198
FXUS65 KVEF 170545
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
1045 PM PDT Mon Jun 16 2025

.KEY MESSAGES...

* Heat will increase Wednesday and Thursday. An Extreme Heat Warning
  has been issued for portions of southeast California, southern
  Nevada, and northwest Arizona.

* Relief from the heat is expected beginning Friday and especially
  over the weekend, but increasing winds beginning Thursday could
  bring another round of high fire danger.

&&

.DISCUSSION...through next Monday.

Midday satellite loop showed a few flat cumulus and lenticular
clouds over the southern Great Basin, with clear skies over the
Mojave Desert. Surface obs showed southwest winds gusting 20 to 30
mph, temperatures a few degrees higher than 24 hours ago, and an
interesting patchwork of dewpoints near or below 0F mixed in among
dewpoints in the 30s and 40s, which was most likely related to
extremely dry air aloft being mixed down in the lee of mountain
ranges. On water vapor satellite imagery, mid level troughing was
seen moving into the West Coast. This will traverse our area
overnight, keeping winds elevated, although gusts will be less
strong than today. Behind this trough, high pressure will
strengthen, with 500 mb heights peaking over our area on
Wednesday. For Wednesday, HeatRisk values have increased and the
coverage of Major HeatRisk has expanded since yesterday. HeatRisk
is a bit less expansive on Thursday, but our area could have the
perfect blend of still-high heights and increasing wind/deepening
mixed layer to result in another very hot day. Thus, it is
anticipated that HeatRisk will increase for Thursday as well. With
this in mind, hoisted an Extreme Heat Warning covering Death
Valley National Park, the northern half of San Bernardino County,
western and central Clark County, central and southern Mohave
County, and the Colorado River Valley. Fortunately, this will be a
short-lived episode, as the aforementioned wind on Thursday is on
the leading edge of an unseasonably deep trough in the Gulf of
Alaska. As this trough moves into the Pacific Northwest and
Intermountain West Friday through Sunday, heights over our area
will crash, and high temperatures will drop approximately 10 to 15
degrees from Thursday to Sunday. However, this relief will come
at a price, as stronger winds and low humidity will cause fire
weather concerns Thursday through Saturday before winds finally
abate Sunday. Temperatures should start to rebound on Monday.

&&

.AVIATION...For Harry Reid...For the 06Z Forecast Package...VFR
conditions will prevail through the TAF period. Southwesterly wind
gusts will drop off early Tuesday morning before swinging to the
northwest as a front passes through. These northwesterly winds will
be short-lived with winds becoming light and variable during the
afternoon before picking up and settling in from the southwest early
tomorrow evening. High temperatures tomorrow will top out around 106
degrees with temperatures over 100 from 19Z to 04Z.

For the rest of southern Nevada, northwest Arizona and southeast
California...For the 06Z Forecast Package...VFR conditions will
persist through the TAF period. Breezy southerly-to-westerly
winds will gradually decrease across the Mojave Desert throughout
the overnight hours. Winds across southern Nevada will swing
around to the northwest as a front passes through on Tuesday
morning. With the exception of the western Mojave Desert, winds
across the region will become light and variable tomorrow
afternoon before following typical diurnal directional trends in
the evening. Winds across the western Mojave Desert will favor a
west-northwesterly direction before picking up and falling back
to the west tomorrow evening.

&&

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

&&

$$

DISCUSSION...
AVIATION...Stessman

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