111
FXUS63 KUNR 041056
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
456 AM MDT Thu Jul 4 2024

.KEY MESSAGES...

- Unsettled 4th of July
- Warmer with smaller chances of storms through Sunday afternoon
- Hot/dry weather develops next week

&&

.DISCUSSION...(Today Through Wednesday)
Issued at 1257 AM MDT Thu Jul 4 2024

06z surface analysis had cold front south of the CWA. Water
vapour depicted upper trough over the Dakotas with cyclonic flow
over the CWA promoting scattered showers/TS. Upper trough
disposition main concern in the short term.

Today, upper trough saunters eastward as moist cyclonic flow
spins through the CWA. Buoyancy (<1KJ/kg SBCAPE peak)/weak shear
in place with steep low level lapse rates. Should see uptick in
convection later this morning/afternoon, most of which will be
pulsey, outflow- dominated. Temperatures will be a bit below
guidance given expected cloud cover/precipitation.

Tonight, weak surface anticyclone brings drier air and quick
dissipation of precipitation. MinT near guidance.

Friday through Sunday afternoon, a couple of weak shortwaves move
across the northern plains per northwest flow aloft. Strongest
wave painted for Saturday with sufficient buoyancy/shear in the
east for a stronger storm. Temperatures will slowly warm.

Next week, confidence continues to increase that western CONUS
upper/thermal ridge builds into the northern plains. 50% chance
90F+ over the west Wednesday spreads east for the end of the week
with 75% chance 90F+ most areas.

&&

.AVIATION...(For the 12Z TAFS Through 12Z Friday Morning)
Issued At 454 AM MDT Thu Jul 4 2024

Scattered showers/storms will redevelop today, the decrease toward
the evening. Otherwise VFR conditions are expected across the
area. Northwesterly winds will become breezy Thursday morning,
especially across the western South Dakota plains, where gusts up
to 35 kts are possible.

&&

.FIRE WEATHER...
Issued At 1257 AM MDT Thu Jul 4 2024

A pattern change to much drier and warm/hot weather is foreseen
for next week. Minimum afternoon relative humidities in the
teens are possible by Wednesday over parts of northeastern WY/far
western SD. Elevated fire weather conditions expected.

&&

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

$$

DISCUSSION/KEY MESSAGES...Helgeson
AVIATION...13
FIRE WEATHER...Helgeson