Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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FXUS63 KFSD 170901
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
401 AM CDT WED AUG 17 2016

.SHORT TERM...(Today and Tonight)
Issued at 400 AM CDT Wed Aug 17 2016

Shortwave exiting the region to the east this morning will be
replace by rising rising heights building from west to east today.
Another pleasant day is in store as light winds early in the day
shift to the southeast, but remain generally under 10 mph. Skies
will be mostly sunny, with some scattered mid level clouds forming
in the afternoon. Some lingering mid level instability across the
Iowa Great Lakes may spark an isolated thundershower or two around
midday, however with the wave exiting and a small window of
opportunity, will leave pops just below mention for now. Highs will
reach the mid 80s to lower 90s, warmest west of the James River.

Boundary lifts near the Missouri Valley by late evening and
northward into south central SD tonight. With weak elevated
instability, warm air advection, and the arrival of the low level
jet across central South Dakota, isolated to scattered showers and
thunderstorms will be possible late evening into the overnight
hours. With fairly weak shear and instability, severe weather
chances are low. Lows will be in the mid to upper 60s.


.LONG TERM...(Thursday through Tuesday)
Issued at 400 AM CDT Wed Aug 17 2016

Active period in the medium range with cut off low over the dessert
southwest phasing with intensifying short wave diving down from
Canada.  On Thursday morning, warm front appears to be situated well
to the north of the forecast area.  With the lack of forcing, thought
about removing pops entirely, but thermal structure in north central
South Dakota allows for elevated convection in virtually an uncapped
environment.  As such, kept slight chance pops through the early
morning hours but expect any lingering activity to quickly exit.

Expect Thursday to be relatively quiet much of the day with
increasing southerly flow ahead of an approaching front. A series of
leading short waves will train across the cold front across central
South Dakota.  Thunderstorm activity will work into the area in the
late afternoon and evening hours.  Thunderstorms should have a strong
wind potential with very dry mixed environment leading to high based
storms with large inverted v sounding near the surface.

Expect additional storms to move across the area on Friday as cold
front shifts south and main piece of energy associated with the
cutoff system works across the forecast area.  Forecast soundings
north of the front are quite saturated, suggesting limited
instability.  However, with the main upper trough to the north
remaining to the northwest till Saturday, could see lingering shower
activity through Friday night if not Saturday in the northwest
Iowa/southwest Minnesota.

More tranquil and mainly dry conditions are expected Sunday through
Tuesday with below normal temperatures.  On Tuesday night, a 30-35
knot low level jet develops across the eastern portions of the
forecast area creating the chance for elevated storms to develop.
Additional storms are possible on Wednesday as a cold front works
through the area.


&&

.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 1054 PM CDT Tue Aug 16 2016

Storms winding down across the area this evening. Clearing skies
may result in some fog east of I-29, but am not expecting it to
affect TAF sites. Could see cumulus develop during the day on
Wednesday mainly east. Very light east to southeast winds should
prevail.


&&

.FSD Watches/Warnings/Advisories...
SD...None.
MN...None.
IA...None.
NE...None.
&&

$$

SHORT TERM...
LONG TERM...BT
AVIATION...BT



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