059
FXUS65 KVEF 010749
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
1249 AM PDT Mon Jul 1 2024

.SYNOPSIS...A dangerous long-duration heat wave is on the way to the
Mojave Desert and southern Great Basin. Excessive Heat Warnings go
into effect beginning Wednesday and Thursday and continue into next
week. Monsoonal moisture will linger in northwest Arizona, bringing
slight chances for thunderstorms in eastern Mohave County today and
possibly Tuesday, before getting pushed away to the east.
&&

.SHORT TERM...through Tuesday night. Midnight satellite loop showed
mid level convective debris clouds over southern and eastern Mohave
County and clear skies over the rest of our CWA. Area radars showed
very weak returns in extreme southern Mohave County, most likely
associated with either sprinkles or virga. Surface obs showed south
to southwest breezes, with peak gusts of around 40 mph in the Spring
Mountains, hot temperatures (still 100F at Bullhead City), and
dewpoints several degrees higher than 24 hours ago, especially in
the Las Vegas Valley. The stickiest surface air was in the southern
Colorado River Valley, where Lake Havasu City had a dewpoint of 61F
at midnight to go along with a 99F temperature. High resolution and
coarser models agree that this moisture will not push much farther
west (barring an unexpected outflow boundary) and could even get
pushed east as early as Tuesday, so thunderstorm chances should
remain confined to Mohave County, and perhaps even stay east of
Kingman. High temperatures today should be similar to yesterday -
maybe even a degree or two lower - before the warming trend begins
Tuesday. More on this in the long term period.

.LONG TERM...Wednesday through the weekend.

A 500mb ridge just off the West Coast will begin to nose into Mojave
Desert and Great Basin on Wednesday. By the weekend, most ensemble
solutions place the ridge axis overhead or just to our west. This
drives temperatures even further above normal, placing most of our
lower deserts in the 105-120 degree range, and the southern Great
Basin zones in the 95-110 range. Daily records will be in jeopardy,
and a few climate sites may flirt with all-time temperature records.
As a result, HeatRisk indices quickly climb to Major and Extreme,
particularly across the western 2/3 of the Mojave Desert. The
excessive heat sticks around through the weekend, producing what
will likely be a long-duration heat wave, and a long-duration
Excessive Heat Warning has been issued. An often overlooked aspect
of these heat waves is the overnight low temperatures, which are
crucial to providing relief from the daytime temperatures. For
places like Las Vegas and the Colorado River Valley, lows may
struggle to fall below 90 degrees, especially by the weekend. In
terms of precipitation, well the chances don`t look very great. PoPs
remain less than 10% across the entire area during this time. If any
place in the CWA were to get an isolated shower/storm, it would be
eastern Mohave County, but again chances are low. Long story short,
July looks to be picking up where June left off: hot and
predominantly dry.
&&

.AVIATION...For Harry Reid...Though there will be periods of
respite, expect gusty south-southwest winds to persist through the
overnight period with gusts ranging from 15 to 25 kts. Gust speeds
will increase to 20 to 30 kts through the afternoon before tapering
off after sunset. Wind speeds will drop below 10 kts overnight
Monday into Tuesday. No operationally significant cloud cover
expected through the TAF period.

For the rest of southern Nevada, northwestern Arizona, and
southeastern California...Gusty south-southwest winds will continue
for the Las Vegas Valley TAF sites through sunset tonight with
speeds between 20 and 30 kts. Breezy north winds at KBIH will become
southerly through the afternoon before returning northwesterly
overnight with speeds between 8 and 12 kts. Gusty west winds will
pick up through the afternoon at KDAG with gust speeds to 30 kts.
Gusty south winds along the Colorado River Valley will bring gusts
between 20 and 25 kts to KIFP and KEED through the afternoon before
subsiding after sunset. No operationally significant cloud cover
expected through the TAF period.
&&

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

$$

SHORT TERM...Morgan
LONG TERM...Woods
AVIATION...Soulat

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