363
FXUS63 KMQT 160714
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
314 AM EDT Sun Aug 16 2026

.KEY MESSAGES...

- Scattered showers continue marching east, departing the UP this
afternoon.

- Hazardous swim conditions are expected for the beaches along Lake
Superior east of Marquette today due to high wave action and strong
rip currents.

- Showers and thunderstorms will be possible (up to 50%) Monday
night into Tuesday.

- Temperatures will be close to seasonal averages most days through
next week, with highs in the 70s and lows around and in the 50s.

&&

.DISCUSSION...
Issued at 313 AM EDT Sun Aug 16 2026

Early morning KMQT radar returns show scattered rain showers over
mainly the central UP around 06Z, though no lightning has yet been
observed. Per RAP analysis, this is ahead of a 1011mb surface trough
over mainly the west half of northern Ontario supported by an upper
trough over the Ontario/Manitoba line. Elsewhere at 500mb, a closed
high is centered over the ArkLaTex region with multiple shortwaves
rotating around the top of the high. Troughs are also present over
British Columbia and off the New England coast. Throughout the
remainder of the weekend, the southern high and Pacific trough will
make no meaningful progress, but the troughs off the East Coast and
over central Canada will progress, leaving the UP in a stable,
northwesterly flow pattern which will keep dry weather in the
forecast from this afternoon (following the departure of showers to
the east) to Monday evening. High temperatures remain seasonable and
comfortable through Monday with highs only exceeding 80 degrees in
the south-central. Tonight into Monday morning, lows fall to around
the 50 degree mark for the interior and around the 60 degree mark at
the Great Lakes shores.

Today through Monday afternoon, a 500mb trough will deepen and
become a closed low as it swings along the Hudson Bay shoreline from
Nunavut to Manitoba. Falling 500mb heights ahead of this closed
low will lead to the formation of a surface trough that will
once again bring rain shower chances to the UP around 00Z
Tuesday. CAMs show some convective activity in Minnesota and
northwest Ontario ongoing at 00Z Tuesday, though if convection
survives crossing the lake and reaching the UP, it will be
moving into stable air (HREF mean MUCAPE struggles to exceed 100
J/kg), though it will be a shear-rich environment as HREF mean
0-3km SRH balloons to 100-200 and deep speed shear is present
(including the presence of a 100+kt jet at 250mb). Model
soundings show meager lapse rates but plentiful deep moisture
(LREF mean PWAT grows to about 1.25 inches, around the 75th
percentile of climatology). Thus, if any thunderstorms can get
going, some heavy rain rates could be observed, but severe
thunderstorms seem unlikely given the timing of the showers not
lining up well with diurnal destabilization. Unfortunately for
the areas of growing drought for the UP, this rainfall does not
look to be widespread, as LREF probabilities of 0.1 inch of rain
by 00Z Wednesday are 25-33% for the west half and 35-55% for
the east half.

Another dry spell then kicks off early Wednesday morning through at
least Thursday evening. Models diverge significantly for the late
week period, though the passage of another deep trough from the
northwest looks to be the next mechanism for bringing shower and
thunderstorm chances to the UP late this week into next weekend.
With the continued background northwesterly flow aloft pattern,
temperatures generally remain seasonal with highs in the 70s and
lows in the 50s.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 148 AM EDT Sun Aug 16 2026

Scattered SHRA over much of the UP is leading to deteriorating
flight categories through this morning, including 50+% chances of
LIFR conditions at CMX and 50-70% chances of IFR at SAW/IWD. Gradual
improvement is expected throughout the day at all sites, with
chances of VFR exceeding 75 percent by 19Z at IWD, 21Z at CMX, and
23Z at SAW, though clouds may SCT out an hour or two prior to
ceilings lifting by that point. Expect winds to shift to the
northwest after the SHRA pushes through, occasionally gusting 15-20
kt in the afternoon hours.

&&

.MARINE...
Issued at 313 AM EDT Sun Aug 16 2026

Wind gusts around or less than 20 kt on Lake Superior this morning
increase over the east half of the lake to around 25 kt out of the
northwest in the wake of rain showers. As the disturbance exits the
region, winds relax to sub-20 kt tonight through Monday night (with
the notable exception of southwesterly wind gusts funneling
between Isle Royale and Thunder Bay Monday afternoon to 20-25
kt). Another disturbance passing over the lake Monday night into
Tuesday will have gusty westerlies for the east-central portion
of the lake to 20- 25 kt for Tuesday afternoon. Winds falling
below 20 kt again Tuesday night will remain thus until the next
disturbance arrives late in the week.

&&

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

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

&&

$$

DISCUSSION...GS
AVIATION...GS
MARINE...GS