Scientific Forecaster Discussion
Area forecast discussion...updated
National Weather Service Aberdeen South Dakota
554 am CST Sat Mar 8 2014
12z updated aviation discussion below.
Short term...today through Monday
A wealth of low and middle level clouds across the Dakotas this
morning that models are not really picking up on. Satellite trends
indicate it will affect the County Warning Area through the morning...but not real
high confidence on areal coverage and overall timing of them. Have
trended forecast cloudier for the morning but still expect clouds
to move off by late morning and afternoon.
High pressure moves off to the east today allowing for southwest
winds and warmer temperatures...although western and central South Dakota get to
feel the warmth. The east will have to wait one more day as they
will still be fighting the overall cooler air mass from the
surface high. Interesting to note about todays highs is that the
00z ec is a bit warmer at 925mb across central South Dakota today so highs
could potentially be a bit higher than whats currently forecast.
For tonight it still appears there will be a downslope wind event
across the Coteau as 40 knot winds at 925mb develop out of the
Sunday shaping up to be a very mild day with impressive warming at
925mb and favorable west/southwest winds. Bumped up highs a few
degrees based on thermal profiles and guidance numbers. The
southwest County Warning Area should be well into the 60s and could even see 50
degrees in Aberdeen. Monday also mild...but slightly cooler at
925mb so will take a few degrees off highs compared to what we see
Long term...Monday night through Friday
the models agree fairly well and continue to show above normal
temperatures through much of the long term. We have to first get
by an upper level low pressure trough moving across the region on
Monday night and Tuesday. This will bring a good chance of rain
and snow mainly west and south in the County Warning Area. Will have to wait
until we get closer to determine any snowfall accumulations.
Otherwise...the models show our region remaining in the mild
Pacific air sector of the upper level flow while surface low
pressure systems track off to the north and east through the
period. For Wednesday through Friday...ec and GFS guidance were
close with highs mainly in the 40s and 50s across the County Warning Area.
12z tafs for the kabr...Katy...kpir and kmbg terminals
As a surface high pressure area pushes east and a surface low
pressure area moves across southern Canada...winds will become
south to southwest for all taf locations. The MVFR/VFR stratus
clouds early this morning will move quickly off to the east into
the late morning/early afternoon hours. Thus...expect VFR
conditions this afternoon and through tonight for all locations.
Will also have to watch for possible low level wind shear later tonight as surface
southwest winds increase to west to northwest to 30 to 40 knots
through the inversion.