410
FXUS65 KVEF 080432
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
932 PM PDT Tue Oct 7 2025

.KEY MESSAGES...

* Dry conditions and a warming trend will continue today and
  Wednesday as high pressure builds across the region.

* Increasing confidence for showers and thunderstorms Thursday
  through Saturday as moisture from Hurricane Priscilla moves into
  the Desert Southwest.

* Pockets of very heavy rainfall and localized flooding are
  possible across parts of Northwest Arizona and Colorado River
  Valley late Thursday through Saturday.

&&

.DISCUSSION...through early next week.

Mostly clear skies dominate the region this afternoon as high
pressure builds across the Southwest. Northerly breezes persist
along the Colorado River Valley thanks to a 1022mb high across the
Eastern Great Basin setting up a north to south pressure gradient
across the region, which funnels down the Colorado River Valley,
but generally light winds exist elsewhere. Meanwhile,
temperatures remain seasonable today, before climbing a few
degrees above normal for Wednesday under continued sunshine and
rising heights.

Changes remain are in store Thursday onward as increasing
moisture from Hurricane Priscilla is advected northward ahead of a
deepening trough off the West Coast. Increasing cloud cover will
spread northward Thursday morning and by Thursday afternoon,
precipitable water anomalies of 250-300% of normal or greater
will encompass most of the Mojave Desert and southern Great
Basin. This deep subtropical moisture will remain in place through
Saturday morning before gradually drying out from west to east
through Sunday as the trough axis sweeps through.

This highly anomalous moisture advection interacting with the
approaching trough and favorable jet dynamics will result in
several periods of shower and thunderstorm activity late in the
week. Forecast guidance seems to be hinting at an axis of
precipitation developing on the western edge of the deeper
moisture collocated with the right entrance region of an upper
level jet by Thursday evening. This precipitation axis sets up
roughly along the I-15 corridor, with additional pockets of
precipitation developing across Northwest Arizona and the Colorado
River Valley into Friday. What remains somewhat uncertain is how
much of the precipitation late this week will be stratiform versus
convective, but given the near record precipitable water values
that will be in play, along with synoptic enhancement from the
approaching trough, heavier downpours could certainly pose a flood
risk. Stay tuned to the forecast as we further hone in on the
details and areas of greatest risk for locally heavier rainfall
and flash flooding.

&&

.AVIATION...For Harry Reid...For the 06Z Forecast Package...Winds
will generally follow diurnal patterns through Wednesday evening,
shifting from the southwest tonight to the east by late morning,
and to the southeast by afternoon, increasing to around 8KT. Late
afternoon through the evening, winds settle more out of the south,
remaining around 8KT, though intermittent higher gusts to 12-15KT
cannot be ruled out. Winds then become light and variable
overnight, with increasing mid and high clouds late evening
onward. VFR conditions prevail.


For the rest of southern Nevada, northwest Arizona and southeast
California...For the 06Z Forecast Package... Winds across the
region will generally favor diurnal directional patterns the next
24 hours, with winds shifting to the southeast and south areawide
by Wednesday afternoon. Sustained speeds largely remain around
10KT or less, though slightly stronger winds with gusts to 15-20KT
are expected across portions of the Colorado River Valley, the
southern Las Vegas Valley, and in the western Mojave Desert. In
the Owens Valley, KBIH will see gusty up-valley winds from
afternoon onward, peaking around 30KT late afternoon through mid
evening. Elsewhere, winds diminish after sunset. VFR conditions
prevail.

&&

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

&&

$$

DISCUSSION...Outler
AVIATION...Phillipson

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