Area Forecast Discussion
Issued by NWS Sioux Falls, SD

Home | Current Version | Previous Version | Graphics & Text | 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 KFSD 221715

Area Forecast Discussion
National Weather Service Sioux Falls SD
1115 AM CST Wed Nov 22 2017

.SHORT TERM...(Today and Tonight)
Issued at 302 AM CST Wed Nov 22 2017

A surface ridge axis currently situated across the region will slide
to the east today, and winds will become southerly behind the
exiting high as a warm front lifts across the area during the day.
The warming will be most realized in our west as temperatures climb
to near 60 over south central SD. Quite a contrast to our east with
readings only making it into the upper 30s through portions of
southwestern MN and northwest IA. It will become rather breezy in
our east this afternoon, this thanks to an increasing gradient as
the surface low driving the aforementioned warm front tracks from ND
into northeastern SD by this evening. Removed mention of
flurries/sprinkles in our east during the afternoon, with any
appreciable forcing/moisture remaining off to our northeast.

The low pulls a weak cold front/trough through the area tonight with
winds briefly turning to the northwest, but in the modified airmass
lows will not be that bad - in the mid 20s to lower 30s.

.LONG TERM...(Thursday through Tuesday)
Issued at 302 AM CST Wed Nov 22 2017

By Thanksgiving Day, winds quickly back to the south again, and
looking at another very mild day with 925 mb temperatures running 10
to 17 C across the area. This will place highs in the upper 40s east
of Interstate 29, to a few mid 60s over south central SD.

The next limited chance of precipitation comes in on Friday as an
upper level shortwave drops through the Northern Plains and a cold
front slides across the area. Most models keep the best energy to
our north, so if anything occurs it would be north of Interstate 90,
though chances look pretty low in the absence of any appreciable
moisture. If any precipitation were to occur, it would be in the
form of rain with mild temperatures at the surface and aloft. With
cold air advection, a tightening gradient, and strong mixed layer
winds, it will be a windy day, and again boosted wind speeds over
given Superblend. In spite of the cold air advection it will be a
mild day with good mixing, and highs 50s to near 60.

After a brief cool down on Saturday behind the aforementioned system,
temperatures begin to rebound again on Sunday and Monday with models
in good agreement on an upper level ridge building across the region
through the beginning of next week. Things begin to become a little
more interesting by the end of the longer term period as upper level
energy begins to carve a trough out over the western CONUS.
Depending on the evolution of this pattern, models are hinting at
possible precipitation in the Tuesday time frame - and at this point
it looks like it could be in the form of snow. Still pretty far out,
though something to keep an eye on in the upcoming days.


.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 1113 AM CST Wed Nov 22 2017

VFR conditions through the period. Potential for some 3-5 mile fog
along and west of the James River but confidence low.




AVIATION...08 is the U.S. government's official web portal to all federal, state and local government web resources and services.