Area Forecast Discussion
Issued by NWS Rapid City, SD

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42
FXUS63 KUNR 290111

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
711 PM MDT Sun May 28 2017

Issued at 709 PM MDT Sun May 28 2017

Main band of showers and thunderstorms has moved south of the
forecast area, into Nebraska. Only a few showers still exist along
the secondary boundary moving southward across the region which
should end around sunset. Have updated forecast to adjust PoPs
lower in all areas.


.DISCUSSION...(This Evening Through Sunday)
Issued at 153 PM MDT Sun May 28 2017

19z surface analysis had low over southern SK with trough into NE
and another into eastern MT. Upper low spinning over the southeast
SK with pinwheeling disturbances rotating around it into the
Dakotas. Upper/surface features tapping into 250-500J/kg MLCAPE to
produce another round of popcorn -TSRA this afternoon/evening.
Activity focused on Black Hills terrain and surface trough. A few
gusty storms will occur given 20-35kt 850mb winds. Activity will
end by 06z tonight as subsidence/drying takes hold. Temperatures
tonight will be tricky with dry air and clearing skies creating
widely varying readings.

Monday and Tuesday, modest upper ridge will bring a couple of nice
days. Little instability noted with general synoptic scale
subsidence supporting continued dry forecast. Temperatures will be

Wednesday through Sunday, split flow regime develops with
increasingly active northern branch of westerlies. PoPs will be
largely diurnal, except perhaps by next weekend when decent
cyclonic/northwest flow develops. Temperatures will be 5-10F above
normal on average.


.AVIATION...(For the 00Z TAFS Through 00Z Monday Evening)
Issued At 511 PM MDT Sun May 28 2017

Showers and thunderstorms and gusty winds will end early this
evening. VFR conditions are expected tonight and on Monday.




AVIATION...10 is the U.S. government's official web portal to all federal, state and local government web resources and services.