676
FXUS63 KABR 101740 AAC
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1240 PM CDT Mon Jun 10 2024

.KEY MESSAGES...

- There is a 40 to 70% chance of showers and thunderstorms late
  this afternoon through tonight. Some storms along and west of
  the Missouri River may become strong to severe this evening.
  Main threats are winds gusting around 60 mph, with hail up to
  quarter size.

- There is a 20-40% chance of showers and thunderstorms Wednesday
  into Wednesday night, mainly along and east of the James River
  Valley. Some storms may become strong to severe.

&&

.UPDATE...
Issued at 1234 PM CDT Mon Jun 10 2024

Aviation discussion updated below for the 18Z TAFs.

UPDATE Issued at 1040 AM CDT Mon Jun 10 2024

No immediate updates needed over the next couple hours. Main
concern today will be strong to severe storm potential over the
western CWA closer to 22Z-00Z. May need to make some adjustments
to PoPs closer to that time based on convective initiation and
movement of cells that develop over UNR CWA. Otherwise, made minor
adjustments to sky grids based on satellite trends. No major
changes to high temps today, which will range from the upper 70s
to mid 80s for most areas. The breezy/gusty south-southeast winds
across central SD today look to stay mostly below advisory
levels (30 mph sustained and/or gusts 45mph).

&&

.SHORT TERM /TODAY THROUGH TUESDAY AFTERNOON/...
Issued at 505 AM CDT Mon Jun 10 2024

A few light showers/sprinkles have popped up across central SD this
morning, but have quickly dissipated as they encounter the sfc high
to the east and lack of instability/forcing. South to southeast
winds will increase today. There are two different model scenarios
for the focus point for this evening`s thunderstorms. One extends a
trailing sfc front down into SD from a low at the Canadian border
with a reinforcing upper trough and its associated PVA. The other
has a Rocky Mountain low moving into the Plains and extending an
inverted sfc trough into central SD. Either solution provides enough
forcing for strong to severe storms. Models start bringing storms
into our west river counties around 0z. Latest RAP only shows 1000
to 2000 J/kg of CAPE right around a narrow corridor near the
inverted sfc trough but strong shear of 40 to 50 kts. Lapse rates
are not that impressive at about 5 to 6. A very concentrated
marginal area seems the most appropriate. Will likely see storms
weaken quickly as they progress east of the Missouri and the best
parameters weaken. Showers and general thunderstorms will spread
east overnight with the upper trough and cold front.

For Tuesday, sfc high pressure builds in again, but the upper trough
will keep temperatures seasonable.

&&

.LONG TERM /TUESDAY EVENING THROUGH SUNDAY/...
Issued at 505 AM CDT Mon Jun 10 2024

The long term portion of the forecast will feature an active weather
pattern with a couple storm systems crossing the region.

The period begins on Tuesday night with an area of low pressure over
the western Dakotas with warm air advection over the eastern
Dakotas. A few storms may develop early Wednesday morning with the
WAA and weak LLJ. The surface low pressure and associated frontal
boundaries will  move eastward on Wednesday, with convection
possible along a cold front over eastern SD and western MN. The
latest rendition of the NBM suggest mostly dry conditions on
Wednesday, with only a 15-20% chance of storms. The thunderstorm
potential increases to 25-40% after 0Z Thursday, which may be too
high based on some deterministic models with the frontal boundary
east of the CWA.

There is some consistency among models with another storm system
crossing the region Wednesday night through Thursday morning with
the NBM showing a 20-40% chance of pcpn. After a brief period of dry
conditions Thursday afternoon through Friday afternoon, a couple of
storm systems will track across the region Father`s Day weekend,
with several rounds of showers and thunderstorms.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1234 PM CDT Mon Jun 10 2024

Terminals KABR,KATY,KPIR,KMBG

VFR conditions are forecast through the TAF period. Will be
watching TSRA/+TSRA potential moving into the KPIR/KMBG vicinities
around 00Z this evening. Due to uncertainty in areal coverage of
storms, stuck with a VC (vicinity) mention for now until activity
forms on radar. Will TEMPO any potential MVFR CIGs/VSBY if a TSRA
approaches a terminal. Any stronger storms are capable of hail
and gusty and erratic surface/near surface winds around 50 knots
or higher.

&&

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

$$

UPDATE...TMT
SHORT TERM...Wise
LONG TERM...SD
AVIATION...TMT