Area Forecast Discussion
Issued by NWS Sioux Falls, SD

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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

000
FXUS63 KFSD 170842
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
342 AM CDT Sat Jun 17 2017

.SHORT TERM...(Today and Tonight)
Issued at 342 AM CDT Sat Jun 17 2017

Latest water vapor and RAP data shows strong 100 to 120 knots upper
level jet spreading into western SD early this morning. This was
allowing a weak mid level trough of low pressure to work into
western and central SD. With increasing mid level moisture
precipitation returns have been on the increase in these areas, but
so far has remained pretty light. Suspect that this trend of fairly
light rainfall will continue through the morning and afternoon
across eastern SD, southwest MN and northwest IA. While some very
minor amounts of elevated instability should exist it should do
nothing more than bring a few pockets of moderate to briefly heavy
rainfall and possibly a few lightning strikes. Suspect that
something close to a quarter inch of rainfall is likely north of
Interstate 90 with decreasing amounts south of the Interstate.

The rainfall should come to a quick end from west to east late this
afternoon into the evening as the main upper level support shifts
east and strong subsidence develops.

As for temperatures, with the precipitation and clouds lowered highs
a bit with lower 70s north of Interstate 90 and mid to upper 70s to
the south. Mild lows in the 50s overnight with a combination of
cooler and drier air but still some cloud cover hanging in.


.LONG TERM...(Sunday through Friday)
Issued at 342 AM CDT Sat Jun 17 2017

Relatively cool temperatures aloft on Sunday will lead to well
below normal temperatures across the area.  Steep lapse rates from
850-700 mb may result instability showers/isolated thunderstorms
through the peak heating of the day.  Have some 20-30 pops across
the east, where the change in temperature with height is most
significant.

Strong mixing could result in an isolated showed/thunderstorm Monday
afternoon across the east.  Limited instability, shear and lack of
moisture is not supportive of severe weather, but could get outflow
with strong inverted V profile.

Dry conditions are expected Tuesday with upper level ridge across
the west.  More unsettled conditions are expected Wednesday through
Friday as upper level northwest flow transitions to more zonal with
a few short waves working through. With the potential for good wind
shear, could have some severe weather especially on Thursday as a
cold front works into the region.

Cooler temperatures expected to round out the week behind the front.
 Have raised winds some behind the front on Friday into Friday
night.


&&

.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 623 PM CDT Fri Jun 16 2017

Will linger a VCTS group for the KSUX TAF site for one hour,
ending it at 01Z as the TSRA complex continues to move toward the
southeast. There will be some isolated to scattered TSRA in
northwest IA through perhaps 01Z to 02Z, but that activity will
likely not be severe at this point and will not affect the KSUX
TAF site. Otherwise, VFR should be the primary category through
the TAF period, with some scattered TSRA activity possible on
Saturday over KFSD and KHON as an upper air disturbance and cold
front swing through. Any TSRA activity on Saturday will likely not
be very strong.


&&

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

$$

SHORT TERM...08
LONG TERM...BT
AVIATION...MJ



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