Severe Thunderstorm Warning 95, NWS Las Vegas, NV

Area Forecast Discussion
National Weather Service Las Vegas NV
1212 PM PDT Mon Oct 3 2022

.SYNOPSIS...Shower and thunderstorm activity is expected to
continue throughout the afternoon and into the evening hours for
the southern and eastern portions of our forecast area. We will
begin to dry out overnight with dry and warm conditions
persisting through mid-to-late week.

&&

.SHORT TERM...through Tuesday evening.

Ongoing shower and thunderstorm activity in Mohave County is
expected to continue into the evening hours. Additional
convection is expected to pop-up in Clark County, eastern San
Bernardino County, and potentially eastern Lincoln County this
afternoon. The primary hazards associated with these storms are
heavy rain capable of resulting in flash flooding, gusty winds,
and frequent lightning. An upper-level shortwave digging into the
region provided the synoptic forcing responsible for these
storms. This shortwave will continue to dig southward and eastward
throughout the day, with storms moving to the southeast out ahead
of the shortwave trough axis. Any convection that pops up behind
the trough axis will experience a more southerly storm motion as
the upper-level and steering flows becomes more northerly. The
12Z HREF boasts a 70% chance of 35+ mph winds in the southern
portion of the Colorado River Valley, including Lake Havasu City,
Needles, and Laughlin. Additionally, the HREF indicates that 35+
mph winds are likely from I-40 south in Mohave County. Convection
will begin to wind down after sunset due to the loss of daytime
heating, and by approximately 04/05Z convection is expected to
have mostly dissipated.

As this trough continues to dig to the southeast and upper-level
flow across the forecast area becomes more northerly, we will see
things begin to dry out overnight and into tomorrow with PWat
values falling below 1.0" across the area by tomorrow afternoon.
This shortwave will stall out over the Four-Corners region late
Tuesday, resulting in dry conditions across the forecast area.

.LONG TERM...Wednesday through Monday.

An amplified ridge nosing inland from the West Coast up through
western Canada will keep our region dry and warm Wednesday and
Thursday but the medium range ensembles indicate a broad closed
upper low spinning up over New Mexico then retrograding across
southern Arizona and northwest Mexico Friday through Sunday which
would produce an easterly and may allow lingering moisture to spread
back into Mohave County and possibly even over eastern San
Bernardino and Clark counties by Sunday for a slight chance of
thunderstorms over the mountains. Temperatures trend downward
slightly for the weekend with highs in the upper 80s to lower 90s
for the Mojave Desert zones which is close to normal.

&&

.AVIATION...For Harry Reid...Northeast winds around 7-10 kts are
expected through the afternoon, but there is the possibility of
various outflow boundaries that could bring varying wind directions
and speeds at times. Thunderstorms are forecast to develop around
the Las Vegas Valley this afternoon, but confidence is low that
storms will directly impact the terminal. Storms are expected to
dissipate by late afternoon with clear skies and generally light
winds overnight. Drier conditions and generally light winds are
expected Tuesday.

For the rest of southern Nevada, northwest Arizona and southeast
California...Generally light and diurnal wind patterns anticipated
today, though sites in the Colorado River Valley should see
northerly breezes this afternoon around 10 kts. SCT thunderstorms
this afternoon across mainly southern Mohave, Clark, and eastern San
Bernardino Counties with wind, hail, and heavy rain being the
primary threats. These are expected to last to early evening before
dissipating with generally clear skies overnight. ISOLD storms
possible over northwest Arizona Tuesday with overall coverage being
much less.
&&

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

SHORT TERM...Stessman
LONG TERM...Adair
AVIATION...Gorelow

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