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Area forecast discussion...updated 
National Weather Service Aberdeen South Dakota
627 am CDT Wednesday Apr 23 2014

Update...
aviation discussion has been updated.

&&
Previous discussion...
short term...today through Friday

Current surface analysis shows the low pressure center now across
far southeast Montana...with a cold front extending across central
Wyoming and into Colorado. A tight pressure gradient /around 25 mb
across South Dakota/ has set up ahead of this system. Winds will
gradually decrease as the cold front approaches...then switch
around to the northwest behind the front. However...until this
happens...strong and gusty southeast winds are anticipated across
the the County Warning Area. BUFKIT soundings show up to 40 kts at the top of the
mixed layer across eastern South Dakota. Showers have also been
able to pull some the winds to the surface...kmbg gusted to 48 miles per hour
with a brief shower last night. A Wind Advisory has been issued to
account for these strong winds. The main area of precipitation is
coincident with modest 700 mb frontogenesis over the northeast County Warning Area
this morning. Additional scattered shower development is ongoing
further west however. Drier air is expected to move into the
central County Warning Area this afternoon...so trended probability of precipitation down across this
region early in the afternoon...whereas precipitation across the
northeast should continue into the afternoon hours. Additional
development is then possible from west to east across the County Warning Area as
the cold front passes over the region.

Perhaps some lingering rain showers will continue across the far
northeast into Thursday morning...but otherwise northwest winds
should transport cooler and drier air into the region. If the
forecast of gusty northwest winds and min relative humidity values below 20
percent across the western half of the County Warning Area holds...red flag
warnings may again be needed Thursday afternoon. Also...given
steep low level lapse rates Thursday and Friday...peak heating
shower development is not out of the question across the northern
County Warning Area. However for now just went with a dry forecast.

Long term...Friday night through Tuesday

The latest models have trended toward a common solution for the
middle level flow pattern/evolution over the central Continental U.S.. strong
trough will enter the California coast early in the weekend and then
cross the central/southern rockies and emerge into the plains
late Sunday. At that point the pattern starts to turn very blocky
and leads to most models cutting off a low over the Central
Plains. Per various uvm forecasts/tropopause map it appears a fair amount
of energy will rotate around that developing upper low and move
across the abr County Warning Area Sunday and Sunday night. Thus those two periods
should see the best opportunity for widespread precipitation. As for
temperatures...one thing stands out vs previous model runs. All
models have trended warmer...especially the European model (ecmwf) early in the
period. Thus have raised temperatures a bit for Saturday and
Sunday although have some reservations about Sunday if precipitation is
indeed as wide spread as models allude to.

&&

Aviation...
12z tafs for the kabr...Katy...kpir and kmbg terminals

Strong southeast breezes and scattered showers are expected across the
region this morning. For this afternoon an approaching front
continue spark more showers and even some thunderstorms over the
area into the evening hours. Meanwhile areas of MVFR ceilings are
expected over mainly eastern parts of the region this afternoon
and evening.

&&

Fire weather...
while minimum relative humidity values will remain in the 30s and
40s today...strong and gusty southeast winds ahead of an
approaching low pressure system will combine with dry fuels to
result in very high fire danger.

Of greater concern is the potential for dangerous fire weather
conditions Thursday. Strong and gusty northwest winds are expected
on the back side of the exiting low pressure system. With steep lapse
rates...drier air should be readily mixed to the surface. This
combination of gusty northwest winds...low minimum relative
humidity...and dead dry fuels...has the potential to result in red
flag conditions across much of central South Dakota. A Fire
Weather Watch has been issued for Thursday afternoon.

&&

Abr watches/warnings/advisories...
South Dakota...Fire Weather Watch from Thursday afternoon through Thursday
evening for lower bad river-Missouri Coteau-upper Cheyenne-
upper James River-upper Missouri Coteau.

Wind Advisory until 10 am CDT /9 am MDT/ this morning for
Campbell-Corson-Dewey-Hughes-Jones-Lyman-Potter-Stanley-
Sully-Walworth.

Wind Advisory from 10 am this morning to 7 PM CDT this evening
for Clark-Codington-day-Deuel-Grant-Hamlin-Marshall-Roberts.

Wind Advisory until 4 PM CDT this afternoon for Brown-Buffalo-
Edmunds-Faulk-hand-Hyde-McPherson-Spink.

Minnesota...Wind Advisory from 10 am this morning to 7 PM CDT this evening
for Big Stone-traverse.

&&

$$
Update...tdk
short term...serr
long term...tdk
aviation...tdk

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