453
FXUS63 KAPX 221034
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
634 AM EDT Sat Aug 22 2026

.KEY MESSAGES...

-- Rain/storms today.

-- Breezy, cool, and showery Sunday with high swim risks.

&&

.DISCUSSION...
Issued at 310 AM EDT Sat Aug 22 2026

PATTERN SYNOPSIS/FORECAST:

Ridge axis stretches from British Columbia down to the Four Corners
region, where the 598/599dm upper level heat dome remains in
place...with an upper low just off the West Coast poised to try to
eject northward. Meanwhile, downstream, NW flow overtaking the
Central US, with sharp trough axis focused from KY northward through
MI into central Ontario...and another shortwave trough dropping out
of Manitoba as of 3z. Shortwave ridge axis over eastern Canada as
upper troughing exits the Canadian coast. Bulk of the moisture
across the continent is focused along the SE US coast along a
boundary stretching loosely down the Atlantic coast and through the
Gulf Coast states...and secondly, across the Upper Great Lakes up
into Hudson Bay near/beneath the incoming troughing. Anticyclonic
flow in the low/mid-levels over central Canada helping to reinforce
cold northwesterly flow across Manitoba and western Ontario, where
850mb temps are in the 4-8C range attm...and a surface cold front
stretching from MN to Hudson Bay reflects this cold advection idea.
A cold front does stretch from the central UP down into the Mid MS
Valley and Central Plains, though for our neck of the woods, the
thermal change is less impressive than the wind shift attm, with
winds distinctly turning around to the NW behind it (as opposed to
the southerly surface flow ahead of it).

Expect this latter feature will be exiting NE MI this morning as
that energy digs nearly straight south from northwestern Ontario.
This should keep the threat for showers and perhaps storms going
through the day as multiple waves dig through the region.
Strengthening pressure gradient between departing pressure falls and
approaching surface high will result in strengthening northwest
winds later today into tonight...and hanging on into Sunday as an
somewhat unseasonable wad of PV drops in and results in a
strengthening of aforementioned pressure falls to our E/NE. Falling
temps aloft should generate overlake instability and lake effect
rain showers to wrap up the weekend. Not impossible this idea hangs
on into the start of the workweek, but attm, appears ridging should
build eastward into the Upper Midwest later Monday...ahead of the
next feature plowing its way across southern Canada...which should
reach us by midweek, though its warm advective influences may reach
us a tad sooner. It is still somewhat unclear attm how the end of
next week will evolve, though signals the last few nights suggest
the flow may try to flatten out across the northern CONUS as bits of
energy continue to track across Canada.

FORECAST DETAILS...

Rain/storm chances today through Sunday (Monday?)...

Think there is a reasonable shot at a PV max lifting through around
midday/afternoon today, and another, more potent bit of PV digging
in from the northwest toward late afternoon/evening...perhaps not
all that dissimilar to yesterday`s setup, but translated eastward a
bit...though certainly possible there will be other, smaller-scale
perturbations to contend with. We will continue to hang onto several
hundred to around 1000 joules of elevated instability this morning,
and think this could have a shot at becoming surface based with time
today, especially toward NE Lower which should remain in the warm
sector longest...though if we are able to warm enough to mix out any
weak nocturnal inversion this morning, we could become surface based
right away with low-LCLs, and do wonder (with my very worst-case-
scenario brain) if a rogue spin-up is possible?...though shear
generally remains weak till perhaps the afternoon (and even at that,
is likely marginal, around 20-30kts at best)...though I am perhaps a
bit aggressively biased toward the idea of lifting/negatively tilted
shortwaves tending to be spicy. Some upscale growth is possible with
shear vectors largely parallel to the boundary, and cooling/weak
stability aloft suggests some marginal hail could be possible...but
some localized heavy rains could also be a concern, especially if
storms move slowly or hang out in an area for an extended time.

