775
FXUS63 KMPX 021907 CCA
AFDMPX

Area Forecast Discussion...CORRECTED
National Weather Service Twin Cities/Chanhassen MN
207 PM CDT Sat Aug 2 2025

.KEY MESSAGES...

- Degraded air quality due to wildfire smoke will persist through
  the rest of the weekend.

- Scattered rain chances spread across western Minnesota tonight
  and continue into early next week.

- Return of Summer heat, humidity, and thunderstorm chances from
  midweek onward.

&&

.DISCUSSION...
Issued at 200 PM CDT Sat Aug 2 2025

Quiet weather continues across the Upper Midwest early this
afternoon, as surface high pressure centered over southern WI
remains the dominating feature. While this has promoted a cooler
and dry weather pattern as of late, large scale subsidence
associated with the surface high has allowed for the persistence
of wildfire smoke particulates near the surface. As such, the
latest AQI sensor readings remain in the orange to red categories
across south central MN and western WI, though some improvement
has been observed today per MPCA. Air Quality Alerts remain in
effect for both MN/WI this weekend given low confidence in
notable smoke dispersion until early in the upcoming week.

Remove the air quality from the equation and it`s a nice
afternoon, with highs on track to finish in the upper 70s.
Locations across eastern MN/western WI will continue to see more
sunshine, where as locations across western MN have more cloud
cover tied to decaying showers across eastern SD. This cloud
cover is the first sign of the return of precipitation chances
starting tonight across western MN. As an aside, skies are
forecast to remain mostly clear across eastern MN/western WI, so
do anticipate the development of patchy ground fog across this
portion of the forecast area around daybreak Sunday.

Visible satellite loops shows cloud debris associated with an MCV
spinning near the ND/SD border. The MCV is tied to an upper-low/low-
amplitude trough which is forecast to slowly transition east of the
Dakotas into northern MN over the next 36-48 hours. The upper-low is
in a region of rather nebulous forcing, given split-flow aloft. As
such, there isn`t much to "drive" the feature eastward. Warm
advective precipitation chances will largely be tied to the low-
level jet, which is forecast to span from northern TX into eastern
SD tonight. Latest grids feature 30-50% PoPs along and west of a
line from Morrison to Brown counties to reflect the chance of
showers overnight through tomorrow morning. With little eastward
motion expected, should see renewed precipitation develop on
the nose of the jet across central/western MN late tomorrow
evening into Monday morning, which is reflected by ~40-60% PoPs.
We`ll keep scattered chances for showers and thunderstorms
around to open the work week, as warm/moisture advection
continues to flow into the region. Latest forecast from WPC
reflects the potential for a half inch to inch of rainfall
across far western MN through Tuesday evening. On the flip side,
it will be a struggle for much of eastern MN/western WI to
register more than a tenth of an inch of rainfall. Finally,
there is at least some threat for a few stronger storms across
far western MN on Monday/early Tuesday, fueled by stronger
instability and ongoing moisture advection. A Marginal Risk
(1/5) is in place across far western MN.

By midweek, the upper-air pattern is forecast to take on a bit of a
different shape. Expansive SW CONUS ridging, characterized by 500mb
heights of nearly 600dm, is forecast to be centered over New Mexico.
The Pacific Jet will become the primary driver of our weather for
the second half of the week, as several transient waves are progged
to "ride the ridge" over Montana/Dakotas and then turn to the
east/southeast over the north central CONUS. Low confidence in the
strength and progression of each disturbance makes timing of
precipitation chances a challenge at this distance. However, the
almost daily PoPs between 30-40% are reasonable given the
conceptual model that this synoptic pattern tends to support. It`s
also possible that some convection may be strong to severe, though
predictability is low at this time. Amplification of the SW CONUS
ridge is forecast to push 500 mb heights into the 590s dm across
the region. This essentially signals the return of hot temperatures,
which is reflected by NBM`s highs Wed-Fri in the mid 80s, then
warming into the upper 80s/near 90 degrees next weekend. In other
words, the extended forecast features a return to hot, humid, and
unsettled Summer weather.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1150 AM CDT Sat Aug 2 2025

Smoke will continue to improve as the period wears on, such that
visibility reductions from that phenomena are not expected.
However, some fog is possible at EAU near sunrise Sunday as
mostly clear, calm conditions should allow for strong
radiational cooling. Have visibilities dropping to MVFR. Clouds
will build in from the west late tonight with western MN seeing
cigs drop to near 5000 feet Sunday morning. Scattered showers
are also possible at AXN and RWF after sunrise Sunday so have
added PROB30s for -SHRA. Southerly winds today will slow to near
or under 5 knots tonight and turn southeasterly. Winds become
southerly again during Sunday.

KMSP...No additional concerns.

/OUTLOOK FOR KMSP/
MON...VFR. Slight chc MVFR/-TSRA. Wind SE 5-10 kts.
TUE...VFR. Wind SE 10 kts.
WED...VFR. Slight chc MVFR/-TSRA. Wind S 5-10 kts.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.

&&

$$

DISCUSSION...Strus
AVIATION...CTG