565 
FXUS63 KFSD 311753
AFDFSD

AREA FORECAST DISCUSSION
National Weather Service Sioux Falls SD
1253 PM CDT Fri May 31 2019

.SHORT TERM...(Today and Tonight)
Issued at 334 AM CDT Fri May 31 2019

Smoke layer continues to stream across the northern and central 
Plains from wildfires in western Canada. With the HRRR indicating 
that this layer will stick around through the day today, have upper 
sky cover slightly. As a result, have also lowered highs a few 
degrees with more filtered sunshine expected. Despite this, 
temperatures will once again be warm, with highs in the lower 80s.

Afternoon heating and instability is expected for fire off showers 
and thunderstorms in south central SD, as a shortwave dives into 
the western Dakotas. A surface frontal boundary nudges eastward 
towards our western border late in the afternoon, then gradually 
sags across the forecast area this evening and overnight. Elevated
instability will provide MUCAPE values around 1500 J/KG, however 
shear will be quite weak around 15 kt or less. With an inverted V 
sounding and good elevated instability, cannot rule out small hail
and gusty winds in any storms that do form, however the overall 
severe risk is low. 

Showers and storms will build into southeast SD and the highway 14 
corridor this evening, then track through the remainder of the 
forecast area overnight. Rainfall amounts will be relatively light, 
but could reach a quarter inch or so under a stronger storm. Lows 
tonight will be in the 50s.

.LONG TERM...(Saturday through Thursday)
Issued at 334 AM CDT Fri May 31 2019

Cooler airmass briefly drops into the region with northwest flow 
aloft and northerly surface winds on Saturday. Clouds decrease 
through the morning, with highs in the upper 60s to mid 70s.

Ridging rebuilds over the High Plains early next week, then 
flattens with more zonal flow arriving Monday night into Tuesday.
Warm front lifting into the region will bring the next potential for 
scattered storms on Monday night and Tuesday, however models are 
still uncertain in where this boundary will track. Precipitation 
chances later in the week will depend on where subtle waves track in 
the quasi-zonal flow. Confidence in fairly low, but cannot rule out 
some spotty activity on Tuesday night. Temperatures will mainly be 
in the 70s through the forecast period with lows in the 50s.

&&

.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 1252 PM CDT Fri May 31 2019

Generally cloud-free skies over the immediate area to start the
period, though still seeing a broken-overcast layer of smoke 
aloft. Will see VFR clouds develop late this afternoon into this 
evening, with increasing chance for showers and embedded storms
moving across the area after 31/23Z. Given dry sub-cloud layer,
storms could produce erratic wind gusts as high as 40+kts. Risk of
showers and storms generally moves east of the forecast area by
12Z Saturday.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&

$$

SHORT TERM...
LONG TERM...
AVIATION...JH