820
FXUS63 KABR 282017
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
317 PM CDT Tue May 28 2024

.KEY MESSAGES...

- Southeast winds will increase on Wednesday, with gusts of 25-45
  mph. The strongest gusts will occur across central South Dakota.

- There is a 60-90% chance of showers and thunderstorms late
  Wednesday night and Thursday. A few storms could be strong to
  severe late Wednesday night west of the Missouri River.

&&

.SHORT TERM /THIS EVENING THROUGH WEDNESDAY NIGHT/...
Issued at 316 PM CDT Tue May 28 2024

Upper level ridging has begun to build over the region, and will be
the dominant upper feature tonight through Wednesday evening, before
a shortwave trough begins to move in during the overnight hours.

At the surface, high pressure currently over the area will remain in
place tonight before sliding east of the CWA on Wednesday ahead of
low pressure tracking across the Rockies. Will see a tightening
pressure gradient during the day Wednesday, with southeasterly winds
increasing into the 15 to 30 mph range during the late morning and
afternoon hours. The strongest winds gusts will occur across central
South Dakota in the afternoon, where some gusts of 40 to 45 mph are
possible. The low to the west and its associated frontal boundary
will reach western South Dakota Wednesday evening, then to about the
Missouri River during the overnight hours. Some weak instability
(less than 500 J/kg) will accompany the front, but the best shear
(40 to 55 knots) will lag behind the front and stay west of the CWA
during the overnight hours. SPC has issued a Marginal Risk for
severe weather for the areas just west of the Missouri River during
this time, but better chances will be west of the CWA.

Low temperatures tonight will be in the lower to mid 40s. High
temperatures on Wednesday will be in the 70s, though a few locations
west of the Missouri River may exceed 80 degrees. Lows Wednesday
night will be in the lower to mid 50s.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Issued at 316 PM CDT Tue May 28 2024

The long term portion of the forecast begins on Thursday with a
frontal boundary moving eastward across the region with an upper
level trough off to the west. A few showers and thunderstorms may be
ongoing Thursday morning west of the James River Valley. As the LLJ
does fade during the mid morning hours, with showers and storms
dissipating some. Convection may redevelop along and east of the
James River during the afternoon hours. Convection should push east
of the CWA between 0-3Z Friday, with mostly dry conditions until at
least 12Z Friday. A trailing shortwave embedded within the trough
axis may provide another round of showers and thunderstorms, mainly
over the western CWA. Some deterministic models suggest limit pcpn
with the trailing shortwave with mostly dry condition remaining
across the CWA until Sunday afternoon. However, model differ overall
with additional chances of pcpn, with the NBM remaining maintaining
pops (20-40) on Friday night into Saturday morning.

A surface low pressure system and upper level trough should cross
the region Sunday afternoon through Monday morning. The storm system
will bring the next best chance for pcpn, with the NBM showing a 40
to 65 percent chance. Modest instability and shear ahead of the
frontal boundary may set the stage for strong to severe
thunderstorms, mainly along and east of the James River. There is a
potential for mid level capping, especially if 700 mb temps reach
+9C, or above the 90th percentile.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1222 PM CDT Tue May 28 2024

Terminals KABR,KATY,KPIR,KMBG

VFR conditions will prevail across the area through the TAF
period. Look for southeasterly winds to increase into the 15 to 30
knot range Wednesday morning.


&&

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

$$

SHORT TERM...Parkin
LONG TERM...SD
AVIATION...Parkin