886
FXUS63 KUNR 081116
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
516 AM MDT Sat Jun 8 2024

.KEY MESSAGES...

- Showers and thunderstorms this morning into this afternoon with
  a chance for an isolated severe storm or two in far southwest
  SD.

- Chances for showers and storms linger through the weekend

- At or above average temperatures through next week

&&

.DISCUSSION...(Today Through Friday)
Issued at 242 AM MDT Sat Jun 8 2024

Current upper air analysis depicts upper level low centered over
central SK. At the sfc a cold front sits oriented from northeast
to southwest across SD. A few showers/storms have developed over
the Black Hills.

Mid-level wave crosses the region this morning with sufficient
moisture in the low to mid levels to trigger some shower/storm
development through the morning hours. Second wave passes south of
the CWA this afternoon with chances for more thunderstorms to
develop across the southern portions of the CWA. Moisture will be
a limiting factor with the convection this afternoon with the
better low to mid level moisture to the south in NE. Effective
shear is also displaced to the north of the higher instability.
Still, extreme southwestern SD could see an isolated strong to
severe storm or two as MU CAPE increases to 500-1000 J/kg this
afternoon with effective shear of 30-40 kt.

Upper level jet diminishes through this weekend as the upper low
over the Great Lakes moves to the east and the upper low over
SK/MB stalls out. Upper ridge will build into the region from the
west through Sunday, putting us under northwest flow. A few
impulses riding along the flow will give daily chances for showers
and storms through the weekend. Trough will move into the Pac NW
by early Sunday and cross the Rockies, dislodging the stalled out
upper low over SK and giving us our next chance at more widespread
showers/storms Monday afternoon and evening as the trough and
attendant front crosses the region. Axis of 1000-2000 J/kg MU CAPE
develops in western SD Monday afternoon with 0-6KM shear of
30-40kt. Along with decent deep layer moisture, we could see some
severe storms developing Monday afternoon.

Models have better consensus on zonal flow developing over the
northern plains by mid-week. Ensembles are in general agreement of
near to above average temps (generally a 80-100% chance for temp
anomalies of 5+F by Wednesday and Thursday) with low (0-20%
chances for 24 hr QPF >0.1") chances for any meaningful precip
through the end of the week.

&&

.AVIATION...(For the 12Z TAFS Through 12Z Sunday Morning)
Issued At 514 AM MDT Sat Jun 8 2024

VFR conds most places. A few areas of MVFR-IFR cigs will linger
over central and scentral SD this morning, trending VFR later this
morning. Sct SHRA will end this morning with additional showers
and storms possible this evening over the SW third.

&&

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

$$

DISCUSSION/KEY MESSAGES...Wong
AVIATION...JC