521
FXUS63 KMQT 171150
AFDMQT

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

.KEY MESSAGES...

- Scattered light showers are expected 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 /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 748 AM EDT Wed Jul 17 2024

Generally MVFR cigs are expected this morning as upper low pivots
overhead with moist upslope flow off Lake Superior. That said, there
are low chances (~15% chance) for brief periods of IFR cigs at SAW
through early this afternoon from additional lake enhancement given
the cooler airmass moving northwest over a longer stretch of warmer
waters in Lake Superior. Overall, this MVFR cloud deck will be
accompanied by isolated to scattered light showers. Prevailing vsby
restrictions not expected, but a brief MVFR vsby in a shower today
can`t be ruled out. Also, expect north-northwest winds gusting up to
20 kts at CMX and SAW. Although not reflected in this TAF, a few
isolated gusts to to 25 kts can`t be ruled out either. Showers
diminish and cigs rise/scatter eventually this afternoon. Clear
skies are expected by tonight as winds taper off. Skies stay mostly
clear on Thursday.

&&

.MARINE...
Issued at 537 AM EDT Wed Jul 17 2024

Northwest winds of 20-25 knots will prevail today, especially across
eastern Lake Superior as a trough axis moves across the lake.  After
light winds on Thursday with high pressure overhead, southwest winds
will gust to 25 knots on Friday, mainly between Isle Royale and the
Keweenaw.  By Saturday winds will shift to the north with frontal
passage and eventually become variable, 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...Jablonski
MARINE...TDUD