Area Forecast Discussion
Issued by NWS Las Vegas, NV
FXUS65 KVEF 242132
Area Forecast Discussion
National Weather Service Las Vegas NV
230 PM PDT SUN JUL 24 2016
.SYNOPSIS...Hot and dry weather will continue for most of the area
through the middle of the week although moisture and thunderstorm
chances begin to return to portions of Mohave and eastern San
Bernardino counties by Tuesday. It is looking favorable for
monsoonal moisture and the potential for thunderstorms to return to
much of the region by next weekend.
.SHORT TERM...Through Tuesday Night.
A low level moisture tongue has expanded up from the lower Colorado
River Valley into southern Nevada as evidenced by surface dewpoints
of 55-60 degrees. A boundary between this moisture and dry southwest
flow could be seen over the central Las Vegas Valley with dewpoints
of 30-35 degrees west of I-15. The moisture appears too shallow to
result in any convection aside from being capped by a warm layer
aloft due to the mid level high overhead. This high is forecast to
meander over southern Nevada and surrounding states and will keep
result in little relief from the elevated temperatures we have been
experiencing. High temps will hold around 110 degrees for the Mojave
Desert region...up to 115 along the CO River Valley and 120 for
As far as thunderstorms go...the steering flow is forecast to become
favorable by Tuesday for Arizona rim country convection to move
toward Mohave County during the afternoon and evening. We should so
more coverage of thunderstorms over central and southern parts
of Mohave County.
.LONG TERM...Wednesday through Saturday.
The two main concerns for the period will be the potential for
excessive heat during the middle of the week followed by a
transition to a widespread return of monsoonal moisture and possible
thunderstorms. The medium range models indicate the area of high
pressure over southern Nevada is forecast to strengthen Wednesday
and Thursday then may shift toward the Four Corners region going
into the weekend. Both the GFS and ECMWF forecast an easterly wave
moving out of Mexico across the northern Gulf of California sometime
between Thursday and Saturday. The GFS indicates more deep
southeasterly flow developing across the Mojave Desert region and up
into the Great Basin. The ECMWF is not quite as favorable with the
mid level flow but it has been consistently indicating a surge of
moisture below 700 mb spreading up into the region. Pops were
increased a little Saturday and Sunday so that most zones have at
least a slight chance of seeing thunderstorms. This is obviously a
long way out yet and we will see if confidence continues to increase.
.AVIATION...For McCarran...Southwest winds with gusts in the 15 to
20 knot range will persist through sunset before decreasing.
Occasional brief periods of variability can be expected as well.
Skies will remain clear although lofted smoke will remain
problematic and reduce slantwise visibility through the TAF period.
Southwest winds will return after 21z Monday.
For the rest of southern Nevada...northwest Arizona...and southeast
California...Gusty southwest winds expected across the western
Mojave desert with breezy south winds along the Colorado River.
Gusts in the 20-25 knot range possible. Winds will decrease
overnight and return tomorrow afternoon. Areas of smoke and dust
will remain problematic, especially across the Western Mojave Desert
and southern Nevada.
.FIRE WEATHER...Dry and hot conditions will persist across southeast
California and southern Nevada through Tuesday. Northwest Arizona
should see increasing thunderstorm coverage by Tuesday afternoon as
storms move off the Arizona rim country from northeast to southwest.
It is looking favorable for a widespread return of monsoonal
moisture and associated thunderstorms by next weekend.
.SPOTTER INFORMATION STATEMENT...Spotter activation is not expected
today although spotters are encouraged to report any significant
weather...including smoke near the surface/visibility reductions
using standard operating procedures. Spotter activation may be
necessary later this week.
Short Term/Long Term/Fire Weather...Adair
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