Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion for western South Dakota and northeastern Wyoming 
National Weather Service Rapid City South Dakota
222 am MST Sat Feb 6 2016

Short through Sunday night
issued at 216 am MST Sat Feb 6 2016

Deep upper trough covers the eastern Continental U.S....with a weak ridge
over The Rockies and a wave pushing into the Pacific northwest. Some high
clouds are streaming over the ridge into the northern plains.
Winds are light and generally westerly...and temperatures are in the 20s.

Warm air will advect into the region with breezy westerly winds as
ridge axis moves over the northern plains today. Highs will reach
the middle 40s to middle 50s. Fast-moving upper wave will quickly push
into the region by this afternoon...bringing cooler air and very
strong winds to northwestern South Dakota. NAM and GFS both showing 50-70kt
winds 850-700mb...with the European model (ecmwf) still slightly weaker. As initial
cold surge moves through the area this evening...may be some strong
gusts in areas north and east of the hills...and so upgraded watch
to warning at 00z to account for this. Expect somewhat of a lull
overnight but still very breezy conditions with continuing cold air advection
across the area...and collaboration with other offices led to
upgrading much of the South Dakota plains to a High Wind Warning by 06z...with
advisories over far southwestern South Dakota. Black Hills are also in a High
Wind Warning for possible tree damage impacts. Pressure gradient
will tighten Sunday morning as low slides into the Great Lakes
region...and isallobaric winds will aid in the strengthening of
winds across the South Dakota plains on Sunday. Sustained winds of 35-45 kts
with gusts near 60 kts are possible. Winds will gradually decrease
Sunday night as low shifts eastward...but still remain
breezy...near advisory criteria...through the night.

A few light rain/snow showers may accompany this system across
northeastern Wyoming and the Black Hills Saturday night...but any
accumulations will be minimal as profiles are fairly dry. Cooler but
near average temperatures expected for the 30s to lower

Long term...Monday through Friday
issued at 216 am MST Sat Feb 6 2016

A large scale ridge builds over the western Continental U.S. On
Monday and Tuesday...before shifting east and breaking down by
midweek. The South Dakota plains will still be windy on Monday...although not
nearly as strong as Sunday. A weak wave passes through the flow
Thursday and then the upper flow becomes more zonal by next
weekend...but there is little to no support for precipitation.
Temperatures will be quite mild through at least middle week...with a
slight cool down for the end of the week into the weekend.


Aviation...for the 12z tafs through 12z Sunday morning
issued at 216 am MST Sat Feb 6 2016

VFR conditions expected through the period. Winds will
increase through the day...with very strong west to northwest winds
beginning around midday across the northwestern South Dakota plains.


Unr watches/warnings/advisories...
South Dakota...High Wind Warning from 11 PM MST /midnight CST/ this evening to
8 PM MST /9 PM CST/ Sunday for sdz024-028-029-043-044-046-

Wind Advisory from 11 PM this evening to 8 PM MST Sunday for

High Wind Warning from 2 PM this afternoon to 8 PM MST Sunday
for sdz001-002-012-013.

High Wind Warning from 5 PM this afternoon to 8 PM MST Sunday
for sdz014-025-026-030>032-072>074.

Wyoming...High Wind Warning from 11 PM this evening to 8 PM MST Sunday for

High Wind Warning from 5 PM this afternoon to 8 PM MST Sunday
for wyz071.



Short term...pojorlie
long term...Johnson

National Weather Service Glossary of Abbreviations