915
FXUS65 KVEF 031944
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
1244 PM PDT Wed Jul 3 2024

.SYNOPSIS...A rare and dangerous long duration heatwave begins
today and will persist into 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 through midweek.

&&

.DISCUSSION...through next Wednesday.

Not much change to the forecast thinking from the past few days
with a major heat wave continuing to be the dominant headline.
High pressure ridge currently situated across the Northeastern
Pacific will build into the West Coast today and tomorrow before
slowly creeping inland Friday and through the weekend. As this
occurs, heights will gradually climb and temperatures will rise.
This rise will be most notable across our western zones (closer to
the ridge axis) today and Thursday, but the heat will spread
north and east over the weekend, and some of our ongoing heat
headlines will likely be expanded. By early next week, the
aforementioned high will begin to drift more overhead across
central Nevada, and its this time period that temperatures are
most likely to reach their peak.

Our latest forecast grids continue to advertise high confidence in
record or near record heat for much of the forecast area. In fact,
NBM forecast highs in Las Vegas are currently suggested to reach
or exceed daily record high values for at least 5 days in a row
(Saturday - Wednesday), while NBM probabilities for setting a new
all-time record high of 118 in Las Vegas peak on Tuesday at about
67%. To describe this heat in another context, Las Vegas averages
about one day per year with high temperatures of 115 or greater,
and we are forecasting at least 5 consecutive days of 115F+ temps
starting Saturday. Needless to say, this is very dangerous heat in
both magnitude and duration, and every effort should be made to
mitigate heat exposure and stay comfortable and hydrated in these
conditions.

There are several ongoing wildfires across northern California and
the 4th of July is tomorrow, so we will need to monitor smoke
quantities in the coming days as they could have implications on
the forecast temperatures. But aside from that, there are few
variables to limit the heat intensity in the coming days. By
midweek, as the high pressure ridge shifts east the flow aloft may
trend more southerly allowing for a very modest return of surface
moisture and a gradual cooling of temperatures from their record
levels.

&&

.AVIATION...For Harry Reid...Winds will continue to follow typical
diurnal trends through tomorrow, with light northeasterly winds this
afternoon and turning to the southwest by evening.  A few gusts to
18kts will be possible once the southwest turn occurs, but
prevailing winds should remain 10kts or less.  Any gusts that do
develop should end after sunset.  Light northeast winds will return
once again tomorrow morning.  VFR conditions will prevail, with
clear skies expected throughout the TAF period.  Temperatures will
remain above 100F through 06Z and then climb back above 100F by 17Z
tomorrow.


For the rest of southern Nevada, northwestern Arizona, and
southeastern California...Winds will continue to follow typical
diurnal trends at area TAF sites through tomorrow.  The Vegas Valley
and Colorado River sites will see a few gusts to 18kts this
afternoon and evening before falling below 12kts overnight. Westerly
winds to 20kts are possible at KDAG into this evening before
diminishing.  Lighter winds are forecast tomorrow, with winds
remaining at 12kts or less at all regional TAF sites.  VFR
conditions will prevail, with mainly clear skies expected through
Thursday.

&&

.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           WED, JUL 3  THU, JUL 4  FRI, JUL 5  SAT, JUL 6
              Record(Yr)  Record(Yr)  Record(Yr)  Record(Yr)

Las Vegas     116(1937)*  115(1985)*  116(2007)*  115(2007)*
Bishop        107(1984)*  107(2007)*  108(2007)*  105(2021)*
Needles       119(2013)*  121(2007)   121(1989)*  120(1922)*
Daggett       115(2001)*  117(1991)   118(2007)   115(2007)*
Kingman       111(1967)   110(2007)*  109(2007)*  108(2017)*
Desert Rock   113(2013)   112(1985)   112(2007)*  111(2007)*
Death Valley  127(2013)   128(2013)   126(2013)*  127(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      WED, JUL 3  THU, JUL 4  FRI, JUL 5  SAT, JUL 6
              Record(Yr)  Record(Yr)  Record(Yr)  Record(Yr)

Las Vegas     92(2013)    91(2015)    89(2013)*   90(1957)*
Bishop        71(2013)    67(2001)    67(1984)    67(1985)
Needles       94(2013)    95(2013)    92(2013)    97(1903)
Daggett       86(2013)    88(2001)    84(1984)*   83(2007)*
Kingman       82(1906)    80(2013)    78(2021)    79(1981)
Desert Rock   86(1996)    83(2015)    80(1981)    83(1992)
Death Valley  102(2013)   100(1915)   110(1918)   99(2013)

&&

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

&&

$$

DISCUSSION...Outler
AVIATION...Planz

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