Strong high pressure brought dangerously hot temperatures to the Mojave Desert.
Every event with a place to put it; 5 filed by county or forecast zone are drawn at its center, in a lighter ring. 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.
Strong high pressure brought dangerously hot temperatures to the Mojave Desert.
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 11, 9:51 AM PST, 1 hour 9 minutes earlier.
Area Forecast Discussion
National Weather Service Las Vegas NV
1051 AM PDT Sat Jul 11 2020
.SYNOPSIS...High pressure will continue over the region this weekend
and into the start of next week, rising temperatures to dangerous
levels. Afternoon breezes continue each day, though pockets of light
cloud cover possible this weekend. Through the work week,
temperatures will lower to more seasonal values.
&&
.UPDATE...Satellite imagery through the morning showed a remnant
MCV over the northern Baja peninsula that continued was slowly moving
north and west through the morning. Scattered light showers and a
few lightning strikes were noted over southern California towards
Yuma, AZ. Moisture associated with this MCV had been edging north,
with PWATs at 1 inch or more through far southern Clark County, San
Bernardino County, and the southern half of Mohave County. Dewpoints
around 50F were reported through this area this morning, which is
higher than expected. Even with this slightly increased moisture,
12Z soundings across the region showed extremely dry air just above
the surface inversion this morning. As a result, not expecting this
moisture anomaly or the moisture boundary to result in precipitation
initiation this afternoon as dry air aloft will quickly mix out and
squash it. Only potential area that may see isolated precipitation
from this feature would be the Morongo Basin into the Daggett-
Barstow, as the remnant MCV (or whats left of it) may reach this
area early this afternoon.
Otherwise, no major changes to the previous forecast high
temperatures. Moisture should not hold back temperatures this
afternoon per the reasons above. Continue to include the isolated
thunderstorm mention in the higher terrain of extreme eastern Mohave
County for this afternoon. Short term models show ML CAPE edging
slightly higher this afternoon with CIN quickly eroding in areas
north of I-40, so a few quick updrafts and rumbles of thunder are
possible. Not expecting any impactful thunderstorms though as
anything that does develop will be extremely high based and
instability will be limited.
&&
.PREVIOUS DISCUSSION...305 AM PDT Sat Jul 11 2020.
.SHORT TERM..through Monday.
Mostly clear to partly cloudy skies being observed across the region
this morning. Second night in a row there has been a decaying MCS
across northern Sonora Mexico. The added moisture in the air making
for a warm night with temperatures at North Las Vegas, Nellis AFB
and Bullhead City running around 10 degrees warmer than 2 am last
night.
Expansive, strong ridge from California east to Texas will make for
a hot weekend in the Mojave Desert and southern Great Basin.
Temperatures will peak on Sunday with only slight relief Monday as
heights start to gradually recede. Weekend temperatures crept up
another degree or two from the previous forecast. The Sunday
forecast for Las Vegas is now 114 which would tie the record for the
date, but also be the hottest temperature Las Vegas as seen since
late July 2018. No change made to existing Heat products through
Monday.
As stated earlier, we've observed a modest increase in moisture
working northward around the western periphery of the expansive
ridge. However, those wishing for thunderstorms the convective
parameters are not looking very impressive. Convective allowing
models/CAPE would suggest a very isolated threat for a brief
shower/thunderstorm along the eastern Mohave County line this
afternoon with Yavapai and Coconino Counties.
South to southwest winds are expected each afternoon with gusts
generally in the 20-30 mph range.
.LONG TERM...Tuesday through Friday.
Subtropical ridge will flatten in response to troughing traversing
the PacNW region Tuesday through Thursday. This will result in
modest cooling with typical mid-July heat resuming and continued dry
conditions. Dry fuels and afternoon breezes will result in elevated
fire danger, though overall wind speeds don't look overly concerning
for a more widespread wildfire risk. High pressure will attempt to
rebuild across the Southwest Friday into next weekend, and a few
ensemble members suggest the possibility of some low-grade monsoonal
moisture attempting to advance into the region, however, most of the
ensemble members suggest fairly minimal moisture intrusions. As
such, forecast remains dry through at least the next week ahead.
&&
.FIRE WEATHER...Moisture working around the western
periphery of expansive ridge will lead to slightly better humidity
recovery this morning and again Sunday night. South to southwest
wind gusts 20 to 30 mph are likely each afternoon through Monday.
There is some concern for extreme fire conditions being observed
Monday based on some of the latest wind forecasts. Not confident
enough at this point to issue a Watch but something for the day
shift to consider and collaborate.
&&
.CLIMATE...
FORECAST HIGH TEMPERATURES / DAILY RECORD HIGH TEMPERATURES
SAT 07/11 SUN 07/12 MON 07/13
Las Vegas, NV 113/116(1959) 114/114(2003) 111/115(1939)
Bishop, CA 103/107(2014) 104/106(2003) 104/107(2014)
Barstow, CA 111/115(2003) 112/114(2003) 110/115(1972)
Needles, CA 117/120(1961) 120/124(1925) 117/123(2005)
Death Valley, CA 124/129(1913) 125/130(1913) 123/131(1913)
Kingman, AZ 107/110(1961) 109/110(1939) 107/110(2005)
FORECAST LOW TEMPERATURES / DAILY RECORD WARM LOW TEMPERATURES
SAT 07/11 SUN 07/12 MON 07/13
Las Vegas, NV 88/91(2012) 89/89(2019) 88/89(2003)
Bishop, CA 61/70(2013) 63/69(1990) 62/68(2002)
Barstow, CA 81/85(2002) 84/87(2012) 84/83(1958)
Needles, CA 87/94(2012) 90/92(2019) 91/93(1906)
Death Valley, CA 96/105(1920) 99/107(2012) 97/100(2002)
Kingman, AZ 76/81(1906) 77/83(1925) 78/81(2004)
&&
.AVIATION...For McCarran...Light and variable winds this
morning through 17z will become predominantly southwest after 18z
with speeds generally between 8-12 kts with occasional gusts to
around 15 kts. Clouds FEW-SCT140-160. Temperatures will climb above
110 through Monday.
For the rest of southern Nevada, northwest Arizona and southeast
California...Winds generally less than 10 kts over most areas
through 17z then turning predominately southwest with speeds 10-20
kts with some occasional gusts up to 25 kts. Clouds FEW-SCT140-160.
Isolated storms possible east of Mohave County this afternoon.
Near record high temperatures expected through Monday.
&&
.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report
any significant weather or impacts according to standard operating
procedures.
&&
UPDATE...Nickerson
SHORT TERM/FIRE WEATHER...Pierce
LONG TERM...Outler
AVIATION...Gorelow
For more forecast information...see us on our webpage:
https://weather.gov/lasvegas or follow us on Facebook and TwitterThe national radar mosaic for the moment the first event began.
6 excessive heat. Local standard time, as filed.
Excessive Heat Warning criteria were reached three days in a row.
Excessive Heat Warning criteria were reached three days in a row.
Excessive Heat Warning criteria were reached three days in a row.
Excessive Heat Warning criteria were reached three days in a row.
Excessive Heat Warning criteria were reached three days in a row.
Excessive Heat Warning criteria were reached three days in a row.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Nevada in 2020Every state in 2020This day in weather historyWarnings in Nevada, July 2020
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: 900094, 900095, 900096, 900097, 900098, 900099.