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521
FXUS63 KMQT 100748
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
348 AM EDT Fri May 10 2024

.KEY MESSAGES...

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- Clipper system brings chances for thunderstorms to the far
  western areas of Upper Michigan Friday afternoon and Friday
  evening.
- Chances for thunderstorms return on Sunday. There is a low (2%)
chance for some marginally severe hail and wind.
- Dry weather returns for the early part of the next work week.
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&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 216 PM EDT Thu May 9 2024

Deeper moisture associated with a midlevel trough pivoting
through the Lower Great Lakes continues to settle south of the
forecast area. Meanwhile, a shortwave ridge axis extends
northeastward from eastern MT to near Hudson Bay. Strong
subsidence between these features continues to spread into the
UP, and surface ridging will continue to build in overnight.
Very dry airmass evident on low- level water vapor imagery
supports model forecast PWATs falling to around 0.25 inches, or
-1 to -2 standard deviations tonight. Diurnal cu/sc exist in
various areas across the UP this afternoon, including along a
convergence boundary where better low-level moisture still
exists on the inland side of the Lake Michigan lake breeze
circulation. These should quickly dissipate with the loss of
diurnal heating tonight, leaving mostly clear skies aside from
possibly a bit of midlevel cloudiness over the eastern UP. It
looks like an ideal setup for radiational cooling, especially
over the western half where the high will be centered, so took
low temps down a couple of notches by blending in METMOS
guidance. This should yield upper 20s over the west half and
low/mid 30s elsewhere.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
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Issued at 347 AM EDT Fri May 10 2024

Rain showers end across the area Saturday as a small high-pressure
ridge moves through the area from the northwest to the southeast.
However, more rainfall returns late Saturday night into Sunday as a
second shortwave drops across the area; while the chance is low
(2%), some marginally severe wind and hail is plausible,
particularly over the south central Sunday afternoon. While high
pressure ridging brings dry weather back over Upper Michigan during
the first half of the next work week, additional rain chances look
to return for the latter portion of next week to end the extended
period. Expect above normal temperatures and precipitation amounts
to continue through the extended period and next weekend. Additional
details follow below.

The shortwave low originally from far northern Manitoba gets pushed
out of the Upper Great Lakes Saturday as shortwave ridging moves
through from the northwest to southeast throughout the day. As this
occurs, the light rain showers associated with the low end across
the U.P. from west to east, with skies becoming mostly sunny across
the region by the late afternoon hours. With cooler air aloft
remaining over the area Saturday, expect temperatures to be around
or slightly below average, with highs getting into the 50s to low
60s in the south central.

The reprieve from the rainfall looks to be a fairly quick one
though, as another shortwave low dropping down from the Northwest
Territories brings showers and thunderstorms back across the area
late Saturday night through Sunday; with cloud cover increasing
Saturday night, expect low temperatures to be in the mid 30s in the
interior east to mid 40s in the west. However, with warm air
advection increasing across the area Sunday, expect the high
temperatures to be in the 60s, with the mid 70s being seen in the
interior west near the Wisconsin border. As the shortwave`s cold
front goes through Upper Michigan during the afternoon hours, there
is a low (2%) chance that we could see some severe weather as
MUCAPEs approach 1000 J/kg and 0-6 km bulk shear is around 30 knots.
With the NAM model soundings showing SBCAPE in the south central by
the afternoon hours, we could see marginally severe hail and wind,
particularly over the south central; we will have to see if the
chances for severe weather increase as we approach this weekend.
Otherwise, outside of possibly some locally heavy rainfall in a few
of the cells, expect light rainfall amounts across most of the area
late Saturday night through Sunday.

Dry weather returns by next Monday and remains for the first half of
the work week as high pressure ridging moves overtop us. While we
could see min RHs approach 30% Monday through Wednesday, with fairly
light winds and around normal temperatures predicted, no elevated
fire weather concerns are expected at this time. Rainfall looks to
return late next week as troughing brings a shortwave pattern back
across the area. Model guidance seems to be pushing the timing back
on the return of the precipitation; while the NBM brings rain
chances back over us Wednesday afternoon, it seems like the latest
deterministic runs in the differing medium range model guidance
suites hold the rain off until late Wednesday night/Thursday.
Therefore, I wouldn`t be surprised if the rain chances get pushed
back in subsequent NBM runs (and thus our extended forecast). The
rain chances look to continue to the end of the period. Beyond the
end of the period, the CPC has a slightly higher chance of above
normal temperatures and above normal precipitation in the 6-10 day
period; in the 8-14 day period, there is an equal chance for above,
near normal, and below normal temperatures whereas there is still a
higher chance for above normal precipitation in the 8-14 day range.
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&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 126 AM EDT Fri May 10 2024

VFR conditions are expected to prevail at the terminals through much
of Friday. A low pressure trough moving through the area will bring
some isolated to scattered rain showers and MVFR cigs to the
terminals late Friday into Friday evening. Light winds will become
light northwest to north behind the trough.

&&

.MARINE...
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Issued at 347 AM EDT Fri May 10 2024

Light winds of generally 20 knots or less dominate the period as
stable conditions prevent the mixing of higher wind speeds down to
the water`s surface.
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&&

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

&&

$$

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