Area Forecast Discussion
Issued by NWS Aberdeen, SD
FXUS63 KABR 230137 AAA
Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
837 PM CDT SUN MAY 22 2016
Issued at 820 PM CDT SUN MAY 22 2016
A north/south oriented line of storms near the Missouri River is
expected to gradually shift east, with some enhancement in areal
coverage possible as the LLJ increases. Unsure of exactly how the
storms will evolve as we loose surface based heating and move
toward elevated convection. The best instability and bulk shear
never really coincide, so unsure how the system will evolve. Many
CAM solutions show storms merging into a subsevere line, and
tracking across the CWA through the night. Will continue to
monitor storms and severe threat.
UPDATE Issued at 629 PM CDT SUN MAY 22 2016
The updated aviation discussion can be found below.
.SHORT TERM...(This Evening through Tuesday Night)
Issued at 353 PM CDT SUN MAY 22 2016
The threat for severe storms this evening through tonight will be
the main forecast concern.
A shortwave currently over northern Utah will continue tracking
towards the Northern Plains tonight. This shortwave will help
advance a surface cold front/dry line across the Dakotas tonight.
Plenty of instability and 0-6 km bulk shear will be located with
this front with strong to severe storms possible....more so for
counties along and west of the Missouri River. If individual
supercells can develop late this afternoon...then tornadoes could be
possible in south central South Dakota where slightly better 0-1 km
bulk shear will be located. That said...most CAMS suggest clusters
of storm to severe storms will be the likely scenario with large
hail and damaging winds the main threat. As storms track eastward
overnight...a strengthening LLJ should help maintain a wind and
large hail. Also...with high PWATS tonight...along with the
possibility for training storms...locally heavy rainfall will
possible tonight as well. Thankfully flash flood guidance is
fairly high due to the recent dry weather.
Most of the convection should diminish toward Monday morning in the
eastern CWA with dry conditions possible around midday. With the
front stalling along I-29...additional thunderstorms will be
possible during the afternoon hours. The threat for severe storms
Tuesday looks mostly dry until the late afternoon hours. This is
when another shortwave will cross the region with showers and
thunderstorms possible Tuesday night for most areas. Severe storms
are not expected.
.LONG TERM...(Wednesday through Sunday)
Issued at 353 PM CDT SUN MAY 22 2016
An active pattern is expected for the long term. Broad southwest mid
level flow will keep a storm track directed at the Central/Northern
Plains for much of the time period. The period with the greatest
potential for decent/widespread rain and thunder will be late
Tuesday night and Wednesday as a strong wave propagates across the
cwa. After that...forecast details become a little muddy. With a
frontal boundary splayed out south of the region...there will be
continued chances for pcpn most periods. Confidence in timing...etc
is low at this point. temperatures are expected to average out near
normal for the period.
.AVIATION...(For the 00Z TAFS through 00Z Monday Evening)
Issued at 629 PM CDT SUN MAY 22 2016
A north/south oriented line of thunderstorms has developed along
and west of the Missouri River. This line of storms is expected to
gradually move east throughout the night. Thunderstorms will
impact the KPIR/KMBG areas through the 03Z/06Z time frame and then
impacting the KABR/KATY TAF sites after 06Z. TAF amendments will
be made as storms approach individual sites.