Canton, Minnesota Weather Forecast Discussion

243
FXUS63 KARX 250615
AFDARX
Area Forecast Discussion
National Weather Service La Crosse WI
115 AM CDT Thu Sep 25 2025
.KEY MESSAGES...
- Unseasonably mild conditions through the middle part of next week
(approx 10 degrees above the late Sep normals). Some locations
likely to push north of 80 degrees starting Friday - especially
along/south of I-90 and in the Mississippi River Valley.
- Staying dry into the start of next week, but could linger until
the following weekend.
&&
.DISCUSSION...
Issued at 115 AM CDT Thu Sep 25 2025
Positively tilted upper level trough axis with closed low over the
great lakes early this morning will finally get a kick east today,
showing some weakening as it moves over the new england states by
Fri morning. Broad upper level ridging builds across the upper
mississippi river valley post the trough, working to shuffle any
west-east moving shortwave activity north of the region.
Moving into the weekend and early next week the GEFS and EPS have
continued to move toward a sharper, stronger upper level ridge
building across the region. The WPC clusters also mimic, and have
shown this trend over the past several days. There is an Omega block
look to it.
Some progression to the upper level pattern for the latter half of
next week in the EPS and GEFS - both suggesting the ridge could
shift east with a trough moving in by the weekend. Forecast
confidence low in this stead as strength of the omega-ish blocking
pattern isn`t certain.
Upshot to all of this? The forecast area is going to stay dry into
the middle part of next week with above normal temps (but not crazy
warm).
> RAIN CHANCES: as mentioned above, the ridge/blocking pattern will
act as strong deterrent to shortwave encroachment as we move through
the weekend into next week. Long range guidance starts to suggest
rain chances could work in by the latter half of next week with a
stronger southerly fetch/shortwave interaction. Again, a ton of
uncertainty here. All in all, look for dry conditions into *at
least* the start of the new work week.
> TEMPERATURES: a mild/warm stretch of days on the horizon thanks to
the upper level ridge. Grand Ensemble paints 70-100% chances for 70+
degree highs through the middle part of next week. Same ensemble
suggests 10-50% likelihood to reach 80+ degrees from I-90 southward,
including locations within the Mississippi River valley. Roughly 10
degrees above the late Sep normals. So, not "hot", but certainly
warm for this time of year.
&&
.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1237 AM CDT Thu Sep 25 2025
Fog trends have generally diminished across guidance late this
evening with the 25.00z HREF and NBH having very low probabilities
(0-20% chance) for category reducing visibilities west of the
Mississippi River overnight and into the morning hours. As a result,
have trended KRST away from 1/4SM in this most recent TAF issuance.
Along the Mississippi River and in its tributaries, valley fog
trends continue with nighttime satellite imagery already showing
some valleys with fog formation. This will likely spread into the
Mississippi River valley over the course over the nighttime hours
resulting in areas of 1/4SM vsbys. The main issue with this valley
fog forecast is the depth of the light wind layer off the surface
shown in the recent RAP/HRRR being only to around 2kft with a light
northerly surface wind. This would suggest that a long duration
1/4SM event at KLSE is unlikely per local research but rather would
be intermittent. Consequently, have kept 1/4SM to a tempo group for
a couple of hours for when dense fog at KLSE would be more likely.
Regardless, with clear skies overhead would expect any fog to lift
by around 15z leaving behind VFR conditions.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
DISCUSSION...Rieck
AVIATION.....Naylor

NWS ARX Office Area Forecast Discussion