608
FXUS63 KABR 210539 AAA
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1239 AM CDT Thu Sep 21 2017

.UPDATE...
Issued at 1239 AM CDT Thu Sep 21 2017

06z aviation discussion updated below.

UPDATE Issued at 929 PM CDT Wed Sep 20 2017

Quiet night and the forecast is on track. Seeing some increasing
cloud cover nearing the far northwestern corner of the forecast
area, but overall a clear/mostly clear sky tonight should be
maintained. A southeast surface wind should persist overnight,
perhaps picking up some toward sunrise on Thursday. Despite the
dry surface/near surface air and relatively clear sky, not
expecting to see temperatures tumble overnight. Generally, lows in
the upper 40s to mid 50s by morning still looks okay.

UPDATE Issued at 659 PM CDT Wed Sep 20 2017

See below for an aviation forecast discussion for the 00Z TAFs.

&&

.SHORT TERM...(This Evening through Thursday Afternoon)
Issued at 312 PM CDT Wed Sep 20 2017

Surface high pressure will slide off to the east tonight as an
elongated low pressure system currently over the Rockies begins to
intensify and push eastward. By late Thursday afternoon, the low
will be centered over Colorado with a boundary extending
northeastward to eastern North Dakota. Conditions will remain dry
during this time period, with southerly flow bringing warmer air up
into the region. Lows tonight will be in the 50s, with highs on
Thursday in the upper 70s to mid 80s.

.LONG TERM...(Thursday Evening through Wednesday)
Issued at 312 PM CDT Wed Sep 20 2017

The long term will characterized as a fairly active period. Positive
tilt western conus mid level trof will come out in pieces through
the period. First chunk of energy comes out Friday into Friday
night. There is good shear/instability, particularly along and east
of the I29 corridor, so SPC slight risk looks good for now. After
Friday night, the entire mean frontal boundary slides a bit
further east, taking the highest amounts of available energy with
it, thus severe weather looks fairly minimal beyond about 60 to 72
hours.

Severals waves of energy aloft and a nearly stationary front will
set up the potential for a couple periods of heavy rain, especially
across the eastern CWA. The first event should be Saturday night
into Sunday. The second event should occur Sunday night into
Monday, but may be slightly displaced southeast of the first heavy
rain band.

As for temperatures, they will likely start out above normal early
in the period, but then trend to below normal over the weekend as
frontal boundary continues to sink south.

&&

.AVIATION...(For the 06Z TAFS through 06Z Thursday Night)
Issued at 1239 AM CDT Thu Sep 21 2017

The forecast currently calls for prevailing VFR conditions at
all four terminals through late Thursday evening. Low level wind
shear should be developing between 1000ft and 2000ft agl within the
next couple of hours at KPIR/KMBG and persisting into Thursday
morning before being mixed out. The low level jet responsible for
generating this wind shear is expected to expand as far east as the
KABR terminal for a few hours prior to sunrise before being mixed
out. Also, there could be a few elevated thunderstorms developing
over northeast South Dakota into west central MN Thursday night.
Will not include in the TAFs this go around, but TS may be needed in
the KABR and/or KATY TAF within the next couple of issuances.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
&&

$$

UPDATE...Mohr
SHORT TERM...Parkin
LONG TERM...TDK
AVIATION...Mohr