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000
FXUS63 KMQT 280008
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
808 PM EDT Sat Apr 27 2024

.KEY MESSAGES...

- Scattered showers and isolated thunderstorms this afternoon.
- Breezy this afternoon into early this evening with 35-40 mph
  gusts expected, strongest gusts this afternoon south central
  and early this evening over Keweenaw and eastern shoreline.
- Active pattern continues as 3-4 low pressure systems track
  across the region over the next week. Above normal
  temps/precip are expected including thunderstorm chances.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 329 PM EDT Sat Apr 27 2024

Water vapor imagery and RAP analysis show a vort max/shortwave near
Thunder Bay, ON tracking ne. At the sfc, weakening low pres
associated with the shortwave wave is analyzed over and just e of
the Keweenaw. Ahead of these features, clusters of sct shra are
occurring into the Upper Great Lakes this afternoon. Maybe a rumble
of thunder could be possible in areas of partial clearing central UP
but fcst soundings suggest mid-level warming/drying will be a big
inhibitor, especially by 21Z this afternoon when any t-storm threat
will probably be gone. Current temps across Upper MI generally range
from the upper 40s in low clouds and cool onshore southerly flow
near Lake Mi southeast to lower to mid 70s into southern Dickinson
and Menominee counties in warm southwest flow and some cloud breaks
there. Most locations range from the mid 50s to mid 60s. Mixing
through 4-6 kft has also allowed for southwest winds to gust around
35 mph into south central areas. As the sfc low continues to track
ne across northern Lake Superior through early evening, moist
wraparound upslope flow on the backside of the low will continue to
support scattered showers into western counties early evening.
Elsewhere, any lingering isolated showers should die out near
sunset.

A 5-7 mb 3-hr pres rise max tracking across northwest Upper
Mi and south central Lake Superior and favorably aligned along the
gradient wind could provide an isallobaric boost to westerly winds
and gusts late afternoon into early evening across these areas,
particularly across the Keweenaw Peninsula where brief gusts near 35-
40 mph could be possible. Brief west gale gusts to 35 knots may also
be possible into south central areas of the lake late
afternoon/early evening.

Winds veering to the north-northeast on the backside of the low
later tonight will maintain mostly cloudy skies across the area but
increasingly anticyclonic low-level flow through the night should
result in dry conditions. Min temps tonight will range from the mid
30s west and north central to the lower 40s south central and east.

&&

.LONG TERM /SUNDAY THROUGH SATURDAY/...
Issued at 456 PM EDT Sat Apr 27 2024

The extended forecast period will be active with fairly good
agreement in the model guidance through Wednesday. Even though the
guidance begins to diverge into the latter part of next week, the
consensus on a wet and active pattern holds true.

Sunday will start off dry with a high pressure over northern Ontario
and the negatively tilted trough over NE and KS. During the day, the
trough lifts northeast toward the Upper Midwest and the associated
sfc low tracks from KS to IA. Weak WAA and isentropic ascent ahead
of the low will try to increase showers from the south, however the
drier northeast flow looks to slow this down and limit showers to
the south central in the afternoon. Showers overspread the UP Sunday
night as the trough moves into MN and the sfc low lifts north-
northeast bringing better forcing and a ~45kt LLJ over the UP. There
could be some rumbles of thunder in the south central Sunday night.
Some breezy east winds are expected to mix down from the LLJ with
gusts up to 35 mph, especially in the eastern UP and Keweenaw Sunday
night through Monday morning. The trough then pivots northeast over
the UP on Monday reinvigorating the showers and possibly providing
enough forcing for some weaker thunderstorms. That being said,
strong storms are not expected as instability is limited with spotty
MUCAPE around 200j/kg, the inversion in model soundings is fairly
strong, and mid level lapse rates are mostly below 6C/km. PWATs
highlight a surge of ample moisture off the Gulf of Mexico, bringing
up to 1" to the UP Monday morning, which is noted above the NAEFS
90th percentile for Sunday night into Monday. This should bring a
good soaking to the UP with 0.5" to 1.5" of rain by Monday night and
help alleviate fire weather concerns for the next few days.

