175
FXUS63 KMQT 170916
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
516 AM EDT Wed Jul 17 2024

.KEY MESSAGES...

- A 20% to 40% chance for scattered light showers today.

- Cooler and drier for midweek with the arrival of high pressure.

- Next chances...albeit low...for showers and maybe some thunder
  return on Saturday and again daily from Monday through
  Wednesday.

&&

.SHORT TERM /THROUGH THIS AFTERNOON/...
Issued at 516 AM EDT Wed Jul 17 2024

Current WV and RAP analysis highlights the mid level trough axis
across western Lake Superior and Upper Michigan. At the sfc,
observations are showing a cool front out just ahead of the mid
level ridge axis over the western UP and central Lake Superior. As
the trough axis continues pivoting over the Upper Great Lakes today,
the cool front pushes southeast out of our CWA through this morning.
As a result, cool northwest flow dominates the short term forecast.

850mb temps are expected to drop to around 5-6C over Lake Superior,
which currently has water temps ranging 15-20C in the open waters;
the nearshores are warmer in the low 20s. With some lake
enhancement, upslope northwest flow, and PVA, scattered light
showers or sprinkles are expected across the UP today. Satellite
imagery is already showing the stratocumulus deck developing over
the west and radar is showing some isolated showers developing.
Although CMX is the only sfc ob showing any rain making it to the
ground so far, the showers and clouds are progged to expand south
and west across the UP through this morning. Given the low available
moisture (PWATs ~0.7-0.9"), not much of any accumulations are
expected. With the cool northwest flow and cloud cover, highs will
be below normal in the 60s to maybe low 70s in the southcentral UP.
While today won`t feel like a beach day, the combination of gusty
northwest winds up to 20-25 mph and waves will create a high swim
risk this morning through Sunset, especially from Marquette eastward
through Alger County.

As forcing diminishes in the afternoon and high pressure with a
drier airmass begins to build in from the west, precip and cloud
cover diminishes from west to east; dry weather expected by this
evening. Winds are also expected to begin tapering off in the late
afternoon and evening hours.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Issued at 509 AM EDT Wed Jul 17 2024

Surface ridge axis will continue to overspread Upper Michigan
Wednesday evening as an upper trough axis pushes farther eastward.
Time cross sections indicate a dry air column through Thursday and
Friday, which will be conducive to ample sunshine and seasonable
temperatures.  Daytime highs Thursday will return to the 70s with
mostly 80s returning by Friday through the majority of the extended
period.  Meanwhile, with little cloud cover, the nights will be able
to cool into the 50s for much of the period.  Wednesday night,
especially, will be the chilliest under clear skies and light winds
as low temperatures dip into the 40s and even some upper 30s across
the areas of the interior west that are prone to cold spots.

Outside of the dry weather, there are a few exceptions. The first
will arrive on Saturday as an upper low drops southeast from the
Hudson Bay into Quebec, while its associated cold front moves
southward across Lake Superior/Upper Michigan.  With limited
moisture, widespread convective activity is not expected.  However,
some isolated showers/thunderstorms cannot be ruled out Saturday
afternoon across the south-central U.P.  Further out, the second
exception to the dry forecast will be another weak cold front that
will dip into the region on Monday and Tuesday, eventually stalling
over southern WI/MI on Wednesday.  This will be the source of daily
(20-30%) chance showers from Monday through Wednesday.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 120 AM EDT Wed Jul 17 2024

Cigs lower today to MVFR levels as an upper low moves in and moist
flow off Lake Superior results. Expect MVFR cigs during the post-
dawn morning hours today along with isolated to scattered showers.
Prevailing vsby restrictions not expected but cannot rule out a
brief MVFR vsby in a shower today. Cigs rise/scatter eventually this
afternoon with skies clearing this evening. North-northwest wind
gusts of 20 kt will be common today.

&&

.MARINE...
Issued at 313 PM EDT Tue Jul 16 2024

As next trough axis pivots across Lake Superior, northwest winds
will increase to 20-25 kts late tonight and last through much of
Wednesday especially over the eastern half of the Lake. High
pressure overhead on Thursday will result in light winds.  The
pressure gradient tightens a little on Friday with the main surface
high over the southern Lakes. Southwest winds could gust as high as
25 knots mainly between Isle Royale and the Keweenaw. A surface
front dropping southward across the Lake Saturday morning will shift
winds to a northerly direction but they will remain below 20 knots
through the weekend into early next week.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
  Beach Hazards Statement through this evening for MIZ005-006.

Lake Superior...
None.
Lake Michigan...
None.

&&

$$

SHORT TERM...Jablonski
LONG TERM...TDUD
AVIATION...Thompson
MARINE...MZ