Sioux City, Iowa 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

560
FXUS63 KFSD 230929
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
329 AM CST Sat Nov 23 2024

.KEY MESSAGES...

- Mild temperatures and dry conditions will dominate this
  weekend, though could see spotty sprinkles/flurries late
  Sunday/Sunday evening.

- Below to well below normal temperatures move in Monday and
  persist through the Thanksgiving holiday week. Aside from a
  brief reprieve in southern areas Tuesday-Wednesday, confidence
  is high (>80%) that temperatures will remain below freezing,
  with moderate (40-60%) chances that highs will not reach 20F
  by the end of the week.

- Light precipitation chances remain low, with chances for light
  snow/flurries peaking at 10-20% Wednesday night. Those with
  more distant travel plans will want to monitor forecast
  trends, though, with higher precipitation chances south of
  I-80 and in northern Minnesota during the holiday travel
  period.

&&

.DISCUSSION...
Issued at 328 AM CST Sat Nov 23 2024

TODAY-SUNDAY: Broad warm advection will result in a fair amount of
mid-upper level cloud cover this weekend. Despite this and a less
than favorable southeast flow, should again see decent warming today
with highs ranging from the upper 30s along the Highway 14 corridor,
to near 50F around Sioux City. The southerly flow (which should draw
lower 30s dew points into parts of the region today) and anticipated
cloud cover should result in a mild night with lows near to slightly
above freezing over much of the forecast area.

Our first cold front will push east across the area on Sunday, with
the strongest cold advection reaching areas west of I-29 during the
afternoon. This should allow Sunday to be another mild day with
highs from the mid-upper 30s west/north of Sioux Falls, to upper 40s
south of Highway 18 in northwest Iowa. Moisture with the passage of
the front and associated mid-upper level trough is limited, but some
forecast soundings do show a brief period of deeper saturation from
south central SD into the Highway 14 corridor Sunday afternoon and
evening. While confidence is low (20-30%) that we`ll see moisture
deep enough to support precipitation reaching the surface, did add a
mention of sprinkles/flurries to this area west through north of
Sioux Falls for the latter half of Sunday.

MONDAY-WEDNESDAY: A secondary push of colder air moves into the
Dakotas and Minnesota Sunday night-Monday. Although clouds should at
least partially clear, 850/925mb temperatures falling through the
single digits below zero will yield sub-freezing highs for much of
the forecast area.

A modest mid-level wave sliding east along the South Dakota/Nebraska
border will bring a surge of warm advection to the region Tuesday,
which will briefly warm daytime highs above freezing, at least south
of I-90, Tuesday-Wednesday. The warm-up will be short-lived, though,
as a more active pattern with several weak waves and associated
shots of cold air dominate the latter part of the holiday week.

The more southern wave which will slide along a low-mid level front
will focus higher precipitation chances south of I-80 and perhaps
primarily in Kansas/Missouri Wednesday-Wednesday night. Meanwhile a
more northern stream wave dropping southeast out of Canada into
North Dakota/Minnesota could bring some light snow to these areas.
While some very light precip (sprinkles/flurries) cannot be ruled
out in our forecast area, the greater forcing seems to split around
us, leaving us with mainly dry conditions for Wednesday-Wednesday
night.

THANKSGIVING DAY-FRIDAY: Additional waves continue to rotate
southeast around a stagnant upper low in eastern Canada during the
latter part of this holiday week. At this time, chances for light
precipitation remain low (<20%) in our forecast area during this
period. However, with model variations in the track of each wave,
travelers will want to monitor trends for the end of the week. The
primary impact for our area during this time will be reinforcing
surges of colder air. NAEFS and ECMWF Ensembles are showing 850mb
temperatures nearing the 10% percentile of climatology across parts
of the northern Plains by late Friday. This will keep temperatures
below freezing on Thanksgiving Day, and perhaps below 20F in some
areas on Friday. Sandwiched between these will be temperatures in
the single digits early Friday, with modest northwest winds pushing
wind chills below zero. Holiday shoppers should plan to dress
accordingly if they plan to spend an extended period of time
outdoors.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1030 PM CST Fri Nov 22 2024

Winds will be light and variable overnight, and there will be a
low probability for patchy fog across the area into Saturday
morning - though latest hi-res ensembles have decreased
probabilities for fog development. Winds will increase a bit out
of the east/southeast by later on Saturday morning. Otherwise,
mid and high clouds will stream across the region through the
period.

&&

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

&&

$$

DISCUSSION...JH
AVIATION...JM