National Weather Service Weather Forecast Office

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

000
FXUS63 KMQT 171856
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
256 PM EDT Wed Apr 17 2024

.KEY MESSAGES...

-Rounds of light to moderately heavy rainfall continue through the
evening with deep, though gradually weakening, low pressure moving
through the Great Lakes.
-Additional rainfall totals of a quarter to half inch are likely
 the before rain wraps up into tonight, highest across the
 eastern UP.

- Temperatures trend below-normal behind a cold front Thursday
  night bringing low chances for light diurnal showers and
  perhaps a bit of lake effect rain/snow mix for
  Friday/Saturday.
- Some fire concerns could resurface again Sunday into Monday under
  breezy conditions and a drier airmass.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 255 PM EDT Wed Apr 17 2024

Deep 1000mb surface low pressure analyzed over central WI will
continue to move ENE into the UP this afternoon with a negatively
tilting upper trough pivoting through the Great Lakes. Bands of
light to moderately heavy rainfall continue to move through the
area, with one round currently tracking into the northern UP. Water
vapor imagery reveals a narrow dry slot curling in behind this,
ahead of another area of lighter showers already moving into
northern WI. These should quickly move through the UP into the late
afternoon and evening. Radar estimated QPF across the UP is
generally up to a quarter to half inch in the heaviest of showers
with this batch moving through right now, which matches up fairly
well with various surface observations. With ongoing convection and
the next additional round of light rain (estimated QPF up to a
quarter inch courtesy of the GRB radar in the most persistent
showers), would not be surprised by another quarter to half inch the
rest of today into the evening - mainly across the Keweenaw and
eastern UP.

Meanwhile, winds remain gusty particulary across the Keweenaw and
eastern UP this afternoon, where gusts up to 35 to 40 mph remain
common. Stronger gusts to 45mph are still occurring closer to the
Lake Michigan shoreline. Still, winds are slowly decreasing as the
surface low is weakening, so although windy conditions continue into
the late afternoon and evening, we should be falling below wind
advisory criteria over the next few hours.

Tonight, showers lift northward over Lake Superior after midnight as
pressure rises behind the departing surface low and drier midlevel
air works in. Lower level moisture should keep in low cloud cover
and perhaps some patchy fog - but will note a narrow core of
stronger winds aloft behind the departing low that could produce a
brief window for breezy conditions mainly across the western UP the
first half of the night. That could limit our potential for patchy
fog.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Issued at 349 AM EDT Wed Apr 17 2024

Thursday`s post-frontal air mass will be considerably drier and
should result in another seasonably mild day albeit perhaps a bit
breezy as GFS soundings indicate the potential for fairly deep
mixing to 7-8 kft away from Lake Superior which could bring down
west wind gusts of 20-25 mph at many locations. Max temps are fcst
to be generally in the mid to upper 50s and steep low-level lapse
rates could result in high-based cumulus forming in the afternoon.

A reinforcing cold front moves through late Thu into Thu night with
modest cold air advection resulting in steep low level lapse rates
through Friday. Additionally, isolated to scattered rain
showers cannot be ruled out along the front late Thu afternoon
into Thu night, especially across the east half of the UP.
Friday will turn chilly as blustery west winds possibly gusting
as high as 40 mph over the Keweenaw will accompany the colder
air advecting into the area. Again, isolated to scattered snow/rain
showers cannot be ruled out on Friday given the steep lapse
rates fm sfc-10kft. Another surface trough moves through Fri
night shifting winds more northwesterly and bringing perhaps a
better chance for some isolated to scattered light lake effect
rain/snow mix into early Sat across northern sections of the cwa
as 850 mb temps lower to -9 to -10C by 12Z Sat.

Temperatures will stay below normal on Saturday, but a warming trend
begins which will end any further lake effect pcpn potential by
Sat afternoon. Successively warmer days to back above normal
temps Sunday into Monday could maybe lead to fire concerns again
as airmass is dry both of these days (especially Sunday) and
west-southwest winds remain somewhat breezy with gusts at least
15-20 mph. Models indicate the next wnw flow shortwave will
move through Mon night into Tue with the next chance of rain
showers. Given its west-northwest trajectory suspect moisture
inflow ahead of this shortwave will be somewhat limited so only
expect light rain showers at this time Mon night into Tue.
Models and ensembles advertise drier and somewhat cooler
conditions behind this shortwave into the middle of next week.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 139 PM EDT Wed Apr 17 2024

Rounds of light to moderately heavy rain showers continue this
afternoon and through the evening with deep low pressure moving
through the Great Lakes. Ceilings are dropping to IFR, and MVFR/IFR
visibility is common where showers are occurring. A brief break in
rain showers behind the batch currently moving into the northern UP
will quickly be followed up by another, lighter round this evening,
with IFR or LIFR visiblity possible. Ceilings continue to lower to
LIFR into the evening hours, and while rain showers finally end by
06Z, lingering lower level moisture and decreasing winds may keep in
patchy fog overnight. A gradual improvement to MVFR is expected the
second half of the night as the low pulls away and drier air begins
to work in, then ceilings lift to VFR late tomorrow morning into the
afternoon. Otherwise, expect gusty winds up to 20 to 30 knots
through the afternoon, then wind gusts to around 20 knots are
possible into the night.

&&

.MARINE...
Issued at 349 AM EDT Wed Apr 17 2024

Northeasterly gales to 45 kt continue over the far western portion
of Lake Superior early this morning but will weaken to minimal gales
to 35 knots just after sunrise before subsiding blo gales this
afternoon. East-southeast gales of 35 to 45 kts will persist across
much of central and eastern Lake Superior today, strongest over the
north central and east half of the lake. Probabilities of storm
force gusts to 47 kts remain low at less than 20%. Winds fall below
gale force early this evening as the weakening low pressure moves
into eastern Upper Mi later this evening. Generally stable
conditions persist over the lake tonight into Friday morning with
southwest to west winds 20-30 kts. A trough/cold front moving across
the lake late Fri into Fri night with winds shifting northwest could
result in gale gusts to 35 knots late Fri into early Sat. Otherwise
winds back westerly and subside to 15 to 25 kts across the lake Sat
night into Sunday.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
  Wind Advisory until 5 PM EDT this afternoon for MIZ001-003-006-
     007-014-085.

Lake Superior...
  Gale Warning until 8 PM EDT this evening for LSZ243>246-250-
     251-264>267.

  Gale Warning until 5 PM EDT /4 PM CDT/ this afternoon for
     LSZ162-263.

  Small Craft Advisory from 8 PM this evening to 8 AM EDT
     Thursday for LSZ244>246.

  Small Craft Advisory until 8 AM EDT Thursday for LSZ247-248.

  Small Craft Advisory until 8 PM EDT this evening for LSZ249.

Lake Michigan...
  Gale Warning until 8 PM EDT this evening for LMZ248.

&&

$$

SHORT TERM...LC
LONG TERM...Voss
AVIATION...LC
MARINE...Voss