422
FXUS63 KAPX 091442
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
1042 AM EDT Thu May 9 2024

.KEY MESSAGES...

- Cool temperatures tonight and Saturday night lead to possible
  patchy frost concerns for interior locations.

- Occasional chance for rain showers over the next several days.

&&

.UPDATE...
Issued at 1042 AM EDT Thu May 9 2024

Little changes to the inherited forecast thus far. Some pesky fog in
and around Grand Traverse Bay has lifted in the last couple hours,
leaving much of the area under some lingering low level stratus
across portions of northern lower, with some altocu elsewhere
(clearer skies noted closer to Saginaw Bay and into the eastern
U.P.). Expectation is that enough diurnal heating should be able to
generate fair weather cumulus amid a veil of cirrus clouds for most
as the most widespread synoptic rain coverage holds to the south in
conjunction with the passing mid level wave (with stalled frontal
boundary largely draped over the I-70 corridor from IL to PA). Just
enough low level moisture remains across the SW CWA to perhaps
generate some shallow diurnal showers after 18z. With instability
largely holding below -10C, probably would be akin to winning the
lottery if folks south of Grand Traverse Bay hear thunder this
afternoon. Expectation is for the wave to clear to our east by the
evening hours, while high pressure near Hudson Bay begins to flex
its influences and we gradually scour out clouds later this
afternoon into the evening, likely allowing for radiational cooling
processes to commence if winds can decouple enough. See the attached
short term forecast for more details.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 238 AM EDT Thu May 9 2024

Pattern Synopsis/Forecast: Early this morning, northeast to
southeast oriented upper-level trough axis draped from Newfoundland
southwestward all the way across the northern Great Lakes/central
Plains into the Four Corners region. This sandwiched between weak
subtropical ridging across the southeast states and shortwave
ridging from British Columbia into the Canadian Prairies. That
trough axis gradually sags south over the next 24 hours...centering
overhead this evening and farther south overnight. Surface low
pressure currently near the IL/IN/KY border will shift off to the
east this morning with a weaker surface reflection progged to slide
across the upper MS Valley and the southern Great Lakes in the day
ahead. By tonight, higher surface pressure trickle in locally from
the north.

Forecast Details: Latest trends over the past 24 hours have
continued a steady southward trend to rain chances today with
current confidence favoring the bulk of shower activity remaining
over northern IL and far southern MI. The exception lies across far
northwest lower this afternoon, generally near and south of Grand
Traverse Bay where isolated to scattered shower development appears
pretty likely. A rumble of thunder or two not of the question in
this activity with up to 250 J/kg MLCAPE, but not anticipating
anything severe. Most likely time frame for this to occur generally
between 18-00z. Perhaps a few sprinkles or a rogue shower up near
the Straits during this time frame as well, but chances are so low
that won`t be reflected in the forecast.

Any lingering shower chances diminish after sunset with a lower than
desired low temperature forecast for the night ahead. Uncertainty
largely focused around cloud cover with at least some clearing
anticipated, but also around our ability to decouple. Think we
should be able to muster at least a few hours with calm winds
overnight, which combined with partially clearing skies should allow
temperatures to efficiently cool. Question is whether interior areas
become cold enough for potential frost development, and if so, what
duration are temps sub 35-36 degrees. All in all, won`t deviate too
far from the inherited low temp forecast...maybe even a degree or
two colder in spots. Despite the uncertainty, it`s one of those
nights where it`s worth taking precautions for sensitive vegetation
with the highest likelihood for patchy frost across the typically
colder/interior areas from Pellston down the spin of northern lower
MI, including places like Atlanta, Grayling and Roscommon.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Issued at 238 AM EDT Thu May 9 2024

PATTERN SYNOPSIS/FORECAST:

An upper-level low tracks near or just south of southwest northern
lower Michigan spreading rain shower chances across the CWA Friday
night into Saturday. Moisture advection and more energy tracking
overhead Sunday into mid-next week will result in the chance for
rain showers once again.


PRIMARY FORECAST CONCERNS:

- Cool temperatures Thursday night and Saturday night lead to
possible patchy frost concerns for interior locations: As high
pressure builds overhead and heights rise into Friday morning,
clouds will clear, and radiational cooling could lead to possible
patchy frost across interior portions of the CWA. The main questions
continue to be if the clouds clear enough and if winds will be
relatively calm enough to promote this concern. Temperatures will
continue to be cooler through Saturday night, continuing the
possibility for interior locations to have patchy frost Saturday
night into Sunday morning. For now, continued with values between 35
and 37 degrees, but will continue to monitor this potential closely.
Stay tuned!

- Occasional chance for rain showers over the next several days:
Friday night into Sunday could have some rain showers possible as an
upper-level low tracks near the region. Guidance continues to agree
that this should remain a minor event with little to no meaningful
impacts. Showers could linger into Saturday afternoon, but another
high pressure builds overhead, promoting clearing and also a warming
trend in temperatures heading into Sunday. Winds will shift more
southerly heading into next week, bringing in a flux of moisture to
the region and more chances for rain showers, and possibly a rumble
of thunder or two, as we look into mid-next week.

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 631 AM EDT Thu May 9 2024

Any patchy/locally dense fog should burn off pretty quickly
this morning with flight conditions expected to be VFR through
the TAF period. Perhaps a shower or isolated thunderstorm at
MBL/TVC this afternoon with otherwise dry conditions. Northeast
winds today, occasionally breezy at times, becoming light
tonight -- potentially calm for a period after midnight.

&&

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

&&

$$

UPDATE...HAD
SHORT TERM...MJG
LONG TERM...NSC
AVIATION...MJG