Monsoon moisture trapped under the big ridge causing excessive heat fueled isolated thunderstorms. A few storms produced high winds and/or flooding.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS VEF wrote it up.
Monsoon moisture trapped under the big ridge causing excessive heat fueled isolated thunderstorms. A few storms produced high winds and/or flooding.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Las Vegas, NV wrote its last area forecast discussion before the first event at Jul 22, 11:33 AM MST, 2 hours 22 minutes earlier.
Area Forecast Discussion
National Weather Service Las Vegas NV
1133 AM PDT Mon Jul 22 2024
.SYNOPSIS...Monsoonal moisture circulating under a strong area
of high pressure will result in diurnal rounds of showers and
thunderstorms, and a continuation of extreme heat. This pattern
looks to hold through the majority of the week before drier
southwest flow over the weekend brings an end to storm chances.
&&
.UPDATE...Another round of afternoon and evening convection is on
tap for the region today. Current visible satellite imagery shows
convection beginning to develop on the higher terrain across
southern Nevada, northwestern Arizona, and Inyo County. This
convection will continue to develop, eventually developing into
showers and thunderstorms within the next few hours. The primary
threats from storms this afternoon and evening will be strong gusty
outflow winds, dangerous lightning, and periods of heavy rain
capable of resulting in flash flooding. If you are recreating
outdoors make sure to stay weather aware and have a way to receive
weather alerts, especially if recreating on area lakes where gusty
outflow winds may result in dangerous boating conditions. Storms
won't be the only impactful weather today, as temperatures across
our southern zones remain a few degrees hotter than normal for late
July. These hot temperatures and afternoon thunderstorm chances will
continue through at least Thursday before an incoming trough scours
out the moisture and brings some relief from the extreme heat we've
experienced the past few weeks.
&&
.PREV DISCUSSION...
.SHORT TERM...Through Tuesday night.
Another late evening/early morning filled with outflow driven
convection. Most intense area of storms developed south of Temple
Bar and has propagated south into Kingman. Those storms did produce
locally heavy rain with one Mohave County ALERT gauge at Pierce
Ferry Rd and Archibald Wash measuring nearly 0.90" in 30 minutes.
Storms look to be finally winding down but several hydrologic
products will remain in effect for that area through 315 am MST this
morning.
Convective allowing models, such as the HRRR suggest similar
conditions evolving for the area today and again Tuesday. Storms
will fire over the higher terrain of southern Nevada, southwest Utah
and northwest Arizona today. Outflow boundaries moving southwest
will initiate new convection within the lower deserts as convection
pushes west toward Barstow and the Morongo Basin late this evening
before convection comes to an end in the early morning hours
Tuesday. HRRR suggests potential for another event Tuesday
afternoon/evening this time for southern Mohave County/lower
Colorado River. As with this most recent round of storms this
morning, gusty winds, locally heavy rain/flash flooding, hail and
lightning will be the concern.
Other issue of course is the continued heat. 597 dm high center
progged to remain situated over the area. Excessive heat product runs
through Wednesday. See climate section below for records.
.LONG TERM...Wednesday through the Weekend...
The latter half of the week will continue to feature a persistent
area of high pressure situated across southern Nevada and Arizona.
This will continue to support very hot temperatures, both during the
day and overnight. The run of 110 plus degree days looks to continue
at Harry Reid Airport, which will put us in a position to see all
time records for the month of July in terms of temperatures. Of
course, this would be the case in most other areas as well where
relentless heat has been a feature of summer 2024 thus far. In
addition, the presence of modest monsoonal moisture will allow for
daily rounds of isolated to widely scattered high based
thunderstorms. The main concern with these, given the deeply mixed
environment will get the potential for gusty downdraft winds on the
order of 40-50+ mph. Lighting and locally heavy rains will also
accompany any stronger storms. Activity will generally diminish
during the late evening and overnight hours each day. Mohave county
in Arizona, a bit closer to the moisture source, will hold the
higher probabilities of daily showers and storms. Elsewhere,
activity will likely be more sparse in nature.
From Friday into the weekend, ensembles are largely suggestive of a
pattern change as the upper ridge flattens and shift south and east.
This will allow a more trough pattern to develop across the
northwest U.S. The southern extent of this may reach the Southwest
U.S., but details regarding a weak cutoff low remain highly
uncertain. Regardless, with a return of more west/southwest midlevel
flow, a generally drier pattern appears probable, along with
temperatures closer to normal for late July. Ensembles are
supportive of this, with a general drying trend noted in a rather
impressive decline in precipitable water values and slight decrease
in max and min temperatures this weekend into early next week.
&&
.LONG TERM...Wednesday through the Weekend...
The latter half of the week will continue to feature a persistent
area of high pressure situated across southern Nevada and Arizona.
