195
FXUS63 KAPX 171911
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
311 PM EDT Mon Jun 17 2024

.KEY MESSAGES...

- Uncomfortable heat to continue.

- Small chances for showers and storms through Tuesday.

- Very hot, humid conditions expected to continue through the middle
of the week.

- Chances for showers/storms at times this week into the
  weekend.

&&

.SHORT TERM /THROUGH TUESDAY/...
Issued at 310 PM EDT Mon Jun 17 2024

True summer airmass has made its presence felt across northern
Michigan, courtesy of sustained deep layer southwest flow between
expanding east coast sub-tropical ridge and broad troughing slicing
east across the Intermountain West. A classic long-wave
configuration to drive heat north, and temperatures are responding
accordingly, with most areas pushing well into the 80 early this
afternoon...with even a few locations in the lower 90s. Tap to Gulf
of Mexico moisture also becoming increasingly established, as
evident by dewpoint temperatures remaining in the 60s and lower 70s
(this despite increased afternoon mixing). Combination of this heat
and humidity has help produce quite a bit of low level instability,
with SPC mesoanalysis displaying over 2K Joules/kg of mixed layer
cape across much of the Northwoods. Despite this, a lack of a well
defined trigger to make use of this instability has prevented much
shower and storm generation...with primary focus remaining to our
west within zone of max deep layer moisture convergence and better
jet dynamics on ridge/trough interface.

Not a terrible amount of change expected as we head through tonight
and Tuesday, with deep southwest flow directed right into the Great
Lakes region. This sets the stage for more uncomfortable warmth
tonight and Tuesday, along with additional low chances for showers
and storms at times.

Primary Forecast Concerns/Challenges:

Temperature trends and addressing any shower/storm concerns.

Details:

Warm and muggy tonight, with lows only falling into the upper 60s
(perhaps not out of the low 70s) for much of northern lower
Michigan. Readings will be a bit cooler for those areas north of the
Straits. Anyones guess with regards to shower/storm potential
tonight. Large scale deep layer forcing is most definitely lacking.
Simple breadth of sustained moisture advection and any passing
impulses/decaying outflow boundaries from previous convection may be
able to pull the trigger on the development of a few showers and
storms. Definitely feel most of the area and much of the time will
remain a dry one. Lack of any organized shear should preclude any
severe threat, but if storms do form, they will be capable of brief
heavy rainfall rates given such a moisture rich environment
(precipitable water values remain over an inch).

Surge of even better Gulf moisture arrives Tuesday, with this plume
of deeper moisture already well displayed rotating north in current
water vapor imagery. Simple extrapolation supports this deeper
moisture spreading directly overhead during the day Tuesday. This
will serve to likely keep actual temperatures from reaching their
full potential (based of column thermal progs) and at least help
increase the odds for a few showers and storms...especially during
the afternoon hours. Again, a definite lack of a well defined
trigger for more organized storm potential, but any subtle forcing
should be enough to support some moist convection. Nothing
widespread anticipated, with most areas again likely remaining dry.
Brief periods of intense rain and marginally gusty winds will be the
primary concern with any storm activity. While no doubt it will
remain uncomfortable warm given combination of highs in the upper
80s to lower 90s and that increasing moisture, simply not seeing
enough evidence for dangerously hot conditions to require any type
of heat related headline. Will continue to hit these uncomfortably
warm conditions in our latest messaging/graphics and hazardous
weather products.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
Issued at 310 PM EDT Mon Jun 17 2024

Strong upper level ridging centered across the East Coast through
mid-week will edge into the Atlantic later this week into this
weekend. This setup will likely allow northern stream troughing to
approach the region from the north. In the meantime, very hot and
humid conditions will continue into at least Wednesday. Not quite as
hot but still rather humid conditions likely continue for a few days
after that. Since it looks like northern Michigan will be located
in the battle ground between the strong ridge and the trough, shower
and thunderstorm coverage will likely increase through the week,
especially as we head into the weekend. Highs of well into the 80s
to the mid 90s Wednesday will be replaced by the upper 70s north to
the mid 80s south Thursday through Saturday. Further cooling with
highs in the 70s to near 80 are then penciled in for Sunday and
Monday. Uncomfortably warm lows Tuesday night in the upper 60s to
mid 70s will be replaced by the mid 50s north to the mid 60s south
for much of the remainder of the long term.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 104 PM EDT Mon Jun 17 2024

Will need to watch for some late night mist and low cloud
development at KCIU, as well as a few afternoon showers and
storms at both KCIU and KAPN. Will continue to cover the latter
with vicinity wording only as overall coverage looks to remain
minimal. Otherwise, expecting VFR conditions to continue under
passing high clouds and some relatively higher based cumulus.
Somewhat gusty southwest winds this afternoon will go light
tonight. Winds become gusty out of the south to southwest again
Tuesday.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...Air Quality Alert until midnight EDT tonight for MIZ020-025-
     026-031.
MARINE...None.

&&

$$

SHORT TERM...MSB
LONG TERM...AJS
AVIATION...MSB