FXUS63 KABR 161720 AAC

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1220 PM CDT Thu Aug 16 2018

Issued at 1015 AM CDT Thu Aug 16 2018

Visibilities have improved across the area this morning as fog has
broken up. Forecast remains on track, so no major changes are
needed. Will be keeping an eye on an impressive smoke plume coming
out of Canada on weak northerly flow that has already worked its
way as far south as the Black Hills. May need to add a mention of
smoke later if it spreads farther south and east.


.SHORT TERM...(Today and Tonight)
Issued at 328 AM CDT Thu Aug 16 2018

Upper level low pressure continues to spin southeastward across
south central SD and into northern NE. Not much for activity on
radar currently, with just a few sprinkles across the eastern CWA.
Most of the precipitation associated with this system is well south
into NE and far southeast SD. Clouds associated with this low are
scattered across the region, and where there has been clearing
recently, we've seen patches of fog develop. Have included fog
mention in the grids/forecast for parts of the CWA through the early
morning hours. Seeing some low clouds develop as well over portions
of the area.

For later today, low pressure will continue to move southeast.
Although, the combination of daytime heating and steep lapse rates
may bring some afternoon showers/thundershowers over the eastern
CWA. Areal coverage and size of the showers are expected to be
small, so will stick with slight chance POPs for the time being.
Warmer air aloft will also be sneaking back into the region, so
looking at widespread 80s across the CWA, with the warmest readings
over western areas where upper 80s are expected.

Surface high pressure will be over the region tonight, with light
winds and mostly clear skies. Dropped Aberdeen's low several degrees
from SuperBlend, and more towards MET guidance.

.LONG TERM...(Friday through Wednesday)
Issued at 328 AM CDT Thu Aug 16 2018

The long term starts off dry under s/w ridging aloft. However, that
is short lived as energy over the Northern Rockies dives southeast
toward the forecast area on Saturday. This system is expected to
provide the region with fairly widespread pcpn Saturday night
through Sunday night. About the only real potential for severe
weather over the weekend could be on Saturday aftn/evening over
central and western South Dakota where MLCAPES may reach 1500 J/kg
with daytime heating. However, during the same time period, deep
layer shear is progged to be quite low as mid level winds remain
lackluster. Most of the pcpn will probably come to an end Sunday
night, with the early part of next week looking dry.

Temperatures for Friday and Saturday will favor warm to hot, but
then will tumble for Sunday as clouds/pcpn move in. The early part
of next week should be mild.


.AVIATION...(For the 18Z TAFS through 18Z Friday Afternoon)
Issued at 1219 PM CDT Thu Aug 16 2018

The departing upper low is continuing to drag some MVFR cigs back
into KATY this afternoon. As the low pulls farther east,
conditions will improve to VFR. All other sites are expected to be
VFR with light winds through the period.




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