Chris Stachelski

Hiko Tornado On August 31, 2000. Photo Credit: Howard Blum.

Although rare, tornadoes do occur in the Mojave Desert and southern Great Basin. This page provides information on the tornado climatology for the area served by the National Weather Service office in Las Vegas. For more information about tornadoes in general, the Storm Prediction Center has an excellent question and answer page.

Tornadoes are now rated by the Enhanced Fujita Scale. Prior to 2007, the original Fujita Scale was used to rate the intensity of tornadoes. This scale was developed in 1971. Before 1971, some older tornadoes were later rated based on the damage description provided in Storm Data and Unusual Weather Phenomena. Due to a lack of data, you will notice several tornadoes that took place in the Mojave Desert and southern Great Basin were never rated. More information on why the original Fujita Scale was revised to the Enhanced Fujita Scale is available from the Storm Prediction Center.

Officially, 49 tornadoes have been documented in the area served by the National Weather Service in Las Vegas since modern tornado records started in 1950. The vast amount of land that is unpopulated and not easily viewed or accessed by humans in this area is a significant factor that likely results in the official number being an undercount. Additionally, many tornadoes are obscurred by the mountainous terrain with only the funnel visible but the portion of the funnel in contact with the ground being out of sight. This makes it extremely difficult to determine whether a funnel actually made contact with the ground. Even in cases where a funnel was observed only barren dirt or sparse vegetation exists which would limit any damage and any clues as to whether the funnel ever made contact with the ground.

Las Vegas Review-Journal Headline of the June 7, 1964 thunderstorm.

The earliest reference in any literature to a tornado in southern Nevada was on July 31, 1949 when reports of a tornado hitting the Virgin Valley were published in area newspapers. Hay crops were destroyed and a number of trees were uprooted. In Mesquite, the storm reportedly blew hay over the mountains. The oldest official dataset report of a tornado in this area was on June 7, 1964 in the Las Vegas Valley. However, despite this thunderstorm even making front page headlines in the Las Vegas Review-Journal little detail on this tornado exists. The official report describes a funnel cloud that moved from near Mt. Charleston to about 5 or 6 miles north of Thunderbird Field (which is now the North Las Vegas Airport) in which at some point the funnel touched the ground. This part of Las Vegas was then open desert, so no damage was reported. However, this remains one of the most intense thunderstorms ever documented in Las Vegas. Winds at Thunderbird Field were reported to have held steady at 85 mph for 3 to 4 minutes and gusted to 100 mph at one point as measured by wind equipment there.

A rare severe weather outbreak in southern Nevada took place on March 30, 1992 triggered by an upper-level low located near the coast of southern California. Showers and thunderstorms were set off across the area with several reports of funnel clouds received in the Las Vegas Valley, including at least one captured on film and home video in the Green Valley area of Henderson. Two of the funnel clouds touched down in the Las Vegas Valley and were confirmed as tornadoes.

Tornado damage to a house in the Las Vegas Valley on March 30, 1992. Photo Credit: Las Vegas Review-Journal.

The number of tornadoes by decade in the current NWS Las Vegas CWA as reported in Storm Data and Unusual Weather Phenomena.

Starting in the 1970s a noticeable increase in the number of tornadoes exists in the Mojave Desert and southern Great Basin. This is likely due to an increased awareness in tornadoes occurring in this part of the country as well as an increase in population (which would increase the odds of a tornado being observed by someone). The 1990s were the most active decade with a sharp drop after that. During the 1990s, Doppler radar was introduced and this promoted more awareness of potentially tornadic storms. This may have resulted in more storms either being investigated and storm surveyed later in order to obtain ground truth. Additionally, the advent of the internet and social media also has opened up many more opportunities to obtain images and reports of tornadoes than the era in which phone calls and hard copies of newspapers were often the dominant sources for obtaining reports of storm damage.

The number of tornadoes by the hour of occurrence in the current NWS Las Vegas County Warning Area (CWA) as reported in Storm Data and Unusual Weather Phenomena using the start time. All times are in standard time.

