Text Products for AFD Issued by VEF

Area Forecast Discussion
Issued by NWS Las Vegas, NV
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FXUS65 KVEF 250937
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
237 AM PDT Thu Apr 25 2024

.SYNOPSIS...An area of low pressure over our region will be pushed
away today by a colder system dropping down from the Pacific
Northwest which will bring scattered to numerous showers and chances
for thunderstorms to southern Nevada and surrounding areas on
Friday. Gusty winds will also occur...especially over the western
Mojave Desert. The system will exit Saturday leading to a gradual
warming trend with dry conditions through the middle of next week.
&&

.SHORT TERM...through Friday night.

A line of showers with isolated thunderstorms occuring over southern
Mohave County this morning extending from Parker Dam up toward
Kingman will slowly push toward the east and exit Mohave County
shortly after sunrise. This was being driven by vorticity advection
and an upper level jet exit ridge just ahead of the trough axis
which could be seen on recent satellite loops. This will pull away
fairly quickly today and is forecast to be over the Four Corners
Region by this afternoon leaving our area under northwest flow on
the back side. There will be sufficient moisture and instability for
scattered showers and isolated thunderstorms over Lincoln County
this afternoon and a few showers may even develop over the Spring
Mountains and could move over parts of the Las Vegas Valley this
afternoon. This is indicated by recent runs of the HRRR, but any
impacts will be fairly minor such as brief gusty winds and light or
trace rainfall amounts.

More noteworthy weather is on the way Friday due to a low pressure
system which could be seen on satellite loops approaching the
Pacific Northwest and this will dig over southern Nevada and
surrounding states Friday afternoon and evening then move away to
the Four Corners late Friday night. This will produce a setup
favorable for scattered to numerous showers and a few thunderstorms.
The latest NBM probability of precipitation grids indicate 50-75%
across much of Nye, Clark and central/northern Mohave counties and
75-95% over most of Lincoln County. General rainfall estimates of
0.10-0.25" are indicated over Nye, Clark and Mohave counties and
0.25-0.50" over the Spring Mountains and Lincoln County. Snow levels
will be 7500-8000 feet and an inch or two of snow will be possible
in the upper reaches of Kyle and Lee Canyons. Small hail will be a
possibility with thunderstorms.

Gusty winds over 40 mph will continue to impact western San
Bernardino County where a Wind Advisory is in effect until 11 pm PDT
Friday evening. Winds gusting over 40 mph may expand down into the
Morongo Basin late Friday afternoon. The rest of the region will see
general gusts 25-35 mph on Friday.

High temperatures will decrease 4-5 degrees today and another 6-8
degrees for most sites on Friday which will resulting in highs in the
lower 70s for Las Vegas and similar elevations in the Mojave Desert
region.


.LONG TERM...Saturday through next Thursday.

Lingering post-frontal northwest winds will continue through the day
on Saturday as a closed area of low pressure pushes eastward out of
our forecast area. Gust speeds will generally remain between 25 and
35 mph, and are unlikely to warrant any wind-related headlines.

Temperatures will begin to rebound on Saturday, with a 4-6 degree
increase from Friday. That said, Saturday will remain below-average
for this time of year... which is around 81F for Las Vegas.
Temperatures will continue to increase through Tuesday as a ridge of
high pressure over the southeastern Pacific rises heights over the
Desert Southwest. This ridge will result in a dry northwesterly flow
aloft, which is known for being conducive for shortwave passages
through the southern Great Basin. Thus, afternoon breeziness cannot
be ruled out each day through Tuesday.

Late Tuesday into Wednesday, the flow aloft briefly becomes zonal
before an approaching closed low drops heights once again. Details
regarding the strength and position of this closed low are still
uncertain, but a decrease in temperatures, an increase in wind
speeds, and a return of chances of precipitation are likely.
&&

.AVIATION...For Harry Reid...Relatively light (8-12 knot) south-
southwesterly winds will continue through late morning when winds
will pick up and become more southwesterly with 20 to 25 knot wind
gusts continuing through later this evening. Winds will fall back to
a more south-southwesterly direction through the overnight hours
with sustained speeds around 8 to 12 knots. There is a chance that
isolated showers around the higher terrain may result in variable
gusty outflow winds between 18 UTC and 00 UTC. Vicinity convection
is most likely to develop in the Spring Mountains to the west of
KLAS or the Sheep Range to the north. Should outflow winds
materialize from showers in either of these locations, their
direction would likely be be somewhere in the 270 to 360 degree
range. Confidence regarding whether or not these showers will make
it off the higher terrain and into the terminal area is currently
low. FEW to SCT low clouds will accompany these showers, but CIGS
are not expected to drop below 12 kft.

For the rest of southern Nevada, northwest Arizona and southeast
California...8 to 12 knot southerly to southwesterly winds will
continue through later this morning at KHND, KIFP, and KEED when
winds will pick up with 20 to 25 knot wind gusts continuing through
the evening hours. KVGT will follow a similar trend but with
northwesterly winds shifting to the southwest and gusts picking up
later this morning/early this afternoon. Similar to KLAS, vicinity
showers in the higher terrain around the Las Vegas Valley may
produce variable outflow winds that may impact KVGT and KHND during
the 18Z to 00Z timeframe. KDAG will continue to favor a more
westerly direction with 25 to 35 knot wind gusts continuing through
the evening hours. KDAG will also see FEW to SCT clouds with bases
aob 5 kft filter through the area today. KBIH will favor a
northwesterly direction with 15 to 20 knot wind gusts picking up
during the early afternoon hours. These northwesterly wind gusts
will continue into the evening.
&&

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

&&

$$

SHORT TERM...Adair
LONG TERM...Varian
AVIATION...Stessman

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National Weather Service Weather Forecast Office
