594
FXUS65 KVEF 250910
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
210 AM PDT Wed Sep 25 2024

.SYNOPSIS...Temperatures will continue to increase through the end
of the week resulting in increased HeatRisk for portions of our
forecast area. Beginning Thursday morning, an Excessive Heat
Warning will be in effect for the Colorado River Valley through
Saturday.

&&

.SHORT TERM...through Friday.

A weak shortwave disturbance will move trough the Pacific
Northwest/northern Great Basin region today, resulting in an uptick
of southerly winds across the Southern Great Basin where wind gusts
will top out around 20 to 25 mph this afternoon. While this system
will displace the ridge axis slightly to our east, it won`t be
enough to slow the warming trend of the past few days. This warming
trend will continue through the end of the week as the ridge shifts
back overhead , resulting in increased HeatRisk during the second
half of the week. HeatRisk will increase to Major (level 3 of 4) in
the Colorado River Valley on Thursday, with pockets of Extreme
(level 4 of 4) popping up as we head into the weekend. As such a
Excessive Heat Warning will go into effect for the Colorado River
Valley beginning Thursday morning.


.LONG TERM...Saturday through next Wednesday.

Saturday will be the hottest day of the forecast period as the
persistent upper-level area of high pressure centered over the Four
Corners region remains in place. The Excessive Heat Warning for the
Colorado River Valley (Lake Mead National Recreation Area and the
lower Colorado River Valley including Laughlin, Bullhead City, Fort
Mohave, Needles, and Lake Havasu City) will continue through
Saturday. We will continue to assess whether or not it needs to be
extended an additional day as we move through the week. Chances of
Las Vegas reaching 100 degrees are up to 90 percent on Saturday.
This is noteworthy, because 2024 currently ties the record number of
100-degree days with 1947 (with 100 days). If Las Vegas observes 100
again this week, then 2024 will break this record.

Through the week, a closed low will meander off the coast of
southern California. Over the weekend, this low will begin to move
inland. As it moves inland, it will weaken into an open wave and
sucked into the flow of the aforementioned upper-level high, pushing
it clockwise out of our area. Little, if any, moisture is associated
with this system, but the subtle drop in upper-level heights will
work to decrease temperatures by a few degrees. Note that the upper-
level high will remain in place, so temperatures will continue to
range 5-8 degrees above seasonal averages through midweek despite
the minor temperature drop.

&&

.AVIATION...For Harry Reid...Light winds with northeast or east
components during the afternoon and southwest components overnight
will continue into Thursday morning. VFR conditions with no
significant clouds.

For the rest of southern Nevada, northwest Arizona and southeast
California...Diurnal winds generally 10 knots or less are expected
at most regional TAF sites into Thursday morning. The exception will
be KBIH where south winds 12-20 knots will develop this afternoon.
VFR conditions will prevail at all sites with no significant cloud
cover expected.

&&

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

&&

$$

SHORT TERM...Stessman
LONG TERM...Soulat
AVIATION...Gorelow

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