Area Forecast Discussion
Issued by NWS Sioux Falls, 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 43 44 45 46 47 48 49 50
FXUS63 KFSD 180708

Area Forecast Discussion
National Weather Service Sioux Falls SD
208 AM CDT Wed Oct 18 2017

.SHORT TERM...(Today and Tonight)
Issued at 203 AM CDT Wed Oct 18 2017

A generally quiet forecast continues this week, with only slight
modifications to the ongoing forecast.  Here are the key areas where
the forecast was modified from populated guidance.

1. Increased high and low temperatures from today through Saturday.
2. Increased wind speeds Thursday night through Friday night.
3. Bumped sky cover upwards slightly Friday/Friday night.

Today: After a warm start to the day, a frontal boundary slides
through the CWA this morning. Expecting cooler temperatures than
Tuesday, but residual warm air behind the front, combined with
decent mixing should still result in 70s for highs.

Tonight: Quiet conditions again expected. Decent radiational cooling
setup should allow lows to drop into the upper 30s in valleys, 40s

.LONG TERM...(Thursday through Tuesday)
Issued at 203 AM CDT Wed Oct 18 2017

Thursday: Models converging on a solution that will breezy, but very
pleasant conditions on Thursday as ridging moves through. with low
level temperatures very similar to those of Tuesday, have bumped up
highs a few degrees, already pushing ensemble max numbers. The
slight southeasterly wind may prevent a repeat.

Friday: Deep southwesterly flow is expected to maintain breezy
conditions into Friday morning, with lows only in the 50s.
Temperatures should climb well through the 70s on Friday, but still
some concerns about stratus or mid-level cloud enhancement in the
afternoon as both major medium range models have mid-level energy
moving through.  Winds will also be an issue Friday. Mixing upwards
of 875-850 mb should tap into a corridor of 40 knots of flow.  Would
not be surprised to see a few 40 mph wind gusts in the afternoon.
Have mixed in stronger MOSGuidance into wind grids.

Friday night - Saturday: Broad warm advection and a stout low level
jet should be able to produce scattered showers or even a rumble of
thunder into Saturday morning.  GFS likely overdone with QPF, but
showing a good forcing signals for some light QPF. A frontal
boundary pushes through Saturday, but models are converging on a
solution that pushes the highest rain chances southeast of the CWA.
Prior to this fronts arrival, expecting very warm overnight lows
likely upper 50s to 60s. Have bumped up low temperatures.

Sunday - Tuesday: Upper pattern begins to evolve towards deeper
troughing in the eastern CONUS and ridging to the west.  We`ll be
stuck in the middle, under northwest to northerly flow aloft.
Temperatures will still be slightly above normal, with only minimal
rain chances.


.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 1030 PM CDT Tue Oct 17 2017

There will be a period of low level wind shear at KFSD overnight.
Otherwise, VFR conditions are expected through the TAF period.




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