346
FXUS63 KUNR 141711
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1111 AM MDT Fri Jun 14 2024

.KEY MESSAGES...

- Chances for showers and thunderstorms through the weekend and
  into next week.

- Above normal temps continue through Saturday, cooling off moving
  into next week.

&&

.DISCUSSION...(Today Through Thursday)
Issued at 214 AM MDT Fri Jun 14 2024

Current surface analysis shows high pressure centered over the
Dakotas, with a surface low over south central Wyoming this
morning. Upper level models show upper ridge sliding over the
northern and central plains, while upper low sits over the
southwestern CONUS. Mostly clear skies this morning, with clouds
moving in from the southwest. Temperatures currently sit in the
mid 50s to mid 60s across the forecast area, with light and
variable winds. Ridging and associated high will allow for another
warm day today, with highs generally in the 80s.

As the high slides east of the forecast area, low level southerly
flow moves in, increasing theta-e and moisture through the day.
Low level jet also sets up over the region this morning,
increasing chances for showers/storms mainly over southwestern SD,
then spreading throughout the region as the day progresses.
Models show increasing CAPE to 1000-2000 j/Kg this afternoon, with
the highest CAPE values from northeastern WY into northwestern
SD. As surface low approaches, increasing cloud cover may hamper
CAPE values for some areas, however if storms are able to fire up,
modest shear (30-40kt) should be enough for supercell potential.
Best chance for severe will be in the afternoon and evening hours
with large hail and stronger winds being the main threats.

Saturday continues the above normal temperatures, with highs
climbing into the upper 80s to low 90s for much of the forecast
area. Daytime heating and some weak instability may allow for some
isolated showers/storms through the day, however better chance
comes later Saturday night into Sunday as a cold front pushes
through the region. Timing of the front may limit any severe
potential for Saturday, but boundary moving through will cool
things down for Sunday into early next week. Mostly dry conditions
through much of Sunday, however mid-level disturbance will
increase precipitation chances late Sunday into Monday and
potentially another disturbance affecting the region on Tuesday.
The latter half of next week, models show broad ridging build over
the central and eastern CONUS, which may push any disturbances to
our north, and bring warmer and drier conditions back into the
region.

&&

.AVIATION...(For the 18Z TAFS Through 18Z Saturday)
Issued At 1108 AM MDT Fri Jun 14 2024

Isolated to scattered thunderstorms will occur into tonight. Some
of the storms this afternoon and evening may contain hail and
strong gusty winds. IFR CIGS due to stratus may develop over
central SD after 04Z tonight. Local MVFR CONDS may occur with
stronger thunderstorms. Otherwise, VFR conditions expected.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...None.
WY...None.
&&

$$

DISCUSSION/KEY MESSAGES...Dye
AVIATION...10