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 151946

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
146 PM MDT Sat Oct 15 2016

.SHORT TERM...(This Evening Through Sunday Night)
Issued at 138 PM MDT Sat Oct 15 2016

Water Vapor analysis reveals broad zonal-like WSW flow over much
of the central and western CONUS. The high/mid level clouds that
impacted the CWA this morning have moved east, and majority of the
CWA is under mostly clear skies. Temperatures at this hour mainly
in the 60s to low 70s outside of the Black Hills.

A 40-50kt LLJ will develop in western/central South Dakota tonight
ahead of approaching surface low in WY/MT. Could see dewpoints jump
up as much as 10 degrees overnight in south-central South Dakota as
LLJ pulls in moisture from the south. Overnight lows will be
relatively mild with upper 40s to lower 50s across the region.

The surface low that was over MT/WY will move quickly eastward
across the CWA by Sunday afternoon. In its wake, dry air and strong
southwesterly to westerly winds will create red flag criteria
conditions in western and central South Dakota. Surface temps will
be about 10 degrees cooler in northeastern Wyoming Sunday afternoon
than western/central South Dakota, so relative humidity will be
slightly higher out there to avoid red flag conditions.

NWP guidance brings isolated to scattered showers mainly across
northeastern WY and the Black Hills Sunday night. Forecast soundings
look a bit dry during this period so am not sure there will be much
in the way of accumulating rain, but will keep small chances of PoPs
in the forecast to account for possible showers.

.LONG TERM...(Monday Through Saturday)
Issued at 138 PM MDT Sat Oct 15 2016

Southwesterly flow aloft will lead to slightly warmer than
average temperatures on Monday, with a chance of showers as a
shortwave trough and sfc cool front cross the forecast area. There
is also a chance of showers on Wednesday, as an upper trough
rotates across the northern plains. Near, or slightly cooler than
average temperatures are expected during the rest of the week,
possibly warming up again by the weekend as the models agree with
developing a high amplitude upper ridge over the western CONUS
then shifting it eastward heading into the weekend. Dry weather is
expected for the end of the week into the weekend.


.AVIATION...(For the 18Z TAFS Through 18Z Sunday)
Issued At 138 PM MDT Sat Oct 15 2016

VFR conditions are expected through the period. Breezy southwest
winds will develop across the area late tonight into Sunday.


Issued At 138 PM MDT Sat Oct 15 2016

Issued At 224 AM MDT Sat Oct 15 2016

Another warm and dry day is expected on Sunday, with hot
temperatures across parts of southwestern into south central SD.
High temperatures in those areas will be in the lower to mid 80s,
and minimum relative humidity values will fall to near 15%. With
gusty southwest winds expected, critical fire weather conditions
will occur over parts of southwestern and south central South Dakota
on Sunday afternoon. A Red Flag Warning has been issued.


SD...Red Flag Warning from noon to 6 PM MDT Sunday for SDZ263>265.



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