925mb temps falling below 14C as early as 3z tonight suggest we will
begin to transition to more of a lake effect regime, and this should
remain firmly in place Sunday as temps fall even further -- 850mb
temps could fall below 4C, which would be sufficient to generate
overlake instability over even the colder waters of central Lake
Superior. Prevailing flow should generally be NW to NNW but may
fluctuate back and forth a bit with the encroaching perturbations,
with more northerly flow likely by later Sunday into Sunday night.
Deepest moisture should remain over NE Lower MI Sunday, and this is
where best coverage should be...though will expect most of the usual
lake effect areas to see a little activity off and on this weekend.
Fly in the ointment for the lake effect idea is that inversion
heights should take a tumble later Sunday into early Monday, which
could limit the extent of actual shower activity into the start of
the work week. Would not be surprised to see some kind of drizzle
hang on where upsloping is maximized...though attm, some (typically
drier) guidance soundings hint at the idea of aggressive drying on
Monday, which could help clear things out quicker. With potential
for steep (15+C) delta-Ts Sunday, and 850mb winds most likely
remaining at or below 30kts (at least till perhaps late), think we
could have a shot at seeing some waterspouts on the northern Great
Lakes, though not a sure bet.

Winds this weekend...Pressure gradient will begin to strengthen this
afternoon...and will only further expand/strengthen through the
night into Sunday as that next wad of PV drops in, kicking
cyclogenesis into high gear toward Georgian Bay/western Quebec. This
should put the strongest synoptic winds generally from the EUP down
into northeast Lower MI...with potential for sustained winds 10-
20kts through Sunday night. The low-level jet should strengthen as
well, from 20-25kts even as early as this afternoon, upwards of
30+kts overnight. Think there could be some isolated gale-force
gusts on the nearshores, but do not have much confidence in this
idea attm, given that winds aloft aren`t necessarily supportive.

As mentioned above, prevailing winds should flit back and forth
between NW and NNW with time as various perturbations pass
through...but this will lead to building waves and dangerous swim
conditions especially along our west/northwest facing beaches of
northwest Lower, and across north(ish) facing shores of northeast
Lower. While we do not specifically issue a beach forecast for
Whitefish Bay, would anticipate much of that north-facing coastline
from Bay Mills/Point Iroquois toward the mouth of the Tahquamenon
River will also see high wave action and dangerous swimming
conditions (not to mention high waves out on the Bay itself). ...Not
that the cool, showery, blustery weather is overly inviting for
beachgoing in the first place.

Cool temps Sunday...Seasonably cool air mass supports highs in the
60s for most, though possibly closer to 70 near Saginaw Bay,
particularly where downsloping and some clearing could come into
play. Given anticipated showers/cloud cover (though it could end up
less bullish than current expectations), have suspicions some of the
interior areas could struggle to get out of the lower 60s, and would
not be surprised if parts of the EUP stayed in the upper 50s.
Combined with showers and breezy winds... it will definitely feel
more like fall than late August. Temps should begin to warm Monday,
about 5-10 degrees compared to Sunday, and if more aggressive drying
occurs, perhaps bounce back up much closer to normal than current
expectations...with potential for lows in the 40s again Monday
night, especially if high pressure settles in overhead, though do
have to wonder if we will end up with fog after the expected showers
this weekend.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 634 AM EDT Sat Aug 22 2026

Areas of lower cigs out there this morning, most widespread in
northern lower MI (mainly MVFR, in spots IFR). These cigs will
tend to gradually improve thru early afternoon. These are also
some showers out there, especially north of TVC. The best
chance for heavier SHRA and TSRA will be this afternoon/early
evening at APN. Precip coverage will decrease somewhat tonight.
Winds become nw and somewhat breezy this afternoon.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Small Craft Advisory from 5 PM this afternoon to 5 PM EDT
     Monday for LHZ345.
     Small Craft Advisory from 5 PM this afternoon to 8 PM EDT
     Monday for LHZ346.
     Small Craft Advisory from 5 PM this afternoon to 9 PM EDT
     Monday for LHZ347-348.
     Small Craft Advisory from 11 PM this evening to 5 PM EDT
     Monday for LHZ349.
     Small Craft Advisory from 5 PM this afternoon to 5 PM EDT
     Monday for LMZ323-341-342-344.
     Small Craft Advisory from 10 PM this evening to midnight EDT
     Sunday night for LMZ345-346.
     Small Craft Advisory from 5 PM this afternoon to 5 PM EDT
     Monday for LSZ321-322.

&&

$$

DISCUSSION...FEF
AVIATION...JZ