Dell Rapids, South Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

947
FXUS63 KFSD 181010
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
410 AM CST Sat Jan 18 2025

.KEY MESSAGES...

- An arctic air mass will continue to settle into the northern
  Plains through the beginning of next week. Confidence is high
  (>90%) that we will see well below normal temperatures today
  through Tuesday, with multiple nights of wind chills colder than
  -20F.

- Temperatures moderate through mid to late next week, with no
  significant winter systems on the horizon.

&&

.DISCUSSION...
Issued at 400 AM CST Sat Jan 18 2025

Influx of an arctic air mass will be the focus through the first
half of this forecast period. A broad mid-upper level trough will
dominate the weather pattern east of the Rockies into early next
week, driving sub-zero 850-925MB temperatures well into the Deep
South. Closer to home, we continue to see low level cold advection
over the area today into tonight which will drive temperatures at
these levels into the -18C to -25C range by late Sunday. This will
be followed by a reinforcing push of even colder air late Sunday
night into Monday as a trailing wave dives southeast through the
western periphery of the trough. 850-925MB temperatures plunge
further into the -25C to -33C range by late Monday, which places
this air mass among the coldest 0.5% of the NAEFS/ECMWF ensemble
climatology for mid-late January.

What does all of this mean for those of us living at the surface?
We`ll see daytime highs rebound to mostly teens today. Highs will
then steadily decline through Monday, with some areas struggling to
climb above zero on Monday despite our lack of snow cover. Local
studies for Sioux Falls specifically suggest Sunday-Monday could be
among the coldest late January days with no snow on the ground.

At the same time, nighttime temperatures will easily fall below
zero, with lows tonight and Sunday night generally ranging from -5F
near the Missouri River Valley to -15F over portions of the Buffalo
Ridge in southwest Minnesota (Lincoln County). These readings fall a
bit further Monday night with most areas reaching double digits
below zero. Unfortunately, these cold temperatures will not be
without at least a modest breeze, as the surface high pressure ridge
remains west of our forecast area until sometime Tuesday. This will
keep winds frequently in the 10-20 MPH range with gusts as high as
25-30 MPH through Monday, with speeds easing slightly on the coldest
night Monday night-early Tuesday. This leads to very high confidence
that we`ll see multiple nights with wind chills exceeding criteria
for the Cold Weather Advisory (-25F for areas north of US Hwy 20 and
-20F for the Hwy 20 corridor/Sioux City).

Given expected recovery above this criteria Sunday afternoon, will
stick with the current Cold Weather Advisory running through noon
Sunday for now. Additional headlines are likely for the next couple
of nights as well, but coordinated with neighbors to hold on issuing
headlines for subsequent nights given some uncertainty in whether an
Excessive Cold Warning may be needed for our coldest areas.

Brief shot of warm advection Tuesday will bring some relief from the
coldest portion of the air mass, with a weak wave sliding through
later Tuesday night-Wednesday. This wave may bring some very light
precipitation chances to the area mid-week, but too much variation
among the models in timing/location to pinpoint low pops at this
time.

While broad pattern does favor temperatures moderating back toward
normal or even slightly above at times during the latter half of
next week, it is difficult to say just how warm on any given day
as we are seeing a broader spread in possible solutions at these
longer range periods. Also cannot rule out some periods of light
precipitation with any mid-upper level waves which may slide
through the region, but at this time we are not seeing signals of
any significant precipitation/snow producers through the end of
next week.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1031 PM CST Fri Jan 17 2025

Areas of MVFR stratus and flurries into late tonight, before
conditions improve on Saturday morning. Northwesterly winds will
be slowly tapering downward, though gusts around 25 kts will
continue through the majority of the TAF period.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...Cold Weather Advisory from 9 PM this evening to noon CST
     Sunday for SDZ038>040-050-052>071.
MN...Cold Weather Advisory from 9 PM this evening to noon CST
     Sunday for MNZ071-072-080-081-089-090-097-098.
IA...Cold Weather Advisory from 9 PM this evening to noon CST
     Sunday for IAZ001>003-012>014-020>022-031-032.
NE...Cold Weather Advisory from 9 PM this evening to noon CST
     Sunday for NEZ013-014.

&&

$$

DISCUSSION...JH
AVIATION...JM