Federal agencies issue warning for 'life-threatening flash flooding' set to hit Barstow

Updated story 4:45 p.m. Monday: Matt Woods, a forecaster with the NWS Las Vegas office, told the Daily Press around an hour into the warning that some thunderstorms and showers appeared to be lingering around the north-northwest area of Barstow but that "at least in the short-term, it looks like Barstow is done with the rain." It's unclear if that meant moisture potentially incoming for nearby residents outside of the city proper, such as those in Hinkley and Fort Irwin.

He said storms of this nature are typical for the summer, forming in high-terrain areas before flowing into lower-elevation areas like the High Desert, though the path of such storms is unpredictable and happened to run over the Barstow area this time around.

"Classic monsoon flow," NWS San Diego forecaster Alex Tardy said in a text.

"The past several days there have been thunderstorms forming from the San Bernardino Mountains and then moving northward across the High Desert," he said. Most of the monsoon effects in the past week have stayed between Lucerne Valley and Lancaster, according to Tardy.

"Today was the best day with the strongest storms moving south to north, and they happened to move right over Barstow," Tardy said.

Original story 4:37 p.m. Monday: The federal government activated its Emergency Alert System to warn people in the Barstow area about a sudden wave of "life-threatening flash flooding" set to hit their specific pocket of the rural High Desert within a few-hour window Monday afternoon.

A National Weather Service emergency alert buzzed the cell phones of people in the Barstow area shortly after 3:30 p.m. with a caution sign declaring the sudden flash flood warning had taken effect and would remain so until 6:30 p.m.

"This is a dangerous and life-threatening situation," the government alert stated. "Do not attempt to travel unless you are fleeing an area subject to flooding or under an evacuation order."

No similar order was issued for people just a few dozen miles south in the Victorville area, which had only a 30% chance of thunderstorms when the emergency alert went out. The temperature in Victorville at this time was 100 degrees Fahrenheit, while in Barstow, a steaming-hot day had quickly dropped to a measure of 81 degrees.

The full Flash Flood Warning from the NWS Las Vegas office indicated that the threat of deadly levels of flooding, an anomaly for mid-summer in the Mojave Desert, would be focused specifically on communities in and around the Barstow area and up to the military mega-base north of it, Fort Irwin.

"EAS ACTIVATION REQUESTED," the warning reads, a reference to the Emergency Alert System jointly run by the NWS, the Federal Communications Commission (FCC) and the Federal Emergency Management Agency (FEMA).

"Locations that will experience flash flooding" were named in the updated warning at 3:34 p.m. as including Barstow, Fort Irwin, Daggett, Owl, Canyon Campground, Newberry Springs, Nebo Center, Yermo Road, Barstow Road, Fort Irwin Road, and Lenwood.

More specifically, it applied the warning to the area between mile markers 182 and 202 on Interstate 15 and between mile markers 1 and 20 on Interstate 40.

"Doppler radar indicated thunderstorms producing heavy rain across the warned area," the warning stated in an update at 3:34 p.m. "Flash flooding is ongoing or expected to begin shortly."

The warning described a "flash flood damage threat" for the area as "considerable."

"Turn around, don`t drown when encountering flooded roads," it stated as precautions for those in the warned area. "Most flood deaths occur in vehicles."

The first warning notification went out as a Severe Thunderstorm Warning at 3:23 p.m. for Daggett and Yermo, per the NWS website, with a warning of "60 (mile-per-hour) wind gusts and quarter size hail."

That warning was then canceled at 3:38 p.m. and translated to the Flash Flood Warning issued a few minutes earlier.

Charlie McGee covers California’s High Desert for the Daily Press, focusing on the city of Barstow and its surrounding communities. He is also a Report for America corps member with The GroundTruth Project, an independent, nonpartisan, nonprofit news organization dedicated to supporting the next generation of journalists in the U.S. and around the world. McGee may be reached at 760-955-5341 or cmcgee@gannett.com. Follow him on Twitter @bycharliemcgee.

This article originally appeared on Victorville Daily Press: Emergency flash-flood warning issued for Barstow , California