720 
FXUS63 KFSD 121129
AFDFSD

AREA FORECAST DISCUSSION
National Weather Service Sioux Falls SD
629 AM CDT Sun May 12 2019

.SHORT TERM...(Today and Tonight)
Issued at 339 AM CDT Sun May 12 2019

Per satellite and surface obs, low to mid clouds persist over the 
region as the upper level low continue to spin east-southeast into 
central Iowa. Light winds and enough moisture in the boundary layer 
have resulted in stratus and patchy fog, mainly along and east of
the I-29 corridor. Areas of fog will linger through mid morning, 
but partly to mostly cloudy skies will stick around through most 
of the day. At the surface, a slow-moving cold front will continue
to move through the area today. With diurnal heating and low- 
level convergence, spotty/isolated showers will be possible. 
Better chances would be along and east of the James River during 
the afternoon hours. Daytime temperatures will reach the upper 50s
to mid 60s. 

Surface high pressure builds in southeast of the FA, keeping the 
region dry under southerly surface flow. Overnight lows will be in 
the 40s.

.LONG TERM...(Monday through Saturday)
Issued at 339 AM CDT Sun May 12 2019

The main feature this week will be warm temperatures as an upper 
level ridge builds across the region. 

The work week start off on the warm side with warm southerly winds 
dominating the region as the upper ridge over the Rockies moves 
east. Highs will climb into the mid to upper 70s on Monday, even 
warmer on Tuesday as 850 mb temperatures rise to around 12 to 16+ C. 
High temperatures could reach the 80s on Tuesday.

A weak shortwave and associated surface front track across the area 
Monday night into Tuesday, bringing a small threat of showers east 
of I-29. Instability and shear look minimal through this period; 
however a few thunderstorms will be possible towards daybreak. 
Warmer conditions are expected through the remainder of the week as 
the upper ridge axis moves overhead. Spotty showers and 
thunderstorms will be possible each day, but minimal impact is 
expected.  

Unsettled conditions return the upcoming weekend as an upper level 
trough pushes into the Northern Plains. While models differ a bit in 
strength/amplitude of this system, they are in better agreement in 
terms of timing. The main concerns will be periods of moderate to 
heavy rain. The ECMWF is the most aggressive than the GFS, 
suggesting high QPF values (around 1" of rain). Timing and 
intensity could change, but this system will usher in better rain 
chances Friday night through Sunday.

&&

.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
Issued at 629 AM CDT Sun May 12 2019

Areas of fog/low stratus producing IFR or lower visibility and
ceilings at times early this morning. Visibility is expected to 
improve rapidly 13Z-15Z, but MVFR ceilings may linger into the
afternoon. Isolated to scattered light showers/sprinkles also
possible with daytime heating by midday, though specific timing
and location of showers too uncertain to include in TAFs. At this
time, not expecting TS nor gusty winds to accompany any SHRA. Any
shower activity expected to decrease with sunset this evening.

Shallow moisture may lead to more fog development late in the TAF
period, but confidence not high enough to include at this time.

&&

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

$$

SHORT TERM...05
LONG TERM...05
AVIATION...JH