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Area forecast discussion 
National Weather Service Sioux Falls South Dakota
1045 PM CDT Friday Oct 31 2014

Short term...(this evening through saturday)
issued at 257 PM CDT Friday Oct 31 2014

High pressure was slowly moving east today with clear skies the
predominant weather for today.

Main issue for tonight to Saturday is increasing wind. With the
aforementioned high to the east and a deepening low to over parts of
the intermountain west...we are squeezed in the middle of a
strengthening pressure gradient. NAM/GFS/ECMWF are all very similar
bringing in 40-50kts at 850 mb by Sat afternoon. With such dry
conditions expect this to mix down resulting in gusts in the 30s.
This will be the case through the majority of the day on Saturday.

Temperatures will be warmer on Saturday than today with highs in the middle
40s to low 50s...although it may not feel that way with a 20-25 miles per hour
sustained wind.

Long term...(saturday night through friday)
issued at 257 PM CDT Friday Oct 31 2014

A tight gradient remains across the region for Saturday night and
Sunday...keeping breezy to windy conditions over the area through
the period. With this and a warm air advection will be
milder with lows on Saturday night in the 30s and highs on Sunday
ranging from the upper 50s east to near 70 through our south central
South Dakota zones.

On Sunday upper level trough over the western Continental U.S.
Pushes eastward in a split flow pattern...with southern stream
energy grazing our area later on Sunday night and Monday. This will
bring a chance of showers to mainly our lower Missouri/lower Big
Sioux River valleys and southwestern Minnesota/northwestern Iowa
zones during that period. While there are some model differences
with respect to timing/placement...they are in overall agreement in
keeping the better rainfall amounts well to our south and east.
Cooler air will filter into the region with this system...knocking
highs back into the 50s area wide for Monday and Tuesday with lows
mainly 30s.

Farther into the extended...model differences become more
apparent...mainly in the timing of synoptic features...with the
European model (ecmwf) a little more progressive than the GFS. Models do indicate a
cold front swinging through the area sometime in the Wednesday time
frame...with little effects in terms of sensible weather other than
a minor cool down for Thursday and Friday of next week. Even
so...readings will remain at or just above normal through the period
with little chance of precipitation.


Aviation...(for the 06z tafs through 06z Saturday night)
issued at 1042 PM CDT Friday Oct 31 2014

The main concern will be the surface winds. Winds already becoming
gusty in western half of County Warning Area. Gradient will shift east during the
overnight and looking at forecast soundings for Saturday...theres
no doubt that stronger winds will mix down to the surface
throughout the day. Ceilings and visibilities will be unlimited through
forecast period.


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


Short term...Sally

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