555
FXUS63 KMQT 110550
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
150 AM EDT Fri Jul 11 2025

.KEY MESSAGES...

- Isolated to scattered showers and thunderstorms are possible
  on Friday, mainly south central 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.

&&

.UPDATE...
Issued at 1050 PM EDT Thu Jul 10 2025

Quiet weather has persisted this evening in the UP as mid level
shortwave shra/tsra activity has remained outside the CWA. This
slowly diminishing precip is N of a stationary boundary stretching
along the S end of the Great Lakes basin out into the Central
Plains. Tonight into Fri, this wave progresses ENE over Lake MI and
Lower MI with the frontal boundary not lifting as N as previously
expected, keeping precip outside the CWA until late in the day Fri
when a secondary wave pivots more NE into the region. Only major
adjustments to the going fcst was to remove PoPs through Fri morning
and back off on PoPs later in the day, aligning more with the mean
of available guidance for a slower onset...holding off until Fri
evening/night.

&&

.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 /SATURDAY THROUGH WEDNESDAY/...
Issued at 207 PM EDT Thu Jul 10 2025

Beginning Saturday, phasing split flow over the Upper Great Lakes
with the passage of a cold front from west to east will result in
showers and thunderstorms moving through the forecast area for a
majority of the day. Increasing jet dynamics in the afternoon and
evening, alongside deep layer shear of 35-45kts and MUCAPE growing
potentially to 1000-1500j/kg should support upscale convective
growth ahead of the front, posing a strong to severe thunderstorm
risk. Location of this risk will depend on the rate of
destabilization ahead of the front through the day. However, with 12z
guidance leaning into the front pushing into the western counties
near 12z, suspect shower and thunderstorm activity may begin early
in the west, with strong to severe potential increasing by late
morning and early afternoon interior west and central, then peaking
in the mid afternoon and evening central and east. Mid-level lapse
rates near 6C/km and DCAPE ~1000j/kg suggest mainly a severe wind
risk, but should a stronger updraft get going, small hail can`t be
ruled out. Shower and storms may have difficulty moving off the
frontal boundary per MBE velocities, which with PWATs increasing to
near 1.5 inches, the warm cloud layer increasing to 10-12k feet, and
some guidance packages suggesting low corfidi vectors, heavy rain
will be possible should backbuilding or training occur. Right now
flash flood potential, per WPC, is marginal (5-14%), but
deterministic guidance suggests potential of 1 to 2 inches of QPF
will be possible for parts of central Upper Michigan. Shower and
thunderstorms looks to exit east near midnight, with surface ridging
building in afterwards. Should notable QPF occur Saturday with
enough dry air afterwards to support clear skies overnight,
overnight fog may develop.

The surface high will dip southeastward through the day Sunday while
maintaining ridging overhead. This keeps conditions mostly dry into
Monday, although a secondary shortwave within the broad transiting
trough may support an afternoon uptick in cloud cover, perhaps
dinurally enhanced. In the past 24 hours, guidance on the next wave
Monday into Monday night has trended more north, although some
deterministic guidance solutions continue to resolve rain/storms.
Further upstream, a deep trough and cold front moving through the
Canadian Prairies and a shortwave lifting northeast from the Central
Plains will shift toward Upper Michigan on Monday. 6z Euro suggest
the two features may remain separate, while the GFS continues to
suggest potential phasing overhead in the Tuesday and or Wednesday
period. Given this uncertainty, confidence in the timing and
position of when that batch of precip occurs is low. Daytime highs
each day look to climb into the 70s to mid 80s. After next week`s
cold front, daytime highs look to climb only into the upper 60s to
near 70. Overnight lows are largely expected to be in the 50s and
60s, with potential for may interior locations to cool into the low
to mid 40s behind next week`s front.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 149 AM EDT Fri Jul 11 2025

VFR conditions are expected at CMX/SAW through the duration of the
6Z TAF period while IWD likely lowers to MVFR early this morning for
FG/BR development. SHRA/TSRA look to return late Fri
afternoon/evening, continuing into Fri night at IWD/SAW. With precip
onset timing near the end of the period and still some spread yet in
guidance, opted to add a PROB30 group in at IWD, but left mention
out at SAW for now. CMX likely holds dry until Sat. Otherwise light
winds are expected with wind direction possibly impacted by a lake
breeze this afternoon.

&&

.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.

&&

$$

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