FXUS63 KUNR 151928
Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
128 PM MDT Sat Jun 15 2019
.DISCUSSION...(This Evening Through Saturday)
Issued at 127 PM MDT Sat Jun 15 2019
An upper low spins over the Hudson Bay area, while a
ridge builds over the western CONUS, placing the northern plains in
northwest flow. Another upper low is over southern Saskatchewan and
Manitoba, sparking some storms over ND and eastern SD. Cumulus have
increased across the region this afternoon, and a shower has
developed along a convergence zone southeast of the Black Hills.
At the surface, a somewhat tight pressure gradient is keeping
northwesterly winds breezy, around 15 to 25 kts. Temperatures this
afternoon are rising into the 70s and lower 80s.
Beneath high pressure, mostly dry weather will continue this
afternoon and evening. The exception may be across parts of
northeastern WY and southwestern SD, where there is a little better
instability. Chances for precipitation will increase tonight across
northeastern WY, as a weak shortwave pushes into the region.
Shortwave energy and weak instability will allow showers/storms to
spread across the CWA on Sunday, but severe weather is not expected.
With the cool airmass over the region, highs Sunday will be in the
Below average temperatures will continue through the next week. A
series of shortwaves early in the week, followed by a stronger low
pressure system later in the week, will bring daily chances for
showers and thunderstorms. With cooler temperatures, instability
will be weak to marginal, and so not expecting much for severe
weather at this time.
.AVIATION...(For the 18Z TAFS Through 18Z Sunday)
Issued At 1107 AM MDT Sat Jun 15 2019
VFR conditions are expected through the period. However, isolated
showers and thunderstorms are possible this afternoon and evening
over far SWRN portions of the area, with chances increasing
between 06-18z over NERN WY, the Black Hills, and SWRN SD. Local
IFR conditions will be found with any of the thunderstorms.
Otherwise, gusty northwest winds will occur across most of the SD
plains today, with the exception being a lee-side convergence
zone (and flow reversal) on the SERN side of the Black Hills.
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