594
FXUS63 KMQT 081839
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
239 PM EDT Tue Jul 8 2025

.KEY MESSAGES...

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

- Rain showers and thunderstorms this afternoon, mainly across
  the west and central.

&&

.SHORT TERM /THROUGH WEDNESDAY NIGHT/...
Issued at 144 PM EDT Tue Jul 8 2025

Satellite and radar imagery shows showers from earlier this morning
continuing but dwindling over the eastern U.P. early this afternoon
as they slowly trudge eastward with time. Meanwhile, pop up showers
and storms have formed over the western U.P. recently ahead of a
cold front moving through the area tonight. While there isn`t too
much energy to work with, the partly cloudy to sunny skies over the
western half of the area this morning have allowed the atmosphere to
recover from the convection that moved through this morning. Thus,
there is enough tall but skinny sfc-based CAPE to pop up showers and
thunderstorms across the west and central this afternoon and
evening. In addition, with effective bulk shear from the SPC RAP
analysis being 30 to 35 knots over the western and central U.P. this
afternoon and evening, we could see up to marginally severe hail (up
to 1" in diameter) and marginally severe winds (up to 60 mph). While
widespread damage isn`t expected, we could see some small, dead tree
branches taken off in the stronger storms and a few isolated power
outages. In addition to sub-severe conditions, thunderstorms could
also produce heavy downpours which could lead to localized ponding
in poor drainage areas. However, given the relatively `fast` storm-
motion today and the lack of training, no flash flood concerns are
expected. The showers and storms look to continue over mainly the
west and central until sunset; the lack of sfc-based instability
will lead to the showers and storms dying over our area not long
afterwards.

Expect patchy to areas of fog to develop over the area late tonight
as weak high pressure ridging traps the moisture at the sfc. While
confidence is not high enough now being so far out in time, I
wouldn`t be surprised if the evening or mid shift put out a few
Dense Fog Advisories or SPSs late tonight/early Wednesday morning.
Expect the fog to continue until Wednesday morning just after
sunrise; expect the sun to erode away the fog at the sfc, with the
north central looking to be the last holdout due to the northerly
upslope flow from Lake Superior.

Wednesday looks to be a pretty pleasant day as cloud cover
progressively scatters out with time. Expect the Lake Superior lake
breeze to dominate as the generally northerly flow continues through
the day. Thus, we can expect cooler high temperatures closer to Lake
Superior, ranging from the 60s closer to the lake to lower 70s
further inland. As for Wednesday night, expect calm winds as the
weak ridging continues, allowing for lows to drop into 40s in the
interior areas.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
Issued at 230 PM EDT Tue Jul 8 2025

Ridging over the area for the end of the work week gives way to a
more active pattern by this weekend as phasing lows over the
Canadian Prairies and Plains lift into northern Ontario by Saturday.
Behind this, shortwave lows could bring additional rain chances back
across the area early to mid next week.

High pressure ridging over the area weakens Thursday and Friday as
two shortwave lows, one over the Canadian Prairies and another over
the Northern/Central Plains traverse eastward late this week. As
these lows approach the Upper Great Lakes, they begin to phase with
each other, pushing troughing into the area by Friday. Thus, we
could see rain chances begin pushing into the western U.P. by
Friday, although the main `hit` of rainfall doesn`t look to impact
the area until the Friday night/Saturday time period when the lows
phase with one another over northern Ontario. While we could see
above normal temperatures ahead of the phasing low`s passage, expect
a return to around normal temperatures behind it on Saturday as
cooler air enters into the region.

Moving into early next week, a Clipper low moving through the
Canadian Prairies could bring a cold front across the area around
the Sunday night/Monday time period, bringing showers and storms
back to the U.P. Behind that, model guidance shows the active
pattern continuing into the mid week as more shortwaves approaches
the region.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1253 PM EDT Tue Jul 8 2025

A weak system moving through the Upper Great Lakes the rest of today
through tonight is expected to bring showers and storms over SAW
again sometime mid to late this afternoon. Afterwards, expect high
pressure ridging to build in, allowing FG to form at SAW and
potentially IWD (40%) and even CMX (10%). Generally, expect VFR
conditions throughout the rest of today at IWD, whereas CMX looks to
slowly improve to VFR throughout the afternoon hours. SAW looks to
be generally VFR this afternoon, but rain showers and thunderstorms
could deteriorate conditions to MVFR or lower. Any FG that forms
over the TAF sites tonight could lower conditions down to as low as
airport mins. Expect the FG to remain the longest over SAW Wednesday
morning as flow becomes northerly across the U.P.

&&

.MARINE...
Issued at 239 PM EDT Tue Jul 8 2025

Winds generally remain generally ~15 kts or less through the
remainder of the work week as weak high pressure traverses the Great
Lakes. However, as two shortwave lows move from west to east late
this week, one over the Canadian Prairies and the other over the
Northern/Central Plains, they begin to phase with one another as
they approach the Upper Great Lakes. Thus, we can expect additional
showers and thunderstorms to form from west to east across the lake
from Friday through Saturday as the more southerly low lifts
northwards across the area. In addition, we could see winds increase
to around 20 knots from the southwest on Saturday from this phasing.
Behind this, expect a brief reprieve from convection before
additional storms potentially move in with a Clipper system next
Sunday night through Monday.

&&

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

&&

$$

SHORT TERM...TAP
LONG TERM...TAP
AVIATION...TAP
MARINE...Jablonski/TAP