Area Forecast Discussion
Issued by NWS Rapid City, SD

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FXUS63 KUNR 280447
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1047 PM MDT MON JUN 27 2016

.SHORT TERM...(This Evening Through Tuesday Night)
Issued at 245 PM MDT Mon Jun 27 2016

Upper air analysis shows upper ridging across the nrn Rockies into
the Great Basin. NWrly flow sits across the Dakotas behind a
departing wave moving into MN. A weak shortwave is crossing
cntrl/ern WY at this time moving toward the Neb panhandle. Surface
analysis showing high pressure stretching from ern MT to through the
CWA into cntrl Neb. Radar showing isolated storms developing across
the cntrl Black Hills. SBCape values over the Hills are reaching 500
to 1000 with generally weak shear. Better shear can be found toward
sw to scntrl SD where better moisture can be found resulting in
MLCape of 1000-2000 J/kg. Stronger storms are thus possible across
sw SD this afternoon and evening. HRRR shows a cluster of storms
pushing from the BH/sw SD toward scntrl SD this evening with perhaps
one or two storms becoming severe. Surface high will slide east of
the area with return flow bringing a surge of higher dewpoints.
Lingering overnight showers/storms may then redevelop northward
toward nw SD as instability increases.

Theta E advection will continue Tuesday bringing dewpoints into the
upper 50s/low 60s across the wrn SD plains. Highs will reach the 80s
to low 90s. Models continue to show storms develop Tue
afternoon/evening across the Black Hills and surrounding areas.
SBCape will range from 2000 to 3000 J/kg with strong shear profiles
suggesting the potential for splitting supercells. Large hail and
damaging winds will be possible. Models continue to show the
evolution of these storms into an MCS which will push E/SE into the
cntrl/panhandle of Neb and East River SD. Convective activity with
then decrease in the late night hours across the CWA.

.LONG TERM...(Wednesday Through Monday)
Issued at 245 PM MDT Mon Jun 27 2016

Rockies high pressure ridge center will remain southwest of the
region, with the northern plains on the northern periphery and
fast flow aloft through most of the period. Mean ne pac upper
trough will remain in place, ejecting weak disturbances into
westerly flow. This will support periodic disturbances into the
area as general easterly upslope flow remains in place in the low
levels. Certainly not expecting any widespread precip, with
scattered nature to precip. Pac ne upper trough is progged to
shift east this weekend, supporting downstream ridging over the
northern plains and potential very hot and windy conds once again
by early next week.

General moist/easterly upslope flow will prevail in the period with
impulse laden wnw flow aloft. Diurnal convection is expected in the
area nearly every day, although coverage will be limited to sct-
isold. Fast wnw flow will support increased deep layer shear through
the period with sufficient cape given moist ll flow. Hence, there
will be a muted severe threat each day as an isolated severe storm
or two is possible given cape/shear progs. Lack of strong upper
level forcing precludes any widespread severe threat. As for temps,
seasonal conds forecast, with generally 80s for highs. Another sig
warm up looks likely early next week with a sfc low pressure pushing
the hot dome east into the region once again.

&&

.AVIATION...(For the 06Z TAFS Through 06Z Tuesday Night)
Issued At 1044 PM MDT Mon Jun 27 2016

Areas of smoke from fires over the Bear Lodge mountains and
northern Black Hills will bring local MVFR/IFR VSBYS to the
northern Black Hills area at times. Isolated TSRA may develop
overnight over NWRN-WCNTRL SD, and could result in MVFR CIGS.
Otherwise, strong to severe thunderstorms will develop over much
of northeastern Wyoming and southwestern South Dakota Tuesday
afternoon and persist through early evening.

&&

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

&&

$$

SHORT TERM...13
LONG TERM...JC
AVIATION...Bunkers



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