Area Forecast Discussion
Issued by NWS Sioux Falls, SD

Home | Current Version | Previous Version | Graphics & Text | 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 39 40 41

FXUS63 KFSD 282036

Area Forecast Discussion
National Weather Service Sioux Falls SD
336 PM CDT SUN AUG 28 2016

.SHORT TERM...(This evening through Monday)
Issued at 335 PM CDT Sun Aug 28 2016

Diffuse boundary draped across north-central South Dakota through
southwest Minnesota this afternoon will lift northward away from the
region this evening. Meanwhile, a slowly advancing cold front drops
southward into northern South Dakota late tonight, stalling near the
Highway 14 corridor midday Monday. With no real mid or upper level
support approaching the region, think that thunderstorm potential is
pretty meager for the better portion of the forecast period. The
HRRR fires some weak convection in south central SD early to mid
evening and skirts it across Beadle county, but without a real
trigger method, will leave out any mention of pops.  Meanwhile,
convection firing to our south in southeastern Nebraska may lift
into portions of east central/southeast Iowa late evening into the
early morning hours with the arrival of the low level jet.

A slightly better chance for convection arrives for Monday, with the
aforementioned boundary draping itself near our northern border. The
boundary could spark isolated to scattered storms where the weak
convergence sets up in the heat of the afternoon. Very weak support,
narrow elevated CAPE, and very weak shear will keep the severe
threat at a minimum. Without a more defined wave in the forecast
area, will leave pops less than 30 percent across the forecast area.
Should be another warm late summer day, with highs in the mid 80s to
lower 90s.

.LONG TERM...(Monday night through Sunday)
Issued at 335 PM CDT Sun Aug 28 2016

By and large, the forecast appears to be fairly typical of late
summer/early fall type conditions.  On Monday evening, there is a
surface boundary to the north of the forecast area with little else
in the way of forcing in the area. Have focused chance pops to the
north, but am not overly confident in evening pops.  If there is
enough convection along the front to push it south, then pops will
need to be raised, but am not confident there is enough forcing to
warrant this.  Low confidence continues into Tuesday morning as a
weak short wave approaches northwest Iowa.  Little in the way of
forcing beyond the short wave, and with inconsistencies in the
models on how to handle this wave, stuck to the middle of the road
with chance pops for now.

The middle of the week appears to be cool and dry with northeast
flow across the region. Have raised forecast highs to near full mix
out to 850 hpa given dry conditions are of late.  Southerly flow
develops in earnest on Friday, and have raised wind gusts and highs
especially across central South Dakota.

Labor Day weekend appears to be somewhat unsettled but not a washout
as a series of disturbances move through the area in relatively fast
southwest flow aloft.


.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1246 PM CDT Sun Aug 28 2016

VFR conditions are expected through the forecast area.


.FSD Watches/Warnings/Advisories...


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