Area Forecast Discussion
Issued by NWS Sioux Falls, SD

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
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 39 40 41 42 43 44 45 46 47 48 49 50
FXUS63 KFSD 272309

Area Forecast Discussion
National Weather Service Sioux Falls SD
609 PM CDT SAT AUG 27 2016

.SHORT TERM...(This evening through Sunday)
Issued at 310 PM CDT Sat Aug 27 2016

Cloudy skies east of I-29 will continue to scatter out or become
mostly clear through the next few hours. Warm frontal boundary
currently located across southern Nebraska is expected to lift
northward towards the mid Missouri Valley tonight. This will allow
temperatures to moderate some, while the southerly flow taps into
slightly higher dewpoints overnight. Several runs of the HRRR as
well as the NMM suggest that an isolated thunderstorm or two may
form in north central Nebraska, possibly lifting into far south
central SD in the early evening, however with the dynamic support
lifting away from this area this afternoon, have opted to keep pops
just below the mentionable threshold.

Later tonight, with the front lifting northward and the low level
jet nosing into the region, isolated to scattered showers and
thunderstorms may pop along a narrow area of elevated instability
near the Buffalo Ridge area of east central SD and southwest MN.
CAMs suggest activity tracks east along our northern border and
quickly exits by around daybreak Sunday. Southerly winds remain
relatively light overnight, especially along and east of I-29. Could
see some patchy fog redevelop late tonight into the daybreak hours
in this location.

Sunday will be pleasant, with southerly winds and mostly clear to
partly cloudy skies. Highs will reach the lower 80s in the east to
lower 90s in the west.

.LONG TERM...(Sunday night through Saturday)
Issued at 310 PM CDT Sat Aug 27 2016

The upcoming week is mainly characterized by an upper ridge across
the plains throughout the week.  This will provide relatively mild
conditions, but ridge is not strong enough to keep disturbances
completely at bay.  On Monday, stationary front across the area will
serve as a focusing mechanism for thunderstorm development through
the afternoon and evening hours.  Steep lapse rates in the 800-600
mb layer will result 2000-2500 j/kg of surface based CAPE.  Wind
shear is very weak, so despite the instability, do not expect much
in the way of severe weather.

Boundary hangs around the area, but convergence becomes weak
along the front thus minimizing the chance for precipitation.
Upper ridge weakens some on Wednesday, before re intensifying late
in the week. There could be a few short waves that track through
the region on Friday as strong upper trough flattens the ridge.
While much of the mid-level wave energy is focused to the north,
have kept consensus chance pops for now.


.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 609 PM CDT Sat Aug 27 2016

VFR conditions expected to prevail through the period at TAF
locations. Will have to monitor KFSD/KSUX closely, though, as we
could see some MVFR-IFR visibility in BR develop east of I-29 in
southwest MN/northwest IA late tonight/early Sunday.


.FSD Watches/Warnings/Advisories...


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