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Area forecast discussion 
National Weather Service Sioux Falls South Dakota
1029 PM CDT Sat Apr 25 2015

Short term...(this evening through sunday)
issued at 327 PM CDT Sat Apr 25 2015

Quiet weather will be the rule through Sunday...with shearing
departure of upper low to south toward the Ohio Valley...and
increasing influence of narrow upper ridge over the northern plains.
Will maintain a drier easterly flow as low level ridge expands from
western Ontario back through Minnesota. Drier air has eroded most of
the lowest cloudiness already today...replaced by higher mixing
stratocumulus field. Many of these clouds over the middle and eastern
County Warning Area will become fairly perishable tonight...making for a gradual
east to west clearing working into eastern South Dakota early
Sunday. A bit moisture trajectory remains through the Missouri
Valley and not out of the question that a bit of patchy fog could
develop late night...but given the continued drying and easterly
gradient...should not become any large concern. Lows in the middle 30s
to lower 40s expected.

The drying and clearing trend persists into Sunday. Little reason
not to expect that it will become more deeply mixed and likewise
toward the drier and warmer side of guidance. Will have to watch to
see if recent local wet spots across southeast South Dakota can
overcome this mixing...and keep dewpoint a bit higher...but area of
heavier precipitation is considerably small and larger impact should
be minimal. Should end up with generally middle to upper 60s.

Long term...(sunday night through saturday)
issued at 327 PM CDT Sat Apr 25 2015

Weak upper level ridging is expected through the first half of next
week. With troughing blocking flow to the east and an upper low
undercutting to the south...fairly pleasant weather will abound in
the northern plains. With the ridge axis parked over the region
Monday...expect light winds and mostly sunny skies. While mixing is
not ideal...did trend warmer towards the bias corrected models with
highs mainly in the upper 60s and lower 70s. A wave slides across
the northern plains Tuesday but looks to be quite moisture starved
as treks through the forecast area. The NAM and GFS remain dry while
the European model (ecmwf) and Gem paint some spotty light rain across our northeast
corner. Decided to remove pop mention in tune with surrounding

Upper ridge strengthens over the plains Wednesday afternoon and
Thursday...ushering in warmer weather and stronger southerly winds.
Could see some fire danger concerns during this period but this will
be dependent on how much moisture return will be realized. Went a
bit pessimistic on dewpoints which drops our relative humidity right around 30 to
40 percent. Another shortwave approaches around the Friday or Friday
night time frame. The European model (ecmwf) is weaker and faster while the GFS
brings in a more robust slow moving wave. Thursday and Friday will
see highs improve into the 70s and 80s.


Aviation...(for the 06z tafs through 06z Sunday night)
issued at 1028 PM CDT Sat Apr 25 2015

VFR conditions will prevail through Sunday. As clouds clear
overnight...cannot rule out the potential for patchy fog. This
should not be widespread however. Light easterly winds will
prevail on Sunday...with winds turning variable in the evening.


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


Short term...Chapman
long term...

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