561
FXUS65 KVEF 112135
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
235 PM PDT Thu Jul 11 2024

.SYNOPSIS...Hotter than normal temperatures will continue through
next week as a ridge of high pressure remains over the Southwestern
US. However, temperatures will decrease over the weekend, remaining
2 to 5 degrees above normal through next week. A welcome reprieve
from the extreme temperatures of this past week. An uptick in
moisture will accompany this slight decrease in temperatures over
the weekend, with increasing chances for isolated showers and
thunderstorms on Saturday and Sunday. Gusty outflow winds, periods
of heavier rains, and dangerous lightning will be the primary
threats from this weekend`s convection, with dry lightning posing a
threat in the Eastern Sierra over the weekend.

&&

.SHORT TERM...Today and Tomorrow.

The historic and record breaking heat of the past week will continue
through the end of the work week with widespread High to Extreme
HeatRisk across much of the area. Current water vapor and satellite
imagery show a ridge of high pressure positioned across the
Southwestern US. If you were to compare satellite imagery from this
afternoon to 24 hours ago you would notice there are significantly
more clouds in the sky, which is indicative of moisture gradually
increasing across southern Nevada, northwestern Arizona, and
southeastern California. This upper-level ridge will gradually shift
off to our east over the next couple of days, resulting in southerly
flow aloft, which will in turn allow for increased moisture
transport into the region. Showers and thunderstorms associated with
this increase in moisture will be limited to Mohave County today and
tomorrow, with more expansive chances this weekend. Gusty outflow
winds, lightning, and periods of moderate-to-heavy rain will be the
primary threats associated with any convection that develops this
afternoon and tomorrow afternoon.

As this aforementioned ridge shifts off to the east and moisture
pushes into the area, we will see temperatures gradually decrease a
few degrees. That means today will be the hottest day for the rest
of the forecast period with temperatures dropping a few degrees from
today to tomorrow. Despite this slight "cool down," HeatRisk will
still remain Major (level 3 of 4) to Extreme (level 4 of 4) for
much of the region. As such, the Excessive Heat Warnings and Heat
Advisories will remain in effect through tomorrow night.

.LONG TERM...Saturday through next Thursday.

It is looking more and more favorable for scattered showers and
thunderstorms to develop over much of Mohave, Clark and San
Bernardino and Inyo counties Saturday as moisture quickly gets
pulled up from northern Mexico/southern Arizona between the closed
high migrating over the Four Corners and an elongated trough just of
the California Coast. NBM pop values have increased and now indicate
30-50 percent probability of measurable precipitation across the
aforementioned areas, including the southern and western parts of
the Las Vegas Valley. This would support all the typical monsoon
hazards (flash flooding, gusty outflow winds, dust, and lightning)
over the southern half of our area...from Clark County southward
where PWAT values of 1-1.5 inches can be expected. Farther
northwest, where low-level moisture will be more limited, flooding
is less of a concern and dry lightning potential increases. A fire
weather watch is in effect for the Eastern Sierra for Saturday and
Sunday. Fuels are very dry, especially after this heat wave, and the
latest NBM thunder chances are 20-30% while wetting rain potential
is less than 10%.

Moisture expands across south central Nevada Sunday for another
potentially active day of convection across most of our forecast
area. The coastal trough is forecast to lift inland across northern
California Monday which should turn the flow a little more
southwesterly and the NBM and model ensembles indicate modest drying
trend Monday through Thursday with a slight drying trend and chances
of thunderstorms confined mainly to Mohave County Tuesday through
Thursday. Temperatures will decrease several degrees with the
increasing moisture, cloud cover and storm influences although highs
will still be in the 105-110 degree range across most of the
desert zones.

&&

.AVIATION...For Harry Reid...Mainly east to southeast winds for the
rest of the afternoon. Winds pick up out of the west to southwest in
the late afternoon with gusts up to around 15 knots possible. By the
late evening, winds should decrease but maintain a southwesterly
direction. FEW mid level clouds move over the area throughout the
forecast period. There is a low probability (< 20%) of stronger
outflow winds between 01-04Z this evening but a 20-40% probability
on Friday evening.

For the rest of southern Nevada, northwest Arizona and southeast
California...A push of slightly elevated westerly to southwesterly
winds will arrive in the late afternoon and evening for the Las
Vegas Valley, Owens Valley including KBIH, and KDAG. Peak gusts
should remain less than 20 knots except for KDAG where gusts of 20-
25 knots may develop. Winds should weaken later in the night and
resume a diurnal pattern. Easterly outflow winds from convection in
Mohave County may reach KEED and KIFP tonight, causing temporary
changes in wind speed and direction. FEW-SCT mid and high level
clouds move across the forecast area today and tonight. Mainly
diurnally driven winds on Friday with the exception of KIFP and KEED
where southerly winds will be common at 10-15 kts.

&&

.FIRE WEATHER...The intense heat of the past few days will continue
through Friday before we see an increase in moisture and a slight
decrease in temperature over the weekend. This increase in
moisture will help relative humidity values recover and will
bring increased chances for showers and thunderstorms to the
region over the weekend. Despite this influx of moisture, chances
for wetting rains remain minimal for much of the region, with an
increased risk of dry lightning due to the lower-levels of the
atmosphere remaining relatively dry. Outside of dry lightning, any
convection that develops this weekend will have the potential to
result in gusty outflow winds, which may cause erratic fire
behavior.

&&

.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 11   FRI, JUL 12
  Record(Yr)    RECORD (Yr)

Las Vegas     116(1959)*   114(2003)*
Bishop        109(2021)*   108(2020)*
Needles       120(2020)*   124(1925)
Daggett       117(2021)*   115(2021)*
Kingman       110(1961)*   111(2020)*
Desert Rock   114(2021)*   112(2021)*
Death Valley  129(1913)*   130(1913)

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 11  FRIDAY, JUL 12
              Record(Yr)   RECORD (Yr)

Las Vegas     91(2012)*     94(2020)*
Bishop        70(2013)      69(1990)*
Needles       96(2021)      96(2021)
Daggett       90(2021)      87(2012)*
Kingman       81(2021)*     80(2021)*
Desert Rock   87(2021)      83(2023)*
Death Valley  105(1920)     107(2012)

&&

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

&&

$$

SHORT TERM/FIRE WEATHER...Stessman
LONG TERM...Adair
AVIATION...Czyzyk

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