693
FXUS63 KMQT 201933
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
333 PM EDT Sat Jul 20 2024

.KEY MESSAGES...

-30-60% chance of showers and thunderstorms over the southern
 half of the UP into early evening. Severe weather not expected.

-Dry through early Monday afternoon with near-seasonal temperatures.

-Showers and thunderstorms from as early as Monday afternoon to as
 late as Wednesday night across the area.

-High pressure and dry weather return to the forecast Thursday
 through Saturday.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 256 PM EDT Sat Jul 20 2024

Upper low over northern Quebec continues to push a weak cold front
southward across Upper Michigan. Showers and isolated thunderstorms
have been spotty along the front as it has moved southward across
Lake Superior. Visible satellite imagery showing mainly scattered
clouds ahead of the front along the WI/MI line and south central U.P.
leading to modest destabilization. This zone will be the area where
shra/tsra activity will be the greatest in coverage prior to 00Z. As
high pressure and drier air builds into the area behind the front
this evening skies will clear. With light winds and clear skies
inland temperatures will fall into the 40s with 50s along the
lakeshores.

&&

.LONG TERM /SUNDAY THROUGH SATURDAY/...
Issued at 332 PM EDT Sat Jul 20 2024

High pressure sits over the western U.S. early this week as low
pressure troughing over northern Quebec slowly moves east with time
from early to mid this week. While ridging over Lake Superior will
keep us mostly dry until Monday, with a shortwave and cold front
moving into our region Monday night/Tuesday into the middle of this
week, we could see showers and thunderstorms return across the Upper
Peninsula as we head into the mid-week. As the high pressure ridging
from the western U.S. slowly trudges eastwards with time, expect it
to finally be felt over our area by around Thursday, keeping our
area dry through the rest of the week into early next weekend.
Additional details follow below.

Expect a very pleasant day Sunday as a weak surface high pressure
moves over Lake Superior. With the weak high strengthening the Lake
Superior lake breeze, expect light north to northeasterly winds up
to 10 mph across most of the U.P. Sunday, save for right along the
Lake Michigan shoreline where the CAMs show the lake breezes
colliding. While we could see a stray shower or two over the far
west early Sunday, decided to keep chances at 10% or less over there
as only the HRRR shows this solution; other CAMs are too dry to
allow for any convection, and the better forcing is south in
Wisconsin. Outside of the sunny skies, we could see min RHs get down
to around 30% in some spots across the interior west and east given
the radiational heating; should rainfall be lower than what`s
expected today, than we could see min RHs dip into the 20 percents
Sunday.

Expect another pleasant night come Sunday night, with clear skies
and lows getting down into the mid 40s across the interior west and
east. Monday looks to be another pleasant day too, with high
temperatures being a few degrees warmer as a cold front begins to
descend from northern Ontario towards us. In addition, conditions at
the surface may be very dry again come Monday, particularly during
the morning as the high pressure over Lake Superior leaves the area;
we could see min RHs get down to 30 percent over the interior east.
Thankfully, expect the winds to still be fairly light and lake-
breeze driven for the most part. That being said, we do have a very
weak shortwave ahead of the cold front moving through Wisconsin that
could bring some showers and t-storms over the interior west by the
afternoon hours Monday. However, given the low shear profile over
our area Monday afternoon, nothing more than garden-variety storms
are expected.

Rain chances across the area begin increasing Monday night through
Tuesday as the weak shortwave interacts with the descending cold
front from Canada. As this occurs, expect rain showers and t-storms
to crawl across the U.P. from west to east Monday night into
Tuesday. As the shortwave low begins to organize and deepen over the
Lower Peninsula Wednesday, some of the rainfall looks to begin
ending over the western U.P. as early as Tuesday night, with the
rain chances ending from west to east Wednesday into Wednesday night
as the low begins lifting into southern Ontario.

Dry weather looks to return to the U.P. by Thursday as the low
continues eastward and high pressure ridging moves overhead. The
high pressure ridging looks to keep us dry for the rest of this week
into early this weekend as medium range guidance shows slowly
warming temperatures to end the extended period (thanks to warm air
advection from the Desert Southwest). Overall, expect temperatures
near normal across the area for this week, with below normal
temperatures seen Tuesday and Wednesday and above normal
temperatures returning by the end of this week/early next weekend.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 133 PM EDT Sat Jul 20 2024

Cold front sagging southward across Lake Superior into the U.P. with
a broken line of shras/isolated tsra has cleared CMX and SAW and
will IWD in the next hour or two.  Then expect VFR conditions at all
sites with clearing skies and generally light north to northeast
winds through the period.

&&

.MARINE...
Issued at 332 PM EDT Sat Jul 20 2024

Lighter winds of generally 20 knots or less continue through the
period as a few weak disturbances move through the area before high
pressure ridging moves in late this week. Other than that, a few
thunderstorms could be seen in the far west near Duluth late this
afternoon/early this evening (30 to 40% chance) and across the
entire lake from west to east with time Monday afternoon through
Wednesday (25% east to 50% west).

&&

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

&&

$$

SHORT TERM...MZ
LONG TERM...TAP
AVIATION...MZ
MARINE...TAP