Le Mars, Iowa 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

299
FXUS63 KFSD 221046
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
446 AM CST Mon Dec 22 2025

.KEY MESSAGES...

- Confidence remains high in an extended period of warmer
  weather through this holiday travel week. Temperatures may
  approach or surpass record values mid to late week, including
  Christmas Day.

- Dry weather will prevail through Christmas Day. May have to
  watch for wintry precipitation chances during post-holiday
  travel, however confidence in timing/location details is low.

- Elevated fire danger will be possible on breezier days in
  snow-free areas, mainly across south central South Dakota
  through the Missouri River Valley.

&&

.DISCUSSION...
Issued at 255 AM CST Mon Dec 22 2025

Band of warm advection light rain has moved east of our
forecast area, and fortunately, temperatures while the rain
was occurring remained in the mid to upper 30s. Amounts on our
AWOS/ASOS stations were limited to a trace, but a few personal
weather stations north of Flandreau-Windom did record 0.01-0.02
inches.

Lingering clouds will decrease through the morning, allowing
more abundant sunshine to aid in warming as the surface-925MB
warm front lifts north across the forecast area, only reaching
the Highway 14 corridor by late afternoon. Although winds are
expected to be on the lighter side, low level temperatures
support highs today ranging from mid 40s along Highway 14 and
into the Iowa Great Lakes, to the upper 50s to mid 60s through
the Missouri River Valley. This is a few degrees above the NBM,
but with the lighter winds/less favorable mixing, held adjusted
highs shy of the NBM 90th percentile. Existing record highs in
the upper 50s to mid 60s at our climate sites (FSD/SUX/HON/MHE)
are likely out of reach, though Sioux City could come within a
few degrees. The lighter winds expected today should also limit
fire danger concerns, though caution is still advised in areas
which have been snow-free for several days.

A subtle wave and associated cool front will drop our highs back
into the 30s & 40s for Tuesday, but this cooldown will be brief
as an unseasonably strong upper ridge builds back across the
northern Plains Wednesday into Thursday. NAEFS/ECMWF ESAT tables
indicate the ensemble means have been trending stronger with
this ridge and warmer with the thermal profiles, most notably on
Christmas Day with several time periods showing 200MB heights
and 850-500MB temperatures near or above the Max of 1979-2009
climatology. With this in mind, it is no surprise that forecast
highs are near to above records in some locations for Wednesday
and Thursday, especially considering we will only continue to
eat away at any remaining snow cover in the coming days.

Lower confidence in temperatures and precipitation chances as
we head into the post-holiday travel period, as models begin to
show less agreement on timing and strength of a mid-upper level
trough which could dig into the northern Plains by the weekend.
This could bring a sharp cool-down and some light precipitation
to the area, however details are too uncertain to make any
significant changes to the NBM.

Prior to the stronger trough, a leading wave slides through
Minnesota on Friday. While NBM is maintaining a dry forecast,
we may have to watch for some light precipitation to brush our
north/northeast counties sometime Thursday night/Friday, as the
broad ensemble shows low (20-30%) chances of measurable precip
within this 24 hour period. However, better chances remain off
to our northeast and confidence is too low to add pops into our
forecast area at this time.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 445 AM CST Mon Dec 22 2025

VFR conditions are expected through most of the TAF period, and
are likely to prevail at our TAF sites through 23/12Z. However,
HREF shows moderate probability that MVFR or lower stratus could
expand south into the Highway 14 corridor east of KHON behind a
cold front late in the period.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
IA...None.
NE...None.

&&

$$

DISCUSSION...JH
AVIATION...JH