The graph above shows the number of tornadoes by hour of occurrence using the start time of the tornado. No nighttime tornadoes have ever been officially reported in the current NWS Las Vegas County Warning Area (CWA). The earliest tornado ever (using standard time) was on August 1, 1983 in Landers, California which was reported at 10:50 AM PST. The latest tornado ever was in the Lake Mead National Recreation Area on July 22, 1984 at 8:00 PM PST. The most active hour for tornadoes to develop was the 4 PM hour which had 12. The 11 AM hour was the next most active with 9.

The number of tornadoes by the month of occurrence in the current NWS Las Vegas County Warning Area (CWA) as reported in Storm Data and Unusual Weather Phenomena.

Tornadoes have been reported officially in every month of the year in the NWS Las Vegas County Warning Area (CWA) except for February. The leading month is August with 14 tornadoes while July ranks second with 9 tornadoes. The majority of tornadoes in this area occur during the North American Monsoon. During the winter, strong cold areas of low pressure in the mid and upper levels of the atmosphere can produce thunderstorms and although most are low-topped (having tops of only 25,000-30,000 feet), a few of these can become strong enough to produce hail and on rare instances a tornado. The fall season and to a lesser extent the spring when the atmosphere is in a state of transition provides a set-up sometimes where low pressure in the mid and upper atmosphere sets up in a position where it pulls an influx of moisture from the south into the Mojave Desert and southern Great Basin and the environment becomes favorable for thunderstorms to develop. Such a pattern would also result in greater shear which would also favor thunderstorms becoming more organized and conducive under the right circumstances to produce a tornado.

The number of tornadoes by the county of occurrence in the current NWS Las Vegas County Warning Area (CWA) as reported in Storm Data and Unusual Weather Phenomena. San Bernardino County and Nye County numbers only include the areas served by NWS Las Vegas.

Tornadoes are much more common in the southern portions of the NWS Las Vegas County Warning Area (CWA) than in northern portions. This is due to two reasons. First, the southern parts of the area get more thunderstorms annually than areas further north with the largest number of thunderstorm days over Mohave County. Secondly, the southern portions are more populated increasing the odds of a tornado being observed. Tornadoes are most commonly reported in towns, along highways and by airplane pilots. The greatest number of tornadoes was near Kingman, Las Vegas, the Lake Mead National Recreation Area, the Morongo Basin and the Barstow-Daggett area. Only one tornado has ever crossed into multiple states in this area. The Tri-State tornado of April 21, 2001 formed in San Bernardino County before moving into Clark County and then entered Mohave County where it dissipated.

Tornado near the southern tip of Nevada on April 21, 2001. Photo Credit: Spotter.

A landspout 10 miles north of Independence, California on the afternoon of November 30, 2012. A landspout is a tornado that does not arise from organized storm-scale rotation and therefore is not associated with a wall cloud (visually) or a mesocyclone (on radar). Landspouts typically are observed beneath cumulonimbus or towering cumulus clouds (often as no more than a dust whirl), and essentially are the land-based equivalents of waterspouts. Photo Credit: California Highway Patrol.

Tornado near the turnoff to Nelson's Landing on August 4, 2014. Photo Credit: Allen Lynn.

Twin landspouts near Landers, California on July 19, 2015. Photo Credit: Joycelyn Rasted.

Most tornadoes in the Mojave Desert and southern Great Basin are short-lived and last only a few minutes. The longest track was 5 miles from a tornado that formed 16 miles southwest of Kingman on November 22, 1996. Widths of most tornadoes also tend to be small with many having a rope-like look to them. Only one tornado in the current NWS Las Vegas County Warning Area (CWA) has ever been rated a F2 which took place on September 7, 1982 six miles north-northwest of Joshua Tree.

Below is a list of all the officially documented tornadoes in the County Warning Area served by the National Weather Service in Las Vegas. This information was taken from Storm Data and Unusual Weather Phenomena.