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Area forecast discussion 
National Weather Service Sioux Falls South Dakota
1109 am CST Wednesday Mar 4 2015

Short term...(today and tonight)
issued at 410 am CST Wednesday Mar 4 2015

Main theme for today will be bitterly cold temperatures as a
secondary cold surge slides through the area. BUFKIT soundings
suggest the possibility of isolated flurries as the colder air
streams into the did include that in the forecast over
portions of the area during the early part of the day. will be a breezy as northwesterly winds increase in
response to the strong cold air advection and rapid pressure rises.
With highs expected to range from the single digits through the
Highway 14 corridor into much of southwestern the
upper teens along the Missouri River...these winds will combine to
produce wind chills below zero.

Surface high pressure slides across the region tonight...and as it
does so winds will drop off. With mostly clear skies...this will
result in a very cold night as lows fall to 10 to 15 below through
our northern and eastern near zero through the MO river
corridor. Apparent temperatures will drop into the 20 to 30 below
zero range in our coldest areas...though winds will most likely be
light enough to preclude a Wind Chill Advisory.

Long term...(thursday through tuesday)
issued at 410 am CST Wednesday Mar 4 2015

Temperatures really the primary concern through the end of this week
and into next. Arctic air mass still has a bit of a hold across the
region Thursday...especially east where lingering cold temperatures
aloft and fresh snow cover will hold highs around 20 degrees. Warmer
low level air begins to work into the west...and with a southerly
flow and no snow cover to our south...should be able to warm the
southwest portions of the forecast area well into the 30s.

Southwesterly low level jet ahead of approaching warm front will
prevent eastern areas from dropping off much Thursday night...with
lows in the middle teens to lower 20s expected. Mild west-southwest low
level flow then begins to take over across the region...bringing our
first taste of above normal highs in over a week...heading into the
first extended stretch of above normal temperatures for most areas
in nearly a month. Remained somewhat conservative with warming over
our northeast for Friday into the weekend given greater existing
snow cover. Models also showing potential for a couple of weak middle
level waves slipping into the upper Midwest this weekend. Should see
greater cloud cover as a result...and could also see a little light
precipitation over northeast parts of our forecast area with these
waves...although with lack of timing consensus in the models makes
it difficult to pinpoint a favored time period just yet. Latest runs
point to Friday night and again Saturday night in the European model (ecmwf)...while
the GFS has a sharper wave during the day Saturday followed by drier
flow the remainder of the weekend. Canadian splits the difference...
siding with the GFS for Saturday...with a second shot supporting the
European model (ecmwf) Saturday night into early Sunday. Inconsistency provides
little confidence in will leave precipitation mention out of
the forecast for now. Will be something to monitor as the weekend
approaches though.

Greater warming on the horizon for early next week as eastern trough
continues to weaken and flow becomes more zonal aloft. Maintain dry
west-southwest flow in the lower levels...which should limit stratus
potential. Highs in the upper 40s and 50s seem quite reasonable for
Monday/Tuesday...and would not be surprised to see readings even a
little higher than that. Though with some subtle differences in low
level pattern...nudged only a little warmer than a straight model
blend for now.


Aviation...(for the 18z tafs through 18z Thursday afternoon)
issued at 1103 am CST Wednesday Mar 4 2015

Scattered ceilings around 2500 feet are pushing into the
area...accompanying cold air advection behind a cold front. While
ceilings may briefly become broken...prevailing conditions are
expected to be VFR. Skies clear around sunset and breezy northwest
winds become light and variable overnight. VFR conditions expected
tonight and Thursday.


Fsd watches/warnings/advisories...
South Dakota...none.


long term...jh

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