817
FXUS63 KUNR 071828
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1228 PM MDT Sun Jul 7 2024

.KEY MESSAGES...

- Popcorn showers/thunderstorms today
- Hot/dry weather develops next week
- Elevated fire weather conditions second half of next week

&&

.DISCUSSION...(Today Through Saturday)
Issued at 136 AM MDT Sun Jul 7 2024

07z surface analysis had low over eastern ND with trailing
stationary front into eastern NE, then into central WY. Features
reflection of upper trough per water vapour across the northern
Plains/upper Midwest. Trough spinning series of weak shortwaves
across the region with one over northwest SD and another over
southern SK. Regional radar loop depicted isolated/scattered
showers/TS. Effects of these features main short term concern.

Today/tonight, last shortwave passes through CWA with weak
buoyancy (300-700J/kg SBCAPE)/shear (<30kts 0-6km bulk) regime.
Overnight precipitation should wane this morning a bit, but most
CAMS depict popcorn showers/TS by afternoon as convective
temperatures are reached, especially over western SD. Decreasing
influence of upper trough tonight combined with loss of solar
insolation will promote end of precipitation. Temperatures will
be near guidance.

Next week, high confidence that western CONUS upper/thermal ridge
expands into the northern Plains. The result will be drier and
increasingly hot weather. High probability of 90F+ MaxT for the
end of the week with 100F readings within reach, especially Friday
and Saturday per probabilistic guidance/EFI.

&&

.AVIATION...(For the 18Z TAFS Through 18Z Monday)
Issued At 1225 PM MDT Sun Jul 7 2024

Isolated TSRA/SHRA will continue through early evening. Otherwise,
VFR conditions will continue.

&&

.FIRE WEATHER...
Issued At 136 AM MDT Sun Jul 7 2024

Confidence is high that next week will be increasingly hot and
dry. Minimum afternoon relative humidities will dip into the teens
over northeastern WY Wednesday, spreading into western SD by the
end of the week. Elevated fire weather conditions are expected.

&&

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

$$

DISCUSSION/KEY MESSAGES...Helgeson
AVIATION...MLS
FIRE WEATHER...Helgeson