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000
FXUS63 KUNR 202355
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
455 PM MST Wed Feb 20 2019

.DISCUSSION...(This Evening Through Wednesday)
Issued at 227 PM MST Wed Feb 20 2019

An upper low across crossing the Dakotas will continue northeastward
into Minnesota and south central Ontario. Weather across the CWA has
been quiet today as surface high pressure continues to build across
the northern Plains. A strong trough is strengthening across the
western CONUS. Ahead of the trough...weak ridging across the Dakotas
along with the surface high will keep quiet weather across the area
through tonight and much of Thursday. Highs tomorrow will again be
in the teens to mid 20s. Southwest flow will increase late tomorrow,
with a weak shortwave approaching from southeast Wyoming. A band of
light snow is expected to develop from south to north during the
afternoon and continuing through the night. The bulk of accumulation
will be south of I-90, with up to an inch or two by early Friday
morning. A stronger wave will push through during the day on Friday
as the large scale upper trough approaches the northern Plains. Snow
will redevelop and push farther north into northwest SD through
Friday morning, then pivot toward south central SD Friday afternoon
into Friday night. This second system will bring up to an inch of
accumulation mostly across the Black Hills area through the
southwest SD plains and the Pine Ridge area. Higher amounts are will
fall across south central SD, with 1-3 inches expected at this time.
Don`t think headlines will be needed right now...especially with the
lack of wind and long duration of the light snow. But if an advisory
ends up being needed, think the most likely location will be across
south central SD. Northwest flow will continue across the region
through the weekend into early next week. Dry weather is expected
Saturday and Sunday as a cold front crosses the region. Highs
Saturday will be in the 20s to low 30s, then much colder Sunday,
with highs in the single digits and teens. A series of waves will
cross the region early next week bringing more unsettled weather for
the first half of the week, along with persistent below average
temperatures.

&&

.AVIATION...(For the 00Z TAFS Through 00Z Thursday Evening)
Issued At 440 PM MST Wed Feb 20 2019

VFR conditions are expected through tonight. After 15Z Thursday
morning. MVFR conditions with some areas of light snow will spread
northeastward into northeastern Wyoming and southwestern South
Dakota areas of IFR conditions are expected over the Black Hills
and near the South Dakota/Nebraska border.

&&

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

$$

DISCUSSION...13
AVIATION...10