This will continue to support very hot temperatures, both during the
day and overnight. The run of 110 plus degree days looks to continue
at Harry Reid Airport, which will put us in a position to see all
time records for the month of July in terms of temperatures. Of
course, this would be the case in most other areas as well where
relentless heat has been a feature of summer 2024 thus far. In
addition, the presence of modest monsoonal moisture will allow for
daily rounds of isolated to widely scattered high based
thunderstorms. The main concern with these, given the deeply mixed
environment will get the potential for gusty downdraft winds on the
order of 40-50+ mph. Lighting and locally heavy rains will also
accompany any stronger storms. Activity will generally diminish
during the late evening and overnight hours each day. Mohave county
in Arizona, a bit closer to the moisture source, will hold the
higher probabilities of daily showers and storms. Elsewhere,
activity will likely be more sparse in nature.
From Friday into the weekend, ensembles are largely suggestive of a
pattern change as the upper ridge flattens and shift south and east.
This will allow a more trough pattern to develop across the
northwest U.S. The southern extent of this may reach the Southwest
U.S., but details regarding a weak cutoff low remain highly
uncertain. Regardless, with a return of more west/southwest midlevel
flow, a generally drier pattern appears probable, along with
temperatures closer to normal for late July. Ensembles are
supportive of this, with a general drying trend noted in a rather
impressive decline in precipitable water values and slight decrease
in max and min temperatures this weekend into early next week.
&&
.AVIATION...For Harry Reid...For the remainder of the morning,
expect generally light east winds of 10 knots or less. A lot of
uncertainty exists with respect to afternoon thunderstorms, which
may develop as early as 22z. The more likely timeframe of
thunderstorm impacts will be in the 23z-05z window, but confidence
remains low enough such that TEMPOs will not be introduced at
this time. Even if storms do not directly impact the airport,
gusty outflow winds will be likely and could come from any
direction, though it appears most likely that storms will develop
north of KLAS and develop southward late afternoon into the
evening hours. Should the stronger scenario play out, wind gusts
of 40-50 knots will be possible, along with heavy rains and
lightning. Activity should diminish by 07-09z with winds returning
to 10 knots or less and resuming their east/northeast direction.
A similar scenario appears probable for tomorrow as well, though
confidence remains low.
For the rest of southern Nevada, northwest Arizona and southeast
California...Showers and thunderstorms, along with gusty outflow
winds may affect almost any terminal this afternoon and evening.
The most likely timing will range from 22z-03z for northernmost
terminals, to 00z-09z for the southern terminals. Gusty winds of
30-50 knots may occur with any stronger storms near terminals this
afternoon and evening. Winds will generally remain diurnal
outside of thunderstorms with KBIH seeing southerlies shifting to
the northwest overnight, KDAG maintaining a generally
west/northwest direction, and winds elsewhere becoming light and
variable overnight. Given relatively high confidence in afternoon
storms, will maintain the TEMPO for TSRA at KBIH with other sites
likely to see introduction of TEMPOs as the afternoon progresses
and confidence increases.
&&
.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 MON, JUL 22 TUE, JUL 23
Record(Yr) Record(Yr)
Las Vegas 115(2023) 115(1942)*
Bishop 109(2003) 106(2016)*
Needles 118(2022) 119(2018)
Barstow-Daggett 115(2023) 112(2006)*
Kingman 109(2023) 108(1996)
Desert Rock 113(2023) 110(2023)
Death Valley 126(2023)* 127(1916)*
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 MON, JUL 22 TUE, JUL 23
Record(Yr) Record(Yr)
Las Vegas 92(2006)* 92(2003)*
Bishop 67(2013)* 72(2003)
Needles 100(2006) 96(2006)
Barstow-Daggett 83(2006)* 84(2003)*
Kingman 82(1912) 82(2023)
Desert Rock 84(2003) 84(2023)*
Death Valley 105(1917) 102(2023)*
&&
.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report
any significant weather or impacts according to standard operating
procedures.
&&
UPDATE...Stessman
SHORT TERM...Pierce
LONG TERM...Austin
AVIATION...Austin
For more forecast information...see us on our webpage:
https://weather.gov/lasvegas or follow us on Facebook and TwitterThe Cedar City radar (KICX), 67 km away, was scanning. The volume nearest the first event began at 20:53 UTC.
3 thunderstorm wind, 1 hail, 1 flood, 1 flash flood. Local standard time, as filed.
Hail took down numerous small tree branches.
There was minor street flooding in Colorado City.
Blowing dust also reduced visibility to 1/4 - 1/2 mile.
The Archibald Wash flooded Pierce Ferry Road.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2024Every state in 2024This day in weather historyWarnings in Arizona, July 2024
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1205922, 1205923, 1205927, 1205930, 1205932, 1205933.