804
FXUS63 KAPX 121813
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
213 PM EDT Mon Aug 12 2024

.KEY MESSAGES...

- Warmer temperatures through this week.

&&

.SHORT TERM /THROUGH TUESDAY/...
Issued at 213 PM EDT Mon Aug 12 2024

Pattern Synopsis / Forecast: Surface high pressure currently making
its presence known, with cloud cover largely limited to some high
cirrus and standard northern Michigan diurnal cumulus for the time
being. Daytime heating has warmed temperatures well into the 70s and
near 80, which has generated some diurnal instability in the order
of about 100-200 J/kg MLCAPE. Due to lack of synoptic forcing, will
have to rely on the mesoscale influences of the Lake Huron breeze to
be the lift mechanism this afternoon, where slight chance PoPs
remain in order (NE lower), though most spots likely hold dry there
regardless. Any activity that does manage to fester up tapers off by
the evening hours and conditions turn back to calm and clear for the
overnight hours. Another cool night expected, with lows dropping
well into the 50s inland, perhaps upper 40s in the typical cooler
locales. Will have to contend with some fog development later
tonight across the board as well, particularly in low-lying areas.

Any lingering fog should lift through the morning hours on Tuesday,
with another seasonably warm day expected as highs climb back into
the 80s. With basically minimal northerly flow, will see some lake
breezes develop again, though as moisture is somewhat limited in the
low levels, this may not be enough to generate sufficient
instability to offset 500mb height rises and warm air advection
aloft. Have reduced chance PoPs to slight chance PoPs for areas
south of M-72, but would not be overly surprised to see this
particular element yoinked out in future forecast cycles.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
Issued at 213 PM EDT Mon Aug 12 2024

Pattern synopsis / Forecast: 500mb ridge axis will move directly
overhead, and with associated height rises and more of a southerly
flow regime, will see warm air advection help boost temperatures
back into the low-to-mid 80s Wednesday and Thursday. More changes
are abound as another trough cresting the ridge over the Plains
intrudes, with associated surface low pressure drawing in deeper
moisture into the region, and with it, the next more widespread
chance of showers and thunderstorms Thursday night through much of
Friday. As this trough and surface low close off basically right
over the Great Lakes, expecting another slow-moving system to drag
out unsettled weather as another intrusion of anomalously cool air
aloft associated with a deep shortwave originating from northern
Canada wraps in behind this system late in the weekend / into next
week. Result will be continued shower chances and a steady decline
in temperatures Friday through the weekend.

Primary Forecast Concerns:

Thursday - Friday: Aforementioned Plains trough is looking like it
will be able to draw in some pretty deep moisture to the region as
it slowly plods eastward across Minnesota and Wisconsin. Ample heat
and humidity Thursday suggests there should be enough instability to
play with later in the day as the better forcing moves in, but the
core of the forcing looks to pass through here late Thursday night
into Friday. Nonetheless, guidance is still quite bullish on rain  /
shower chances with this synoptic support within this moist regime
(latest guidance has PWATs progged between 1.6-1.9, or about 175-
200% of the climatological norm). This brings some heavy rain
chances into play given these parameters, but still a lot of
uncertainty to sort out with the timing of this system. Nonetheless,
the Weather Prediction Center is keying in on this system passing
through, with northern Michigan already being thrown into the mix
with a Marginal Risk for excessive rainfall for the Day 4 and Day 5
Excessive Rainfall Outlook(s).

Weekend - Beyond: Latest guidance has through particular shortwave
trough becoming closed off just to our east, bringing about a cooler
airmass to the region. Not the best handle on temperatures at this
juncture with most guidance spitting out highs ranging from near 70
to the mid 70s Friday through the remainder of the forecast period.
Continued influence of this trough will likely keep some scattered
showers around for the time being through the weekend. 850mb temps
in the low teens suggests that the second installment of "Autumn in
August" (temps largely in the 60s) may wait until the core of the
northern Canadian trough intrudes into next week.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 139 PM EDT Mon Aug 12 2024

VFR conditions across the board today as high pressure moves
overhead. Only caveat will be if any isolated shower activity can
intrude on APN... otherwise, winds go calm again tonight, though
patchy fog looks to develop, with potential reductions to at least
MVFR and IFR in spots... particularly PLN, CIU, and MBL late tonight
into Tuesday morning. Expecting that fog to lift through the morning
and a prompt return to VFR conditions across the board by late
Tuesday morning.

&&

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

&&

$$

SHORT TERM...HAD
LONG TERM...HAD
AVIATION...HAD