843
FXUS65 KVEF 311946
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
1246 PM PDT Sat Oct 31 2026

.KEY MESSAGES...

* A few showers and thunderstorms remain possible through early
  this evening with localized heavy downpours, mainly across
  southern Nevada.

* Widespread wetting rain moves in late tonight and continues
  through Sunday afternoon. Locally heavy rainfall and a few
  instances of flash flooding will be possible.

* Conditions dry out on Monday as gusty north winds pick up across
  the region. Temperatures remain slightly below normal next week.


&&

.DISCUSSION...through next weekend.

Afternoon satellite imagery depicts a broad cloud shield extending
northeastward off our approaching low pressure system off the
Pacific Coast into the southern Great Basin. Meanwhile, to the
south of this feature, filtered sunshine and modest clearing are
allowing for some minor instability to develop across southern
Nevada and northwest Arizona. With a little additional heating,
surface based CAPE values are forecast to climb into the 250-500
j/kg range, will will be just enough to spark a few isolated
showers and storms again this afternoon. Storms today are not
expected to be as intense or widespread as observed Friday thanks
to a sharp warming aloft and weaker wind shear, but the
environment remains quite moist so brief but locally heavy
downpours will remain possible.

By tonight, precipitation coverage will shift from predominantly
convective to almost entirely stratiform as considerable
subtropical moisture overspreads the region. This is in response
to an impressive low pressure system off the SoCal coast that will
move inland through Sunday. Todays forecast guidance appears to
have converged on a common theme in terms of precipitation totals
and coverage areas - with increased confidence in locally heavy
rainfall totals exceeding 1 inch across Lincoln and northeastern
Clark Counties. In fact, this mornings guidance suggests 24 hour
precipitation totals in the Mesquite area may rival or exceed 24
hour totals rarely seen in a typical ten year interval. There is
also concern that additional rainfall will cause additional
flooding in the Colorado River Valley which is still recovering
from pockets of locally heavy flooding on Friday. With these
considerations in mind, went ahead and expanded the Flash Flood
Watch further west. The flood watch remains in place for Northwest
Arizona as well where confidence remains high that heavy rainfall
will occur.

Closer to the Las Vegas Valley, some degree of rain shadowing
remains expected which will work to limit the intensity of the
rainfall. Nonetheless, still anticipate several periods of
rain starting by late tonight and continuing into at least Sunday
morning. Rainfall totals in general are expected to range in the
0.25-0.50 range, though there are hints the far southwest Vegas
Valley may be a little lower due to the rainshadow effect. Periods
of heavier rainfall are expected in the Spring Mountains, with
rainfall totals exceeding 1 inch very likely. Snow levels will
remain above 9000 feet through the event so we`re not anticipating
any snow related impacts beyond accumulations at the top of
Charleston Peak and higher reaches of Lee Canyon ski area. Points
further west across Inyo county and western San Bernardino County
can generally expect more showery conditions with generally light
rainfall totals expected.

Conditions will tend to dry out from west to east Sunday
afternoon, though pockets of embedded thunderstorms are expected
- especially across Northwest Arizona where flood risk will remain
elevated. By Sunday night, drier conditions will overspread the
region with northwesterly breezes filtering in behind the storm
system.

The remainder of the week looks quiet through there may be some
patchy morning fog in low lying and moist valleys which observed
significant rainfall in the past week. Temperatures will hover a
few degrees below normal.

&&

.AVIATION...For Harry Reid...For the 18Z Forecast Package...Sky
conditions gradually deteriorate throughout the day as ceilings
lower and precipitation chances increase. Isolated showers (and a
10% chance of thunder) are possible as early as mid-afternoon, but
the more widespread precipitation arrives tonight. Latest guidance
has a 50% chance of CIGs getting down to 2kft between 09z and 13z
Sunday. Some visibility reductions due to rain are possible, but
precipitation intensity should mostly be on the light side. Some
improvement in sky conditions is anticipated Sunday afternoon, but
timing and extent are still uncertain. South-southwest winds will be
on the increase as this occurs.

For the rest of southern Nevada, northwest Arizona and southeast
California...For the 18Z Forecast Package...Moisture and cloud cover
continue to increase, with the best precipitation chances along and
north of I-15 through the afternoon. This evening and overnight,
rain chances spread to areas south and east. Precipitation intensity
will largely be on the lighter side, but periods of increased rain
rates and reduced visibility are possible. Expecting CIGs to drop
down to 2-4kft across most of the area tonight and Sunday morning,
resulting in MVFR conditions and significant terrain obscuration.
Gusty south winds expected across our northwestern zones today, with
lighter breezes elsewhere.

&&

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

&&

$$

DISCUSSION...Outler
AVIATION...Woods

For more forecast information...see us on our webpage:
https://weather.gov/lasvegas or follow us on Facebook and Twitter