Harrisburg, South Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

855
FXUS63 KFSD 210917
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
317 AM CST Thu Nov 21 2024

.KEY MESSAGES...

- An extended period of quiet weather through the weekend is
  likely. Temperatures gradually warm back into the 30s to 40s
  during this time.

- Progressive flow pattern develops for the week of
  Thanksgiving, potentially suggesting more active weather next
  week.

&&

.DISCUSSION...
Issued at 316 AM CST Thu Nov 21 2024

Quiet, yet breezy, conditions continue across the region, with
latest observations showing northwesterly gusts between 25 to 35 MPH
and temperatures in the 20s. Wind chills have also begun to plummet,
resulting in values in the teens to single digits.

As alluded to in the previous discussion, expect upper level ridging
to build across the Plains today, allowing the SPG to gradually
weaken. Nonetheless, will still see gusts between 20 to 30 MPH
persist for much of the day under a lingering stratus deck,
especially in areas east of I-29. Thus, only have highs rising into
the low to mid 30s, the coldest occurring north of I-90 in areas of
higher elevation.

Should see more clearing overnight, with winds progged to become
light and variable. While some patchy fog may certainly be possible
given the recent moisture in place, think the bigger impact will be
overnight lows falling into teens with the aid of efficient
radiational cooling. That being said, should see temperatures
rebound into the mid 30s to 40 by Friday afternoon under partly
cloudy skies.

Upper level ridging amplifies across the central CONUS this weekend,
keeping conditions dry and cool across our area. Still seeing decent
agreement in guidance that a moisture starved cold front will dive
across the Dakotas Saturday night into Sunday, causing southeasterly
winds to turn northwesterly in the wake of FROPA. Do have gusts
increasing to 20 to 35 MPH along and west of I-29 during this time,
the strongest occurring west of the James River Valley.

Temperatures flip back below normal early next week as upper
troughing deepens and moves into the Great Lakes.  Stronger
northwesterly winds and cold advection aloft results in highs in the
20s to lower 30s for much of the new week. Taking a peek ahead in
the forecast suggests that we may trend towards a more progressive
zonal flow pattern into Thanksgiving. This type of pattern can bring
greater potential for more frequent, fast moving waves with rather
poor predictability, through the Plains.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1030 PM CST Wed Nov 20 2024

Light snow and flurries continue to taper off for areas east of
I-29 through the early overnight hours; little to no additional
accumulation expected. Soundings and hi-res guidance continue
to be more pessimistic with MVFR stratus lingering into the mid
morning hours, and have continued to trend slower with
improvements to VFR conditions. Strong winds could lead to
localized reduced visibility, especially in falling snow, but
expect visibility to remain MVFR or higher.

Northwesterly winds remain strong through late Thursday
afternoon, with a slow taper in both sustained winds and gusts.
Could see 30-35 knot (isolated higher) gusts through 21.09z,
decreasing to around 20-25 knots during the daylight hours.
Winds less than 10 knots expected after sunset Thursday.

&&

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

&&

$$

DISCUSSION...SST
AVIATION...SG