Area Forecast Discussion
Issued by NWS Aberdeen, SD

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FXUS63 KABR 270527 AAC

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1227 AM CDT Thu Oct 27 2016

Issued at 1226 AM CDT THU OCT 27 2016

See updated aviation discussion below.

UPDATE Issued at 903 PM CDT WED OCT 26 2016

No major changes this evening. Still expect some late night fog,
especially over the northeast CWA where the heaviest rain occurred
yesterday. Also, it does appear that the stratus over the far east
has stopped advecting east, and will now probably form or move
back west overnight across the James Valley. Based on latest
dewpoints, it appears overnight lows are okay.


.SHORT TERM...(This Evening through Friday Night)
Issued at 326 PM CDT WED OCT 26 2016

A weak wave passing through the Western Lakes region allowing for a
wind shift to southwesterly, and thus portions of the forecast area
has broken out of low clouds. Models continue to bring the breakout
into the James valley this evening, however as surface flow backs
around to the south/southeast the clearing line will stall and we
could see some redevelopment of stratus/fog overnight due to an
abundance of low level moisture from recent rainfall. The gradient
continues to increase Thursday with around 8mb across the state
resulting in a decent south breeze. 850/925 warm advection will
deliver much above normal temperatures to the CWA Thursday into
Friday with highs/lows upwards of 20 degrees above average. A
surface low/trof will pass through Friday morning, but with only
weak cold advection to follow. West/northwesterly flow through the
day Friday will result in favorable mixing conditions to counteract
any mid level cooling. Mixed winds will top out with gusts upwards
of 25mph.

.LONG TERM...(Saturday through Wednesday)
Issued at 326 PM CDT WED OCT 26 2016

Good agreement with the models early on in the long term with
divergence later on which would affect the forecast. A large surface
Canadian high pressure area over the region to begin the long term
will push east and southeast through Sunday. All of the models show
a short wave trough and mid level waa moving across the region on
Saturday. This will spread mid level clouds and light rain across
the region through Saturday. The issue will be the dry Canadian air
may overwhelm much of the light rain with not much making it to the
surface. Saturday will be cool with the clouds and Canadian air with
highs in the 40s and lower 50s. Warmer air will then return for
Sunday into Monday warming into the 50s and lower 60s on Sunday and
into the 60s on Monday. The issue then comes with the differences
all three models have tracking an upper level low pressure trough
and its associated surface low pressure area across our region from
the southwest for Sunday night and Monday. Depending on the track,
there will be some chances of light rain or it may remain dry. Have
in some weak chances at this time. Otherwise, a cool front will push
through with cooler Canadian high pressure pushing in for Tuesday
and moving east into Wednesday. The EC was much slower with the
movement of the high pressure area building it east. Highs should be
mostly in the 50s both days.


.AVIATION...(For the 06Z TAFS through 06Z Thursday Night)
Issued at 1226 AM CDT THU OCT 27 2016

IFR/MVFR cigs and possibly even vsbys are expected to gradually
spread from eastern South Dakota back west toward the James Valley
overnight. Improvement is expected Thursday morning with the advent
of daytime heating and better mixing. KPIR/KMBG should be VFR
through the entire time period.




SHORT TERM...Connelly
AVIATION...Parkin is the U.S. government's official web portal to all federal, state and local government web resources and services.