rest of the
afternoon. While precipitation was initially falling mainly as snow,
the building warm nose aloft and surface temperatures riding to near
and just above freezing is supporting a changeover to a wintry mix
of rain, snow, and perhaps sleet/freezing rain. Any additional
snow/ice accumulations the next few hours should be light across
most of the UP, with snow totals generally below an inch and just a
glaze of ice. However, this could still lead to slick driving
conditions through the evening commute. The Keweenaw remains the
exception. There, temperatures stay cool enough for accumulating
snow and spotty freezing rain through the rest of the afternoon and
evening. With another 1-3in of snow and some patchy ice possible,
will allow the Winter Weather Advisory to continue. Will also allow
the advisory over southern Schoolcraft county to run its course the
rest of the afternoon with (albeit lighter) snow/wintry mix
persisting there while winds begin to increase.

While on the topic: southeast winds had been fairly benign most of
the afternoon, but are on the increase at this time. Gusts in excess
of 30mph have become common across the eastern UP, and soundings
continue to indicate that we could tap into 40+kt winds present
below the inversion. Stronger gusts are also expected across the
Keweenaw, particularly in the southeast downsloping areas nearer to
Lake Superior. With winds on the increase, the Wind Advisory remains
in effect across portions of the eastern UP.

As we head into the evening hours, the surface low continues to
track northeastward over far eastern MN and should be moving over
western Lake Superior/Upper Michigan around/after 00Z. Surface
temperatures rise above freezing from south to north, allowing for a
change over mainly to rain from around 21Z onwards. Rain slowly
wraps up the first half of the night, but as the low continues to
track northeastward over Superior and the cold front begins to track
through, expect slowly cooling temperatures and lake effect/enhanced
snow showers the second half of the night. Snow should be confined
to the westerly wind belts of the western UP. Additional snow totals
are expected to be light, below an inch.

&&

.LONG TERM /THURSDAY THROUGH WEDNESDAY/...
Issued at 315 PM EDT Wed Apr 2 2025

Come Thursday morning, ~990mb sfc low pressure will be continuing
its northeastward departure towards far southern James Bay, placing
the UP within the system`s dry slot, slowing or shutting off precip
altogether. Wrap around snow showers within the comma head region of
the low with a little lake enhancement from chilly WNW flow across
Lake Superior may linger through the early afternoon across the west
half, but little to no additional snow accumulations are expected.
Otherwise with strong pressure rises (10-15mb / 6hr) Thursday
afternoon, expect gusty W to WNW winds upwards of 30-40 mph during
the early afternoon hours, particularly in the Keweenaw where
ensemble members suggests max gust potential between 45-50 mph.
Winds should quickly retreat into the evening and moreso into Friday
as the pressure gradient slackens amidst incoming ridging and sfc
high pressure.

Finally, after a very busy March and active start to April, the
extended forecast looks rather "boring" with no major systems set to
impact Upper Michigan through at least the next 7 days. A cold front
passing across the Upper Great Lakes may kick off some weak lake
enhanced/effect showers Saturday and Sunday. Beyond this weekend a
building western US ridge forces downstream troughing in the NE US
and Canadian Maritimes, allowing chilly N/NW flow into the Great
Lakes early next week. LREF 850mb temps reach as low as -15C by
Monday, supporting a period of lake effect snow. Model guidance
begins to spread on the pattern through the midweek, however, there
are no signs of anything majorly impactful.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 719 PM EDT Wed Apr 2 2025

Snow and mixed precip will end this evening followed by lingering
low level moisture, which will support LIFR ceilings and visibility
restrictions. Models suggest the greatest vis reductions are
expected this evening at KSAW, potentially resulting in IFR/LIFR
visibilities for a few hours before improving overnight. Otherwise,
ceilings should improve to IFR by Thursday morning, with further
improvement to MVFR and VFR through the day. Gusty winds will
persist at KCMX in this period; however, expect easterly and
southerly flow to weaken this evening and overnight, before becoming
westerly and increasing upwards of 35kts again Thursday. KSAW/KIWD
may continue to see gusts near 20kts this evening, but light winds
overnight should increase to near 25kts Thursday under westerly flow.

&&

.MARINE...
Issued at 315 PM EDT Wed Apr 2 2025

East to southeast winds continue building this evening as a low
approaches from the Upper MS Valley. Gusts are expected to reach
high end Gale / Storm force (45-50 kts) across the north and east-
central lake close to the international border during the late
afternoon and evening hours. Additionally, waves will peak between
10-18ft. Once the sfc low pressure moves directly overhead the west-
central lake, winds will briefly weaken to 25-30 kts lakewide in the
early morning hours Thursday. As the low pulls to the northeast
early Thursday, winds to increase from the west coinciding strong
pressure rises. Westerly gales of 35-40 knots are expected along the
Keweenaw shorelines eastward across the east-central lake with waves
reaching 8-12 feet near Caribou and Michipicoten Islands.

As high pressure quickly builds in behind the departing low, expect
winds to begin dying down, weakening to 20 knots or less by the late
evening. Lighter winds continue through Friday and Saturday as high
pressure dominates the Upper Great Lakes and a shortwave low misses
us well to the south. However, we could see a return to northwest to
north-northwest winds of 20 to 25 knots late this weekend into early
next week as a cold front pushes through the region.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
  Winter Weather Advisory until 8 PM EDT this evening for MIZ001-
     003.

  Wind Advisory until 10 PM EDT this evening for MIZ006-007-085.

Lake Superior...
  Gale Warning until 11 PM EDT /10 PM CDT/ this evening for
     LSZ162-242-243-246>250-263-265.

  Gale Warning from 2 AM EDT /1 AM CDT/ to 2 PM EDT /1 PM CDT/
     Thursday for LSZ241>244-263-264.

  Storm Warning until 11 PM EDT this evening for LSZ244-245-251-
     264-266-267.

  Gale Warning from 5 AM to 2 PM EDT Thursday for LSZ265.

  Gale Warning from 5 AM to 5 PM EDT Thursday for LSZ266.

  Gale Warning from 8 AM to 5 PM EDT Thursday for LSZ267.

Lake Michigan...
  Gale Warning until 8 PM EDT this evening for LMZ221-248-250.

&&

$$

SHORT TERM...
LONG TERM...BW
AVIATION...JTP
MARINE...BW