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.

Weather conditions were tough for the Amgen Tour of California cyclists cranking over Mill Creek Summit yesterday. The Mill Creek RAWS recorded an average temperature of 35°F, with winds of 25 mph, gusting to 40 mph, at about the time the peloton cleared the summit. The Clear Creek RAWS, where riders turned right onto Angeles Crest Highway, recorded about 0.20 inch of rain during the afternoon, with the temperature hovering at around 40°F.

As bad as it was for the tour cyclists, the system was generally not as wet as expected -- particularly in the Los Angeles County mountains, where precipitation amounts ranged from about 0.25 inch to about 1.0 inch. Similar rainfall amounts were recorded in the Los Angeles basin and valleys.

Downtown Los Angeles (USC- KCQT) recorded 0.07 inches of rain Saturday, and 0.46 inches Sunday, bringing the water year total (since July 1) to 13.37 inches, which is about 3.1 inches above normal for the water year to date.

Since mid-week last week some Sierra snow sensors have recorded as much as 8 or 9 inches snow water equivalent of precipitation -- the rough equivalent of 6 or 7 feet of snow. Today's Statewide Summary of Snow Water Equivalents, provided by the California Cooperative Snow Surveys, reports the Sierra snowpack at 119% of normal for the date and 101% of the average April 1 seasonal total.

It looks like most of the west coast weather action will be shifting to the Pacific Northwest for the next week or so. Today's NWS 6-10 Day and 8-14 Day Precipitation Outlooks for Southern California continues to indicate Below Normal precipitation. We'll see!

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

The last of a series of storms that have been producing rain and snow in the western U.S. the past several days moved eastward and (mostly) out of the region today. According to preliminary NWS data, Downtown Los Angeles (CQT) recorded 2.00 inches of rain in the course of the event, bringing its water year total to 4.41 inches -- 1.54 inches above normal.

Precipitation totals in the Los Angeles area from Friday morning to this morning generally ranged from 2-5 inches in the basin and valleys, and from 5 to 10 inches or more in the local foothills and mountains. San Marcos Pass, near Santa Barbara recorded nearly 11 inches of rain, and OPIDS Camp, near Mt. Wilson, recorded nearly 13 inches of precipitation. Here is an archived copy of a NWS Public Information Statement with preliminary rainfall totals for the rain event, and an AHPS Precipitation Analysis of California precipitation for the 7 day period ending 4:00 a.m. this morning.

According to today's Summary of Snow Water Equivalents from California Cooperative Snow Surveys, the series of storms increased the Sierra Snowpack to 111% of normal for the date -- up from 60% at the end of 2007.

Another fast moving shortwave is forecast to primarily affect areas north of Pt. Conception Tuesday into Wednesday, with only a small chance of showers in the Los Angeles area.

So far this rain season, Southern California has dodged a La Nina bullet. This AHPS Precipitation Analysis for the water year to date indicates much of the area having received near normal to above normal precipitation. Even though the Climate Prediction Center's revised precipitation outlook for January, issued December 31, indicates above normal precipitation in the western U.S., the JFM Precipitation Outlook, issued December 20, remains pessimistic. We'll see!

Updated January 10, 2008. The ESRL-PSD Composite ENSO plots page was updated today to correct an issue that resulted in the wrong set of years being used for its Winter La Nina composites. As a result the La Nina composite precipitation map in the October 9, 2007 Weathernotes has been updated. Note that the average La Niña rainfall indicated for coastal Southern California is in the 7.0-10.5 inch range, rather than the 10-15 inch range previously indicated in the ESRL-PSD graphic.

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

According to preliminary NWS data, Downtown Los Angeles (CQT) recorded 1.24 inches of rain as a result of Tuesday night's storm, bringing the water year total to 3.69 inches. This amount is about 3/4 inch above normal for the date, and exceeds the 3.21 inch total recorded at Los Angeles during the record setting dry water year of 2006-2007.

Rainfall totals around the Los Angeles area generally ranged from about 0.75 to 1.25 inch in the basin and surrounding valleys, with as much as 1.5 to 3.0 inches (or more) recorded in some foothill and mountain locations. Here's a copy of a NWS Information Statement listing some rainfall totals for the storm.

In terms of percent of normal rainfall over the past 90 days, Southern California and the Desert Southwest have fared better than might be expected during a La Niña. The snowpack distribution in the Sierra is also somewhat unusual for a La Niña. Today's Summary of Snow Water Equivalents reports that the Sierra Southern Section snowpack is at about 77% of normal for the date, while the Central and Northern sections are at 53% and 61% of normal.

Today's NWS 6-10 Day Outlook projects above normal precipitation in Southern California, while the the 8-14 Day Outlook projects normal precipitation. We'll see!

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