733
FXUS63 KAPX 270926
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
526 AM EDT Thu Aug 27 2026

.KEY MESSAGES...

- Areas of fog this morning over eastern upper

- Slight chance for afternoon showers and storms over NE lower today

- Warmer temperatures and times of showers and storms will begin
  Saturday and linger through early next week. The potential
  for repeated rounds of rain could lead to flooding concerns.

&&

.DISCUSSION...
Issued at 130 AM EDT Thu Aug 27 2026

Currently surface observations and satellite depict low clouds, fog,
and intermittent drizzle over the eastern U.P. this morning. In this
post-frontal environment, cooler air over the moist maritime Great
Lakes airmass has been contributing to the patchy fog and low
stratus. This airmass will continue towards northern lower, brining
low clouds, patchy fog, and off and on drizzle to some spots through
sunrise. 24 hour rainfall totals show a handful of an inch or
greater swaths, focused in NE lower and eastern upper. Other places
saw a couple hundredths to a half of an inch.

In the upper levels, an upper shortwave is exiting to the east this
morning, with drier mid-level air gradually moving in behind this. A
larger scale PNA pattern over the CONUS exists today, with upper
ridging reaching into the NW Territory. The broad upper low over the
Hudson Bay remains anchored in place, keeping MI locked in NW flow
aloft. As this drier mid level air continues to march through
northern MI today, the weak moisture boundary will reside over NE
lower during peak diurnal heating. A few afternoon showers with a
storm or two will be possible, as around a couple hundred j/kg of
instability exists. NW lower will face drying air and shallow
instability, keeping better chances closer to the sunrise side.
Minimal shear exists in this marginally unstable atmosphere, keeping
the main hazards brief heavy rain and lightning. Storms are expected
to form right along an area of lower level convergence as the
boundary reaches the lake shore (convergence set up is due to winds
over the waters). This could keep most activity off shore, over Lk
Huron.

Friday, surface high pressure will be overhead. Light winds and
times of sunshine will be seen over northern MI. A couple of
stronger storm systems near the Pac NW will attempt to beat the
upper ridge over the west down. This in turn, will create a southern
extent of the upper jet over the central Rockies, which will produce
lee cyclogenesis near CO. Hot and humid central plains air will push
northward in the warm sector towards WI Friday. Warmer and wetter
conditions will reach northern MI this weekend, with light rain
chances starting as early as Saturday evening for eastern upper and
parts of NW lower. Warmer temperatures, clouds, light rain, and
embedded showers/storms will continue through early next week as the
upper level trough takes it time moving across the northern rockies
(inducing a couple of lee side lows during this time).

Global ensembles show this pattern in the QPF footprints. Most
(ENS/GEFS and their AI counter parts) of them do highlight a
bullseye of mean total QPF at 1" or more over northern MI by
Wednesday of next week. These courser models will have a tough time
with amounts, but can capture where the moisture and forcing will
be. There is more of a spread in timing of when the deeper moisture
reaches northern MI, as some hold off until Sunday. However by
Sunday afternoon, 82% of LREF members have PWATs of at least 1.4"
over KGLR. The high confidence in deeper moisture remains through
early Tuesday morning, then PWAT spread increases Tuesday into
midweek.

Conceptually, the set up has the potential to orient the
jet stream parallel to a few warm frontal boundaries that reach
northern MI. This could result in training of storms producing heavy
rainfall, which would lead to flooding. This is very dependent on
the path of surface cyclones, and the warm front has been known to
stall just to the south producing ideal conditions for convective
initiation, which "eats" the moisture before it has time to reach
northern MI. Guidance is pointing towards the synoptic scale forcing
to be present to lift these features pretty far north, but that
could change as we get closer to the event.

Worse case is repeated rounds of training thunderstorms starting
late Saturday and lasting through Tuesday, producing swaths of 2 to
4 inches or more and resulting in flooding. With this said, this
worse case is not favored (LREF probs of total QPF are only at 25%
for 2 inches or more by Wednesday across parts of norther MI). The
when and exactly where of this rain will determine impacts, and that
can still change as we remain 4 to 5 days out.

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 525 AM EDT Thu Aug 27 2026

MVFR to LIFR conditions will improve this morning with
terminals expected to return to VFR by the afternoon, prevailing
through the remainder of the issuance period. Northwest winds
will be breezy today with gusts 20-25 kts in the afternoon,
becoming light tonight. Some BR/FG development late tonight into
early Friday morning will be possible, dropping otherwise VFR
conditions to IFR or lower at times.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Small Craft Advisory until 10 PM EDT this evening for LSZ321.

&&

$$

DISCUSSION...ELD
AVIATION...NSC