000
FXUS63 KABR 291109 AAA
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
609 AM CDT Thu Sep 29 2022

.SHORT TERM...(Today through Friday Afternoon)
Issued at 408 AM CDT Thu Sep 29 2022

The generally quiet weather pattern over the Northern Plains will
continue for a couple more days at least. Currently, energy is
digging into the Northern Rockies, with flat ridging continuing over
the Western High Plains. That digging energy will result in a cutoff
low over the Northern Rockies within about 24 hrs. Then the low is
not expected to move much for the next 48-60 hrs. Any pcpn
associated with this system will remain west of the ABR CWA through
at least Friday. Meanwhile, a couple of weak s/ws are forecast to
ride the ridge and come across the region today/tonight. For now it
appears conditions will remain dry with only some virga looking
possible from mid level cloudiness. Soundings just look too dry to
support any measurable pcpn. Temperatures will continue to be above
to well above normal under ridging aloft, and those warm/mild temps
are expected to persist through the upcoming weekend per 2m/H850
temp anomalies.

Lastly, winds will again be a bit breezy/windy across especially the
eastern CWA. Grassland fire danger is again likely to reach the very
high category over much of the forecast area. However, lowest
afternoon relative humidity appears to bottom out around 30-35
percent within the highest wind corridor. So, for now, will handle
the fire danger with a Special Weather Statement.

.LONG TERM...(Friday Evening through Wednesday)
Issued at 408 AM CDT Thu Sep 29 2022

At the start of the period Friday evening, models are in good
agreement about the placement of a cut-off upper-low across the
northern Rockies, and about this feature being underneath an
anonymously strong/amplified upper ridge. At the surface, low
pressure will most likely be positioned across western/central South
Dakota. Despite the development of a LLJ and associated lift across
eastern SD (~20kt 850mb mean from the ECMWF/NAEFS), precipitation
chances will be higher further west in the state, nearer the highest
low-level moisture and shortwave energy rotating around the upper-
low. The main challenge is determining the movement and evolution of
this low (can be a big challenge), as this will dictate
precipitation chances (or the continued lack there-of, and thus a
continued potential for fire danger). The WPC Cluster Page reveals
continued good agreement in the presence of a cut-off low through
00z Sun to 00z Mon, with only 24% of the total ensembles evolving it
into an open wave (this feature in either form still centered across
the Northern Rockies). Potential solutions diverge more by 00z Mon
to 00z Tue, with about 51% of the ensembles depicting a more
progressive open wave entering the Northern Plains (mainly GEFS) and
the other 49% maintaining a closed upper-low across Montana (mainly
ECMWF). A faster evolution to a progressive open wave would bring
unsettled conditions/precipitation chances sooner. By the end of the
period, during the middle of the week, this system exits east and a
more conventional upper-level ridge to the west of the area and
upper-trough to the east appears.

Temperatures should remain above average out ahead of the upper-low
with persistent southerly winds, and then decrease to near normal
readings as the system moves through. Confidence remains below
normal on exact timing of this shift, as described above.

&&

.AVIATION...(For the 12Z TAFS through 12Z Friday Morning)
Issued at 608 AM CDT Thu Sep 29 2022

Terminals KABR,KATY,KPIR,KMBG

VFR skies/vsbys are expected through today along with gusty winds.

&&

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

$$

SHORT TERM...TDK
LONG TERM...Lueck
AVIATION...TDK