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Area forecast discussion 
National Weather Service Sioux Falls South Dakota
259 PM CST Tuesday Mar 3 2015

Short term...(this evening through wednesday)
issued at 259 PM CST Tuesday Mar 3 2015

Will be letting the advisory go at 3 PM for the South Dakota side as
visibilities are up and winds will only get lighter through the
afternoon. Will let southwest Minnesota continue through 0z as
visibilities are still running about 1 to 3 miles around the Buffalo

A widespread 1 to 3 inches along and mainly north of Interstate 90
last night into this morning a little less than anticipated but will
still affect temperatures to some degree tonight into tomorrow.
North winds will gradually diminish this evening then drop to or a
little below 10 miles per hour late tonight into early Wednesday morning. The
combination of winds and cold temperatures just low enough down
Highway 14 to need a Wind Chill Advisory. Expecting lows from around
5 below in the north to 5 above in the far south where little to no
snow fell.

Northwest winds will increase a bit again on Wednesday...but a more
general 10 to 20 miles per hour or so in most locations. This will keep the day
pretty darn cold though so with highs mainly in the single digits to
lower teens wind chills likely at or a little below zero through the
day. The exception will be the far southern County Warning Area where highs were
raised a bit due to little or no snow. Looking at highs near 20 from
Yankton to Sioux City.

Long term...(wednesday night through tuesday)
issued at 259 PM CST Tuesday Mar 3 2015

Cold start to the extended with good radiational cooling across the
area leading to a cold night...especially across the east. With the
good radiative conditions across the east...fresh snowcover...and
925 hpa temperatures around -20c have dropped forecast lows in the east.
With return flow developing after midnight across central South
Dakota...expect temperatures to steady out if not even rise
slightly. Therefore...tightened the gradient in low temperatures
Wednesday night.

Strong Chinook pattern sets up thereafter with nice warming
expected. With the Hudson Bay low weakening....area remains under
warm west to northwest flow. Have nudge forecast highs upwards on
Thursday into Friday...but was fairly conservative with remaining
snow cover. Wave expected to drop through on northwest flow
Saturday night into Sunday morning. While moisture appears
limited...could see some light snow across southwest Minnesota
Sunday morning. Also have cold air advection for 6-8 hours behind
the front...but with good mixing conditions...still erred towards
the warmer side of guidance.

Blostered highs more on the Sunday through Tuesday time frame with
strong westerly flow. 850 hpa temperatures forecasted by the European model (ecmwf) are
only a few degrees away from record highs...and with progressive
westerly flow am not too worried about stratus potential. Guidance
values are too cool compared to temperatures aloft and limited snow have sided towards the warm end of guidance.


Aviation...(for the 06z tafs through 06z Tuesday night)
issued at 1053 PM CST Monday Mar 2 2015

VFR will prevail in the near term...but a band of snow will move
into the Huron area during the pre dawn hours Tuesday...with a
strong wind shift to the north and northwest following by day
break. The strong wind across the forecast area will hit very
suddenly...with fairly light winds in a pre frontal trough ahead
of the cold front. But behind the front...the winds will rapidly
increase to 30 to 45 miles per hour and last that way for around 6 hours.
During falling snow...especially at Huron...visibilities will be
greatly reduced Tuesday morning into the lower end IFR category.
The snow will not be as great at Sioux Falls...and certainly not
at Sioux City. Therefore visibility reductions will likely be less
severe and more brief. One thing to keep an eye on however is the
potential for light freezing drizzle at kfsd and ksux between 09z
and 12z Tuesday. This hinges on stratus developing ahead of the
cold front and there is a question as to how low any stratus will
form. By Tuesday afternoon...conditions should be MVFR under
instability cumulus with slowly decreasing winds.


Fsd watches/warnings/advisories...
South Dakota...Winter Weather Advisory until 3 PM CST this afternoon for sdz050-

Wind Chill Advisory from 3 am to 9 am CST Wednesday for

Minnesota...Winter Weather Advisory until 6 PM CST this evening for mnz071-

Wind Chill Advisory from 3 am to 9 am CST Wednesday for mnz071-



Short term...08
long term...

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