585
FXUS63 KMQT 170909
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
509 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 WEDNESDAY NIGHT/...
Issued at 227 PM EDT Tue Jul 16 2024

GOES-16 Day Cloud Phase imagery shows an agitated cu field
across much of the central and western UP with clear skies over
the Keweenaw and otherwise fair weather cu over the eastern UP.
A line of showers briefly passed over Isle Royale and some
thunderstorms look to be following the US/Canada maritime border
over Lake Superior. Radar returns show a couple isolated
showers among the cu field but nothing of particular note
otherwise.

HREF guidance shows the pattern of isolated to scattered light rain
showers persisting until sunset when diurnal heating ceases. SBCAPE
maximum in the HREF is maybe 1,000 J/kg and is more likely closer to
250 J/kg. Therefore, a rumble of thunder cannot entirely be ruled
out but precip totals should be low today, which will provide some
relief to the basins that are still draining from yesterday`s
convection. Overnight should remain dry until the very early morning
hours, when PoPs increase gradually as the base of an upper trough
over northern Ontario swings south to be over the UP by 09Z
Wednesday. Once again, impacts should be low as no HREF members show
an inch of rainfall over the UP prior to 12Z Wednesday.

&&

.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...GS
LONG TERM...TDUD
AVIATION...BW/Thompson
MARINE...MZ