Monsoon thunderstorms to increase in Southwest following one of driest latest starts in history
The North American monsoon is ramping up across the southwestern United States after one of the driest and latest starts to the season in history.
Despite the advantages of the welcome rainfall the monsoon brings, residents and visitors across the region must remain aware for lightning dangers, flash flooding, strong winds and haboobs (intense dust storms).
Monsoon thunderstorms to increase in Southwest following one of driest latest starts in history
“Clockwise flow around an area of high pressure over the Plains will help to steer moisture from Mexico northwestward into the Southwest throughout this week,” according to AccuWeather Senior Meteorologist and western U.S. weather blogger Brian Thompson.
A large dust storm, or haboob, sweeps across downtown Phoenix, Saturday afternoon, on July 21, 2012. Dust storms are common across Arizona during the summer, and walls of dust more than a mile high can blanket an area in a matter of seconds, sometimes reducing visibility to zero. (AP Photo/Mark Evans)
Combined with the strong heating of the day, that moisture will fuel thunderstorms daily across the Southwest.
“As is typically the case during the monsoon, thunderstorms will tend to blossom over the highest terrain during the afternoon hours and drift toward the lower elevations into the evening and overnight,” according to AccuWeather Meteorologist Reneé Duff.
The mornings will be the better time for hikers to head to the Grand Canyon in northern Arizona, Gila National Forest in southwestern New Mexico or San Juan National Forest in southwestern Colorado before thunderstorms erupt in the afternoon.
“Afternoon thunderstorms will pop up as far west as the mountains of Southern California,” Thompson added.
“Be watchful for rapidly growing or darkening clouds, which can be a sign that a thunderstorm is brewing,” Duff stated. “If thunder is heard or lightning is seen, head immediately downhill to a valley or depression in the terrain.”
It may be wise for hikers to not venture too far away from secure buildings that offer proper protection from both lightning and downpours.
Heavy thunderstorms throughout the Southwest can cause streams or dry creek beds, known as arroyos, to rapidly fill with dangerously fast-flowing water. Remember that quick-moving water at a depth of 6 inches can knock a person off their feet, and 12 inches can sweep most vehicles away.
The strongest thunderstorms may also kick up strong wind gusts, which may lead to localized damage and power outages. Dust storms that can rapidly drop visibility to near zero and raise the danger for multi-vehicle accidents can also be triggered in the deserts.
