016
FXUS63 KAPX 111739
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
139 PM EDT Sun Aug 11 2024

.KEY MESSAGES...

- Cool with scattered showers today into early evening.

- High pressure and quiet weather builds this week. Temperatures
  return to average for mid August.

&&

.UPDATE...
Issued at 930 AM EDT Sun Aug 11 2024

Just some minor PoP tweaks to account for recent trends this
morning, but overall, no changes to be made to the forecast.
Aforementioned unseasonably strong upper low continues to
slowly be forced eastward by ridging to our west. Save for some
heavier shower activity across Grand Traverse Bay, mainly light
showers have been the rule this morning, particularly in the
eastern Yoop and far northeast lower. As of now, coverage has
been lackluster at best, but with temps crawling back up into
the 60s and 70s, expectation is that enough diurnal instability
materializes and a few showers initiate, particularly across
northeast lower. Thunder seems rather unlikely at this juncture,
but overall can`t rule out a rogue rumble. Oblong area of
surface high pressure stretching from Saskatoon to Louisville
will slowly move eastward through the day, inducing subsidence
and beginning the process of scouring moisture out of the region
from west to east later this evening into tonight.

&&

.SHORT TERM /THROUGH MONDAY/...
Issued at 231 AM EDT Sun Aug 11 2024

Unseasonably strong closed upper low/deep trough axis currently
extends from Quebec thru SE Ontario into the Western Great Lakes
early this morning. Enhanced area of shower activity is impacting
much of our CWA attm as this sharp trough axis rotates thru Northern
Michigan. No thunder to speak of within this area of showers due to
lack of instability. Temps are holding mainly in the 50s.

Sharp trough axis will continue to swing thru our CWA today...and
will gradually slide east of Michigan tonight. Deep cyclonic flow
combined with ample low level moisture and colder air aloft will
continue to produce scattered showers today into early evening.
Shower chances should finally come to an end by 00Z tonight...with
clouds gradually diminishing from west to east during the balance of
the night as subsidence and drier air begin to build into our
region.

Expect another unseasonably cool day across our Northwoods...with
afternoon highs only warming into the upper 60s to lower 70s. Low
temps tonight will cool into the low to mid 50s.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Issued at 231 AM EDT Sun Aug 11 2024

PATTERN SYNOPSIS/FORECAST:

Anomalous upper low still hanging over the Upper Great
Lakes...centered over Ontario, with a handful of lobes of vorticity
swirling around this. Easterly flow through Hudson Bay running into
a deformation axis stretching from Alberta to MN/WI...resulting in
flow splitting northward into the anomalous ridge over northern
Canada...and southeastward into the troughing over us. Coldest air
aloft (850mb temps around 6C) focused just to our northeast under
the core of the upper low. 100+kt upper jet stretches zonally across
the CONUS. Otherwise...bulk of the moisture trapped along/just off
the East Coast ahead of the leading edge of the trough...and also
beneath the upper ridge centered over TX...though some is being
funneled into SoCal with a bit of a Rex Block look out there.

Expecting the upper low to hang out for one more day...before slowly
exiting stage right Monday. Appears some kind of warm advection
activity should develop upstream along the approaching ridge, though
uncertain as to how far north this will get and how fast it will
move through Monday afternoon into Monday night/early Tuesday. The
further north track would bring a greater chance at additional rain
(especially for our southwest counties), while a further south track
could set us up under a nebulous col region that could lead to
patchy fog Monday night. Even behind this for Tuesday/Tuesday
night...appears flow could trend nebulous, leaving general high
pressure and the potential for patchy fog around into
midweek...along with some shot at lake breeze development...though
temperatures should slowly moderate toward more normal for mid
August. Ridge axis finally arrives Wednesday for a pleasant late
summer day. Uncertainty increases in the forecast beyond
midweek...as to how the pattern progresses behind the upper ridge
axis...though things seem to be coming into better agreement on the
idea of an unsettled end to the week.

Primary Forecast Concerns:

Overnight patchy fog potential...Expecting a nebulous flow regime to
slip in for the early part of the week...along with general surface
high pressure. Think patchy fog will be possible given the recent
showery activity boosting low-level moisture...but do have some
concerns that high clouds could diminish some of the radiational
cooling potential that might otherwise improve overnight fog
potential in this sort of a regime.

Afternoon pop-up showers Monday and Tuesday...While there is some
uncertainty in the track of that warm advection precip Monday/Monday
night...do think that we may still be at risk of diurnal heating
driven convection (i.e.,  afternoon pop-ups) both Monday and again
Tuesday, particularly combined with potential for lake breezes given
the otherwise light flow. Monday`s activity could be related to
lingering cold air aloft still hanging over the area, as guidance
soundings suggest a more fall-like, low-topped shower environment.
Do think Tuesday will be the better shot, though, as return flow
should be a bit better...giving us potential for a bit deeper
instability and a better chance of thunder compared to Monday. Not
expecting anything dramatic, by any means, and chances are small
attm...but will be something to keep an eye on, particularly for the
interior.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 139 PM EDT Sun Aug 11 2024

Upper trough over Georgian Bay will continue to slowly slide east as
high pressure encroaches later tonight. Potential for scattered
showers through the evening (particularly CIU, APN, and PLN) before
activity diminishes. Modest west to northwest flow holds from 10-
15kts, perhaps some gusts approaching 20kts at times before
diminishing this evening, even becoming calm overnight. Mainly VFR
conditions expected, perhaps dropping to MVFR in the vicinity of any
shower activity this afternoon. More of a westerly flow of about
10kts expected tomorrow, with VFR conditions holding strong as
high pressure moves overhead.

&&

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

&&

$$

UPDATE...HAD
SHORT TERM...MLR
LONG TERM...FEF
AVIATION...HAD