Eastern Pacific Hurricane Hilary made landfall on the Baja Peninsula early on the morning of the 20th and reached Southern California as a tropical storm that afternoon. The cyclone brought major flash flooding and damaging winds to the Spring Mountains, along with less severe flooding elsewhere in southern Nevada.
Every event with a place to put it; 1 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.
Eastern Pacific Hurricane Hilary made landfall on the Baja Peninsula early on the morning of the 20th and reached Southern California as a tropical storm that afternoon. The cyclone brought major flash flooding and damaging winds to the Spring Mountains, along with less severe flooding elsewhere in southern Nevada.
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 Aug 19, 12:38 PM PST, 4 hours 54 minutes earlier.
Area Forecast Discussion National Weather Service Las Vegas NV 138 PM PDT Sat Aug 19 2023 .SYNOPSIS...Rich moisture related to approaching Tropical Cyclone Hilary will begin to advance into the Mojave Desert today with increasing shower and thunderstorm activity expected. This trend will continue into Sunday as the remnants of Hilary lift northward. Widespread heavy rain, gusty winds, and instances of major flooding are expected. Hilary's remains will exit the region by Monday but moist monsoonal conditions will persist much of the week with daily storm chances and temperatures remaining below normal. && .SHORT TERM...through Monday night. Our region still on track to see historic rainfall through Monday which will lead to significant flash flooding for parts of the Great Basin and Mojave Desert. Currently, Category 2 Hurricane Hilary lies off the southern Baja Peninsula. Satellite shows a considerable amount of mid/high clouds already streaming northward into the region. What has changed from last nights update is that the official track shifted slightly to the east. In intensity, Hilary is forecast to be tropical storm strength as it reaches southern California Sunday afternoon. Hilary will go through further weakening as it moves rapidly northward at around 30 kts becoming extra-tropical Monday. Precipitable water values are currently 150-250% of normal across southern California. As Hilary approaches those values rise to 250- 300% of normal across a large swath of western San Bernardino, Inyo, southern Nye and Esmeralda Counties. This coincides well with WPC's Excessive Rainfall Outlook of Moderate to High Risk for those regions. QPF Outlook still paints 2-4" in the lower elevations and 4" up to as much a 10" for the mountains in those risk area. Eastern Clark and Mohave Counties remain of the eastern side of the heaviest rainfall predictions, falling somewhere between 1-2" possible. This will likely come in several rounds, particularly tonight-Sunday morning and again Sunday night through Monday morning, then tapering off Monday afternoon and evening. Regarding wind threat. With Hilary forecast to be tropical storm strength as it arrives in southern California Sunday afternoon guidance continues to support sub-tropical storm strength south to southeast winds across southern San Bernardino County, lower Colorado River Valley and southern Mohave County. However, there remains some uncertainty in how strong these winds will be as Hilary may interact with the Baja Peninsula and weaken over the next 36 hours. Would like to wait at least 1 more model run before we consider wind advisories or even a short fused high wind warning for southern San Bernardino and southern Mohave Counties late Sunday afternoon and night. Temperatures through the short term period will be well below normal thanks to the abundance of clouds and moisture, with high temperatures Sunday likely to challenge record daily low maximum temperatures for many areas. .LONG TERM...Tuesday through Saturday. Following the exit of what is left of Hilary on Monday, widespread low level moisture will remain in place. Synoptically, an expansive ridge will remain parked over the central US with a southerly flow featured across the southwestern states. This will result in at least low-grade monsoonal conditions persisting most of next week, with daily storm chances favored in the higher terrain, but possibly drifting into the lower elevations in the afternoon and evening hours. Subtle shortwave features embedded in the flow may also result in some days being more active than others and promote more