Severe Thunderstorm Warning 93, NWS Las Vegas, NV

Area Forecast Discussion
National Weather Service Las Vegas NV
158 PM PDT Mon Sep 12 2022

.SYNOPSIS...A large circulation moving across southern Nevada and
surrounding areas through Tuesday night will produce scattered to
numerous thunderstorms with additional rounds of heavy rain possible.
Southwest flow should finally bring a drying trend the second half
of the week into the weekend.
&&

.SHORT TERM...through Wednesday.

Abundant moisture remains in place and also dynamic support from
from disturbances rotating around the remnant circulation of Kay
will lead to another an active period for showers and thunderstorms
through Wednesday. Storms that were firing early this afternoon were
very efficient rain producers...some dropping a half-inch of rain in
less than 10 minutes. This activity will continue into early this
evening then convection should diminish until early Tuesday morning
as the center of the large upper level circulation crosses southern
Nevada and heads toward southwest Utah. The threat of widespread
showers and thunderstorms will focus over southern Nevada and
northwest Arizona...primarily Lincoln, central/northeast Clark and
northern Mohave counties early Tuesday morning through Tuesday
night. The Flash Flood Watch remains in effect for these areas from
5 AM Tuesday until 5 AM Wednesday. Our area will be on the back side
of the system by Wednesday, but plenty of moisture will remain and
will combine with surface heating leading to another threat of
showers and thunderstorms over areas mainly north and east of Las
Vegas.

.LONG TERM...Thursday through the Weekend.

With residual moisture still in place Thursday, there is a continued
chance for showers and storms as pieces of energy and additional
upper level support from the jet streak move over the area. Moisture
will be on the downward trend though, so expecting lower
precipitation chances and impacts.

By Friday, dry air will be in place over the region. Ensembles show
zero probabilities for PWATS over 1in by Friday afternoon. The
current forecast has no chances for precipitation across the region
Friday through the weekend. Afternoon breezes are possible this
weekend, however impactful winds are not expected at this time.
Temperatures the second half of the week will actually warm slightly
each day, however they will not get much above normal as on
Wednesday we will be starting below normal.

&&

.AVIATION...For Harry Reid...The break in shower/thunderstorm
chances continue through about 20z then increase mainly south
through west of the valley. Storms are expected to initiate over the
higher terrain with a decent shot of moving into the valley mid-late
afternoon. The main impacts from storms today will be associated
with erratic winds and strong gusts to 30 knots, along with the
possibility of CIGS dropping briefly to or below 5k feet and lower
visibility due to moderate-heavy rain. There continues to be a
threat of storms developing in or around the valley during the
overnight hours through about midday Tuesday.

For the rest of southern Nevada, northwest Arizona and southeast
California...KVGT and KHND are expected to follow similar trends to
KLAS after 20z with shower and thunderstorm chances increasing.
Possible impacts include erratic winds with gusts to 30 kts and low
CIGS at or below 5k feet with potential for a reduction in
visibility to 1-3 SM in moderate or heavy rain. KBIH and KDAG will
see their shower/storm chances increase this afternoon while KEED
and KIFP are expected to remain dry although wind impacts from
thunderstorm outflow is a possibility. Confidence is too low to
include in the TAF.
&&

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

SHORT TERM...Adair
AVIATION...Salmen
LONG TERM...Nickerson

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