825
FXUS63 KAPX 162324
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
724 PM EDT Sat Aug 16 2025

.KEY MESSAGES...

- A few showers and thunderstorms expected into tonight.

- Cooler and drier weather to end the weekend.

- Better shot of perhaps more widespread and much needed rain returns
  Monday into Tuesday.

&&

.SHORT TERM /THROUGH SUNDAY/...
Issued at 1229 PM EDT Sat Aug 16 2025

Pattern Synopsis/Forecast:

Quasi-zonal mid/upper level flow found across the northern Great
Lakes early this afternoon, with region centered between lower
Mississippi Valley ridging and Hudson Bay centered troughing. Weak
mid level perturbation riding east within this flow and attendant
just as weak surface boundary is managing to drum up a few showers
and thunderstorms (most widespread earlier this morning)...with most
of this activity currently impacting the Straits into parts of
eastern upper Michigan. Otherwise, dry and seasonably warm
conditions found across the Northwoods. Lurking upstream is well
defined convectively agitated wave rotating rapidly east across
central Wisconsin. Area of rain with embedded storms tied to this
impulse, with the leading edge of this activity pushing into
central/eastern Wisconsin into western upper Michigan.

Upstream wave will continue to rotate east/southeast into our area
this evening...dampening some as it does so. Large scale flow regime
goes through some changes thereafter into Sunday...with ridge
amplification off to our west with subsequent digging troughing into
the eastern Great Lakes and New England.

Primary Forecast Concerns:

Shower/storm evolution the remainder of this afternoon into tonight.
Temperature trends through Sunday.

Details:

Expect upstream showers and thunderstorms to continue to propagate
east into our area later this afternoon into this evening. Axis of
greatest instability gradient aligns northwest to southeast with
time...aligning from eastern Wisconsin into southern Michigan this
evening and overnight. Simple pattern recognition suggests this will
be the corridor for more organized storm development/propagation.
Thinking this is where the better stronger storm threat and heavy
rain potential will reside...largely remaining southwest and south
of area area. Expect the northern portion of the activity to become
a bit more disorganized as it moves into northern Michigan as it
outruns that better instability gradient. Can`t completely rule out
a stronger storm or two through...particularly across eastern upper
and northeast lower Michigan where lake breeze enhanced low level
convergence will be maximized. Otherwise, kinda the same old story,
with most areas receiving little in the way of any appreciable rain.
Shower/storm threat gradually slides further south overnight as
Canada originated high pressure slowly builds south as pattern
amplification mentioned earlier begins.

That Canadian high pressure further builds south into our area on
Sunday, displacing active baroclinic axis into the lower Lakes and
Ohio Valley. Dry and somewhat cool northeast winds around these
parts, with decreasing clouds and afternoon highs mostly ranging
through the 70s.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
Issued at 1229 PM EDT Sat Aug 16 2025

Pattern Synopsis/Forecast:

Most important feature of interest is expected passage of low
amplitude but relative moisture rich wave early on during the work
week. Evidence of slow pattern retrogression heading further out
into the extended...eventually placing northern Michigan in
more direct northwest flow aloft.

Primary Forecast Concerns:

Main focus in the long term is addressing rain potential Monday into
Tuesday. Secondary focus centered on temperature trends through the
period.

Details:

Monday and Tuesday period continues to look potentially active as
relatively moisture rich shortwave trough works slowly through the
region. Still plenty of details to of course work out (most
importantly how does expected upstream convection drive enhanced
convergence corridors and development of enhanced mid level
perturbations). Still, expected passage of primary wave directly
overhead and good sub-tropical moisture connection does at least
theoretically support some more widespread and significant rain
potential. We shall see.

Not a whole lot to talk about for the remainder of the week as large
area of high pressure looks to work slowly across the Lakes.
Temperatures through the period expected to fall well within the
range of what is considered normal as we head further into the
second half of August.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 724 PM EDT Sat Aug 16 2025

A larger area of showers is moving into nw lower MI, with spotty
lighter showers elsewhere. Cigs will tend to worsen tonight
across the area, with periods of MVFR cigs overnight into Sunday
morning. Improving thru the day Sunday.

Our winds become northerly tonight, ne on Sunday.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...Beach Hazards Statement from 6 AM EDT Sunday through Sunday
     evening for MIZ018-024-030-036-042.
MARINE...Small Craft Advisory from 6 AM to 11 PM EDT Sunday for
     LHZ347>349.

&&

$$

SHORT TERM...MSB
LONG TERM...MSB
AVIATION...JZ