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Area forecast discussion 
National Weather Service Sioux Falls South Dakota
1052 PM CST Thursday Mar 5 2015

Short term...(this evening through friday)
issued at 338 PM CST Thursday Mar 5 2015

Much milder weather is returning to the region with significant
improvements in temperature heading into tonight and Friday. A minor
shortwave drops southeast through the forecast area this evening
into the early morning hours...but should only bring an increase in
middle and high clouds. South winds turning southwest will allow
temperatures to remain mild overnight...beginning with a slight
dip in the evening hours then steadying or slowly rising overnight
as warm air advection intensifies. Lows will be in the teens to
lower 20s...marking a 20 to 30 degree improvement over this
mornings lows.

Winds turn westerly on Friday while middle and low temperatures
continue to warm. 925 mb temperatures build to 5c to 7c in the
Missouri Valley and along and west of the James River. This should
translate to very pleasant highs in the upper 40s to middle 50s. Moving
eastward...less abundant warming and a relatively fresh snowpack
will hold high temperatures closer to freezing in east central South Dakota
and southwest Minnesota. Elsewhere...readings in the 40s are
expected. Middle and high clouds will be on the increase through the
day ahead of a shortwave dropping into the upper Midwest...but dry
conditions will prevail.

Long term...(friday night through thursday)
issued at 338 PM CST Thursday Mar 5 2015

Models still continue to suggest a series of waves dropping through
the northern plains both Friday night and Saturday night. Friday
nights wave is tricky...as the lift is relatively weak. There is
some middle level moisture...but very little low level moisture and the
dendritic layer remains dry. Given the lack of ice production...any
precipitation would likely be drizzle so went ahead and added mention of
drizzle across southwest Minnesota. Tough call on forecast highs on
both Saturday and Sunday as models varying on strength of the cold
air working down during the day. GFS is strongest with the cold air
advection...while the European model (ecmwf). Given the NAM is hedging towards the
warmer solutions...kept forecast highs above normal with the coolest
temperatures in the east with lingering snowcover and coolest 925
hpa temperatures.

Models are all showing the wave on Saturday night into Sunday to be
stronger than 24 hours ago...so have went ahead and raised probability of precipitation with
this feature. Once again...moisture is limited with this wave...but
dendritic layer is saturated so kept precipitation type snow.

Monday and Tuesday look to be quite mild with strong westerly flow
driving 925 hpa temperatures into the upper single digits and lower teens.
Have continued to hedge towards the warm side of
guidance...especially on Tuesday when cloud cover looks to be less
of an issue.

GFS shows backdoor front coming down next Wednesday with
substantial cooling behind the boundary...while the European model (ecmwf) stalls the
boundary to the north of the forecast area keeping temperatures
quite mild. For now...split the difference by warming things
slightly over guidance in the south...and leaving temperatures in
the north as is for now.

&&

Aviation...(for the 06z tafs through 06z Friday evening)
issued at 1052 PM CST Thursday Mar 5 2015

VFR conditions expected through the period.

&&

Fsd watches/warnings/advisories...
South Dakota...none.
Minnesota...none.
Iowa...none.
NE...none.
&&

$$

Short term...
long term...
aviation...chenard

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