951
FXUS63 KMQT 101756
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
156 PM EDT Thu Jul 10 2025

.KEY MESSAGES...

- Isolated to scattered showers and thunderstorms are possible
  on Friday, mainly south central in the morning and far west
  in the late afternoon.

- More showers and thunderstorms are expected Saturday. Some of these
  storms may produce strong winds and heavy downpours.

- Seasonable temperatures persist in the Upper Peninsula for the
  work week.

&&

.SHORT TERM /THROUGH FRIDAY NIGHT/...
Issued at 122 PM EDT Thu Jul 10 2025

While high clouds streamed into the west, mostly clear skies were
observed this morning in the east. Near 1130EDT, diurnal clouds
began developing in Schoolcraft and Luce counties, but by then,
temperatures had already warmed into the low 70s. In the west, where
the high cloud cover has limited heating some, high 60s were still
being observed then, but light downsloping winds helped other
locations quickly warm into the mid 70s. Expecting additional
heating through the afternoon, with most locations climbing into the
upper 70s to low 80s. The cloud cover is associated with an upstream
shortwave over southern Minnesota and a warm front draped southeast
from there into Iowa. Other then the cloud cover, rain/storms
associated with this feature will stay out of the forecast area this
afternoon. CAMs highlight this precip flaring this afternoon over
south-central Wisconsin and near Duluth, but diminishing this
evening. Its possible some showers may scrape the far west, but
probability appears to be rather low (<15%). Overall, expecting a
mostly dry but mild night with temperatures dipping into the 60s
west and 50s east.

Late tonight into Friday, a warm front will lift into the Upper
Great Lakes. Where exactly, will depend on where the front ends up
today. While there does appear to be a weak trend among the CAMS of
the boundary lifting close enough for showers to develop and move
into Menominee County by 12z Friday, solutions presented by a
majority of the other deterministic guidance suggests this activity
would stay to the south. This impacts shower and thunderstorm
potential through the day, as the more northern solutions of the
RAP/HRRR would result in isolated showers/storms near Lake Michigan
and eastern Upper Michigan by afternoon, while the more southern
solutions keep the east dry. Upstream in Minnesota, convection
developing along a cold front will press east toward our forecast
area. Similarly to the precip in the east, there are timing
questions on when precip will factor in for the west. Latest CAMS
suggest diminishing showers/storms moving slowly the west after
midnight, while some 0 and 6z medium range guidance holds precip
together longer into the evening and overnight hours for the west
half. Warmer temperatures are expected Friday thanks to the warmer
airmass over the area. Expecting mostly low to mid 70s except upper
70s by Manistique. Mild overnight Friday night is also expected,
with widespread 60s for lows.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
Issued at 225 PM EDT Wed Jul 9 2025

Beginning Friday, mid-upper ridge axis will lay through Upper
Michigan, with a series of shortwaves embedded within split stream
flow stream upstream over the Central and Northern Plains. Various
placement of previous night MCVs are apparent in the different
deterministic packages, which supports my initial uncertainty in the
timing of the key features for Upper Michigan. Although 12z guidance
appears to have produced a better consensus which overall looks
to pull a warm front or the attendant surface low through the
forecast area Friday afternoon or overnight. This while the mid-
level shortwave to the west moves from the Dakotas into
Minnesota/western Lake Superior. This main shortwave begins to
take on a negative tilt, which might absorb the original
low/shortwave. 6z and 12z guidance is unclear if this will
actually take place overhead or downstream in northern Ontario.
Regardless though, the cold front will help push the surface low
through the region Saturday and Saturday night. While questions
of the timing and location of the initial features exists,
showers, potentially mixed with thunderstorms should be
expected. Given the temporal clarity of the initial timing of
precip, instability/shear may be present over the region, which
could support stronger storms late Friday. DCAPE values suggest
an isolated strong to severe wind threat, but model soundings
show light background winds upwards of 25k ft, suggesting this
potential is low (<25%). Guidance also suggests potential for
mid-level lapse rates increasing to ~7C/km, which may be enough
to support hail should a stronger updraft get going. Showers and
storms will press through the region overnight while the cold
front moves in from the west. Given the questions about phasing
and the timing of the initial showers/storms, its unclear if
precip will occur all day Saturday, or be mainly limited to the
afternoon/evening hours ahead of the front.

From there, another shortwave migrates through the region Sunday
evening and overnight while surface high shifts from the Upper
Midwest to the Lower Great Lakes. The high looks to keep the region
mostly dry Sunday, but a line of showers may accompany the wave late
Sunday night/Monday morning. A deep trough moving through the
Canadian Prairies and a shortwave lifting northeast from the Central
Plains will shift toward Upper Michigan on Monday. There are notable
timing differences in the model suites regarding these and whether
or not they`ll phase overhead next week. Right now the main window
for precip associated with these features focuses on Tuesday to
Wednesday. Daytime highs each day look to climb into the 70s to mid
80s and with overnight lows dipping into the 50s and 60s.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 122 PM EDT Thu Jul 10 2025

VFR conditions and light winds are expected to prevail at all sites
in this TAF period. The exception could be the development of
fog/mist late tonight into Friday morning at KIWD/KCMX. Latest
guidance also slows the incoming showers and thunderstorms, so these
were removed from this issuance.

&&

.MARINE...
Issued at 155 PM EDT Thu Jul 10 2025

Winds generally remain around 15 kts or less into the weekend with
the exception of some 15 to 20 kts over eastern portions of the
lake. By Saturday though, 15 to 20 kt winds out of the southwest
will become more widespread through Sunday before decreasing again
late Monday. This will coincide with some disturbances moving
through the Great Lakes Region over the weekend. With these
disturbances, showers and thunderstorms will overspread the lake
from west to east Friday through Saturday. Further out, additional
shower and thunderstorm chances will accompany a Clipper system late
Monday through Tuesday. Also of note, patchy fog could result in
reduced visibilities across far western portions of the lake
tonight.

&&

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

&&

$$

SHORT TERM...JTP
LONG TERM...JTP
AVIATION...JTP
MARINE...TDUD