100
FXUS63 KAPX 111022
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
622 AM EDT Fri Sep 11 2026

.KEY MESSAGES...

- Rain chances return Saturday, esp north; cooler Sunday

- Heavy rain possible early next week

&&

.DISCUSSION...
Issued at 356 AM EDT Fri Sep 11 2026

PATTERN SYNOPSIS/FORECAST:

Rather quick flow across the northern tier of the country
attm...with 100-120kt upper jet axes from WA to Manitoba ahead of a
positively tilted trough axis over western Canada...and from the
Lower Great Lakes northeastward into ME ahead of another elongated
positively tilted trough axis stretching from the Central Plains to
the OH Valley. Deepest absolute moisture (pwats greater than 1.5-
2in) ahead of the latter feature across the SE US and Gulf Coast,
and its attendant surface front draped from TX to OH up toward Boston
     though some Pacific moisture (pwats 1-1.5in) is located along and
ahead of the former, from the Northern Plains to Manitoba/Ontario,
and down into the Upper Midwest. Mid-level warming and upper-level
cooling resulting in steepening lapse rates across the northern
Plains, with cooling aloft steepening lapse rates beneath the trough
axis itself over western Canada. Cold baroclinic zone/surface
boundary stretches from central Canada to the PacNW (where a nice
baroclinic leaf is evident on satellite imagery over WA, attendant
to a PV max digging in from the Pacific), and warm baroclinic zone,
from Manitoba down into the Upper Midwest/Central Plains...with
850mb temps in the teens and 20s across the Plains. Return flow
developing across the Plains/southern Canada around surface ridge in
the Upper Great Lakes...resulting in a maximum of warm advection
across Ontario/Manitoba, shunting the pool of 0C 850mb air eastward
across James Bay. In the meantime, beneath said surface ridge and
abundant subsidence...we are calm, dry, and cool...with temperatures
dropping back into the upper 40s and lower 50s as of 3z under clear
skies.

Upper ridge axis builds overhead today, with generally quiet
conditions expected, though return flow will be strengthening ahead
of upstream perturbations. This should also lead to some warm
advection cloud cover drifting through today. The upstream trough
axis will approach late tonight into Saturday, dragging a SW-NE
oriented surface trough eastward across the Upper Midwest, resulting
in even stronger return flow on Saturday, and think some convective
activity will be around the Midwest into Ontario during this
timeframe, most likely impacting our area later Saturday into
Saturday night as the trough axis sweeps by to our north, while OH
Valley activity likely remains to our south. Hot on its heels,
however, is another perturbation over the Canadian Prairies, which
currently looks to dig a little deeper into the Great Lakes than the
first system, keeping things active early Sunday...and bringing some
cooler air into play. We could see a brief break in the action
Monday, unless warm advection convection rears its head...and warm
advection will certainly be a concern ahead of a sharper PV maxima
digging across the US/Canadian border upstream Monday. This
currently looks to pass by the area Monday night into Tuesday, and a
notable concern with this is that signals currently point toward a
wide-open Gulf and subsequently, potential for deep moisture and
heavy rainfall in the Upper Midwest. Southwesterly flow aloft
generally looks to persist across the eastern US/Great Lakes into
the latter half of the week, with additional perturbations in the
northern stream trying to affect us toward Wednesday/Thursday,
though quite a bit of uncertainty attm in the details/timing of
these. Overall, expect active weather off and on through the course
of the next week.

FORECAST DETAILS...

Rain/storm chances tonight into Saturday... Non zero chance some
activity could sneak in toward Saginaw Bay Saturday morning on the
very northern edge of the OH Valley system`s influence, noting
signals for an increase in low-level moisture...and there are some
signals for a subtle positively tilted PV maxima to slip through
around 12-15z...though not sure if this will be enough to generate
precip or not. Primary concern tonight/Saturday morning will be how
quickly the upstream warm advection precip moves in from the
W/NW...and given that we are likely to stay quite dry in the low-
levels today, think onset of rain will be a tad slower. Most likely
chance of anything getting in during the early morning would be for
the EUP and perhaps Straits. Better chance for rain/storms would be
in the afternoon and evening from west to east along/ahead of the
front, particularly toward the EUP and NE Lower where there is
potential for somewhat deeper moisture and better influence of
synoptic forcing from the PV max...and where there are signals for
an increase in low-level fgen toward 18-0z.

Rain/storm chances Saturday night into Sunday... Current expectation
is for temps to fall rather dramatically behind the front Saturday
night, with 850mb temps approaching 4-5C or colder by 12z Sunday.
This should result in at least some daytime instability, if not
overlake instability...and think we have a reasonable shot at NW
flow lake enhanced showers through Sunday, especially with a sharper
PV max looking to dig across the area Sunday afternoon. This latter
feature could set off some better shower activity across parts of
northern Lower (M-72/M-55 corridors) during the afternoon into the
evening hours, before things quiet down again...but not impossible
the lake-induced clouds (and/or showers?) hang on into the
overnight.

Chilly Sunday/Sunday night... Sunday will be quite cool otherwise
(highs in the lower to middle 60s likely), with warmest temps in the
morning hours and especially across the Saginaw Bay region. With
high pressure likely moving in Sunday night...not impossible we
could be looking at more widespread lows in the lower 40s, and
perhaps a few more of the typical interior cold-spots make a run at
the middle to upper 30s by Monday morning, noting signals for the
air mass to dry right out behind that PV max Sunday afternoon.

Rain/storm chances Monday night into Tuesday (Heavy Rain
potential?)...Return flow Monday into Monday night should result in
a slug of Gulf moisture (pwats in excess of 1.5in) and a maximum in
theta-e advection over the Upper Midwest and Great Lakes region
Monday night into Tuesday with a strong S/SW low-level jet through
the MS Valley. Combined with a PV maxima slipping by to our north
during this timeframe, will need to monitor for heavy rain
potential. There are signals for weak stability aloft which could
support better rainfall production, and freezing levels should be
well above 3km again (noting 700mb temps around +8C Monday/Monday
night); current mean wind vs low-level flow suggests potential for
slower moving (perhaps training?) cells, which could also boost
rainfall amounts across some lucky (sarcasm) portion of the region.
Not impossible better convective activity could develop to our
southwest and track by to our southwest (the usual idea)...though
the low-level jet looks to remain strong enough far enough north
into the Upper Midwest that we may well end up in the path of better
convection. Probabilistic guidance (currently based more on global
than hi-res guidance given this is still 96-120hrs out) suggests a
40-50 percent chance of 24-hr totals of at least an inch across WI
into parts of northern MI, with decreasing certainty in 24-hr totals
in excess of 2in, though worth noting that the potential for
rainfall in excess of 3in is not zero attm. The current area of
interest seems to be the EUP and perhaps the Straits/Tip of the
Mitt...stretching back into WI where ensemble guidance hints at a
climatologically high maximum in moisture transport late
Monday.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 621 AM EDT Fri Sep 11 2026

VFR conditions are expected to persist through the issuance
period with sout-southhwest winds increasing through this
afternoon with gusts around 15 kts. Winds will turn more
southerly tonight and slightly decrease before increasing and
turning southwest through Saturday afternoon. Light scattered
showers will also be possible Saturday.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Small Craft Advisory from 1 PM this afternoon to 6 PM EDT
     Saturday for LMZ341.

&&

$$

DISCUSSION...FEF
AVIATION...NSC