Area Forecast Discussion
Issued by NWS Sioux Falls, 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 46 47 48 49 50

FXUS63 KFSD 202305

Area Forecast Discussion
National Weather Service Sioux Falls SD
605 PM CDT Mon Mar 20 2017

.SHORT TERM...(This evening through Tuesday)
Issued at 353 PM CDT Mon Mar 20 2017

Dry atmosphere is in place across the region with northeast flow in
the near surface layer.  A series of shortwaves are expected to move
across the region after 06z tonight.  Will be fighting the dry air
in the low levels, but dynamics should win out where 700 mb
frontogenesis is the strongest. Will get some assistance with the
right entrance region of a jet streak across the area through the
event, but will need to the low level dynamics to overcome the dry
air in the low levels. Dynamics are relatively quick moving, so
expect snow amounts to be fairly light mainly extending from south
central South Dakota along the South Dakota/Nebraska border.

Atmosphere dries out aloft Tuesday afternoon shutting down any
lingering precipitation. Still a fair amount of clouds around with
low level cold air advection, so kept temperatures fairly cool
throughout the day.

.LONG TERM...(Tuesday night through Monday)
Issued at 353 PM CDT Mon Mar 20 2017

Upper level riding with a weak wave moving through the far Northern
Plains will set the stage for the upcoming deeper trough expected to
spread across the area Thursday into Friday. Moderate warm air
advection will move through the area during the day on Wednesday
with snow, possibly mixed with rain becoming a threat. Overall
amounts will be pretty light with the main story Wednesday a fairly
stiff southeast breeze, cloudy and fairly cold. Highs in the 30s to
lower 40s.

Wednesday night should not see any precipitation as the ridging
bumps up a little and the trough to the west moves into the Rockies.
With clouds and a south wind lows will be on the mild side from 30
to 40.

Thursday into Friday will see an almost guarantee of rainfall with a
very good chance for a fairly widespread inch or more of rain.
Snowfall looks to be a minor threat at this time as cold air should
not be a problem. Something to continue to monitor of course but for
now not a concern. We will likely see rain and a few thunderstorms
on Thursday night, possibly into Friday morning, but none are
expected to become severe. Any storms that develop will be elevated
with some of the more unstable air located close to the 750mb
boundary. Generally looking at highs in the 40s to mid 50s Thursday
and Friday with lows only 5 to 10 degrees cooler.

The pattern stays potentially busy into the extended with dry
weather on the weekend other than some rain or snow showers ending
on Saturday morning. Mild conditions Saturday and Sunday but another
wave could bring some rain or snow into the area Monday into


.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 602 PM CDT Mon Mar 20 2017

VFR conditions for much of the area through the TAF period. The
exception will be through the Missouri River Valley, including
KSUX, where light snow is expected to develop after 06Z tonight
and continue through Tuesday morning. MVFR ceilings and
visibilities will be found with this activity.




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