National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS63 KMQT 122013
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
413 PM EDT Fri Apr 12 2024

.KEY MESSAGES...

- Deep low pressure over Quebec continues gusty north to
  northwest winds up to 30-40 mph, stronger winds are expected
  over the eastern UP.
- Periods of showers into next week, including Saturday night
  and then through much of next week.
- Temperatures on most days will be above normal through the
  first half of next week.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 352 PM EDT Fri Apr 12 2024

Current RAP analysis shows the strong low pressure system northeast
of Lake Huron over the Ontario/Quebec province line with weak sfc
high pressure along the Dakotas/Minnesota state lines. The mid level
trough is located just southwest of sfc low and is centered over
Lake Huron/southern Ontario. A broad mid level ridge is analyzed
over the Rockies/Plains with a closed low off the western U.S.
coast. With the sfc low and mid level trough no longer vertically
stacked well, the sfc low will weaken into tonight as it lifts north
through Quebec while the trough progresses east-northeast into
Quebec/New England. Lingering light rain showers over the far
eastern UP will diminish from west to east into this evening as the
sfc low departs. No major accumulations beyond 0.01" are expected.

This set up continues a tighter pressure gradient over the UP into
tonight resulting in some gusty northwest winds, especially over the
east. Gusts around 20 to 30 mph are expected over the western third
of the UP with the remainder of Upper Michigan gusting up to around
30 to 40 mph; some gusts along the eastern lakeshores could reach 45
mph yet this afternoon. Thus, the wind advisory will continue
through 8 PM EST this evening for Alger/Delta counties eastward.
While the northwest winds off Lake Superior have kept the eastern
lakeshores cooler in the low to mid 40s, temps elsewhere have warmed
up into the mid 40s to mid 50s with the warmest over the south
central UP; not much if any additional warming is expected today.

Tonight, sfc high pressure will gradually build in from the west and
the pressure gradient overhead will slacken. PWATs show a 0.1" drop
across the UP as drier air moves in from the northwest, something
already noted in the water vapor imagery over Minnesota. The drier
air will help clear skies out as northwest winds weaken; gusts drop
back down to around 20 to 30 mph by Saturday morning with strongest
winds located near the eastern lakeshores. Clearer skies will also
help bring lows down into the upper 20s to mid 30s, warmer near the
lakeshores.

&&

.LONG TERM /SATURDAY THROUGH FRIDAY/...
Issued at 412 PM EDT Fri Apr 12 2024

Saturday starts off dry and sunny with weak ridging over the area,
but a shortwave dropping into northern MN touches off waa/isentropic
ascent toward Upper MI by evening. This should bring an increase in
clouds ahead of a quick round of showers overnight. With an
advancing sharp 850mb theta-e gradient and vigorous upper diffluence
from the right entrance region of a 100kt upper jet streak extending
from northern Lake Superior into the Lower Great Lakes by the
evening, scattered showers should spread into w/nw Upper MI
generally after 00Z. That said, some of the simulated reflectivity
(though usually a little too aggressive with the onset timing) do
show some shower activity kicking off during the late afternoon in
the western UP. Scattered showers end by sunrise Sunday. A pool of
elevated instability of 100-400 j/kg builds toward Upper MI for Sat
night, and it may be just sufficient toward the MI/WI stateline for
a rumble or two of thunder. Following the showers on Sat night,
Sunday looks to be a nice mid-Apr day under increasing sunshine.
Highs Sat will be in lower 60s over the interior west half and
mostly in the lower to mid 50s elsewhere. Highs Sun will be well
into the 60s F across the interior w half and south central and
mostly in the mid to upper 50s elsewhere.

Will note a potential for dewpoints to drop both Saturday and Sunday
afternoon, with well-mixed and very dry model soundings. Increasing
clouds Saturday may inhibit this at least across the western UP. This
environment could see RH falling to as low as 20-25% across much of
the interior UP Saturday, while a somewhat more moist airmass Sunday
nevertheless may see RH falling into hte 30% range during the
afternoon. Fortunately, winds will be decreasing from west to east
Saturday morning, but some 15 to 20 mph gusts will be possible
during the afternoon Sunday.

