982
FXUS63 KAPX 040515
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
115 AM EDT Mon Aug 4 2025

.KEY MESSAGES...

- Fog issues tonight...continued hazy/smoky Monday.

- Precip chances Monday afternoon??

- Still trending dry/warm into midweek.

- Small rain chances for the end of the week...expected to be warm/humid
  as well.

&&

.SHORT TERM /THROUGH TUESDAY/...
Issued at 359 PM EDT Sun Aug 3 2025

Pattern Synopsis/Forecast: Split large scale flow pattern across
North America; northern branch displaced well to the north around a
ridge over the Canadian Prairies and troughing over Quebec and
Atlantic Canada.  Weaker southern branch meandering beneath the
upper ridge with several disturbances rippling through.  Flow over
the Great Lakes is weak (500mb wind a mere 9kts off the 1200Z KAPX
sounding)...the resultant stagnation has allowed a layer of wildfire
smoke to linger across Michigan today.  Not quite as thick as
Saturday but still persistent and reducing surface visibility a bit.
Closed mid level high over Michigan with a sharper trough over the
Plains along with a narrow axis of deep layer moisture that extends
up into Minnesota.  Decently strong low level baroclinic zone north
of Lake Superior...narrow theta-e ridge has some convection along it
across far northern Ontario/northwest Quebec.  Associated surface
cold front just south of James Bay/north of Lake Superior extending
west into Manitoba. South of the front an extensive area of high
pressure extends from the upper Mississippi Valley east through the
Great Lakes and across the mid Atlantic/southern New England.

Water vapor imagery shows a couple of vorticity centers northwest of
Lake Superior this afternoon within northwest flow aloft...as cold
front to the north approaches in a weakened form by Monday morning.
Looks like the boundary will get hung up to the northeast while
another surface high rolls east into Quebec.

Primary Forecast Concerns:

Fog issues tonight...continued hazy/smoky Monday:  Little change in
air mass suggests a lot of the same tonight and Monday...namely some
fog development tonight and continued smoky/hazy conditions Monday.
Air Quality Advisory for all of Michigan has already been extended
into Monday...and smoke concentration aloft should be similar to
this afternoon so another day of a hazy quality to the sky cover is
expected.

Precip chances Monday afternoon??: This is not going in the
forecast...but a few hints of some instability showers Monday
afternoon across central Lower Michigan.  But not certain at all
about the magnitude of the instability given the stagnant quality to
this air mass...so won`t worry about it for now (until they pop
up tomorrow afternoon and I have to begrudgingly add PoPs to
the forecast).

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
Issued at 359 PM EDT Sun Aug 3 2025

Days 2-3 (Tuesday-Wednesday): High pressure over eastern Canada for
the Tuesday/Wednesday time frame...with increasing southerly flow
though even through Wednesday not a big indication that things are
going to become outrageously humid.  But will continue to be warm
and maybe we`ll finally be able to clear out this smoky air mass
(especially by Wednesday)...with high temperatures creeping closer
to 90F.

Days 4-5 (Thursday-Friday): Will introduce rain chances back in the
forecast starting Thursday...though probably more likely the farther
north you go especially Thursday.  But an increasingly humid air
mass and passing nearby disturbances will increase the probabilities
that we will see some precipitation by week`s end.  Still warm and
should be more humid...how warm will depend on potential
precipitation evolution.

Days 6-7 Outlook (Saturday-Sunday): Initial weekend outlook still
looks warm/humid...will have to evaluate precipitation chances in
this air mass (would think there will be some probability for
precipitation but a typical weakly forced summertime air mass makes
the details uncertain).

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 113 AM EDT Mon Aug 4 2025

Still expecting visibilities to lower early this morning,
especially at KMBL where some IFR producing fog will likely
develop. Any fog/mist will again burn off quickly after sunrise,
leaving behind hazy skies with lingering smoke. Light winds with
local afternoon lake breezes expected.

&&

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

&&

$$

SHORT TERM...JPB
LONG TERM...JPB
AVIATION...MSB