Area Forecast Discussion
Issued by NWS Aberdeen, SD

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FXUS63 KABR 161208 CCA

Area Forecast Discussion...CORRECTED
National Weather Service Aberdeen SD
708 AM CDT Fri Mar 16 2018

Issued at 651 AM CDT Fri Mar 16 2018

12z aviation discussion updated below.


.SHORT TERM...(Today and Tonight)
Issued at 357 AM CDT Fri Mar 16 2018

A dynamic storm system is ongoing this morning with precipitation
moving northwestward across northern Nebraska. Even with
temperatures hovering in the lower 30s, several lightning strike
have been reported. As the storm continues evolving, we should see
pcpn reach south central SD before 12Z. Warm layer aloft, the p-type
will be a mix of freezing rain and sleet. Mixed precipitation should
change over to all snow during the mid to late morning hours.
Snowfall amounts will depend on the change over time from the mixed
pcpn. The 6z 3km NAM suggest mixed pcpn lasting a bit longer in
Hughes/Lyman County area, while heavy snow falls in Jones County.

Impressive pcpn rates are expected, especially in south central SD,
or along the I-90 corridor. Convective allowing models are showing
high reflectivity, which is reasonable with tremendous lift in the
mid levels. HREF shows a high probability of one inch an hour pcpn
from the mid morning hours through the mid afternoon.

Upper level lift begins to wane fairly quickly late this afternoon
with a rapid drop off in pcpn expected. Lower levels of the
atmosphere will remain saturated through tonight with patchy
freezing drizzle possible.

Did make minor changes to headlines. With Eagle Butte area seeing 3
to 5 inches, have decided to add Dewey county into an advisory.
Buffalo county could see more than 6 inches of snow, thus will
upgrade to a winter storm warning.

.LONG TERM...(Saturday through Thursday)
Issued at 357 AM CDT Fri Mar 16 2018

The long term begins with a very large upper level low pressure area
over the western U.S. with a several short waves/vort lobes rotating
around it. The main short wave trough in the base will progress
slowly east and across the Central Plains Sunday through Monday.
Behind this will be a couple weaker short waves dropping across the
Northern Plains from the northwest Monday through Tuesday night. All
of the models agree well on chances of rain/snow beginning Sunday
afternoon through Monday night into Tuesday morning. Still have in
good chances of precipitation with this system for this time period.
After this moves by, upper level ridging along with warmer air will
push into the region for Wednesday and Thursday. The new snowfall
along with the existing snow cover will continue to have an affect
on the high temperatures. Extensive cloud cover over the next
several days is also expected to affect temperatures. At this time,
highs are expected to be mainly from zero to 10 degrees below normal
for much of the long term with a warm up for Thursday. Highs will be
mainly in the mid 30s to the lower 40s through most of the long term
with mid 40s to the lower 50s by Thursday. Again, snow and cloud
cover differences will affect these temperatures.


.AVIATION...(For the 12Z TAFS through 12Z Saturday Morning)
Issued at 651 AM CDT Fri Mar 16 2018

Some sleet/freezing rain will move up into the Pierre area this
morning and then change over to all snow by late morning. The snow
could be heavy before ending by evening. Otherwise, VFR ceilings at
MBG, ABR, ATY will lower and become low VFR/MVFR this evening and
overnight. Will also have to watch for some areas of freezing
drizzle possible tonight.


SD...Winter Storm Warning until 7 PM CDT /6 PM MDT/ this evening for

     Winter Weather Advisory until 7 PM CDT /6 PM MDT/ this evening
     for SDZ015-034.

     Winter Weather Advisory until 1 AM CDT Saturday for SDZ036-037.



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