863
FXUS65 KVEF 171157
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
457 AM PDT Sat May 17 2025

.SYNOPSIS...Widespread gusty winds are expected across the region
today as a weather system moves in. A few showers and
thunderstorms are possible across the southern Great Basin as
well. Temperatures will cool slightly today through Monday with
northwesterly breezes hanging on through Monday afternoon. A
warming trend will commence Tuesday onward with temperatures
climbing well above normal.

&&

.SHORT TERM...through Monday.

Morning satellite imagery depicts our next weather system making
its way onshore along the Pacific Northwest Coast, and will
continue to dig south into the Great Basin through this
afternoon. Ahead of this trough, the main story will be the wind
with a belt of strong southwest winds forming from the Western
Mojave Desert near Daggett, eastward into Southwest Utah and
Northwest Arizona. Widespread gusts of 35 to 55 mph are expected
across the Mojave Desert and Northwest Arizona and this remains
well covered by the wind advisory for today. A few gusts near or
around 60 mph are possible near Barstow this afternoon and evening
as the pressure gradient maximizes. Further West, high resolution
guidance remains fairly insistent on strong downslope winds in
the Sierra and Owens Valley this afternoon, despite a somewhat
suboptimal flow pattern lacking a strong cross-barrier component
of the flow aloft. Given the trends in model support, went ahead
and added the Sierra/Owens Valley/White Mountains to the wind
advisory as well.

In addition to the winds, a belt of showers and isolated
thunderstorms are expected to develop along the cold front and
base of the trough axis this afternoon and evening across the
southern Great Basin. These storms will traverse from west to
east, and exit our region late this evening. While a stray shower
may form as far south as Las Vegas, chances are greatest across
mainly central Nye and Lincoln Counties.

Temperatures today will cool a few degrees from yesterday and
remain cool through Monday as the trough moves through and
additional disturbance drops southward Sunday night reinforcing
cool temps and northerly breezes.

.LONG TERM...Tuesday through Friday

Temperatures increase through the workweek as the trough exits to
the east and heights aloft rise. The probability of reaching 100
degrees in Las Vegas on Thursday is now 75 percent. On Thursday and
Friday, expect widespread Moderate (Level 2) HeatRisk across the
desert valleys, a level of heat that affects anyone sensitive to
heat, especially those without adequate cooling or hydration. There
is also the potential for some Major (Level 3) HeatRisk along the
Colorado River, which affects anyone without effective cooling or
hydration. Zonal flow aloft should help maintain non-impactful winds
through at least Thursday, but may have to watch an approaching
shortwave towards the end of the week.

&&

.AVIATION...For Harry Reid...For the 12Z Forecast Package...Light
southwesterly winds will continue through 15Z when winds will begin
to ramp up with 20 to 25 knot gusts. 30 to 40 knot wind gusts are
expected this afternoon, decreasing to 20 to 30 knots after sunset.
Winds will flip to the northwest later tonight as the trough axis
swings through. 10 to 15 knot sustained winds with 20 to 25 knot
wind gusts will accompany this wind shift. These northwesterly winds
through the overnight period with winds occasionally becoming
lighter and gusts briefly dropping off at times before returning.
VFR conditions will prevail with bases remaining AOA 12 kft AGL
through the TAF period.

For the rest of southern Nevada, northwest Arizona and southeast
California...For the 12Z Forecast Package...Winds at the remaining
Las Vegas Valley TAF sites will follow similar trends to those of
Harry Reid, described above. Light northwesterly winds will continue
at BIH through later this morning when winds will pick up and fall
to the west-northwest. This wind shift will be accompanied by 20 to
30 knot wind gusts. Winds will shift back to the northwest early
this evening, continuing to maintain 20 to 30 knot wind gusts
through the overnight hours. Across the western Mojave Desert,
including KDAG, westerly winds will continue through the TAF period
with gusts to 40 knots likely this afternoon.  Gusty southerly winds
are forecast in the Lower Colorado River Valley today with gusts to
35 knots developing by late morning, continuing through the
afternoon and into the evening hours. FEW to BKN mid-to-high clouds
will filter through the area with bases AOA 10 kft.

&&

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

&&

$$

SHORT TERM...Outler
LONG TERM...Meltzer
AVIATION...Stessman

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