346
FXUS65 KVEF 171722
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
1022 AM PDT Tue Jun 17 2025

.KEY MESSAGES...

* An Extreme Heat Warning remains in effect for portions of
  southern Nevada, northwest Arizona, and southeast California on
  Wednesday and Thursday.

* Gusty southwesterly winds will pick up across the area during
  the latter half of the week, resulting in another round of
  increased fire danger.

* Expect relief from the heat as temperatures cool down over the
  weekend.

&&

.DISCUSSION...Today through Next Tuesday.

For today, heights will be slow to build and the flow will remain
west to northwest, so expecting high temperatures to be cooler than
yesterday but will remain above normal. On Wednesday and Thursday,
high pressure will quickly build over the region and temperatures
will warm in response. With anomalously high heights overhead, high
temperatures will climb to 5-10 degrees above normal. Major Heat
Risk (level 4 of 5) is forecast in many desert valley locations
Wednesday and Thursday where an Excessive Heat Warning is in
effect. Heat this extreme can be dangerous to much of the
population, especially those who do not have access to hydration
or cooling, people who are sensitive to the heat, and anyone who
is unprepared for this level of heat. Elsewhere outside of the
Excessive Heat Warning areas, Moderate Heat Risk (level 3 of 5) is
expected and precautions should still be taken to prevent heat
related impacts.

Late Thursday and Friday, an upper level trough will swing into the
region. The pressure gradient will increase as the incoming trough
pushes out the ridge which will result in gusty south to southwest
winds. Breezy winds with widespread gusts of 25-30 MPH are
expected each afternoon Thursday through Saturday. The strongest
winds should be Saturday afternoon when there is at least a 50%
chance for impactful wind gusts over 40 MPH in the Western Mojave
Desert across far southern Nevada and into parts of Mohave County.
In addition to the increased winds, it will remain dry through
the period with no rain chances and afternoon relative humidities
dropping to 10% or less. Fire danger will be a concern the second
half of the week, and SPC shows a widespread 40% chance low RH and
strong winds leading to increased fire danger Thursday through
Saturday, and now includes a 70% chance in parts of southeast
Nevada and western Arizona (an increase from the previous
forecast).

Temperatures are expected to cool with the upper level trough
starting Friday. Heat Risk will decrease from its peak on
Wednesday and Thursday. Anomalously low heights will move overhead
by Saturday when temperatures are forecast to drop back to near
normal. Sunday into the beginning of next week, ensembles favor
low pressure sitting over the region which will keep temperatures
cooler compared to current levels. Sunday will be the coolest day
of the forecast period as high temperatures drop to about 5
degrees below normal for this time of the year.

&&

.AVIATION...For Harry Reid...For the 18Z Forecast Package...
Northwest winds 8-10 knots with a few gusts to 15 knots are
expected through mid afternoon. Thereafter a period of more
variable winds will take hold, eventually shifting to a more
southwest direction this evening and south overnight. Winds will
be more diurnal in nature by Wednesday, with a shift to the
north/northeast by mid morning. Otherwise, clear skies and hot
temperatures are expected with highs exceeding 100 degrees 20z-04z
today, peaking around 106 degrees.


For the rest of southern Nevada, northwest Arizona and southeast
California...For the 18Z Forecast Package...
Winds to generally remain light at 10-15 knots or less. The
exceptions being KVGT and KDAG, where a few gusts to 20 knots will
remain through mid afternoon. Thereafter, winds should decrease
with more of a diurnal pattern taking shape by Wednesday.
Otherwise clear skies and VFR conditions expected.

&&

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

&&

$$

DISCUSSION...Nickerson
AVIATION...Austin

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