The fifth and final system of the series that began Sunday brought thunderstorms, damaging winds, record low pressure, heavy rain and snow to Southern California yesterday. The unusually large trough associated with the system covered most of the northeastern Pacific yesterday, and unsettled weather is expected today as it continues to move onshore.

Very strong wings, possibly a tornado or thunderstorm downburst, felled trees and damaged structures in Ventura and Santa Barbara. Record rainfall for the date was recorded at Santa Maria, Palmdale, and Lancaster, but more extraordinary, new all-time records for lowest barometric pressure were set at several locations in the Los Angeles area. Note: The NWS documented an EF-0 tornado in Ventura (3Mb PDF).

Here are some preliminary rainfall totals from around the area, compiled by the NWS, for the period 10:00 p.m. Tuesday to 10:00 p.m. this evening. Note that this combines rainfall from system #4 on Wednesday, and our current Thursday-Friday system. And here's an NWS Public Information Statement with some impressive snowfall totals for the week. Wow -- Mt. Baldy got 7 feet of snow! (Updated 01/23/10)

As of yesterday, Downtown Los Angeles (USC) has received 4.21 inches of rain from the series of storms, bringing its water year total to 9.34 inches, which is 3.44 inches above normal. Over the week, the Sierra Nevada has received several feet of snow, and the statewide average snowpack is now above normal.

Please refer to www.weather.gov/losangeles for the latest warnings and weather information.

More information concerning Southern California weather can be found using our WEATHER LINKS page.

Monsoonal flow that began last Thursday has resulted in numerous thunderstorms in the mountains and deserts of Southern California, with flash flooding and debris flows reported in several locations.

Areas in or near recently burned terrain are particularly susceptible, and flash floods and debris flows appear to have originated in the 2007 Oak Fire burn area in the eastern Sierra, and the still burning Piute Fire burn area near Lake Isabella.

This sequence of three GOES-WEST VIS/IR satellite images from NRL's NEXSAT web site shows the explosive development of a convective cell north of Mt. Whitney on Saturday afternoon. This appears to be the thunderstorm that produced the heavy rain in the area burned by the Oak Fire, and resulted in the Oak Creek debris flow near Independence. Here's an AVI loop, generated on the NEXSAT web site, for the period 3:00 p.m to 6:00 p.m. PDT on Saturday.

A particularly large thunderstorm cell/complex developed in the Sierra Nevada south of Mt. Whitney midday Saturday and drifted south down the Kern River drainage over the course of the afternoon. At about 2:45 p.m. the cell/complex was centered near the confluence of the Little Kern River and N.F. Kern River and measured about 44 miles in diameter. Here's a Google Earth image of the cell/complex with a 250m resolution True Color Aqua cloud layer imported from the MODIS Rapid Response System.

This GOES-East/West Precipitable Water composite from 9:00 this morning indicates precipitable water values as high as 1.6" in some areas of Southern California, and the possibility of more mountain and desert thunderstorms continues today.

Update July 25, 2008. The large cell/complex that developed south of Mt. Whitney on Saturday, July 12, and drifted south down the Kern River drainage appears to have produced the flash flooding and debris flows on Erskine Creek and other creeks in the Lake Isabella area late Saturday afternoon. This cell/complex can also be seen in sequence of three GOES-WEST VIS/IR satellite images and the AVI loop previously referenced.

More information concerning Southern California weather can be found using our WEATHER LINKS page.

More Wet Weather Possible Today and Tomorrow.

The unseasonably energetic upper level low that replaced our unseasonably strong high has resulted in dramatic weather in Southern California, including heavy rain, hail, thunderstorms, lightning, and even a pair of tornadoes near March Air Force base. This UCAR regional radar image from yesterday at 5:00 p.m. shows the intense cell that likely spawned the tornadoes.

In Los Angeles County, very heavy rain was recorded in the San Gabriel Valley. According to a NWS Public Information Statement, as of 7:00 p.m. yesterday, 2.29" was recorded at Santa Fe Dam, 1.51" at Whitter Narrows, and 1.42" at the San Gabriel River at Valley. Yesterday, Downtown Los Angeles (USC) recorded 0.05 inch of rain, bringing the water year total to 13.47 inches.

Intellicast radar shows showers continuing in Southern California this morning. The upper level low is forecast to remain over Southern California into Sunday, and BUFKIT analysis of 12z NAM data for several Southern California stations (VNY, LAX, ONT) suggest on and off rain showers may occur through Sunday morning. As long as the cut-off upper low remains over the area there is also the possibility of an isolated heavy shower or thunderstorm developing. We'll see!

Update Sunday, May 26, 2008. Here is an archived copy of a NWS Public Information Statement with rainfall totals for this event through 6:00 p.m. Saturday.

More information concerning Southern California weather can be found using our WEATHER LINKS page.