053
FXUS65 KVEF 171148
AFDVEF

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

.KEY MESSAGES...

* An Extreme Heat Warning is in effect for portions 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 forecasted 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 25-25 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 their peak on
Wednesday and Thursday. Anomalously low heights will move overhead
by Saturday when temperatures are forecasted 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 of this time of the year.

&&

.AVIATION...For Harry Reid...For the 12Z Forecast Package...Winds
will shift to the northwest this morning, with gusts to around
15-20KT expected for several hours before becoming light and
variable by early this afternoon. Thereafter, winds trend toward
typical diurnal patterns, with speeds 10KT or less. VFR conditions
prevail with clear skies, and temperatures today exceeding 100
degrees between 20Z-04Z, peaking at 106 degrees around 00Z.


For the rest of southern Nevada, northwest Arizona and southeast
California...For the 12Z Forecast Package...Intermittently gusty
northwesterly winds are expected this morning across the southern
Great Basin and Las Vegas Valley as a front progresses through the
area, diminishing quickly by early afternoon. Winds largely become
light and variable across the region this afternoon, with the
exception of the Western Mojave Desert where gusty west winds
persist. Otherwise, VFR conditions prevail areawide with clear
skies the next 24 hours.

&&

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

&&

$$

DISCUSSION...Nickerson
AVIATION...Phillipson

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