-- Discussion containing changed information from previous version are highlighted. --
051
FXUS63 KABR 121209 AAA
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
709 AM CDT Wed Jun 12 2024

.KEY MESSAGES...

- There are slight chances to chances (15-45%) of showers and
thunderstorms through tonight. The precipitation chances Wednesday
afternoon look to remain along and east of the James River Valley
and mainly east of I-29. Some storms may become strong to severe.

- High temperatures today are forecast to warm into the upper 80s to
mid 90s, which is 10 to 15 degrees above normal.

- A storm system Friday night through Saturday night and early
Sunday will bring a 30-60% chance of showers and thunderstorms. The
storm system may produce locally heavy rainfall over eastern SD and
western MN.

&&

.SHORT TERM /TODAY THROUGH THURSDAY AFTERNOON/...
Issued at 453 AM CDT Wed Jun 12 2024

Showers and general thunderstorms have developed early this
morning on the nose of a llj. Over the next few hours, sfc and
850mb winds are expected to become more southwesterly with
westerly winds aloft. That direction lends itself more to drying,
downslope winds rather than moisture converging, convection
developing flow, so will need to see if that cuts off some of
this activity. But, either way, all of the precip is expected to
exit to the east later this morning.

Models then diverge considerably from each other for this afternoon
and evening. Most do not have any further convective development
over this cwa. A couple, including the NAMNest and the ARW, have a
few storms developing either in west central MN or in Deuel county
between 22z and 0z beore quickly exiting. SPC`s expansive slight
risk seems overdone to the west given these solutions. There is a
corridor of 3000 to 4000 J/kg of CAPE on models like the RAP with 45
kts of bulk shear along and east of the Coteau, so if any supercells
do form, they would produce large hail and strong winds. Confidence
is low on late afternoon development.

A weak baroclinic zone sets up tonight, though some guidance keeps
it farther south while others have it as far north as ND. Still,
added in some pops for tonight, though precip will have to overcome
the mid level dry air that is also moving in on westerly flow.

&&

.LONG TERM /THURSDAY EVENING THROUGH TUESDAY/...
Issued at 453 AM CDT Wed Jun 12 2024

The long term portion of the forecast begins on Thursday night with
a surface high pressure over the region with an upper level ridge
building over the northern Rockies. A deep upper level trough over
the desert southwest will begin lifting northeast by Friday morning
with perhaps some return flow developing over the Black Hills of
South Dakota. A weak shortwave crossing the area Friday afternoon
may cause convective developed over western South Dakota with the
convection spreading eastward Friday night through Saturday. An
increasing 30-40 knot LLJ, as well as upper level support for an
upper level trough should cause more robust convection Saturday
morning, mainly over eastern South Dakota and western Minnesota. The
NBM maintains a 20-35% chance of one inch of QPF over a 24 hour
period ending at 0Z Sunday. Eastern and especially southeastern SD
has the best potential of seeing moderate rainfall. Convection from
this initial round of storms should push east of the CWA Saturday
morning with a period of dry conditions possible Saturday through
Sunday.

However, an upper level trough and surface low pressure system
crossing North Dakota Saturday night into Sunday may produce
convection along the ND/SD border. Warm 700 mb temps of +12C may
limit the thunderstorm potential. Beyond Sunday, the weather pattern
remains active with two additional low pressure systems crossing the
region, bring more showers and thunderstorms early next week.

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
-- Changed Discussion --
Issued at 704 AM CDT Wed Jun 12 2024

Terminals KABR,KATY,KPIR,KMBG

VFR conditions are expected through the period except in
thunderstorms. Thunderstorms will move near KATY until 15z this
morning.
-- End Changed Discussion --

&&

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

$$

SHORT TERM...Wise
LONG TERM...SD
AVIATION...Wise