411
FXUS65 KVEF 162031
AFDVEF

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

.KEY MESSAGES...

* A Red Flag Warning remains in effect until 8 PM across portions of
  southern Nevada and northwestern Arizona. Winds are expected to
  decrease this evening.

* 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.
&&

.FIRE WEATHER...A Red Flag Warning remains in effect until 8 PM
today across southern Nevada (Zones 462, 464, 465, 466) and
northwestern Arizona (Zones 101, 102). Winds should begin to
decrease around 8 PM, lessening the threat. Another period of strong
winds and low humidity is likely to occur Thursday through Saturday,
and fire weather headlines may be needed again.
&&

.AVIATION...For Harry Reid...For the 18Z Forecast Package...Gusty
wind is still the primary concern. Winds will gradually veer from
southerly to southwesterly through the afternoon, with gusts
increasing to 25 to 30 knots. Gusts should decrease around sunset,
although gusts of 15 to 20 knots could persist through much of the
night before ending early Tuesday morning. Winds are expected to
shift to northerly Tuesday morning, with speeds 10 knots or less. No
operationally significant clouds or weather through the period.
Temperatures will be 100 degrees or greater between 18Z-04Z, peaking
at 108 degrees around 23Z.

For the rest of southern Nevada, northwest Arizona and southeast
California...For the 18Z Forecast Package...Another round of gusty
southwesterly to westerly wind is expected across the region through
early this evening. Gusts of 20 to 30 knots will be common, with
stronger gusts around 40 knots over the Sierra Nevada. Winds will
decrease a little overnight, but intermittent gusts of 20 to 25
knots can be expected. No operationally significant clouds or
weather expected.
&&

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

$$

DISCUSSION...Morgan
AVIATION...Morgan

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