844 
FXUS65 KVEF 072302
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
Issued by National Weather Service Flagstaff AZ
402 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 00Z Forecast Package...Light
east winds will persist into the early evening before turning 
southwest around sunset. While wind speeds will generally remain 
below 6 knots, a few gusts to around 12 knots will be possible 
through 01Z. Light and variable winds will continue overnight 
before turning southeast tomorrow afternoon. VFR conditions will 
prevail through tomorrow afternoon under mainly clear skies.

For the rest of southern Nevada, northwest Arizona and southeast 
California...For the 00Z Forecast Package...Most areas will see 
winds of less than 8 knots through the remainder of the afternoon,
except in the Colorado River Valley, where north winds gusting to
around 20 knots will persist through sunset. All areas will see 
light winds overnight, followed by increasing southeast winds by 
tomorrow afternoon. VFR conditions will prevail through tomorrow 
afternoon under mainly clear skies.


&&

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

&&

$$

DISCUSSION...Outler
AVIATION...Planz

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