623
FXUS63 KAPX 201904
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
304 PM EDT Sat Jul 20 2024

.KEY MESSAGES...

- Isolated to scattered showers and storm chances into this
  evening, and again on Sunday.

- Shower/storm chances through Monday...

- Patchy fog at times during the overnights??

- Better shower/storm chances Tuesday into Wednesday...

&&

.SHORT TERM /THROUGH SUNDAY/...
Issued at 302 PM EDT Sat Jul 20 2024

Pattern Synopsis:

A closed mid/upper-level low will continue to churn over eastern
Canada as weak troughing sagging south of the main feature will
linger over the Great Lakes/Mississippi Valley through the weekend.
After a diffuse cold front works from north to south across northern
Michigan later this afternoon into tonight, a nebulous surface
pattern looks to set in across the region through the remainder of
the period in absence of appreciable forcing aloft.

Forecast Details:

Isolated to scattered shower/storm chances -- Ongoing showers will
continue to track across parts of the eastern U.P. over the next few
hours, working into areas near the Straits later this afternoon and
early this evening. MLCAPE around 1,000 J/kg will support the chance
for a few thunderstorms to develop. While gusty winds and small hail
will be possible with any stronger storms, severe weather is not
expected through this evening. While shower activity is expected to
work its way south across the northern lower peninsula this evening,
chances will diminish with time as diurnal support wanes -- likely
ending chances across the area by midnight tonight. After an
anticipated break in rain chances overnight, additional chances for
showers and a few storms will return to parts of northern lower
Michigan Sunday -- although confidence is low at this time.
Seasonable lows in the mid 50s to low 60s are in store for tonight
with temperatures warming back into the upper 70s/low 80s for most
areas Sunday afternoon.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
Issued at 302 PM EDT Sat Jul 20 2024

PATTERN SYNOPSIS/FORECAST:

Broad troughing over the eastern US/Canada...with anomalous trough
over Quebec. Anomalous ridge over northwestern Canada...with broad
northwesterly flow into the central US attm. A handful of niblets
along this flow...with a primary swirly over MN/IA this
morning...with some convection amid better difluence over the Mid MS
Valley into the southern Plains. Bulk of the deepest moisture
trapped over the SE US...south and east of a boundary stretching
from the Carolinas back into Louisiana. Closer to home...PV strand
stretches across northern MI from W to E this morning, with some
convective activity in its wake over Lake Superior...along a
backdoor cold front dipping into the region from the north. Somewhat
better moisture pooling along this front...with pwats approaching an
inch (just over at GRB at 12z). A bit of haze from Canadian
wildfires around otherwise.

Looking ahead...expect this front to drop through and generally wash
out over the region...as swirly over IA slowly meanders around the
Mid MS Valley. Another niblet of energy tries to swipe the NE half
of our CWA Sunday...and appears this too, may try to stall out/wash
out over the area for Monday...as the IA swirly gets booted
eastward. This idea suggests we will end up seeing mildly unsettled
weather to start next week as little bits of forcing meander through
the region. The best chance attm for unsettled weather looks to be
Tuesday into Wednesday....as broad troughing over Ontario begins to
dig into the Upper Midwest Tuesday night. While there`s a pretty
reasonable shot that the best moisture remains to our southeast...we
should still have enough to contend with that it will bear watching
going forward. Improvements expected going into the latter half of
the week...as ridge axis becomes shunted eastward over southern
Canada through the week...leading to potential for surface high
pressure and some return flow into the Canadian Prairies.

Primary Forecast Concerns:

Shower/storm potential for the next couple days... Not impossible
that any showers/storms that develop Sunday afternoon could linger
into the evening and perhaps the overnight...though unclear if this
will happen at all, given decent signals for a warm nose aloft to
hold things down, as well as a pretty dry layer off the deck through
about 5kft. However...not impossible that we could get a few showers
(perhaps a rumble of thunder?) Sunday night over NW Lower, with the
PV swirly meandering over southern Lower MI and/or northern IN/OH
Sunday night. Better chance of afternoon pop-ups seems to come
Monday...with some potential for the remnants of that boundary to
slowly meander back northward....though signals for instability
aren`t overly impressive attm. Given general lack of synoptic
forcing...suspect we`d be looking at sort of generic summertime pop-
up showers/ storms, specifically along the lake breezes as they
develop with diurnal heating.

Patchy fog potential?... Guidance soundings suggest we should mix
out very well the next few days, with largely dry afternoons on
tap...and are not terribly supportive of the prospect of fog
development during the overnights. However...I can`t help but notice
how nebulous the flow is as we become almost col-y for a
time...which suggests potential for stagnant weather and perhaps
patchy fog development, particularly if we are able to see any rain
during the afternoon that allows for better boundary layer moisture
to hang on.

Better shower/storm potential Tuesday into Wednesday... Slightly
better threat for showers/storms arrives Tuesday with the shortwave
trough aloft approaching the area. Do question how well things will
make it to the ground initially, given the aforementioned concerns
about low-level dryness...but do think we will eventually begin to
see rain make it to the ground. Some signals for better instability
with this, as well as better moisture pooling along the front
associated with the trough...but attm, winds aloft are only on the
very marginal end of supporting any kind of storm organization...so
it remains unclear just how busy the weather will be on Wednesday.
For now, though, think the Tuesday-Wednesday timeframe will have the
best chances for more widespread activity over the region.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1248 PM EDT Sat Jul 20 2024

VFR conditions are anticipated across most of the area through the
duration of the issuance period. Isolated to scattered showers and
storms look to work across parts of the eastern U.P. and northern
lower Michigan this afternoon into this evening. Brief drops in VSBY
will be possible should any storms track over TAF sites -- primarily
CIU and PLN. West/northwest winds around 5-10 kts will go weak/calm
overnight after a cold front pushes through the area from north to
south. Mainly light east/northeast winds are in store for northern
Michigan on Sunday.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.

&&

$$

SHORT TERM...DJC
LONG TERM...FEF
AVIATION...DJC