963
FXUS63 KAPX 260704
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
304 AM EDT Sun Jul 26 2026

.KEY MESSAGES...

- Shower/thunderstorm chances through Monday along with the threat
for severe storms.

- Bit cooler/breezy for Tuesday/Elevated swim risk and cold
upwelling possible.

- Dry during the midweek period.

&&

.DISCUSSION...
Issued at 304 AM EDT Sun Jul 26 2026

Pattern Synopsis/Forecast: Basic ridge west/trough east pattern
across North America early this Sunday morning...beneath a high
latitude Rex block in the vicinity of Baffin Island...and south of a
strong +AO/polar vortex. Long wave trough/-PNA off the west coast of
North America...and a strong (598dam/nearly +3 sigma) 500mb high
south of the Aleutians (WPO is off the charts negative phase). North
American ridging is centered over the Four Corners states...while
eastern trough axis crossed Michigan earlier Saturday and is over the
lower Lakes and along the Ontario/Quebec border. Short wave trough
is climbing up the backside of the western ridge into British
Columbia/Alberta... attached to an elongated latent PV anomaly that
comes over the top of the ridge and into the upper Great Lakes. Flow
around the ridge is also dragging a lot of wildfire smoke from the
Pacific Northwest and western Canada into the Midwest/Great Lakes.
Elevated mixed layer spreading east from the Rockies and into the
upper Midwest. Strong low level warm advection also spreading east
across the Midwest and into the Great Lakes with 0000Z 850mb
temperatures of 20C crossing the Mississippi River. At the surface...
Great Lakes sandwiched between a cold front across Northern
Ontario...and a warm front snaking its way southeast from North
Dakota/Minnesota...across the Ohio Valley and eventually off the
coast of the Carolinas. Surface dew points well into the 70s on the
warm side of that frontal boundary.

Great Lakes will remain in between the upper high over the southwest
and southern Plains...and an upper low over Hudson Bay with
prevailing northwest flow.  Short wave trough will ripple southeast
across Michigan later Monday/Monday night...reinforcing the mean
trough downstream (and possibly splitting it into two pieces). This
whole process just looks to slow things down... especially if a
closed low develops in the southern branch across the mid Atlantic/
New England. As it is the northern branch becomes blocked (going
from a high latitude Rex block to a high latitude omega block across
the North Atlantic). May see some height rises into the upper Lakes
beyond midweek but that evolution is definitely tied to southern
branch troughing downstream.

Cold front north of Lake Superior doesn`t look like it will make
much progress into Michigan today...with a broad/disorganized area
of low pressure across the Midwest/upper Lakes by Monday morning.
Short wave trough for later Monday will drag a surface reflection
across Michigan Monday night...and some cooler/gusty north winds
Tuesday in its wake.  High pressure will try to muscle into the
region Wednesday...how successful that will be will depend on how
stubborn the southern branch upper wave is.  End of the work week
could see another short wave trough digging across the Great Lakes.

Primary Forecast Concerns:

Shower/thunderstorm chances through Monday along with the threat for
severe storms: Have been watching some wannabe showers trying to
pop across eastern Lake Superior/eastern Upper most of the night as a
passing short wave trough works on a low level theta-e ridge and
associated moisture convergence. Haven`t seen much south of M-68 and
water vapor imagery suggesting subsidence is already spreading into
northwest Lower. So will keep some PoPs across parts of eastern Upper
and northeast Lower to start the day along/ahead of the passing
short wave trough. Will hold off on northwest Lower for now given
water vapor presentation unless trends suggest otherwise. Morning
clouds should scatter out with time...allowing temperatures (through
a smoky haze aloft) to warm into the 80s. Some surface based
instability expected to develop though there will likely be some
inhibition as well depending on how much dew points may mix out
(think most areas will stay at or above 60...maybe some upper 50s
across interior northern Lower). Best chance for development this
afternoon is probably along the Lake Superior lake breeze in Chippewa
County... and along the northeast Lower shoreline as well.

The main show for convective potential will arrive tonight...all
depending on how thunderstorms develop across northern Minnesota/
Wisconsin along the edge of the EML (saturation thickness
considerations suggest an initiation corridor from the Boundary
Waters and Minnesota Arrowhead southeast into northern Wisconsin/far
western Upper.  Storms that develop should propagate southeast...
thus the greatest threat for severe storms should be across northwest
Lower around and after midnight...with upstream convection likely
transitioning from supercells to a squall line/wind damage threat by
the time it reaches Lake Michigan. Will just have to see how much
inertia this activity will have by then...and/or starts to take a
harder dive toward southwest Lower.

As for Monday`s forecast...hard to get a good feel for that at this
point.  Much will depend on the evolution of tonight`s activity...
and potential for new showers/thunderstorms developing for most of
Monday ahead of surface wave expected to move into Lower Michigan
later in the day (which is my suspicion).  For now will simply run
with widespread PoPs for Monday...may be a bit more cautious with
high temperatures as cloud cover could be a spoiler. Still solidly in
the SPC slight risk for Monday.

Bit cooler and breezy for Tuesday/Elevated swim risk and cold upwelling
possible: Tighter gradient and some cold advection will make for a
breezy day Tuesday with gusts 20-25+mph expected from the north.
Elevated swim risk for northern Lower beaches in play for Tuesday...
and currents driven by northerly flow Ekman spiral may result in
cold water upwelling along the northwest Lower shoreline (hope you
enjoyed swim season while it lasted). Temperatures should be back in
the 70s for the most part.

Dry during the midweek period: High pressure nudging in from the
north expected to keep things dry Wednesday and Thursday...with rain
chances returning to the forecast Friday.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1037 PM EDT Sat Jul 25 2026

ISO to SCT showers and a few storms are possible tonight into early
Sunday morning along a weak boundary. Activity will slowly move east
to southeast with time, with precipitation chances between 6Z and
12Z. Pretty low confidence in direct terminal impacts, so most sites
have VCSH for the time being. Otherwise, low clouds will fill in for
a few hours behind this feature, with MVFR to IFR CIGs, best chance
at KCIU and KPLN. That being said, confidence increasing in a couple
hour window of MVFR or lower CIGs at KTVC and KMBL as well. VSBY
reductions also anticipated, especially KCIU and KMBL, with BR,
perhaps FG for a period. Quick return to VFR by mid to late morning,
with generally light west winds through the day.

&&

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

&&

$$

DISCUSSION...JPB
AVIATION...JLD