Area Forecast Discussion
Issued by NWS Rapid City, SD

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FXUS63 KUNR 300810
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
210 AM MDT THU JUN 30 2016

.SHORT TERM...(Today Through Friday Night)
Issued at 204 AM MDT Thu Jun 30 2016

Northwest upper flow continues over the region, with a ridge over
the Rockies and a trough over the eastern states. Most of the storm
activity associated with a weak upper wave has moved out of the
CWA, but there are There are some showers over parts of
northeastern WY, and newly developed showers over the southern
Hills. Cold front is beginning to move into SD from the north.
Winds are light and variable, and temperatures are in the 50s to
lower 60s.

Light northeasterly winds may result in some fog/low clouds across
northwestern SD this morning, which several models are hinting at.
Brought mention southward to the northeastern foothills for any
upsloping that might occur.

Cool high pressure will slide into the northern plains today, as
cold front stalls across northeastern WY. Pressure gradient will
tighten a bit across the area, and northeasterly winds will become
breezy across the western SD plains. Southeasterly return flow will
develop across southwestern SD into northeastern WY, where some weak
instability will develop. Showers and thunderstorms are expected
across northeastern WY, the Black Hills, and southwestern SD today.
These will be enhanced by another shortwave passing through in the
evening, but the threat for severe weather should stay south of the
CWA where instability is better. Highs will be around 80s, with 70s
in the Black Hills.

Showers/storms may continue across the same areas overnight along
the baroclinic zone, with some weak instability available. Lows will
be generally in the 50s.

Surface high shifts southeastward Friday, and breezy return flow
develops across the CWA. Forecast soundings show fairly moist
profiles and weak instability. Under continued active flow, expect
scattered showers and thunderstorms Friday, gradually decreasing
Friday night. Cool airmass and easterly low-level flow will result
in 70s for highs Friday, with 60s in the Black Hills.

.LONG TERM...(Saturday Through Wednesday)
Issued at 204 AM MDT Thu Jun 30 2016

Upper ridging over northern plains will give way to more of a
zonal flow pattern late in the weekend, then becoming
southwesterly flow aloft early next week as an upper trough moves
into the Pacific Northwest. A shortwave trough will pass to the
south of the area Sat & Sun, with some storms possible, mainly
over southern SD although there might be enough instability in to
produce isolated thunderstorms in a narrow N-S band on either side
of the WY/SD border. As the upper flow transitions to
southwesterly early next week, will continue to see isolated to
scattered thunderstorms as southerly low level flow continues to
advect moisture into the region. Temperatures will be near average
on Saturday, with highs climbing to 10-15 degrees warmer than
average early next week.

&&

.AVIATION...(For the 12Z TAFS Through 12Z Friday Morning)
Issued At 204 AM MDT Thu Jun 30 2016

Lcl IFR conditions in patchy fog are possible over
northwestern South Dakota and along the Spearfish-Sturgis foothills
generally from 10Z-15Z this morning, otherwise VFR conditions will
prevail. Isold-Sct showers and thunderstorms are expected over parts
of northeastern Wyoming, the Black Hills area and southwestern South
Dakota this morning with better chances for thunderstorms over those
same areas this afternoon and tonight.

&&

.UNR Watches/Warnings/Advisories...
SD...None.
WY...None.
&&

$$

SHORT TERM...Pojorlie
LONG TERM...10
AVIATION...10


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