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fxus63 kunr 221119 

Area forecast discussion for western South Dakota and northeastern Wyoming
National Weather Service Rapid City South Dakota
419 am MST Fri Nov 22 2019

Discussion...(today through thursday)
issued at 139 am MST Fri Nov 22 2019

Fast northwest flow will dominate through the weekend, supporting mild
pac air over the forecast area. Near daily impulses will traverse the region,
although weak forcing and lack of sufficient moisture will
support dry trough passage through Saturday. However, winds will
respond with each system supporting breezy conds at many
locations, esp northwest South Dakota. Warm trough now pushing into central Canada
will support warm air advection over most of the northern plains today. Near 100%
sunshine will allow deeper mixing, esp in the Lee of the Black
Hills, supporting a mild day today with highs in the 40s and 50s.
Sfc trough will push through the region tonight, supporting
increased ll flow and winds, allowing temps to hold warmer. Nearly
the same story for Sat, albeit a few more clouds and warmer
thermal fields. Have bumped highs up for both today and Sat, with
better mixing expected than what forecast models are indicating.
However, this pattern will begin to break down Sunday as Gulf of
Alaska ridging ensues, supporting antecedent western/central noam
troughing. This will ensue locally with the passage of a cold
front and associated upper trough Sunday. This system will mainly
split the fa, similar to last weds system, with best chances
for snow accums SW of the forecast area. Cold northerly flow will persist
early next week. SW Continental U.S. Trough is expected to eject NE at some
point next week, with the evolution of this system still very
uncertain at this point and highly dependent on trough evolution
over the eastern Pacific. The eventual track of an expected sfc
low will have to be watched for potential local impacts.


Aviation...(for the 12z tafs through 12z Saturday morning)
issued at 419 am MST Fri Nov 22 2019

VFR conditions are expected through the forecast period.


Unr watches/warnings/advisories...
South Dakota...none.

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