558
FXUS65 KVEF 090235
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
734 PM PDT Sat Jun 8 2024

.SYNOPSIS...An incoming trough approaching the west coast sends
high pressure to our east, bringing an end to the heatwave that
has plagued the area for the past several days. A heat dome
builds and strengthens to our east Tuesday and Wednesday,
leading to the next heatwave for our area. However, it is
forecast to be less intense and relatively brief this time around.
This is due to a combination of synoptic scale weather features
that are forecast to bring relief from the heat later in the
week.
&&

.UPDATE...Isolated thunderstorms developed across the Southern Great
Basin and northern Inyo County late this afternoon as moisture
lifted up and over a ridge axis situated over the Western US. No
significant impacts were reported with these storms as low level
moisture was limited- mostly just some lightning in storms in the
terrain. Over the past few hours, thunderstorm activity has been
waning as the sunsets and we lose diurnal heating. This trend will
continue through the rest of the evening with all hi-res models
showing precipitation ending by early tonight.


Another hot day across the Southwest US, though not as hot as
yesterday as the ridge axis continues to break down and shift east.
No new record high temperatures were set this afternoon and high
temperatures in general were about 5 degrees cooler than yesterday.
The excessive heat warning continues until 9PM PT tonight and will
let that continue (especially as many locations at this current hour
are still over 100F, including Las Vegas, NV).

Overall- no changes were made to the evening or overnight forecast.
As previously mentioned, thunderstorms will end quickly after
sunset. Clouds will linger in Western Arizona through the night, but
elsewhere skies should clear. Overnight temperatures will be a few
degrees cooler than last night.
-Nickerson-
&&


.Previous DISCUSSION...159 PM PDT Sat Jun 8 2024.
.DISCUSSION...Sunday through Monday.

The strong high pressure ridge we have been dealing with the past
several days finally shifts east of the area on Sunday in response
to an incoming Pacific trough. The ridge moves over the central
U.S. and holds firm, leading to a disassembling of the trough
into two separate components. The northern portion of the trough
is progressive and easily rides over the top of the ridge while
the southern portion stalls, gets pinched off from the main flow
and becomes a cutoff circulation off the coast of southern
California and northern Baja. What we end up with weatherwise in
our area, is a couple of days where temperatures are several
degrees cooler and well below record levels. Add to this, the
possibility of more cloud cover from the closed circulation to our
southwest and breezy winds during the hottest part of the day.

Tuesday and Wednesday...

The northern jet stream is forecast to remain active for the
upcoming week with waves of energy sweeping across the northern
tier states. This acts to suppress the ridging over the central
U.S. and allows the building of a heat dome over Arizona, New
Mexico, and northern Mexico on Tuesday and Wednesday. This will
lead to a less intense, shorter duration heatwave for our area
where high temperatures surge back to 10 or more degrees above
normal Tuesday and Wednesday. Heat Risk increases with major
impacts possible for parts of area beginning Tuesday and becoming
more widespread on Wednesday. This will present the next
opportunity for the issuance of excessive heat related products
for our area.

Thursday through next Saturday...

The combination of a strong Eastern Pacific shortwave approaching
the northwest coast coupled with a building heat dome to our east
latches onto the cutoff low to our southwest and drags/guides it
into the southwestern states on Thursday. It is almost certain to
drop temperatures again but could also bring a brief increase in
moisture to the area on Thursday. The latest run of the NBM isn`t
suggesting much of an impact from the low other than lowering
temperatures a few degrees on Thursday and keeping them stable
into the weekend.

&&

.AVIATION...For Harry Reid...Southeast wind components with
gusts 15-20 knots can be expected until about 02Z followed  by south-
southwest winds with gusts diminishing after sunset. South-southeast
winds will likely develop Sunday morning with gusts 15-20 knots
through the afternoon. FEW-SCT clouds, with bases at or above 12 kft
AGL.

For the rest of southern Nevada, northwest Arizona and southeast
California...Afternoon south-southeast winds gusting 20-25 knots
will occur at most TAF sites in the area through Sunday with speeds
decreasing to less than 10 knots after sunset into the early morning
ours. The exception to this is KDAG, where the wind direction will
be generally from the west through the period. At KBIH, isolated
thunderstorms in the vicinity late this afternoon will lead to a 30-
50% chance of west-northwest outflow gusts up to 30 kts reaching the
airport. Scattered clouds around 10 kft AGL with broken clouds
above, while the rest of the sites should only see FEW-SCT clouds
at or above 12 kft AGL.

&&

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

&&

$$

DISCUSSION...Salmen
AVIATION...Adair

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