974 
FXUS63 KFSD 042354
AFDFSD

AREA FORECAST DISCUSSION
National Weather Service Sioux Falls SD
654 PM CDT Thu Apr 4 2019

.SHORT TERM...(This Evening through Friday)
Issued at 252 PM CDT Thu Apr 4 2019

Cloudy skies continue through the evening with periods of drizzle. 
After sunset, mid-level clouds will begin to clear. But don't expect 
clear skies: Recent rain, moisture advection in the boundary 
layer, and weak surface winds will be a recipe for fog. Fog will 
be widespread across the region after midnight and could be dense 
in spots. Light south winds Friday morning will help to increase 
surface mixing, which should encourage fog dissipation by mid to 
late morning.

Friday high temperatures will be notably warmer than Thursday, with 
widespread 60s. The warmth will come with moisture, so scattered 
afternoon and evening showers are possible. A little bit of mid-
atmospheric instability means that isolated weak thunderstorms are 
also possible during the evening into the overnight.

.LONG TERM...(Friday Night through Thursday)
Issued at 252 PM CDT Thu Apr 4 2019

Mild spring-like conditions continue into the weekend, as an upper 
level ridge to the east will keep the area under southwesterly flow 
aloft. A few shortwave impulses are expected to move through the 
southwesterly flow, likely encouraging showers and a few weak 
thunderstorms as abundant low-level atmosphere moisture continues 
streaming in from the south. Many locations could see rain amounts 
of 0.25 to 0.50 inches by the end of the weekend, with higher
totals where thunderstorms manage to form.

A cold front Sunday evening will bring drier air into the region 
along with decreasing chances for showers Monday. The decreased 
moisture Monday afternoon along with clearer skies will still encourage
warming into the upper 60s with less humidity. A Canadian surface
high pressure then moves through Tuesday, bringing a cooler air
mass which will knock highs down into the 40s. 

For the middle of next week, Wednesday into Thursday, a strong 
longwave trough moves eastward across the Plains. There is a lot of 
uncertainty with low confidence in the forecast during the timeframe 
due to model differences. For now, have leaned on a consensus blend 
for the forecast, showing good chances for either rain or snow with 
abundant cloud cover during the middle of next week.

&&

.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 645 PM CDT Thu Apr 4 2019

MVFR and IFR ceilings are expected through the overnight hours,
however skies are expected to clear mid to late morning on Friday.
Visibility will also become further reduced this evening and
overnight, with widespread fog expected. Locally dense fog with
visibility of 1/2sm or less will also be possible, mainly east of
the James River.

&&

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

$$

SHORT TERM...VandenBoogart
LONG TERM...VandenBoogart
AVIATION...