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fxus63 kfsd 192305 

Area forecast discussion
National Weather Service Sioux Falls South Dakota
605 PM CDT Mon Aug 19 2019

Short term...(this evening through tuesday)
issued at 350 PM CDT Mon Aug 19 2019

Area of stratus across central South Dakota highlighting an area of
low level moisture working north ahead of a short wave moving east
along the South Dakota/Nebraska border. With strong 850 hpa warm
air advection ahead of this wave, expect thunderstorms to develop
this evening once warm air is able to work around the elevated mixed
layer around 700 mb. Atmosphere is unstable with steep mid level
lapse rates leading to 2500-3000 j/kg of cape. With 0-6 km bulk
shear near 50 knots along the I-90 corridor (with greater shear
values to the north), expect some storms to be severe. With the
freezing level embedded in the steep mid level lapse rates, expect
hail to be a possibility, along with strong damaging winds with a
wealth of dry air aloft. 12z sounding out of top indicated nearly
1.70" of precipitable water, which is near the 90 percent moving
average. Dew points have climbed to near 70 f south of I-90,
indicative of moist airmass working into the region. Training of
storms may lead to very heavy rainfall overnight.

Long term...(tuesday night through monday)
issued at 350 PM CDT Mon Aug 19 2019

More tranquil conditions are expected Tuesday into Wednesday as high
pressure builds into the northern plains. Disturbance moving across
Nebraska Tuesday night into Wednesday may lead to some light
rainfall along the South Dakota/Nebraska border.

Flow becomes more active late this week as dirty zonal flow Ushers a
series of disturbances in the northern plains. This will result in
potential for unsettled weather for the weekend into the early part
of next week.


Aviation...(for the 00z tafs through 00z Tuesday evening)
issued at 554 PM CDT Mon Aug 19 2019

Isolated to scattered thunderstorms are expected to develop
through the James River Valley after 01z, then track eastward
across the area overnight. A few of these storms could produce
large hail and strong wind gusts, especially over northwest Iowa.
MVFR/IFR stratus will develop behind the convection from the
Interstate 29 corridor and eastward, then slowly lift during the
day on Tuesday.


Fsd watches/warnings/advisories...
South Dakota...none.

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