Area Forecast Discussion
Issued by NWS Aberdeen, SD

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FXUS63 KABR 181809 AAC
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
109 PM CDT Wed Apr 18 2018

.UPDATE...
Issued at 107 PM CDT Wed Apr 18 2018

Aviation discussion updated below for 18Z TAFs.

UPDATE Issued at 1038 AM CDT Wed Apr 18 2018

Made some modifications to POPs based on current radar trends.
Otherwise, the forecast is on track for the most part, but will
have to monitor if cloud cover has an effect on temperatures. Did
cool highs a bit along the area near FSD CWA border as they should
be in clouds/precip the longest today. Reports across central SD
this morning show generally 1 to 4 inches of snow have fallen. Do
not expect much in the way of accums any more today as temps are
in the low to mid 30s and will continue to slowly rise as the snow
tapers off.

&&

.SHORT TERM...(Today through Thursday Afternoon)
Issued at 245 AM CDT Wed Apr 18 2018

With temperatures still above freezing in most of the Missouri River
valley, snow has struggled to accumulate. Decided to cancel the
advisory as totals are expected to max out around 2.5 inches. The
one spot that may see a bit more is Murdo where cameras show snow is
already sticking on pavement. Radar also shows a more enhanced band
directly over and just to the east of Murdo. Precip has yet to begin
in Pierre, even though radar would indicate otherwise.

Temperatures will rebound quickly on Wednesday. As precipitation
rotates in on an inverted trough, it will lose some forcing through
the morning. Reduced rates will lead to lower potential
accumulations as will rising temperatures. Highs will climb into the
40s with portions of north central SD jumping into the lower 50s
after clouds start to break up in the afternoon.

Sfc high pressure and upper ridging build in Wednesday night.

.LONG TERM...(Thursday Evening through Tuesday)
Issued at 245 AM CDT Wed Apr 18 2018

Looks like with the limited snow accumulations with the current
system we can go forwards with a slightly warmer forecast in the mid
term timeframe as guidance has come in a little milder Thursday &
Friday. The only notable weather features are an upper low that
tracks mainly south of the CWA for the weekend, and in which the
GFS/Canadian and ECMWF all bring some moisture this far north.
Profiles support mainly light rain. There is another system for the
start of next week, however there is a wide array of outcomes
between deterministic guidance and POPs are probably overdone. This
is because the Canadian (which is an outlier) leaves an upper low
sitting over the area while the GFS is far more progressive and the
ECMWF deflects a weak wave to the south. Also noted is much warmer
air in this round of blended extended guidance for next week.

&&

.AVIATION...(For the 18Z TAFS through 18Z Thursday Afternoon)
Issued at 107 PM CDT Wed Apr 18 2018

Areas of MVFR/IFR CIGs will continue to affect KMBG/KPIR early
this afternoon before conditions begin to improve to VFR. Over
KABR/KATY, VFR CIGs are expected this afternoon. For the
overnight, areas of FG/BR are possible over the region.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
&&

$$

UPDATE...TMT
SHORT TERM...Wise
LONG TERM...Connelly
AVIATION...TMT



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