520
FXUS63 KMQT 110819
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
419 AM EDT Sat May 11 2024

.KEY MESSAGES...

- Light rain showers end from west to east this morning.

- Could flirt with borderline fire weather conditions near the
  Wisconsin border late this afternoon as min RHs dip to around
  30%, northwest winds could gust up to 20 mph at times, and
  high temperatures could get to the low to mid 60s.

- Scattered thunderstorms to develop Sunday afternoon,
  especially south central. There is a low chance (2%), for
  marginally severe hail and/or wind.

- Dry weather returns by Monday, continuing through Wednesday
  afternoon.

&&

.SHORT TERM /THROUGH THIS AFTERNOON/...
Issued at 240 AM EDT Sat May 11 2024

With some breaks in the clouds, some of us were able to see the
Aurora Borealis over us this past evening into very early this
morning from time to time, including us at the forecast office here
in Negaunee Township. As the low pressure now over northern Lake
Michigan continues to spin away from the area today and high
pressure ridging moves in from the northwest, skies clear out and
the light rain showers cease. The rain showers are looking to be
limited to the far eastern U.P. (Chippewa and Mackinac counties) by
the early afternoon hours as the ridging builds in. However, a few
upslope sprinkles from the modest northwest flow could be seen over
the highlands of the Keweenaw and the north central U.P. from time
to time until the middle of this afternoon. In addition, the Euro is
wanting to bring some sprinkles over the south central this evening.
However, with hires model soundings showing an inversion up to 4-5
kft by the mid afternoon hours over the south central, any rain
droplets hitting the ground seems very doubtful (90+% of being
precip-free this afternoon). With mostly sunny skies across the U.P.
by the mid-afternoon hours and slight warm air advection occurring
throughout the day, thinking the high temperatures will be in the
low to mid 60s over the interior west half and the 50s in the east
and along the lakeshores. While winds aren`t expected to be all that
impressive today, we could see some northwesterly gusts up to 20 mph
in the interior areas by the afternoon hours today. With min RHs
looking to get down to around 30% near the Wisconsin border, we may
flirt with borderline fire weather concerns late this afternoon in
the interior west.

&&

.LONG TERM /TONIGHT THROUGH FRIDAY/...
Issued at 419 AM EDT Sat May 11 2024

Starting dry tonight as a weak sfc high pressure over the UP and the
mid level trough over the Lower Great Lakes both depart
southeastward. Another trough to the north moves east along northern
Ontario. This northern trough sends some weak shortwave energy over
the lake superior. With the support of WAA and isentropic ascent,
light showers spread east, mainly over the west half of the UP.
Chances for showers increase in the afternoon as a cold front
associated with a sfc low to the north passes southeast over the
area. With the timing of the cold front in the late afternoon, peak
daytime heating will help fuel some showers and thunderstorm
development, especially over the south central UP. Highs will be
above normal climbing into the upper 60s to mid 70s save for the
east where southerly winds off Lake Michigan keeps the area cooler
in the mid 50s to low 60s; the Keweenaw should see low to mid 60s.
While moisture is not terribly high with dewpoints only in the the
mid to upper 40s, lapse rates will be pushing near 9C/km with mid
level lapse rates around 7C/km which should yield enough buoyancy.
The 5/11 0z HREF mean SBCAPE is around 250-750 j/kg with higher
models such as the GFS/NAM plotting up to 1000 j/kg mainly along the
WI/MI state line (especially near south central Upper MI). That
accompanied by an HREF mean bulk shear of around 45 kts leaves the
potential for isolated severe storms with the main threats being
hail and winds. This stronger thunderstorm development also depends
on the previous precip and lingering cloud cover.

Chances for thunderstorms diminish Sunday evening with dry weather
returning to all the UP by around midnight. A secondary cold front is
progged to pass over the UP Sunday night with really no impacts
beyond slight wind shifts and increased cloud cover. Dry northerly
flow behind the cold front accompanying a sfc high pressure will
keep dry conditions through Wednesday afternoon as the mid level
trough slowly meanders east toward Quebec and another shortwave
trough makes its way from the Plains to the Appalachians. This will
yield a few days of sunny skies, better mixing, and drier RHs
nearing 30%. Lake breeze interactions are also likely with the high
pressure extending overhead, helping keep cooler conditions by the
lakeshores. Highs look to be in the upper 50s to upper 60s in the
interior next week. Upper 40s to mid 50s by the lakeshores early
next week increase to mid 50s to low 60s by Friday. Lows are
forecast to increase from their coldest Monday night in the 30s to
low to mid 40s by the end of the work week.

Chances for showers and possibly some thunderstorms increase late
Wednesday night/Thursday onward as we track out the next trough to
move along the Canadian/U.S. border toward the Great Lakes. With
significant differences in the model guidance on track and timing,
opted to leave the NBM chance PoPs alone beyond Thursday.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 110 AM EDT Sat May 11 2024

Wraparound moisture from low pressure deepening over northern Lake
Mi will continue scattered showers overnight mainly into central
Upper Mi. SAW will be most impacted from this system seeing VFR
conditions lower to MVFR in these showers and perhaps briefly to IFR
overnight before quickly improving back to MVFR late Saturday
morning and to VFR Saturday afternoon as high pressure builds back
in from the west.  Expect VFR conditions to mostly prevail at IWD
and CMX.

&&

.MARINE...
Issued at 419 AM EDT Sat May 11 2024

Winds are mainly expected to mainly remain below 20 kts through the
entire forecast period. However, the best chances for wind gusts to
around 20-25 kts is expected Sunday night as an approaching cold
front tonight increases southerly winds, stronger over the east half
where the pressure gradient is tighter. That being said, the
strongest winds are mostly limited to the higher observing platforms
due to the stability within the chilly marine layer. The cold front
does bring a slight chance for thunderstorms along the southern
nearshores Sunday afternoon. Then on Monday, high pressure begins
building over the lake. This weak high pressure continues through
mid week before moving northeastward into Canada keeping light winds
and dry weather in the forecast.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.

&&

$$

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