Swansea, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

198
FXUS65 KVEF 150747
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
1247 AM PDT Thu May 15 2025

.SYNOPSIS...Temperatures will continue to warm through Friday before
another potent weather system drops into the region over the
weekend, bringing strong gusty winds, a chance of precipitation, and
a drop in temperatures. Calmer and warmer weather is expected next
week.
&&

.SHORT TERM...through Friday night. Midnight satellite loop showed
scattered mid level clouds slowly decreasing in coverage over
portions of Inyo, Esmeralda, Nye, and Lincoln counties. A band of
cirrus was moving east over southern Inyo and northern San
Bernardino counties. Surface obs showed generally light winds and
mild temperatures. Heights will rise areawide through Friday night,
resulting in quiet weather with temperatures rising back to near mid-
May normals. Southerly winds will start to increase Friday and
Friday night, well ahead of the low pressure system which will be
discussed in the long term section.

.LONG TERM...Saturday through Wednesday.

Heading into the weekend, a potent trough of low pressure will drop
through the western CONUS. Impacts will include strong southwesterly
pre-frontal winds, strong northwesterly post-frontal winds, a return
of scattered showers / isolated thunderstorms, and a drop in
temperatures over the weekend...once again.

Details continue to be worked out as we hash out the exact intensity
and timing of this system. However, what we know is that PWATs will
increase to 125 to 175 percent of normal (generally between 0.50 and
0.75 inches), which will allow for moderate-to-heavy rain rates
beneath any thunderstorms that develop, but generally light rainfall
elsewhere. Best chances for precipitation currently reside across
the southern Great Basin from Saturday afternoon through Saturday
night into Sunday, though occasional model runs bring precipitation
chances well into the Mojave Desert. Both the ECMWF and GFS ensemble
means have this trough entering the Desert Southwest with a negative
tilt, which will increase thermodynamic instability and wind shear,
meaning severe-level thunderstorms capable of strong winds, large
hail, and frequent lightning cannot be ruled out. At this time, it
looks like the greatest threat of thunderstorms will be across
central Nye and northern Lincoln counties Saturday and across
central Nye and the remainder of Lincoln County Sunday.

Regarding wind potential, the NBM is slowly trending gustier with
both pre-frontal and post-frontal winds. The latest run has 50-70
percent chances of west-southwest gusts in excess of 40 mph across
the Mojave Desert (along the Interstate 15 corridor) on Saturday and
30-50 percent chances of northwest gusts in excess of 40 mph across
the southwestern Great Basin on Sunday. The LREF has greater
probabilities for both times/locations... 60-90 percent and 40-70
percent, respectively.

Behind the trough, ridging sets up for the start of the work week
that will result in Las Vegas chances for 90 degrees rapidly
increasing through the week and "Moderate" HeatRisk (Level 2 on a
scale from 0 to 4) returning to the low valleys.
&&

.AVIATION...For Harry Reid...For the 06Z Forecast Package...Light
southwest winds will continue through the overnight period before
becoming variable before daybreak.  A period of north to northeast
winds is included in the latest TAF package, although it is possible
that winds will remain more variable through tomorrow afternoon.
Typical west-to-southwest drainage winds will return tomorrow
evening. VFR conditions will persist through the TAF period with
only FEW to SCT clouds, with bases AOA 12kft AGL expected.

For the rest of southern Nevada, northwest Arizona and southeast
California...For the 06Z Forecast Package...Conditions at Las Vegas
area TAF sites will be similar to those forecast for Harry Reid.
Elsewhere across the region, winds will follow typical diurnal
directional trends on Thursday with speeds generally remaining 12
knots or less.   The exception to this will be at KDAG, where a few
gusts to 20 knots will be possible tomorrow evening.  VFR conditions
will prevail at all area TAF sites with only a FEW to SCT clouds
with bases AOA 12kft AGL.
&&

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

$$

SHORT TERM...Morgan
LONG TERM...Soulat/Gorelow
AVIATION...Planz

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