Area Forecast Discussion
Issued by NWS Rapid City, SD

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FXUS63 KUNR 240001

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
601 PM MDT Mon Oct 23 2017

Issued at 600 PM MDT Mon Oct 23 2017

Forecast updated to allow wind headlines to expire.


.DISCUSSION...(This Evening Through Monday)
Issued at 243 PM MDT Mon Oct 23 2017

Upper level analysis shows a trough over the eastern CONUS and a
ridge over the west. In between, a 140-kt jet is moving over the
Rockies and central US. Satellite shows cumulus developing across
the northern plains, and radar indicates some scattered showers
across central SD. A tight pressure gradient at the surface is
keeping northwest winds strong, sustained around 30-40 kts with
gusts of 40-50 kts. Temperatures are in the 40s and 50s.

Winds will gradually diminish this evening but remain breezy
overnight. Lows will range from the 20s across the Black Hills and
northeastern WY to the mid 30s across central SD.

The upper trough and jet will shift eastward on Tuesday, as upper
ridging spreads over the central CONUS. Under mostly sunny skies,
winds will be breezy, and highs will be around 60.

Another upper shortwave will approach the region on Wednesday, and
westerly winds will again become breezy ahead of the surface trough.
Wednesday will be the warmest day of the week, with widespread highs
in the 70s. A strong cold front will begin crossing the region
Wednesday evening, and winds are expected to become very gusty
overnight and into Thursday. Additionally, a few rain/snow showers
will be possible across northeastern WY, the Black Hills, and
northwestern SD, with minimal accumulations.

Much cooler weather is expected for the end of the week, as cold air
wraps into the northern plains behind the low. Highs Thursday and
Friday will be in the 30s and 40s. Temperatures will warm back into
the 50s and 60s for the weekend as the upper ridge rebuilds over the
western CONUS.


.AVIATION...(For the 00Z TAFS Through 00Z Tuesday Evening)
Issued At 508 PM MDT Mon Oct 23 2017

VFR conditions will continue through the period. Gusty northwest
winds will continue to diminish this evening.


Issued At 243 PM MDT Mon Oct 23 2017

Wednesday will be very warm and dry, with highs in the 70s and
minimum RH 10-20%. Some areas could see frequent wind gusts of 25+
mph, so have issued a Fire Weather Watch for Wednesday afternoon
and early evening for northeastern WY, the Black Hills, and much
of western SD.


SD...Fire Weather Watch from Wednesday afternoon through Wednesday
     evening for SDZ260>263.

WY...Fire Weather Watch from Wednesday afternoon through Wednesday
     evening for WYZ259-297>299.



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