Monsoon-fueled thunderstorms drenched pockets of California Thursday afternoon, leading to scenes like this:
Acton, California which sits at about 2,700 feet above sea level, north of Los Angeles, took the brunt of the flash flooding on Thursday. As of Thursday night there was a report of a water rescue, however no injuries or fatalities from the flooding at this time. We spoke with the National Weather Service in Los Angeles and Meteorologist Robbie Munroe said a rain gauge in that area measured about 1.4 inches of rainfall in a little more than 30 minutes’ worth of time. That kind of quick rainfall can produce flash flooding, especially across hillier terrain.
As a matter of fact, there have been some recent ‘burn scars’ in this area as well. Our own Meteorologist Meredith Garofalo says recent wildfires in this area can worsen flash flooding because the runoff of rainfall happens more easily and quickly than a more heavily forested and “grown-in” area.
The National Weather Service out of San Diego, CA also provided pictures of mud and water covering this road Thursday.
Rainfall in the 24-hour period ending Thursday night showed localized downpours. The image may not seem like much at first glance, but if you look more closely you can see dots of yellows and reds which indicate 1-2″ of rainfall and most often that rainfall comes in a short amount of time.
The monsoon-related thunderstorms will slowly shift north and east in the next couple of days. Generally the Southwest can expect thunderstorms each afternoon, however ever so slightly the concentrated area of storms moves northeast through Saturday. The green colors above show the locations where thunderstorms are expected. The biggest impacts through the weekend will be flash flooding followed by lightning. If you plan to be outside in this area, make sure your mobile device is charged up. If a flash flood warning is issued for your location, you should receive an alert, as long as you have some cell service. If not, a NOAA weather radio is the next best thing because you can program it to alert you about such events in your location.
For WeatherNation, Meteorologist Steve Glazier