Monsoon moisture which had been fueling thunderstorms over southern Nevada and northwest Arizona for days seeped west into southeast California, triggering several flash floods.
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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 which had been fueling thunderstorms over southern Nevada and northwest Arizona for days seeped west into southeast California, triggering several flash floods.
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 26, 9:39 AM PST, 1 hour 21 minutes earlier.
Area Forecast Discussion National Weather Service Las Vegas NV 1039 AM PDT Mon Jul 26 2021 .SYNOPSIS...Widespread showers and thunderstorms are expected again today before drier conditions return Tuesday and Wednesday. Thereafter, another uptick in monsoonal moisture is expected, with increasing thunderstorm chances through the weekend. Temperatures through the week will be near to slightly below normal. && .UPDATE...The KESX radar remains down this morning. Due to lightning proximity as seen via satellite, our best guess is that it was struck by lightning. Our electrical technicians are on their way to the radar now, and hopefully can get it up and running. Thankfully, it appears that for the short term, shower activity is focused within the range of KEYX at Edwards Air Force Base. Light rain showers can be seen across the forecast area this morning. The MCS from last night likely did a good job at eating up the majority of the instability in the region, but there remains a substantial amount of moisture in the atmosphere today. Coupled with the dynamics of the shortwave trough, moderate to locally heavy rainfall can certainly not be ruled out this morning. Though isolated thunderstorms are possible area-wide today, our primary concerns lie across San Bernardino County this morning as the low moves across our area, and Inyo County later this afternoon. Rain chances will push north-northwestward, potentially impacting western Clark County as well. Pahrump in particular has quite a bit of storm-related damage from last night's storms, and has the potential to experience another round of storms today. Locally heavy rainfall, isolated flash flooding, frequent lightning and gusty winds would all be possible with storm formation in the area. What currently has our eye is a complex moving northwestward along the state line from Primm that could clip Pahrump in the next couple of hours. A number of flash flood-related products have already been issued this morning for portions of San Bernardino County as we watch this complex push through the region. Our concern turns to Death Valley National Park this afternoon, as the area is incredibly prone to flash flooding, and PWAT values across Death Valley are in excess of 2 inches... that's higher than anywhere else in our forecast area. Storms from last night have reportedly had no impact to the park, so we have reason to believe that any moisture the soil was going to take up... has already been taken up. Will keep a close eye on storms as they move across eastern Inyo County as a result. Additionally, there are a couple of wildfire burn scars including the Taboose and Inyo Creek in the Sierra Nevada mountains that could produce debris flows when in contact with heavy rain rates. Flash flooding will be the primary concern in southeastern California today. As such, the Flash Flood Watch remains in effect through 11pm PDT tonight, and looks to be in good shape, so no edits necessary this morning. Made some changes to the PoP grids to accommodate local models, but otherwise, made no changes to this morning's forecast. Will keep you posted on the status of the radar as we learn more information. 1038: Technicians are unable to get into the radar at this time, as current rainfall in the area has made it hazardous to do so. At first glance, they say that there is no cosmetic damage, but will be able to learn more and assess the full extent of the issues once the rain ceases. - VARIAN && .PREVIOUS DISCUSSION...243 AM PDT Mon Jul 26 2021/ .DISCUSSION...through next weekend. Very active weather to start the shift, so running behind this morning. MCS which blasted through Clark County was petering out as it crossed into SGX's part of San Bernardino County at 130 AM. Light rain was still tracking westward over western San Bernardino and southern Inyo counties, and new showers were popping up over the Morongo Basin, possibly helped along by outflow from the decaying MCS. Debris clouds covered the rest of our CWA. Surface wind field had been completely disrupted along and near the track of the MCS, but as it has weakened since midnight, the peak gusts have been decreasing. Surface temperatures were also a mess, with several stations already at or below the forecast morning lows thanks to heavy rain and/or rain-cooled outflow winds. Made substantial manual adjustments to min temp grids and lesser adjustments to PoP grids to account for current trends. The main concerns for one more day remain thunderstorms and flash flooding. Shortwave trough seen on mid level water vapor imagery over the Gulf of California will move north across southern California today, helping to lift the soggy airmass in place across our area. Main concern is whether or not the atmosphere can recover from the effects of the MCS and recharge in time to respond to the forcing of the shortwave trough. In recent days, nocturnal debris clouds have cleared out in the early mornings, allowing plenty of afternoon heating and destabilization. Given these trends, plus the very juicy airmass in place, will leave the Flash Flood Watch as is. Also started the northern zone grouping at midnight instead of 5 AM due to ongoing warnings and flooding in a couple of the zones. As the wave lifts through our area during the day, more stable air will start to move in behind it, shutting off precip chances along and south of I-40 by afternoon and CWA-wide by sunrise Tuesday morning. There will still be plenty of moisture available, and sunshine Tuesday and Wednesday will be sufficient to pop scattered thunderstorms over the higher terrain, but with less coverage and intensity than in previous days. Temperatures will climb back to near normal for late July thanks to the extra sun. Meanwhile, a low pressure area which was over the Gulf of Mexico early this morning will be drifting west around the big dome of high pressure covering much of the US. This low is forecast to approach our area beginning Thursday and stick around at least through Saturday, bringing increased chances for showers and thunderstorms again. && .AVIATION...For McCarran...The severe thunderstorm complex has now cleared the Valley leaving mostly light and variable winds in its wake. Low confidence in wind directions overnight but do not believe they will be operationally significant. Also low confidence that some light fog could develop overnight as moisture is high across the valley from the intense rainfall. For tomorrow, another round of afternoon TS development is expected, but with flow to the northwest, any development that occurs on higher terrain should push away from the valley. Thus, only included VCTS but did not include a wind impact at this time. For the rest of southern Nevada, northwest Arizona, and southeast California...A decaying but strong complex of thunderstorms was moving southwest along the I-15 corridor towards KDAG. Expecting this to reach the terminal by 0630-07Z with gusty winds over 35kts and possible BLDU. After passage, some lingering showers and thunderstorms will be possible overnight but greater confidence is in re-development near KDAG tomorrow morning. In addition to KDAG, KBIH looks to see thunderstorms tomorrow afternoon which could create outflow gusts from the southeast to 35 kts. For the LV and CO River valley, storm development should be much more isolated and confidence in direct impacts is low. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && DISCUSSION...Morgan AVIATION...Boucher For more forecast information...see us on our webpage: https://weather.gov/lasvegas or follow us on Facebook and Twitter
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LAS VEGAS NV
1145 AM PDT MON JUL 26 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1135 AM FLASH FLOOD PAHRUMP 36.21N 115.98W
07/26/2021 NYE NV NWS EMPLOYEE
FLOODING AT THE INTERSECTION OF 372 AND 160.
ROAD IS CLOSED.
&&
BEPThe national radar mosaic for the moment the first event began.
7 flash flood. Local standard time, as filed.
Highway 127 was flooded and impassable.
Highway 127 was flooded.
The intersection of Highway 190 and Cow Creek Road was impassable due to mud and water. Flooding also damaged a water main, cutting off water service to nearby homes.
State Line Road was flooded east of Death Valley Junction.
Water one to two feet deep flowed over the intersection of Highway 190 and Beatty Road.
Twenty Mule Team Road was closed due to flooding.
Titus Canyon Road was closed due to flooding.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2021Every state in 2021This day in weather historyWarnings in California, July 2021
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: 977108, 977110, 977113, 977114, 977116, 977117, 977118.