936 
FXUS63 KFSD 161725
AFDFSD

AREA FORECAST DISCUSSION
National Weather Service Sioux Falls SD
1225 PM CDT Tue Jun 16 2020

.SHORT TERM...(Today through Wednesday)
Issued at 358 AM CDT Tue Jun 16 2020

As we remain sandwiched between a low pressure system off to our 
west and a high pressure system off to our east, warm and windy 
conditions remain across the area. As the low marches eastwards, the 
pressure gradient is expected to be at its strongest this afternoon 
and has thus prompted a wind advisory to be issued westward along a 
line from Brookings county to Charles Mix county. Sustained winds of 
30-35 MPH are expected across the area for a couple hours, with 
gusts up to 50 MPH possible mainly across the MO River Valley where 
winds atop the boundary layer are pushing 50 knots.

Thanks to a strong low level jet providing WAA across the area, 
maximum low temperatures were threatened on Monday although no 
records were set at our climate sites. This sets the stage for 
another warm day with temperatures in the mid to upper 90s. Heat 
index values will be restrained to the 90s, with relative humidity 
values down into the lower 30s providing some concern for fire 
weather conditions. As the cold front sweeps across central SD, 
there is a very minor chance that areas along the MO River Valley 
could see some rain or a thunderstorm overnight, but latest thinking 
is that the activity will remain off to our west. 

As the upper level low meanders eastwards across Canada, our area 
remains under southeasterly flow at the surface leading to another 
warm and windy day. Temperatures will again reach the mid 90s, with 
relative humidity values dropping into the lower 30s. The cold 
front will be knocking on our door out west by the late afternoon 
hours, and will provide our next chance at showers and 
thunderstorms. 

With ample daytime heating and dew points in the lower to mid 60s, 
CAPE values will be pushing 3000 J/KG along the MO River Valley. 
However, the stronger shear is farther west behind the front which 
means storms that are lifted up by the leading edge of the cold 
front will struggle a bit to remain organized. Elevated instability 
is present behind the front, so the threat for severe thunderstorms 
is there although the instability does decrease overnight. SPC's day 
2 marginal/slight risk highlights the area nicely, and agrees well 
with the thoughts for large hail, damaging winds, and an isolated 
tornado being possible.

.LONG TERM...(Thursday through Monday)
Issued at 358 AM CDT Tue Jun 16 2020

The cold front will continue moving through the area on Thursday, 
looking like it will exit the area out east by early afternoon. 
Showers and thunderstorms will be likely as the front is passing 
through, ending from west to east into the morning hours on Friday. 
The cold front will limit temperatures to the upper 70s to mid 80s 
on Thursday and Friday, and will also bring a noticeable drop in 
wind speeds. 

Active weather continues into the weekend as the upper level trough 
axis moves overhead, leading to continued chances for showers and 
thunderstorms on Saturday with temperatures in the 80s. 
Northwesterly flow develops aloft on Sunday, looking to keep things 
active for the area into next week while limiting temperatures to 
the 80s. 

&&

.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1217 PM CDT Tue Jun 16 2020

VFR conditions prevail, with clear skies across the area, with 
just a few cirrus. Southerly winds remain gusty today, with gusts
for most 35-45 mph. Higher gusts, near 50 mph, are possible along
and west of a Brookings, SD to Alexandria, SD to Wagner, SD line.
Sustained winds of 20-30 mph continue this afternoon as well. 
Winds decrease a bit overnight, with some gusts up to 30 mph still
possible. LLWS is expected again tonight into Wednesday morning 
across the area. Although slightly lighter, gusty southerly winds 
continue tomorrow. 

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...Wind Advisory until 10 PM CDT this evening for SDZ038>040-050-
     052>055-057>060-063-064.

MN...NONE.
IA...NONE.
NE...NONE.
&&

$$

SHORT TERM...APT
LONG TERM...APT
AVIATION...SG