lower elevation activity. For now, NBM PoPs keep fairly generous storm chances going through the week across Northwest Arizona and southern Nevada, with slight chances across most of southeast California. With the abundance of moisture and continued daily storm activity, temperatures remain cooler than average by 5-10 degrees, but should trend warmer heading into the end of the week. && .AVIATION...For Harry Reid...Dense overcast likely will limit any convection in and around Las Vegas the rest of this afternoon and evening. Leading edge of deeper moisture ahead of Hilary will arrive this evening and continue into Sunday morning with periods of moderate rainfall, lower cigs and lower visibility. Prevailing visibility will be 3-5SM with cigs around 3-4 kft, but they could potentially fall below 3 kft. Air mass looks to become more unstable Sunday afternoon with breaks in the clouds as several bands around a decaying Hilary pass across southern Nevada. Prevailing winds should remain less than 10 kts and favor an east to southeast component this afternoon. For the rest of southern Nevada, northwest Arizona and southeast California...Scattered thunderstorms are expected across the region once again today. The best chance is into this evening across northwest Arizona and Inyo County. Any storms that do develop will be capable of producing gusty, erratic winds. Away from thunderstorm activity, winds of less the 10kts generally from the east and southeast can be expected. Moisture from Hilary will begin to spread across the area this evening into Sunday, resulting in steady light to moderate rain developing from south to north. In addition to the moderate rain reduced visibilities down to 2 to 4 SM at times and CIGs less than 2kft will be possible, with the degraded conditions continuing into Sunday night. && .SPOTTER INFORMATION STATEMENT...Heavy rain, high winds, and flash flooding reports are requested through the weekend as the remains of Hurricane Hilary lift through the Western Mojave Desert. && SHORT TERM/AVIATION...Pierce LONG TERM...Outler 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
153 PM PDT Sat Aug 19 2023
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0102 PM Flash Flood 7 WNW Panamint Springs 36.36N 117.58W
08/19/2023 Inyo CA Law Enforcement
California Highway Patrol reports roadway
flooding and debris across Highway 190
between mile marker 45-46.
&&
MSPreliminary Local Storm Report
National Weather Service Las Vegas NV
200 PM PDT Sat Aug 19 2023
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0750 PM Flash Flood 4 ENE New Kingman-Butle 35.28N 113.95W
08/18/2023 Mohave AZ Dept of Highways
Arizona Department of Transportation reports
flooding on Route 66.
&&
MSPreliminary Local Storm Report
National Weather Service Las Vegas NV
239 PM PDT Sat Aug 19 2023
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0222 PM Flash Flood 5 SSE Keeler 36.43N 117.82W
08/19/2023 Inyo CA Law Enforcement
California Highway Patrol reports a road
washout at the junction of State Route 190
and State Route 136.
&&
MSPreliminary Local Storm Report
National Weather Service Las Vegas NV
554 PM PDT Sat Aug 19 2023
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0900 PM Flash Flood 9 ESE Wonder Valley 34.12N 115.72W
08/18/2023 San Bernardino CA Emergency Mngr
Local Emergency Manager reports that Highway
62 is closed due to flooding from the State
Route 177 junction to 2.9 miles east of
Twentynine Palms.
&&
MSThe Las Vegas radar (KESX), 96 km away, was scanning. The volume nearest the first event began at 01:35 UTC.
5 flash flood, 1 high wind. Local standard time, as filed.
Eastbound Ute Rd was closed at I-15 due to flooding.
Ranch Rd was closed from Highway 168 to Eiseman St due to flooding.
The peak gust was measured 3 miles NE of Mount Charleston. Several trees were blown down.
Severe flash flooding affected the Spring Mountains. Many roads and underground pipes were washed out, several trails and parking areas were damaged or destroyed, and the fire station was damaged. Video showed multiple feet of water flowing down the mountain.
Water covered Highway 95 8 miles WNW of Amargosa Valley.
Hafen Ranch Rd was flooded.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Nevada in 2023Every state in 2023This day in weather historyWarnings in Nevada, August 2023
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: 1136452, 1136453, 1136454, 1136455, 1136470, 1136472.