Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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

FXUS63 KFSD 130455

Area Forecast Discussion
National Weather Service Sioux Falls SD
1055 PM CST Mon Feb 12 2018

.SHORT TERM...(This evening through Tuesday)
Issued at 335 PM CST Mon Feb 12 2018

Still looking at the chance of a little light snow over the western
and northern portions of the CWA tonight, as a weak shortwave tracks
through the region on a southwesterly upper level flow and midlevel
warm air advection overspreads the area. Deep moisture will be
lacking, although there will be some saturation in the dendritic
layer allowing for light snow/flurries to develop. Any accumulations
will be very light - generally only around a couple of tenths. The
low level flow will take on a more southerly component overnight as
surface high pressure over the Mississippi Valley slides eastward.
While this will allow for some warming compared to last night, it
will still be a very cold with lows in the single digits.

The southerly flow becomes even more prominent on Tuesday, and with
decreasing clouds highs will bump up into the mid 20s to lower

.LONG TERM...(Tuesday night through Monday)
Issued at 335 PM CST Mon Feb 12 2018

Wednesday still looking like the warm day of the week out ahead of a
surface trough dropping into the region, with highs in the 40s. A
frontal boundary then slides across the area on wednesday night into
Thursday, with models in decent agreement on the system producing a
little light snow on Thursday. This will be the lead in to much
colder air for Thursday and Friday as the upper level flow
transitions to northwesterly and arctic high pressure builds into
the region. Highs both day will run in the 20s.

The cool down will be short lived however, as the upper level
pattern transitions back to a west/southwesterly flow. With that,
highs climb back into the 30s and 40s for next weekend. It looks to
be dry through the period.


.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1055 PM CST Mon Feb 12 2018

Brief period of MVFR conditions possible with band of light snow
lifting through southwest Minnesota to start the period. Otherwise
anticipate VFR conditions to dominate through this TAF period.
Some models are indicating widespread stratus developing beneath
a strengthening inversion Tuesday afternoon/evening. However,
confidence in this development is low at this point, so will keep
TAFs VFR for now.

Warming aloft will be accompanied by southerly flow in excess of
35kt. This will result in low level wind shear for areas mainly
along and east of Interstate 29 after 08Z-09Z through mid morning




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