Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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 202328

Area Forecast Discussion
National Weather Service Sioux Falls SD
528 PM CST Wed Feb 20 2019

.SHORT TERM...(This evening through Thursday)
Issued at 307 PM CST Wed Feb 20 2019

Drier air settling into the area late this afternoon and evening
will bring an end to the snowfall. A skinny surface ridge of high
pressure will drift north and allow winds to drop off in many
locations. Lowered lows in many locations with a widespread fresh
snow cover. Went fairly close to the 90th percentile for cold lows.
Southwest MN may hold on to wind through the night so lows there
should be the least cold.

Thursday will be a quiet day ahead of the next system. Light winds
and increasing clouds will couple with highs in the 20s. By late
afternoon a mid level boundary will work into central SD and may
bring some light snow to the Gregory area and possibly as far east
as Yankton. Amounts before sunset should be fairly minor.

.LONG TERM...(Thursday night through Wednesday)
Issued at 307 PM CST Wed Feb 20 2019

Thursday night another broad area of warm and moist advection
develops with temperatures cold enough for all snow. Frontal
forcing and a little hint of instability above the boundary
suggest that there could be a bit of banding so this time around
the eastern edge through Friday afternoon could decrease while the
core of the frontal forcing could increase. Will not change the
forecast to show this as error in where the boundary will likely
end up is also a potential 36 to 48 hours out. For now, expecting
a fairly widespread snow Thursday night into Friday along and west
of a Windom to Yankton line. Much of northwest IA could stay
fairly dry through Friday afternoon.

Friday night into Saturday should prove to be a transitional period
as the main wave ejects onto the central Plains. Latest models have
continue to trend just a bit to the south so the highest potential
for winter impacts on Saturday and Saturday night will be northwest
IA. Still a very potent, wrapped up system that will bring strong
winds Saturday night into Sunday. If we do manage to get some
snowfall ahead of these winds we could see some blowing and drifting
problems. Many areas now seeing snow depths of 1 to 2 feet so not
nearly as difficult to get drifting and reduced visibility. Also of
concern over northwest IA and parts of southwest MN will be the
potential for mixed precipitation. Confidence not real high on this
right now as there are a lot of details to still be worked out.

Another round of snow will likely return Monday night into Tuesday.
Below normal temperatures are still anticipated through next week.


.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 526 PM CST Wed Feb 20 2019

Light flurries around the region will come to an end as drier air
works into the region. Could see some patchy fog develop in the
Missouri River Valley overnight. Added mention of fog in KSUX TAF
after 10Z Thursday through a few hours after sunrise.




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