Showers lift north out of the UP Monday night as the trough and sfc
low lift over Lake Superior, temporarily bringing dry weather back
to the UP for Tuesday and diminishing winds. WAA during the day
accompanied by clearing skies will bring above normal highs in the
50s near Lake Superior and in the far east with 60s elsewhere. The
dry weather is quickly replaced Tuesday evening as a shortwave races
across the Plains, passing over the Upper Great Lakes Tuesday night
into Wednesday morning. The sfc low associated with this shortwave
looks to pass northeast through MN into northern Ontario bringing a
round of showers Tuesday night into Wednesday. Instability again is
fairly low, so only a few rumbles of thunder are expected at this
time.

Dry weather looks to follow for Wednesday with some breezy west
winds behind the low pressure system`s cold front. Current NBM
probabilities of wind gusts exceeding 40 mph is around 15-30%, so
expected gusts are around 25-35mph. Uncertainty begins to grow in
the forecast for the rest of the week, but chances for precip
increase toward the end of the week as we track out the next low
pressure system or two to move through the Great Lakes.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 808 PM EDT Sat Apr 27 2024

Poor flying conditions to continue in west-northwest flow as
moisture wraps around departing low pressure system.  IWD will
consistently remain at IFR/LIFR levels in the upsloping.  Meanwhile,
LIFR at CMX will gradually improve to IFR early tonight and
eventually MVFR by early Sunday morning.  SAW, on the other hand,
will be on a downward trend from VFR this evening to MVFR and then
IFR/LIFR early tonight.  In addition, west-northwest winds will gust
up to 24 kts through this evening at CMX and SAW.


&&

.MARINE...
Issued at 456 PM EDT Sat Apr 27 2024

A few west gale force gusts to 35 kt are possible for a brief period
late this afternoon into the evening across eastern Lake Superior as
the low pressure moves northeast into northern Ontario. Winds back
northeasterly late tonight into Sunday as the next system approaches
from the southwest. Northeast gales up to 40 kt are expected across
the far western lake Sunday afternoon with northeast becoming
easterly gales to 40 kts spreading across the entire lake Sunday
night. While a few gusts may exceed 40 kts Sunday night into Monday,
highest probabilities are on the low end (25-45%). The strongest
winds are expected in the far east as well as the north central
portion of the lake between the Keweenaw and Isle Royale where there
could be some channeling. Gales quickly diminish Monday afternoon as
the low pressure tracks across western Lake Superior Monday night.
The Gale Watch has been upgraded to a Gale Warning, now starting at
18z Sunday in the far west (3z Monday elsewhere) and ending at 21z
Monday.

During the gale event, waves will be highest from Duluth Harbor to
the Bayfield Peninsula, with significant wave heights up to 14 ft
possible Monday morning. Wave heights Monday morning around Isle
Royale will also be higher, up to 13 ft. Waves across the lake fall
below 8 ft Monday evening. There also is a slight chance for
thunderstorms on Monday.

Winds fall below 20 kts Monday night, mainly remaining below until
Wednesday morning.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
  Gale Warning from 2 PM EDT /1 PM CDT/ Sunday to 5 PM EDT /4 PM
     CDT/ Monday for LSZ162.

  Small Craft Advisory from 3 PM EDT /2 PM CDT/ Sunday to 8 AM
     EDT /7 AM CDT/ Monday for LSZ241.

  Small Craft Advisory from 3 AM Sunday to 8 AM EDT Monday for
     LSZ242.

  Small Craft Advisory from 1 AM to 11 PM EDT Sunday for LSZ243.

  Gale Warning from 11 PM Sunday to 5 PM EDT Monday for
     LSZ243>246-263>266.

  Small Craft Advisory until 11 PM EDT Sunday for LSZ244-245.

  Small Craft Advisory until 11 PM EDT this evening for LSZ248.

  Small Craft Advisory until 8 AM EDT Monday for LSZ249>251.

Lake Michigan...
  Small Craft Advisory until 5 AM EDT Sunday for LMZ248-250.

&&

$$

SHORT TERM...Voss
LONG TERM...Jablonski
AVIATION...TDUD
MARINE...Jablonski