010
FXUS65 KVEF 090758
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
1258 AM PDT Sun Jun 9 2024

.SYNOPSIS...A trough reaching the West Coast brings short-lived
relief from the heat today and Monday, before high pressure builds
overhead again and pushes temperatures back to dangerous levels
Tuesday and Wednesday. The peak of the heat should only last two
days, but the stretch of above normal temperatures which has been
ongoing since late May will continue.
&&

.SHORT TERM...through Wednesday night. Midnight satellite loop
showed scattered cirrus over the Mojave Desert and convective debris
clouds over the southern Great Basin. Surface obs showed generally
light winds areawide and temperatures averaging a few degrees lower
than 24 hours ago. The advertised heat relief is here as the weak
trough pushes into the West Coast, but it won`t last long. Models
are in good agreement showing this trough splitting (and there are
already signs on mid level water vapor), with the northern piece
zipping away to the east across the northern Rockies on Monday while
the southern piece forms a cut off low off the southern California
coast. This leaves a skinny east-west oriented ridge axis over our
area, which builds through Wednesday, with 500 mb heights reaching
590 dam Tuesday and Wednesday. This will lead to another round of
heat, with the NBM showing a 63 percent chance of Las Vegas reaching
110F again on Wednesday, and a swath of Major HeatRisk through the
lower elevations of Inyo, Clark, and Mohave counties Tuesday and
Wednesday. Thus, issued an Excessive Heat Watch for these areas. As
far as thunderstorm chances go, high resolution models correctly
forecast the downward trend in chances from Friday to Saturday, and
the consensus is for chances to drop even further today and become
nearly absent beginning Monday as heights build overhead.

.LONG TERM...Thursday through Saturday.

A cut off low that has been hanging out off the Baja California
coast will lift northeast through the region Thursday through
Saturday, with decent agreement among long term models in timing and
overall set up as this occurs. A cool down in temperatures from the
peak heat midweek is likely. For example, the probability for 110F
in Las Vegas is around 60% on Wednesday, but quickly falls to 30% or
less for the rest of the period. Temperatures will fall back closer
to normal and HeatRisk drops to widespread moderate levels at most
Thursday through the weekend. Most likely, it will remain dry with
probabilities for any precipitation for Thursday through next Sunday
remaining low to near zero. PWATs do increase to near normal levels
as the low crosses the region Friday and Saturday, but with very dry
low levels it makes sense that no measurable precipitation is
currently expected. Expect afternoon breezes but no impactful winds
with this system either. In general, the low should come through
with minimal impacts, just will kick down temperatures a few
degrees.
&&

.AVIATION...For Harry Reid...South-southeast breezes persist through
most of the day, only turning to the south-southwest after sunset
this evening. Until then, wind direction is expected to be generally
between 150-190. The probability of 10+ knot winds remains below
50% until around 17z, with a 60+% chance of 20+ knot wind gusts from
18z-00z. Wind speeds will gradually weaken during the evening and
overnight hours. FEW-SCT mid and high clouds through most of the
period, with cloud bases aoa 12kft.

For the rest of southern Nevada, northwest Arizona and southeast
California...Another day of breezy south-southeast winds across most
of the area, with wind gusts this afternoon of 20-25 knots. Again,
the exception to this will be KDAG where wind direction is forecast
to be west-southwest. There`s a low (15%) chance of a shower at KBIH
this afternoon. Should this materialize, there could be a brief
period of erratic outflow winds. Otherwise, the rest of the sites
remain dry as FEW-SCT mid and high clouds linger through the day.
&&

.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report
any significant weather or impacts according to standard operating
procedures.
&&

$$

SHORT TERM...Morgan
LONG TERM...Nickerson
AVIATION...Woods

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