831
FXUS63 KMQT 310513
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
113 AM EDT Fri Jul 31 2026

.KEY MESSAGES...

- Widespread chances for showers and thunderstorms Friday
  (40-70%). Much lower chances on Saturday (15-25%), only over
  the east half of Upper Michigan. Severe weather is not
  expected over the next few days, but there is a threat for
  heavy rainfall with any thunderstorms that develop.

- Temperatures will fall back into the 70s to low 80s for the
  weekend, coolest near Lake Superior. Lower dewpoints will
  result in a more comfortable airmass on Sunday and Monday.

&&

.DISCUSSION...
Issued at 319 PM EDT Thu Jul 30 2026

Early this afternoon upper air analysis and GOES-R water vapor
imagery showed a flattening ridge over the central U.S. with
shortwaves embedded in the flow. Southerly low level flow was
bringing moisture back into the U.P. with surface analysis showing
dewpoints in the 60s to low 70s. This combined with temperatures in
the 80s was making for a very warm and muggy afternoon. Instability
was also increasing with RAP analysis showing upwards of 2000 J/kg
mucape. Overall shear was lacking, 25kt or less, reducing the risk
for organized convection. PWATs were high though, around 1.7" over
the central and western U.P. A few showers and thunderstorms had
developed this afternoon with very heavy rain rates and occasional
lightning being the main threats. Parts of the western U.P. received
between 1 and 2 inches of rainfall with thunderstorms this morning
with up to around 3 inches near the Porcupine Mountains (radar
estimated precip).

Expect showers and thunderstorms to continue to pop up through the
afternoon in a very weakly capped environment and also supported by
a 300mb jet streak and diffluent flow aloft. Any showers and
thunderstorms will continue to have the threat for very heavy rain
rates and WPC has included the western U.P. in a marginal risk for
excessive rainfall. As a 850mb LLJ spreads across the area there is
a chance for backbuilding of the showers and storms, which is being
picked up by some of the CAMs. It does appear that showers and
storms will dissipate later this evening with the loss of daytime
heating and upper level support. It will remain muggy tonight with
lows in the 60s.

For Friday into the weekend a shortwave will deepen as it moves from
the Dakotas to the Lower Great Lakes. Much of the energy with this
system will stay well south of the area. However, continued moist
low levels and diurnal heating will bring increasing instability
under a generally weak flow and low shear environment. Expect
thunderstorms to develop in the afternoon, especially in an area of
surface convergence along a Lake Superior lake breeze boundary.
While the risk for organized or strong convection remains very low,
heavy rain will continue to be a threat and slow storm motions will
increase the risk for excessive rainfall. WPC has most of the U.P.
in a marginal risk for excessive rain on Friday. High temperatures
Friday will be close to seasonal averages, upper 70s to low 80s,
though it will remain muggy with dewpoints near 70.

A cold front will push south through the area late Friday night with
850mb temperatures falling to 8-10C by Sunday. This will bring
northerly winds and cooler temperatures for Saturday and Sunday with
highs in the mid 70s over the interior and near 70 closer to Lake
Superior. Most notable will be drier air for Sunday into Monday with
dewpoints in the 50s, resulting in more comfortable conditions. A
few lingering showers are possible on Saturday, mainly in the south
and east.

Temperatures warm back into the 80s for Monday and Tuesday with
humidity increasing on Tuesday ahead of an approaching cold front.
Showers and thunderstorms may accompany the front on Tuesday but the
risk for organized convection remains uncertain at this point in
time, with global models showing lower instability and shear.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 112 AM EDT Fri Jul 31 2026

Mainly VFR conditions are expected through the forecast period.
However, additional spotty showers and storms are possible from
around 10-15Z at all terminals, followed by an additional batch of
showers and storms after 18Z. This later batch is most likely at
SAW, and tapers off closer to 06Z. Any storms could briefly lead to
reductions in visibility and ceilings, as well as erratic winds.
Otherwise, expect winds to shift over to the W/SW for tonight and
Friday, peaking at around 5-10kts.

&&

.MARINE...
Issued at 319 PM EDT Thu Jul 30 2026

The lake will remain under a weak pressure gradient through Monday
resulting in mainly light winds, 20kt or less. Thunderstorms will be
possible through Friday with a few stronger storms possible over the
far west this afternoon and early evening. Otherwise expect quiet
weather through Monday, with the chance for thunderstorms returning
on Tuesday.

&&

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

&&

$$

DISCUSSION...NL
AVIATION...LC
MARINE...NL