537
FXUS63 KMPX 082317
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
617 PM CDT Tue Sep 8 2026

.KEY MESSAGES...

- Slight chance for showers or storms across southeastern MN &
  western WI this evening. Most locations will remain dry.

- Quiet weather the next couple of days. Active weather returns
  Friday with a chance of strong to severe thunderstorms.

- Extended forecast features additional rain chances heading into
  early next week.

&&

.DISCUSSION...
Issued at 100 PM CDT Tue Sep 8 2026

Morning batch of much welcomed rain and thunderstorms has exited the
region this afternoon. CoCoRahs network displays a swath of 1-3"
reports across east central MN into western WI (north of I-94) which
is good news for the ongoing severe drought situation. For the rest
of the afternoon, expect mostly dry and breezy conditions with
temperatures warming into the upper 70s to lower 80s. Additional
precipitation chances arrive this evening as a surface cold front
slides eastward across the forecast area. Observations place the
front near the SD/MN border at this hour, which is also depicted in
a sharp cut-off in cloud cover on visible satellite. A pool of low
70s dew points is advecting northward across western MN and will
yield moderate instability and combine with sufficient shear to
support isolated thunderstorm development. However, with the
strongest kinematic forcing displaced to the north across
southern Canada, CAMs are not particularly impressed with
coverage of additional convection. Followed HREF trends and
added in slight chance to chance (20-40%) PoPs across
southeastern MN & western WI this evening. In other words, those
with outdoor plan should keep an eye to the sky for a passing
shower or storm ahead of the frontal passage, but we anticipate
most locations will remain dry. Winds turn WNW behind the front
and will support the advection of 50s dew points into the
region.

The next couple of days will be dry, sunny, and comfortable with
highs in the upper 70s to near 80 each afternoon. The one variable
of note will be breezy WNW winds that are forecast to gust
between 25-30 mph tomorrow afternoon. Otherwise we anticipate a
quiet few days of weather with patchy fog possible in the
morning hours (especially eastern MN/western WI).

Our next round of active weather arrives Friday afternoon and
evening. An active Pacific jet will send a shortwave and associated
50-60kt belt of upper-flow across the northern Plains Friday. At the
surface, an area of 990s mb low pressure is progged to develop
across the Dakotas and work in tandem with a cold frontal passage to
support the development of potential severe thunderstorms. While the
usual model uncertainties remain, the potential environment does
highlight potential organized severe convection. Frontal approach
and the intensification of a seasonably strong 45-50kt LLJ will
assist in the erosion of a capping inversion, allowing for
surface based convection in an environment highlighted by 1500+
J/kg of CAPE across a warm sector characterized by low-level
curvature in the hodographs. Would like to see stronger vertical
shear, which seems to be lagging to the west given the placement
of the upper-wave, though 30-40kts of effective shear in tandem
with the low-level directional shear bears watching. Additionally,
the displacement of large scale forcing does add some question
into the overall extent of the threat, but the intensification
of the LLJ would likely counter this. Should trends continue, an
all-hazards type of risk may develop across the region, which
is highlighted by severe weather probabilities by all of NCAR`s
AI-Convective outlooks. SPC has issued a Day 4 15% (Slight Risk)
across much of the MPX forecast area.

Quiet weather returns briefly on Saturday, prior to the arrival of
additional rain chances Sunday into the start of next.
Deterministic, ensemble, and machine learning guidance are in decent
agreement with a stronger bowling-bowl upper low coming ashore in
the Pacific NW this weekend and moving across the central CONUS
towards the start of next week. Consensus track places a region of
broad ascent and isentropic upglide over the eastern Plains into the
Upper Midwest, which in turn brings widespread (perhaps moderate to
heavy) rain chances into the forecast. It`s going to be some time
before we can dial into the exact placement of the heaviest rainfall
axis, however the pieces are coming together for another chance of
much needed rain early next week. The NBM features these chances
with 70-80 PoPs already loaded into Sunday PM/Monday AM grids! Early
week rainfall followed by the influence of a cooler Canadian airmass
has resulted in cooler temperatures (60s for afternoon highs) next
week.

&&

.AVIATION /00Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 604 PM CDT Tue Sep 8 2026

Scattered to broken low-end VFR clouds currently stretch from
southern MN into eastern MN and WI ahead of a cold front. This
cloud cover will advance east with the front through this
evening, eventually leaving mostly clear skies in its wake for
the entire area tonight. One or two showers are possible along
the cold front, but this activity will be very isolated and not
impactful to TAF sites. Radiational cooling and lingering
surface moisture into Wednesday morning will bring chances for
fog at EAU. Currently have conditions dropping to IFR with
visibilities falling to 2sm by 09z. Fog will burn off quickly
after sunrise. VFR is expected area wide the remainder of the
period with some diurnal cumulus near 5000 feet Wednesday
afternoon. South-southwesterly winds ahead of the cold front
shift to west-northwesterly after frontal passage. Speeds fall
to near or under 5 knots overnight before increasing to 10-13
knots Wednesday afternoon with gusts near 20 knots.

KMSP...Removed PROB30 mention of -TSRA this evening as any
precip looks to be too sparse and weak to significantly affect
MSP. Cigs quickly lift by 04z. West-northwesterly winds will
gust to near 23 knots during Wednesday afternoon.

/OUTLOOK FOR KMSP/
THU...VFR. Wind SW 5-10kts.
FRI...Mainly VFR. SHRA/MVFR likely late. Wind S 15G25-30kts.
SAT...VFR. Winds NW 10kts.

&&

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

&&

$$

DISCUSSION...Strus
AVIATION...CTG