Cottage Grove, Minnesota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

984
FXUS63 KMPX 302352
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
652 PM CDT Fri May 30 2025

.KEY MESSAGES...

- Degraded air quality due to Canadian wildfire smoke across
  MN/WI through Monday.

- Warming trend through Monday, topping out with highs in the
  lower 90s on Monday.

- Cooler and more active weather starting Monday night,
  continuing through the middle of next week.

&&

.DISCUSSION...
Issued at 232 PM CDT Fri May 30 2025

Surface analysis this afternoon depicts sprawling 1020+mb high
pressure over much of the central CONUS, from the Dakotas
through Texas and the Rockies to the Mississippi River. One weak
cold front emanating from a low pressure center over northern
Saskatchewan drops SW over MT into ID with a second cold front
lingering off the Pacific NW coast. Aloft, a generalized ridge
sits over the western CONUS, centralized over northern CA with a
shortwave trough over Saskatchewan-MT-WY atop the broader
ridge, and a digging trough axis over the eastern Pacific.

Aside from a swath of mid-level east-west oriented clouds
dropping southward over western WI on the backside of a
departing longwave trough, the Upper Midwest remains fairly
devoid of cloud cover. That is not to say the sky is clear
because upper level Canadian wildfire smoke has been making
strong inroads into the region given the upper level pattern.
The smoke will only continue to increase in coverage and
intensity across the region, to the point that both the MPCA and
WIDNR have issued Air Quality Alerts across all of MN/WI with
air quality dropping to the Orange AQI level, which is Unhealthy
for Sensitive Groups. The smoke particulates are expected to
remain in place through the weekend as several waves of smoke
move across the region, keeping the degraded air quality in
place and thus the Air Quality Alerts going into Monday.

Otherwise, the weather will remain rather quiet through the
weekend and into Monday as the ridging out west make very little
eastward movement and high pressure at the surface generally
prevails. There will be a bit more of a southerly surge of
warmer air into the Upper Midwest, which will result in a
gradual warming trend into Monday. The kink in this plan is a
north-south-oriented backdoor cold front over northern MN into
northern WI that will slide westward over eastern MN tonight
through Saturday. This combined with the smoke could produce a
wide range of high temperatures across the WFO MPX coverage area
from west to east. In western MN, highs tomorrow will reach the
mid 80s while eastern MN into western WI will halt in the mid
70s to around 80.

This backdoor front will wash out and slide eastward on Sunday,
allowing the broader warmer air to infiltrate the entire
coverage area for Sunday-Monday, with highs ranging 80-90
degrees on Sunday followed by highs 88-94, highest in western
MN, on Monday. That said, with dewpoints only in the mid-upper
50s on Monday, heat index values will only feel as high as the
actual temperature, thus heat headlines are not a concern.

By the time we get to Monday, this is when the aforementioned
front and trough aloft over the Pacific become a concern for our
portion of the country. The cold front will traverse the
northern Rockies and the Dakotas over the weekend into Monday,
putting the Upper Midwest squarely into the warm sector,
resulting in the 90- degree temperatures. However, the cold
front will be the leading edge of a much cooler airmass. In
conjunction with the front will be the associated positively-
tilted longwave trough aloft. PoPs steadily increase Monday
evening through Monday night, resulting in widespread showers
and thunderstorms for our coverage area Monday night. There is a
signal for strong/severe thunderstorms with this front,
particularly as model soundings indicate steep lapse rates over
the Dakotas which may translate eastward into western MN, which
could be conducive to storms with large hail or damaging winds,
but it becomes a timing/alignment issue between the dynamics and
airmass instability. SPC maintains a 15% severe thunderstorm
probability over far western MN for Monday. The rainfall will
then continue Tuesday through Tuesday night, eventually waning
on Wednesday. This system is capable of some moderate-heavy
rainfall at times with PWATs over 1.5 (and nearly 2.0) inches
during its duration. This cold front will shift well east of our
coverage area Wednesday, with more tranquil but noticeably
cooler temperatures for the latter half of the week, including
highs only in the 70s and lows in the 50s going deeper into the
first week of June.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 634 PM CDT Fri May 30 2025

A broad area of smoke continues to blanket much of the Upper
Mississippi Valley, with the majority of the smoke remaining
aloft until the backdoor cold front sags south overnight. Winds
will turn more northeasterly behind this front, but will
generally be at or below 10 kts. This front will be weakening
the further south it moves, so confidence remains low in what
the extent of smoke will be able to mix down to the surface and
impact visibility. There is a scenario where visibility jumps
up and down throughout the day, rather than a steady period of
vis impacts.

KMSP...The most likely timing for the front to move through is
around 13-15z at KMSP. This period is also when any smoke aloft
would be favored to mix down. There is low confidence in the
persistence of visibility impacts during the day, but any smoke
near the surface should begin to clear westward by the late
evening.

/OUTLOOK FOR KMSP/
SUN...VFR. Wind WSW 5-10kts.
MON...VFR. Wind SW 5-10G20kts.
TUE...MVFR, chc IFR w/-TSRA. Wind S 10-15G25kts.

&&

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

&&

$$

DISCUSSION...JPC
AVIATION...BED