238
FXUS65 KVEF 041551
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
850 AM PDT Thu Jul 4 2024

.SYNOPSIS...A rare and dangerous long duration heatwave will persist
at least through the middle of next week as a strong ridge of high
pressure sits over the region. Numerous long standing heat records
are likely to be challenged or broken. Dry conditions will prevail
through the period with no signs of monsoon moisture until
Wednesday at the earliest.
&&


.UPDATE...Another hot day in store as broad high pressure ridge off
the Pacific Coast begins to creep inland.  Temperatures across the
region at this hour are running pretty close to yesterdays values,
with high temps expected to finish off similar to yesterday.  Use
caution in todays temperatures if planning outdoor holiday
activities, and be advised even the upper elevations will be quite
warm.

-Outler-


&&

.DISCUSSION...through Wednesday. At midnight, skies were clear
areawide and temperatures were even hotter than previous nights,
with Needles and Bullhead City still at 104 degrees. As expected,
high temps yesterday went up about four degrees areawide from
Tuesday, and very slight rises are expected each day through
Saturday before the worst of the heat arrives Sunday and stays in
place at least through Tuesday if not longer. Any lowering of temps
beyond Tuesday will be meager and driven by a modest return of
monsoonal moisture, so even if temperatures go down a few degrees,
the increased humidity may offset it. With all this in mind, plus
the long holiday weekend, plus HeatRisk reaching Major to Extreme in
places like Lincoln County and northern Mohave County where we
rarely see it, have expanded the Excessive Heat Warning to cover
Lincoln and northern Mohave beginning Saturday, plus hoisted Heat
Advisories for the Spring Mountains, Sheep Range, and White
Mountains of Inyo County beginning Saturday. Ran the new headlines
through Wednesday, and also extended the preexisting ones through
Wednesday.

Record watch: NBM probabilities for reaching 118F at KLAS have been
fluctuating run to run as should be expected. The 01Z run gives a
56% probability for Sunday, 32% for Monday, 52% for Tuesday, and 35%
for Wednesday.

As noted by the previous shift, one wild card will be smoke from
fires in California and Utah swirling in the anticyclonic flow over
the West and bringing hazy skies. This could make a difference of
one or two degrees, maybe even more in areas of thick haze. This
could be enough to prevent a temperature record or two from falling,
but it will not be enough to make this intense, long-duration heat
wave less dangerous. Please stay safe.
&&

.AVIATION...For Harry Reid...Light and variable winds will give way
to breezy east-northeast winds through the entire day. 40 percent
chance of sustained speeds exceeding 10 kts through the morning with
occasional gusts to 15 kts. Chances will drop below 10 percent after
23Z. Variable wind directions expected around sunset, but will
ultimately favor the northwest overnight. Expect a return of breezy
northeast winds Friday morning. No operationally significant cloud
cover expected through the TAF period. Temperatures will exceed 100
degrees between 16Z and 07Z.

For the rest of southern Nevada, northwestern Arizona, and
southeastern California...Breezy northeast winds between 8 and 10
kts expected in the Las Vegas Valley with speeds peaking in the mid-
morning and waning through the afternoon. Light winds at KBIH will
give way to gusty northwest winds to 20 kts around sunset with
speeds decreasing through the evening. KDAG will experience breezy
west winds through the morning before becoming light and variable in
the afternoon. Gusty west winds return around sunset. Gusty north
winds will prevail through the Colorado River Valley this afternoon
with speeds to 20 kts. No operationally significant cloud cover
through the TAF period.
&&

.CLIMATE...Numerous climate locations have a forecast high
temperature and/or forecast warm low temperature within 3 degrees of
the daily record.

The table below shows the daily record maximum temperature and the
year the record was last set. An asterisk (*) denotes which records
are in jeopardy (within 3 degrees of the forecast).

MAX           THU, JUL 4  FRI, JUL 5  SAT, JUL 6  SUN, JUL 7
              Record(Yr)  Record(Yr)  Record(Yr)  Record(Yr)

Las Vegas     115(1985)*  116(2007)*  115(2007)*  116(2017)*
Bishop        107(2007)*  108(2007)*  105(2021)*  107(2021)*
Needles       121(2007)   121(1989)*  120(1922)*  122(2017)
Daggett       117(1991)   118(2007)*  115(2007)*  116(1989)*
Kingman       110(2007)*  109(2007)*  108(2017)*  112(2017)
Desert Rock   112(1985)*  112(2007)*  111(2007)*  111(2017)*
Death Valley  128(2013)   126(2013)*  127(2007)*  129(2007)*

The table below shows the daily record warm minimum temperature and
the year the record was last set. An asterisk (*) denotes which
records are in jeopardy (within 3 degrees of the forecast).

WARM MIN      THU, JUL 4  FRI, JUL 5  SAT, JUL 6  SUN, JUL 7
              Record(Yr)  Record(Yr)  Record(Yr)  Record(Yr)

Las Vegas      91(2015)    89(2013)*   90(1957)*   93(2018)*
Bishop         67(2001)    67(1984)    67(1985)    72(2014)
Needles        95(2013)    92(2013)    97(1903)    95(1942)
Daggett        88(2001)    84(1984)*   83(2007)*   80(2018)
Kingman        80(2013)    78(2021)    79(1981)    80(1917)
Desert Rock    83(2015)    80(1981)    83(1992)    82(1981)
Death Valley  100(1915)   110(1918)    99(2013)   101(2021)
&&

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

$$

DISCUSSION...Morgan
AVIATION...Soulat
CLIMATE...JS/JS

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