Area Forecast Discussion
Issued by NWS Rapid City, SD

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FXUS63 KUNR 090443

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1043 PM MDT Wed Jul 8 2020

.DISCUSSION...(This Evening Through Wednesday)
Issued at 245 PM MDT Wed Jul 8 2020

Currently, an upper level low is centered over the Northern Rockies
in Canada, with a trough extending southward through the Inter-
Mountain west, with an upper ridge over the Central Plains. These
features are producing southwesterly flow aloft over the forecast
area. At the surface, a stationary boundary extends across the
Eastern Dakotas into the Nebraska Panhandle, with a dryline/lee trof
extending through the Black Hills. Satellite imagery shows a
shortwave pushing through southeastern Wyoming, with limited cloud
cover currently over the area. Winds are gusty across southern
Campbell and Weston County with relative humidity values of 10 to 15

For this afternoon and evening, southwesterly downslope winds are
continuing in the Red Flag Warning area. KGCC is currently at
criteria, but expect conditions to improve in the next hour or two as
winds become northerly. Therefore will hold off on expanding the
Red Flag Warning area. As far as storms this afternoon and evening,
could see some widely scattered strong storms, but severe potential
should be limited due to the timing of the shortwave being a little
later. Winds will decrease later this evening with lows falling into
the lower 50s to lower 60s.

An upper ridge will build over the area on Thursday and Friday
leading to warming temperatures. On Thursday, easterly low level
flow may produce isolated thunderstorms over and near the eastern
slopes of the Black Hills. There is a better chance of thunderstorms
over western and central South Dakota on Friday as southerly flow
increases the low level moisture to the east of a surface trough. A
transient upper ridge will lead to dry weather on Saturday with more
unsettled weather for the beginning of next week.


.AVIATION...(For the 06Z TAFS Through 06Z Thursday Night)
Issued At 1041 PM MDT Wed Jul 8 2020

VFR conditions will generally continue through the TAF period.
Areas of TSRA continue to impact south-central SD this evening,
which could produce localized MVFR conditions and gusty, erratic
winds. A few other storms are possible overnight tonight into
Thursday morning, mainly across southern SD. Otherwise, VFR
conditions continue overnight tonight through Thursday.


Issued at 245 PM MDT Wed Jul 8 2020

Critical fire weather conditions will continue through this
afternoon over fire weather zones 315 and 317 in northeastern
Wyoming. The minimum RH in those areas is already 10-15 percent
with westerly winds of 15-25 mph, gusting to 30-35 mph. A Red
Flag Warning continues into the evening.




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