920
FXUS63 KMQT 161949
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
Issued by National Weather Service Gaylord MI
349 PM EDT Thu Oct 16 2025

.KEY MESSAGES...

- Widespread rain expected tonight/parts of Friday.

- Gusty winds in spots tonight/more widespread Friday.

- Above normal temperatures Friday.

- Some showers to start the weekend...but a rainy/blustery end
perhaps?

- Lingering rain chances through midweek with plenty of unknowns.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 347 PM EDT Thu Oct 16 2025

Pattern Synopsis/Forecast: Large scale pattern shows the Great Lakes
sandwiched between upper lows over Atlantic Canada and the central
Rockies (the latter being in the southern branch of a split trough
over western North America...with short wave ridging in between
extending from the eastern Gulf northward into northwest Ontario.
Large area of 1.00-1.50 inch precipitable water values in between
the upper ridge axis and Rockies trough over much of the mid/upper
Mississippi Valley and adjacent northern Plains...resulting in an
east-west oriented moisture gradient across the Great Lakes. Low
level warm advection developing across Upper Michigan this afternoon
with thermal trough displaced well to the east...ribbon of 850mb dew
points above 12C also getting pulled northeast along this baroclinic
zone...resulting in extensive cloud cover across Wisconsin and
spreading across western Upper this afternoon though with minimal
precipitation coverage thus far.  1027mb surface high is centered
over the upper Lakes this afternoon...strung out area of low
pressure from South Dakota back into the high plains of
Colorado...warm front extends from the South Dakota low into
Iowa/eastern Missouri.

Short wave ridge axis will cross Upper Michigan tonight while the
South Dakota surface low lifts northeast toward Lake Winnipeg.  Warm
sector ahead of the surface cyclone spreads across Wisconsin/Upper
Michigan Friday...as associated cold front approaches the region by
Friday evening.

Primary Forecast Concerns:

Widespread rain expected tonight/parts of Friday: Broad isentropic
ascent and some more focused low level frontogenesis expected to
result in an increase in precipitation coverage over the next
several hours...and spreading across the Upper Peninsula as the
evening progresses. Some weak elevated instability won`t hurt the
cause with an increase in low level theta-e...pretty warm aloft with
the upper ridge axis so wonder if we would see a deep enough
unstable layer to allow for charge separation and thus lightning/
thunder (more of a gee whiz thing at this point).  Precipitation may
end across far western Upper during the early morning hours...with
drying likely pushing east across the forecast area with some dry
slotting ahead of the approaching cold front through the morning.
Will see some showers develop along the cold front as it approaches
western Upper/northwest Wisconsin Friday afternoon...not much in the
way of destabilization forecast ahead of the boundary.

Gusty winds in spots tonight/more widespread Friday: Southerly
boundary layer wind will increase late this afternoon and tonight
across Upper Michigan. Some stronger gusts (20+mph) expected in some
of the downslope favored areas along the south shore of Lake
Superior.  Strongest surface gradient arrives Friday (30-40kt 1000mb
geostrophic winds) and even with shallow mixing gustiness expected
to become more widespread (20-30+mph from the south).

Above normal temperatures Friday: The gusty winds and some breaks in
the clouds will warm temperatures up across Upper Michigan on
Friday...with an east-west temperature gradient expected with highs
in the lower-mid 60s east to the lower 70s west (normal highs are in
the lower-mid 50s).

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
Issued at 347 PM EDT Thu Oct 16 2025

Days 2-3 (Saturday-Sunday): Cold front slowly crossing the upper
Lakes Friday night/Saturday will drag showers across the
state...likely ending across the western half of Upper Michigan
Saturday but rain chances may linger across the east through the
day.  Sunday looks infinitely more interesting with a couple of
phasing short wave troughs spinning up a new surface low along the
cold front over the mid Mississippi Valley...which then wraps up
across Michigan.  This could result in a rather rainy/blustery day
as winds swing around to the northwest and rain wraps around the
circulation...especially across the eastern half of Upper Michigan.
But how rainy/blustery will depend on the ultimate evolution of this
system.

Days 4-5 (Monday-Tuesday): Monday looks cooler...could see some lake
induced showers but the boundary layer wind direction is somewhat in
question at this point.  Potential for another cold front passage
later Monday into Tuesday will keep the rain threat going.

Days 6-7 Outlook (Wednesday-Thursday):  A lot more uncertain into
the midweek period regarding short wave trough evolution.  Doesn`t
look particularly cool...in fact 6-10 outlook which covers Wednesday-
Sunday is leaning more warm and dry (though the warm/dry part may be
more apt for next weekend).

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 140 PM EDT Thu Oct 16 2025

Initially VFR ceilings at KCMX/KSAW but KIWD already high end
MVFR...with the expectation of at least widespread MVFR ceilings
and occasional visibility restrictions as precipitation coverage
should increase during the late afternoon. Precipitation should
continue into the evening at KIWD/KCMX before likely tapering
off with ceilings lifting during the early morning hours...while
suspect ceilings will drop to IFR at KSAW later tonight. Low
level wind shear expected to develop by early evening at all
terminals and will likely persist through late Friday morning.

&&

.MARINE...
Issued at 347 PM EDT Thu Oct 16 2025

Surface low lifting northeast from South Dakota into Manitoba
tonight will push a cold front toward the upper Lakes...along with a
strengthening pressure gradient which will increase winds from the
south/southeast tonight into Friday.  Winds tonight expected to be
strongest over central/eastern Lake Superior gusting over 25kts
tonight and Friday...as well as on Lake Michigan where long fetch
southerly winds expected to push wave heights to 4-8 feet Friday
within the northern Lake Michigan nearshore zones.  Cold front
crossing the upper Lakes Saturday will allow winds to veer more
southwesterly and should weaken as the pressure gradient slackens.
Frontal wave expected to develop over the mid Mississippi Valley
Saturday...and strengthen as it lifts northeast across Michigan
Sunday.  How strong this low gets is still up in the air...as some
of the probabilistic guidance is trying to push gales across eastern
Lake Superior on Sunday.  At the very least winds are expected to
swing around to the northwest as a result of the low passage.  Winds
then expected to be shifting around for Sunday/Monday as a a surface
ridge crosses the upper Lakes Sunday...and then another low/cold
front Monday.

&&

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

&&

$$

SHORT TERM...JPB
LONG TERM...JPB
AVIATION...JPB
MARINE...JPB