Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Aberdeen South Dakota
1224 PM CDT Friday Oct 31 2014
the forecast looks OK for now so no major changes expected for
short term...today through Sunday
the forecast challenge will be winds today through Saturday.
As of 8z...a cold Canadian high pressure is located over the
eastern Dakotas with temperatures in the teens and lower 20s. A
tight pressure gradient has already developed over the western
Dakotas with a few observation showing gusts exceeding 20 knots. As the high
pressure slowly moves east of the region today...the pressure
gradient will begin affecting north central South Dakota with
gusty southeasterly winds. Based on GFS buffer sounding at klem
and the GFS lamp guidance at kphp...will issue a Wind Advisory
Corson and Dewey counties. Winds along the Missouri River will
likely remain below advisory levels. Models are showing the
strongest 925 mb winds of 40 plus knots occurring tonight. The
thermal inversion tonight is not particularly strong so it is
possible for the 925 mb winds to mix down to the surface. The
strong winds will continue on Saturday...especially for the
eastern half of the County Warning Area where another Wind Advisory maybe needed.
An area of low pressure sliding across the region on Sunday will
bring much warmer temperatures into the County Warning Area. Temperatures at 850 mb warm
to the middle teens...which is near two Standard deviation above
normal. Highs should easily warm into the 50s and 60s across most
of the area.
Long term...Sunday night through Thursday
as the period unfolds...there continues to be general agreement on
energy within an approaching longwave trough lifting out across the
plains Sunday night through Monday. What still appears to be
lacking at the moment to get precipitation going over this County Warning Area is lift
and focused forcing over this County Warning Area. Superblend probability of precipitation basically
paints precipitation potential across the far southern zones Sunday night
and then shifts potential eastward into Minnesota on Monday.
So...the trend for...basically...a dry extended forecast continues.
The only other tidbit of forecast thought to pass along revolves
around forecast high temperatures Wednesday and Thursday. As the
upper flow pattern takes on more of a dirty ridge
look-and-feel mid-week...925hpa thermal forecasts are forecast to
stratify into a rather pronounced SW to NE gradient where high
temperatures across the far southwestern part of the County Warning Area could be
warming into the upper 60s to middle 70s on days 6 and 7
respectively...while high temperatures across the far northeastern
County Warning Area only warm into the upper 40s to middle 50s. So...it looks as
though a tricky temperature forecast may be setting up for a while
18z tafs for the kabr...Katy...kpir and kmbg terminals
VFR conditions at all taf sites. Gusty southeast winds for
kpir/kmbg today. Wind shear conditions potentially for all
taf sites...earlier for kpir/kmbg verse kabr overnight and Katy
towards morning...as surface winds fall to 10 to 20kts while 2kft
winds top out around 50kts. All taf sites will see those strong
winds mix down again Saturday.
South Dakota...Wind Advisory until 6 PM MDT this evening for Corson-Dewey.
short term...South Dakota