822
FXUS65 KVEF 311142
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
443 AM PDT Mon Aug 31 2026

.KEY MESSAGES...

* Isolated-to-scattered thunderstorm activity is expected over
  northwest Arizona today, some of which may lead to flash flooding.

* Dry and relatively cooler conditions are on track for most areas
  through the rest of the workweek.

&&

.DISCUSSION...Today through Saturday.

The primary forecast concern for today is heavy rainfall potential
over northwestern Arizona. The current pattern aloft includes high
pressure over the southern half of the United States and a trough
off the Pacific Coast. Southwesterly flow between these two features
maintains dry conditions for most of the region west of the Colorado
River. However, ensembles indicate between 1.0 and 1.6 inch of PWAT
over northwestern Arizona as well as eastern Lincoln and Clark
counties. At the same time, a shortwave will push through the Great
Basin, providing a boost of instability and lift. High resolution
guidance shows upwards of 2400 J/kg SBCAPE over Mohave County
coinciding with the shortwave passage. Between instability and
moisture, robust storms with efficient rain rates leading to flash
flooding is the main concern. Issued a Flood Watch for this morning
through the evening for northern Mohave County where the flood
threat appears the greatest. Looking ahead, the trough may be able
to draw moisture from Hurricane Karina, but forecast soundings show
it mainly in the form of high cloud cover, if it makes it at all.
Also watching for another potential push of tropical moisture at the
end of the week, but confidence remains low at this time.

Besides precipitation, southwesterly flow and enhanced 850 mb winds
between 30 and 40 knots will maintain gusty surface winds through
most of the week. The strongest gusts will be over high terrain in
the Mojave Desert, generally peaking between 35 and 40 mph.
Temperatures should also bottom out on Wednesday with highs around 5
degrees below normal for this time of year.

&&

.AVIATION...For Harry Reid...For the 12Z Forecast Package...
Daily wind pattern expected again today with breezy afternoon
conditions. Light southerly winds at or under 8 kts persist through
mid morning before, then begin increasing after 15-16z. Isolated
gusts to 15 kts possible after 16z then more consistent S-SSW gusts
20-30 kts expected after 18z and persisting through sunset. Light
southerly winds continue into the overnight hours tonight. Some
uncertainty Monday evening as outflow from storms in northwestern AZ
tries to reach the valley. If it does (30% chance), expect an
easterly or northeasterly wind shift. For now, highest confidence in
a forecast keeping winds southerly at KLAS. Few to scattered clouds
above 10kft.

For the rest of southern Nevada, northwest Arizona and southeast
California...For the 12Z Forecast Package...Light winds give way to
another round of southerly to westerly breezes on Monday. Afternoon
gusts generally 20-30 knots, waning in most locations around sunset.
Isolated to scattered convection anticipated in Mohave County and
eastern Lincoln County, posing the risk of strong outflow winds and
heavy rain. Will have to see if thunderstorm outflow can reach sites
in the lower Colorado River Valley (50% chance) and the Las Vegas
Valley (30% chance) Monday evening. Will update the TAFs accordingly
as storms evolve later this afternoon and evening. Precipitation
chances begin to wane after sunset. Isolated to scattered clouds at
or above 10kft in most locations, with scattered to broken
conditions where convective coverage is greatest.

&&

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

&&

$$

DISCUSSION...Meltzer
AVIATION...Moore

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