000
FXUS63 KUNR 220758
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
158 AM MDT Tue Aug 22 2017

.DISCUSSION...(Today Through Monday)
Issued at 157 AM MDT Tue Aug 22 2017

High clouds are streaming into the region through northwest flow,
as an upper level ridge builds over the northwestern CONUS.
Surface high pressure sits over the western Dakotas. With light
and variable winds, temperatures are in the 50s.

Upper ridge will keep weather mild and mostly dry through Wednesday.
Highs today will be in the low to mid 80s, with highs Wednesday
warming near 90. Some weak instability on Wednesday may allow for a
few afternoon and evening showers and thunderstorms over the hills.

On Thursday, a trough will begin breaking down the ridge over the
Pacific Northwest, and an approaching shortwave will interact with a
stationary boundary draped across the region. Showers and
thunderstorms are expected to develop mainly across the southwestern
half of the CWA. Precipitation will be more widespread on Friday as
the upper wave continues its slow track eastward.

Another ridge will begin building over the west coast Saturday. Both
the ECMWF and GFS are hinting at another weak wave bringing a few
showers/storms to the area Saturday, but generally a period of dry
weather will begin this weekend into early next week. Temperatures
for the end of the week through the weekend will be in the 80s.


&&

.AVIATION...(For the 06Z TAFS Through 06Z Tuesday Night)
Issued At 1131 PM MDT Mon Aug 21 2017

VFR conditions expected through the period as high pressure
slides through the region.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...None.
WY...None.
&&

$$

DISCUSSION...Pojorlie
AVIATION...Helgeson