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 43 44 45 46 47 48 49 50
FXUS63 KUNR 302002

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
202 PM MDT MON MAY 30 2016

.SHORT TERM...(This Evening Through Tuesday Night)
Issued at 124 PM MDT Mon May 30 2016

20Z sfc analysis shows low pressure centered to the east of the
Black Hills with a sfc trough extending southward to west of
Valentine Neb. Sfc cool front has moved into western SD. Scattered
showers and thunderstorms are increasing in coverage and strength
over northwestern SD and over and east of the Blkhls as the sfc
low continues to move east. Dewpoints are in the upper 50s to
lower 60s to the east of the low, providing ample moisture for
deep convection this aftn/eve. Diurnal heating, lift along the
many sfc boundaries and sfc moisture have combined to push MUCAPE
to 1500-3000J/KG to the east of the sfc cool front this aftn.
Shear is sufficient to produce supercellular thunderstorms with
some large hail already reported over part of nwrn SD this aftn.
Expect to see the convection eventually develop into a n-s
oriented line over central SD moving rapidly east this evening.

Later this evening, subsidence and drying push most precipitation
out of the CWA although a few lingering showers or possibly
thunderstorms are not out of the question as main bubble of
vorticity wraps around upper low. Temperatures will be near

On Tuesday, the upper low stacks up with surface low in ND with a
secondary upper shear axis and subsequent surface trough move
through CWA. 850mb winds 20-30kts, so gusty winds expected given
deep mixing and weak cold air advection. Moisture will be limited,
but steep lapse rates should contribute to pops in the north
through east during peak heating. Temperatures will be near

Tuesday night, surface high moves in bringing quieter weather.

.LONG TERM...(Wednesday Through Monday)
Issued at 124 PM MDT Mon May 30 2016

An upper level ridge will build over the western CONUS
and the Northern Plains from mid week into next weekend. Mainly dry
weather is expected through the extended period. Highs Wednesday
will be in the 70s, warming to the 80s Thursday into next weekend.


.AVIATION...(For the 18Z TAFS Through 18Z Tuesday)
Issued At 124 PM MDT Mon May 30 2016

Strong to severe thunderstorms will move across western
South Dakota this afternoon and evening. MVFR to IFR visibility and
gusty winds are possible in/near any storms. Strong northwest winds
of 20-30 kts with gusts near 40 kts will follow a cold front this
evening. Strongest shower/storm activity will shift east of the area
by 06Z tonight with VFR conditions expected through Tuesday morning.


.UNR Watches/Warnings/Advisories...


AVIATION...15 is the U.S. government's official web portal to all federal, state and local government web resources and services.