349
FXUS63 KMQT 212327
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
727 PM EDT Fri Aug 21 2026

.KEY MESSAGES...

- Scattered showers and thunderstorms move eastward with a cold
  front over central and eastern Upper Michigan through this
  evening.

- Additional scattered showers and thunderstorms are possible
  across mainly central Upper Michigan tomorrow with minimal
  rainfall totals.

- Seasonable temperatures are expected through next week with
  the exception of slightly below normal temperatures Sunday and
  Sunday night.

&&

.DISCUSSION...
Issued at 319 PM EDT Fri Aug 21 2026

Afternoon RAP analysis indicates the weak sfc low has made it over
central Lake Superior, opening up into a trough which extends
northward into northern Ontario. Sfc obs place the cold front just
past the far western UP with temps in the upper 60s to mid 70s ahead
of it. Tds in the low to mid 60s support SBCAPE in the 500-1500 J/kg
range, but lapse rates are unimpressive. Bulk shear is also below 25
kts, so strong to severe storms are not expected. Latest radar
mosaic has showers along this boundary with Day Cloud Phase RGB
satellite imagery showing glaciation and GLM/ground networks
indicating lightning activity is just starting. These are expected
to progress eastward through this evening before diurnal instability
decreases and lingering convection falls apart. PWATs of ~1.3 inches
indicate some isolated higher amounts up to 0.5 to 1 inch are
possible (30-50% chance, highest central UP), but most likely
accumulations will be less than 0.25 inches.

In the wake of this front, isolated showers and a few rumbles of
thunder are possible (15-30% chance) with a shortwave and limited
elevated instability tonight. Lows settle into the upper 40s to low
60s, coldest interior west. Additional scattered showers and weak
storms are possible on Saturday as another cold front and shortwave
drop southeast overhead. That said, CAMs are even less impressed
with this round. Outside the south-central where some spots could
reach up to 0.25 inches, accumulations remain below 0.1 inches.
Highs will be in the upper 60s to mid 70s.

Temps continue to decrease this weekend, bottoming out Sunday as a
mid level trough deepens over the Great Lakes. CAA lowers 850 mb
temps to between 3-6C, yielding highs in the 60s to low 70s and lows
in the 40s to mid 50s. Some interior spots likely will dip back into
the upper 30s Sunday night. Northerly winds are expected to gust up
to 20 mph on Saturday and between 20-30 mph on Sunday, highest
east...particularly near Lake Superior. High pressure moving in from
the west keeps weather dry through Monday, likely through most of
Tuesday as well before the next mid level trough moves through the
region. This brings back shower and storm chances for Tuesday night
and Wednesday, then dry weather is favored the rest of the work week.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 727 PM EDT Fri Aug 21 2026

Weak low pressure continues to bring a few areas of showers over the
central UP this evening. Low stratus trailing the showers was
bringing MVFR cigs to CMX but conditions should improve to VFR over
the next hour as satellite shows a well defined clearing line
approaching the Keweenaw Peninsula. A few showers will impact KSAW
with MVFR conditions over the next hour and a period of MVFR cigs
through late this evening as the low stratus moves through. For late
tonight through Saturday afternoon expect mainly VFR conditions.
Isolated showers and perhaps a thunderstorm are expected over the
western and central U.P. on Saturday afternoon but with the isolated
nature there is too much uncertainty to included in the TAF at this
time.

&&

.MARINE...
Issued at 348 PM EDT Fri Aug 21 2026

Lake Superior - Northwest winds behind a cold front increase on
Saturday to 20-30 kts over the east half of the lake by late
afternoon, strongest near the south-central shores. Gusts approach
20 kts over the west. As winds become more northerly Saturday night
behind a second cold front, central lake superior winds increase to
15-25 kts; the stronger winds to 30 kts over the east persist. This
holds into Sunday morning before winds gradually simmer down from
west to east into Sunday night. This builds significant waves of 3-7
ft over the southeastern waters this weekend. Probabilities for
gales to 35 kts are only between 15-25%, highest south of Stannard
Rock and along the Marquette/Alger County shores. Winds otherwise
remain below 20 kts through Tuesday before the next system brings
back winds up to 20-25 kts Tuesday night into Wednesday morning.

Northern Bay of Green Bay and northern Lake Michigan - Southerly
winds of 15-25 kts ahead of the cold front this afternoon drop off
into this evening, becoming northwest for Saturday. Scattered
thunderstorms are expected this evening, but severe storms are not
expected. Winds increase to 20-30 kts this weekend as a colder
airmass descends over the Great Lakes. Winds fall back below 20 kts
Sunday night, remaining below 20 kts through much of next week.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
  Beach Hazards Statement until 10 PM EDT this evening for
     MIZ014.

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

&&

$$

DISCUSSION...77
AVIATION...NL
MARINE...77