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000
FXUS65 KVEF 270929
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
229 AM PDT Tue Jul 27 2021

.SYNOPSIS...Drier and warmer conditions are expected today and
Wednesday with the focus for thunderstorms expected across
northern Inyo and Esmeralda counties. Thunderstorm chances return
to much of the region during the second half of the week and into
the weekend as we anticipate impacts from another easterly wave.

&&

.SHORT TERM...Today and Wednesday.

From water vapor satellite imagery this morning, drier mid level
air has pushed into southeast California and southern Nevada while
high pressure has shifted east to the central Rockies and plains.
Moisture remains in place but PWATs are lower then what we had
yesterday. Although the location of the high maintains a favorable
east to west flow across the southwest, there is no discernible
wave or feature to assist storm maintenance today other than
orographic lift and daytime heating. Thus, we are looking at a
much needed down day in thunderstorm coverage. One area where
there could be scattered thunderstorms capable of producing heavy
and potentially excessive rain both today and also on Wednesday is
across the northwestern section of the forecast area including
the Sierra and into Esmeralda County from Dyer to Goldfield NV.
Elsewhere, storms will primarily be tied to the mountains where
orographic lift and weak instability from daytime heating will
combine in storm development. Not to downplay potential impacts
from storms forming in this moist environment however. They will
be capable of producing brief heavy rain which could lead to
localized flash flooding.

For Wednesday, the deeper moisture is forecast to be east of
Mohave County while moisture in our area is similar to today or
even a little drier. The exception will be the northwest portion
of our forecast area which will see the best chance of storm
development once again. Ridging on Wednesday is centered over the
central plains maintaining a favorable position for steering an
easterly wave across Texas. The long term forecaster will discuss
the details of this wave and it`s potential impacts heading into
the second half of the week and into the weekend. Expect a rebound
in temperatures today and Wednesday with highs closer to normal.

.LONG TERM...Thursday through Monday.

Features of interest at the start of the period will be positioning
of the high center over the central high plains. With the ridge axis
that far north the region will continue to lie under an east-
southeast flow aloft keeping the door open for additional monsoon
storms. There is also an inverted trough positioned over the Big
Bend region of Texas southward into northern Mexico that bears
watching.

There is some indication of smaller features embedded in the flow
moving west across northern Arizona Thursday and Friday, as the
inverted trough moves into southeast Arizona. NBM PoPs do increase
areawide Thursday and Friday. Some uncertainty between the models on
just how far west the inverted trough will make it as moves
northward across Arizona Saturday. At any rate, Saturday looks to be
another active day. Potential for heavy rain and flash flooding
impacts expected Friday and Saturday.

Late in the period we may see a drying trend as a trough near the
west coast. NBM does show PoPs decreasing from west to east Sunday
and Monday.

&&

.AVIATION...For McCarran...Tranquil weather is expected around the
terminal area today. A few cloud buildups with bases 10-12 kft will
be possible over the surrounding mountains, but the probability is
less than 5 percent that any storms would impact the terminal area
this afternoon and evening. Light and variable winds this morning
will be followed by southeast components 6-10 knots this afternoon
the light south-southwest tonight.

For the rest of southern Nevada, northwest Arizona and southeast
California...Fairly tranquil can be expected across the region today
with only isolated thunderstorms over the southern Sierra which
could lead to thunderstorms near BIH this afternoon. Prevailing
winds will be generally less than 10 knots for all TAF sites except
for possible thunderstorm gusts near BIH this afternoon.

&&

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

&&

$$

SHORT TERM...Salmen
LONG TERM...Pierce
AVIATION...Adair

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