916
FXUS63 KAPX 201735
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
Issued by National Weather Service Detroit/Pontiac MI
135 PM EDT Mon Jul 20 2026

.KEY MESSAGES...

-Showers and thunderstorms move across the Northwoods Monday
afternoon through Monday night.

-Seasonably cool temperatures and breezy conditions continue though
Wednesday.

-Overall quiet weather returns the rest of the week with little to
no additional precipitation.

&&

.DISCUSSION...
Issued at 247 AM EDT Mon Jul 20 2026

Pattern Synopsis: An elongated 500mb ridging pattern remains
positioned over the western two-thirds of the country, with
downstream longwave troughing centered over Northern Quebec. An
embedded shortwave trough currently over the Manitoba/Ontario border
with attached surface low pressure will dig across the Great Lakes
Region this afternoon through evening, producing widespread showers
and thunderstorms tonight with enough moisture and instability.
Latest guidance continues to support enough energy for severe storm
potential followed by a frontal passage overnight that will draw a
cool northerly air mass into the area.


Aforementioned longwave troughing will extend south of Michigan this
Tuesday, returning a cooler Canadian Air mass influence.
Temperatures Tuesday, Wednesday and Thursday are expected to remain
below normal for late July with highs in the upper 60s to low 70s
and breezy northwest flow. Chances of precipitation remain rather
limited beyond the midweek as Upstream midlevel subsidence supports
surface high pressure. A few embedded weak waves will likely support
light periods of scattered showers through the end of the week, but
little to no QPF is expected at this time.


Forecast Details:

Today and tonight: The primary concern for the forecast rests on the
approaching shortwave moving across Ontario today. Moisture
advection ahead of the front will drive dew points into the mid 60s
along with moderate instability produced via diurnal heating.
Showers and storms will become more widespread tonight. Latest model
soundings depict a quasi inverted-V profile with adequate mid-
level lapse rates and a strong low-level jet that favors any severe
storms producing damaging wind gusts. Severe potential aside, PWAT
near climatological maxima and skinny CAPE profiles could create
localized heavy rainfall well over an inch for some parts of
Northern Lower this evening through the overnight hours.

Tuesday and Wednesday: Cold air advection behind the shortwave will
move into the Great Lakes Region as the aforementioned deep
mid/upper level trough dips its axis south of Michigan. Boundary
layer flow will keep conditions breezy this Tuesday and Wednesday
with gusts building around 30 knots. Temperatures will be noticeably
cool as highs are only expected to climb into the upper 60s to low
70s. While synoptic moisture will be rather limited behind Monday
night`s frontal passage, cold 850mb temperatures will interact with
the warm lakes to keep low-level cloud cover across the CWA with
even one or two locations typically affected by northwest flow
observing light showers/drizzle.

Thursday through Sunday Outlook:Surface high pressure builds firmly
over the Great Lakes region by Thursday. Subsidence aloft will
create light winds and temperatures slowly warming through the
remainder of the forecast period as the core of the Canadian air
mass shifts eastward. High temperatures will return toward the mid-
to-upper 70s by Friday and approach climatological normal
temperatures around 80 degrees over the weekend. Overall quiet and
dry weather will dominate the remainder of the forecast period.
However, a few weak, moisture-starved waves pivoting around the
northeastern midlevel trough could bring brief periods of scattered
showers, with little to no QPF expected.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 135 PM EDT Mon Jul 20 2026

Decaying batch of showers will provide some light rain at CIU, PLN,
and TVC early this afternoon - without much impact other that a
brief visibility restriction.  Smoke will still pose some minor
visibility concerns for the balance of the day.  The main weather
maker is the developing line of thunderstorms over the western Upper
Peninsula - which is expected to expand in coverage through the
afternoon hours.  Forecast timing has be adjusted to an earlier
arrival given the current observed development.  Otherwise, some
MVFR clouds behind the front through the rest of the night as winds
flip around to west-northwest. Clouds will lift Tuesday morning and
the smoke is expected to be less of an issue.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...Beach Hazards Statement through Tuesday morning for MIZ016-024-
     025-031-095-096-098.
MARINE...Small Craft Advisory until 8 AM EDT Tuesday for LHZ345.
     Small Craft Advisory from 2 PM this afternoon to 8 AM EDT
     Tuesday for LHZ346>349.
     Small Craft Advisory until 8 AM EDT Tuesday for LMZ323-341-342-
     344>346.
     Small Craft Advisory from 2 PM this afternoon to 8 AM EDT
     Tuesday for LSZ321-322.

&&

$$

DISCUSSION...SJC
AVIATION...Mann