Dry weather persists for much of Monday with the ridge still over
the Great Lakes. However, by late in the day the quasi-zonal flow in
the vicinity of the U.S./Canada border will be breaking down as a
shortwave drops out of the Gulf of Alaska into the NW U.S.
Downstream, the upper jet will be forced to lift northward, again
placing right entrance region upper diffluence over the area. There
are also hints of a weak shortwave tracking toward Upper MI. This,
in addition to some diurnal instability, could lead to a few showers
mainly over the western UP during the afternoon/evening.

Attention then turns to the wave over the Southwest U.S. that gets
kicked northeast by the shortwave dropping from Gulf of Alaska
through the NW U.S. Surface response will be a deep sfc low
organizing in the lee of the Colorado Rockies. This low will reach
peak strength over the Plains on Tuesday, and then weaken as it
lifts northeast into the Upper Great Lakes and northern
Ontario/Quebec Tue night into Wed. With a good surge of Gulf
moisture ahead of the approaching low (layer precipitable water
values increase to over an inch or 200-250pct of normal), expect
widespread showers, and maybe some thunder, to develop late Tue into
Wed. However, in spite of the high PWATs, ensemble probability
guidance is not very bullish on total rainfall from this system,
probably since the system and associated dynamics are weakening as
it moves across the area. Ensembles suggest a 60-80 pct probability
of a half inch or more of rainfall over south central portions with
less than 50 pct chance of a half inch across the rest of the fcst
area. Breezy conditions will develop as well Tue into Wed. Models
suggest showers may taper off a bit late Wed into Wed night behind
the low as it lifts to the northeast and a dry slot works in.
However, additional shortwaves ahead of and with the passage of the
approaching western CONUS trough and associated closed low could
reinvigorate showers late in the week. Otherwise, expect above
average temperatures to finally trend lower behind the midweek
system, falling below normal by Friday.

 &&

.MARINE...

Deep low pressure is lifting NE of Georgian Bay this afternoon, with
NNW gales to 40-45 knots ongoing throughout eastern Lake Superior.
Winds will gradually decrease through the first half of the night as
the low pulls away and ridging builds into the Great Lakes. Winds
fall below gale force into Saturday morning, and below 20 knots into
the afternoon. Winds stay generally below 20 knots Sunday through
Monday. Another deep low will begin to organize on the lee side of
the Rockies late on Mon. Easterly winds will begin to increase late
Mon night to 25-30kt, highest over the western third of the lake.
Ensemble guidance indicates a 70 to near 100 pct chc of easterly
gales of 35-40kt Tue aftn into Tue night across much of Lake
Superior. The gales may linger into Wed morning before diminishing,
but winds stay elevated at around 20 to 30 knots through the rest of
the week.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 157 PM EDT Fri Apr 12 2024

Lingering MVFR cigs at IWD will return to VFR this afternoon as
light rain showers end within the next hour. Otherwise VFR
conditions will prevail the remainder of the 18Z TAF period as a
strong low pressure system just northeast of Lake Huron lifts north
into Quebec. The tight pressure gradient across the UP is yielding
some gusty northwest winds up to 25 kts at IWD and 35 kts at SAW and
CMX this afternoon. As the low departs and high pressure builds in
from the west, winds will weaken overnight into Saturday. Some low
level wind shear is possible at SAW tonight, however was left out of
the TAF for now as confidence remains low. Dry northwest flow will
also work to clear skies overnight.

&&

.MARINE...
Issued at 412 PM EDT Fri Apr 12 2024

Saturday starts off dry and sunny with weak ridging over the area,
but a shortwave dropping into northern MN touches off waa/isentropic
ascent toward Upper MI by evening. This should bring an increase in
clouds ahead of a quick round of showers overnight. With an
advancing sharp 850mb theta-e gradient and vigorous upper diffluence
from the right entrance region of a 100kt upper jet streak extending
from northern Lake Superior into the Lower Great Lakes by the
evening, scattered showers should spread into w/nw Upper MI
generally after 00Z. That said, some of the simulated reflectivity
(though usually a little too aggressive with the onset timing) do
show some shower activity kicking off during the late afternoon in
the western UP. Scattered showers end by sunrise Sunday. A pool of
elevated instability of 100-400 j/kg builds toward Upper MI for Sat
night, and it may be just sufficient toward the MI/WI stateline for
a rumble or two of thunder. Following the showers on Sat night,
Sunday looks to be a nice mid-Apr day under increasing sunshine.
Highs Sat will be in lower 60s over the interior west half and
mostly in the lower to mid 50s elsewhere. Highs Sun will be well
into the 60s F across the interior w half and south central and
mostly in the mid to upper 50s elsewhere.

