648
FXUS63 KMQT 170013
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
813 PM EDT Tue Jul 16 2024

.KEY MESSAGES...

- Low impact showers with perhaps a rumble of thunder this evening.

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

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

- Next chances...albeit low...for showers and maybe some thunder
return on Saturday.

&&

.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 /WEDNESDAY THROUGH TUESDAY/...
Issued at 313 PM EDT Tue Jul 16 2024

Upper trough axis will pivot through the area on Wednesday.  Pretty
cool airmass aloft for July with 85H temps down to 3-4C will result
in a broken strato cu deck and even a few light showers at least into
early afternoon. Temperatures will cool, topping out in the lower to
mid 60s for most. While it won`t necessarily feel like a beach day,
the combo of gusty northwest winds and waves will create a high swim
risk especially from Marquette eastward through Alger County.
Thermal troughing will shift east of the area by late in the day
Wednesday as surface ridge axis builds into the Upper Lakes from the
Northern Plains. With dry air column, clear skies, and light winds
inland temperatures Wednesday night will easily fall into the 40s
and perhaps even a few upper 30s in typically colder locations. High
pressure overhead for Thursday and Friday will allow for lots of
sunshine and seasonable temperatures.

An upper low dropping southeast from Hudson Bay into Quebec on
Saturday will push a cold front southward across Lake Superior and
the U.P. Antecedent conditions are pretty dry and anticipate mainly
a dry frontal passage with just a wind shift to the north. The front
will hand up near the WI border as it dissipated and may be enough
to force an isolated shra/tsra Saturday afternoon.

Another weak front will sag into the U.P. from the north late Monday
into Tuesday which could initiate a few diurnal shras/tsras but most
locations will likely see a mostly dry 7 day stretch beginning
tomorrow into the middle of next week.

After tomorrow`s cooler day, temperatures will be seasonable into
next week.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 812 PM EDT Tue Jul 16 2024

The main forecast concerns for the TAF period are MVFR cigs and
gusty northwest winds tomorrow.

Spotty showers are entering the far west U.P. and will linger near
IWD and CMX for a few hours until sunrise. Low clouds and scattered
showers are expected to develop in the morning, likely dropping
conditions to MVFR before clearing back to VFR in the afternoon.
Northwest winds begin to increase through the afternoon as well,
potentially gusting upwards of 25 kts, particularly at CMX and
SAW, before diminishing in the evening.

&&

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

&&

$$

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