Area Forecast Discussion
Issued by NWS Rapid City, SD

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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

000
FXUS63 KUNR 211701
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1101 AM MDT SUN AUG 21 2016

.SHORT TERM...(Today Through Monday Night)
Issued at 229 AM MDT Sun Aug 21 2016

Upper trough has pushed over the Great Lakes region, while broad
upper ridge builds over the western CONUS. Skies are mostly clear
across the northern plains. Winds are becoming southerly with
surface ridge axis cutting across the central Dakotas, and
temperatures are falling into the 40s and lower 50s.

Under high pressure, the weather today will be warm, dry and sunny.
As thermal ridge pushes into the area, temperatures will warm well
into the 80s. Winds will be southerly around 5-10 mph.

Next trough will begin approaching the region tonight. A low-level
jet will develop ahead of the trough, with 850 mb winds of 20-40
kts over the CWA. This will translate to some breezy southerly
winds at the surface, especially across south central SD. Lows
will be milder than recently, in the 50s to lower 60s.

Upper/thermal ridge will peak Monday, with continued dry weather and
highs in the 90s. Some places across central SD may reach 100
degrees. Surface low pressure will move over the CWA, resulting in
continued breezy southerly winds across south central SD, and winds
shifting to the west across northeastern WY and western SD. Breezy
winds will keep lows in the 60s across south central SD, with 50s
farther west.

.LONG TERM...(Tuesday Through Saturday)
Issued at 229 AM MDT Sun Aug 21 2016

Progressive but amplified flow expected in the period. Dry wx
forecast through most of the period given dry westerly flow with
limited return flow ahead of any impulses. Any convection that
does develop will be very high based with limited precip outside
scentral SD. Another strong trough is progged by the middle of the
week, which will knock down temps quite a bit and bring slight
chances of precip toward the end of the week, given unsettled
cyclonic flow as mean upper troughing persists. Temps will cool to
below seasonal norms wed-fri with a slight warm up by next
weekend. If a stronger upper trough does verify by mid week, much
cooler temps would be expected for wed-thu.

&&

.AVIATION...(For the 18Z TAFS Through 18Z Monday)
Issued At 1101 AM MDT Sun Aug 21 2016

VFR conditions expected through the period. Low level wind shear
will develop in the SD plains later this evening into early Monday
morning, especially over south central SD.

&&

.FIRE WEATHER...
Issued At 229 AM MDT Sun Aug 21 2016

Hot and dry conditions will return today and Monday. Minimum
relative humidity values will range from near 10% across
northeastern WY to around 25% across south central SD both days.
However, winds in the driest areas should be light enough to
preclude headlines. The breeziest winds are expected across south
central SD on Monday, where min RH should stay above 15%.

&&

.UNR Watches/Warnings/Advisories...
SD...None.
WY...None.
&&

$$

SHORT TERM...Pojorlie
LONG TERM...JC
AVIATION...Helgeson
FIRE WEATHER...Pojorlie



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