Will note a potential for dewpoints to drop both Saturday and Sunday
afternoon, with well-mixed and very dry model soundings. Increasing
clouds Saturday may inhibit this at least across the western UP. This
environment could see RH falling to as low as 20-25% across much of
the interior UP Saturday, while a somewhat more moist airmass Sunday
nevertheless may see RH falling into hte 30% range during the
afternoon. Fortunately, winds will be decreasing from west to east
Saturday morning, but some 15 to 20 mph gusts will be possible
during the afternoon Sunday.

Dry weather persists for much of Monday with the ridge still over
the Great Lakes. However, by late in the day the quasi-zonal flow in
the vicinity of the U.S./Canada border will be breaking down as a
shortwave drops out of the Gulf of Alaska into the NW U.S.
Downstream, the upper jet will be forced to lift northward, again
placing right entrance region upper diffluence over the area. There
are also hints of a weak shortwave tracking toward Upper MI. This,
in addition to some diurnal instability, could lead to a few showers
mainly over the western UP during the afternoon/evening.

Attention then turns to the wave over the Southwest U.S. that gets
kicked northeast by the shortwave dropping from Gulf of Alaska
through the NW U.S. Surface response will be a deep sfc low
organizing in the lee of the Colorado Rockies. This low will reach
peak strength over the Plains on Tuesday, and then weaken as it
lifts northeast into the Upper Great Lakes and northern
Ontario/Quebec Tue night into Wed. With a good surge of Gulf
moisture ahead of the approaching low (layer precipitable water
values increase to over an inch or 200-250pct of normal), expect
widespread showers, and maybe some thunder, to develop late Tue into
Wed. However, in spite of the high PWATs, ensemble probability
guidance is not very bullish on total rainfall from this system,
probably since the system and associated dynamics are weakening as
it moves across the area. Ensembles suggest a 60-80 pct probability
of a half inch or more of rainfall over south central portions with
less than 50 pct chance of a half inch across the rest of the fcst
area. Breezy conditions will develop as well Tue into Wed. Models
suggest showers may taper off a bit late Wed into Wed night behind
the low as it lifts to the northeast and a dry slot works in.
However, additional shortwaves ahead of and with the passage of the
approaching western CONUS trough and associated closed low could
reinvigorate showers late in the week. Otherwise, expect above
average temperatures to finally trend lower behind the midweek
system, falling below normal by Friday.

 &&

.MARINE...

Deep low pressure is lifting NE of Georgian Bay this afternoon, with
NNW gales to 40-45 knots ongoing throughout eastern Lake Superior.
Winds will gradually decrease through the first half of the night as
the low pulls away and ridging builds into the Great Lakes. Winds
fall below gale force into Saturday morning, and below 20 knots into
the afternoon. Winds stay generally below 20 knots Sunday through
Monday. Another deep low will begin to organize on the lee side of
the Rockies late on Mon. Easterly winds will begin to increase late
Mon night to 25-30kt, highest over the western third of the lake.
Ensemble guidance indicates a 70 to near 100 pct chc of easterly
gales of 35-40kt Tue aftn into Tue night across much of Lake
Superior. The gales may linger into Wed morning before diminishing,
but winds stay elevated at around 20 to 30 knots through the rest of
the week.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
  Wind Advisory until 8 PM EDT this evening for MIZ006-007-013-
     014-085.

Lake Superior...
  Small Craft Advisory until 5 PM EDT /4 PM CDT/ this afternoon
     for LSZ241>243.

  Gale Warning until 5 PM EDT this afternoon for LSZ244-264.

  Small Craft Advisory until 8 AM EDT Saturday for LSZ244.

  Gale Warning until 7 PM EDT this evening for LSZ245-248-265.

  Small Craft Advisory until 8 AM EDT Saturday for LSZ245-248.

  Small Craft Advisory until 11 PM EDT this evening for LSZ246-
     247.

  Gale Warning until 2 AM EDT Saturday for LSZ249-250-266.

  Small Craft Advisory from 2 AM to 2 PM EDT Saturday for LSZ249-
     250.

  Gale Warning until 8 AM EDT Saturday for LSZ251-267.

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

&&

$$

SHORT TERM...Jablonski
LONG TERM...LC
AVIATION...Jablonski
MARINE...LC