Weathernotes Archive July 2007

A Little Rain is Better Than None!
Weathernotes for Tuesday, July 24, 2007.
(Any updates will be found at the end of this discussion. Last month's notes are archived here.)

Although only a trace of rain was observed at Downtown Los Angeles (USC) yesterday, several stations in Los Angeles County recorded some precipitation. Rainfall amounts ranged from 0.01 inch or so, to as much as 0.15 inch at Opids Camp in the San Gabriel Mountains.

Monsoon moisture wrapping around a weak upper level low currently centered over Ventura County, and circulation around an area of building high pressure area over the Four Corners area is forecast to maintain a chance a showers and thunderstorms, mainly in the Southern California mountains and deserts, through the remainder of the week.

Most dynamic coupled climate models have been forecasting La Niña conditions to develop this year, and recent TAO/TRITON data and ENSO indicators seem to be showing renewed progress in that direction.

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

Driest Water Year On Record.
Weathernotes for Wednesday, July 4, 2007.
(Any updates will be found at the end of this discussion. Last month's notes are archived here.)

There was no measurable rain recorded this May or June at Downtown Los Angeles (USC). The most recent measurable rain was on April 22 when 0.04 inch of rain was recorded. From July 1, 2006 to June 30, 2007, Los Angeles recorded only 3.21 inches of rain, breaking the record set in 2001-2002 as the driest year since recordkeeping began in 1877. For more information see this archived NWS Information Statement.

Looking back through NWS records, 3.21 inches is the total amount of rain recorded in Downtown Los Angeles from May 23, 2006 through today, July 4, 2007 — a period of more than year. Given that our rain season is essentially over, this amount of rainfall — or a few hundredths more — may be all that is recorded over a period of 17-18 months!

It's been quite a decade for weather extremes in the Los Angeles area. The second driest water year on record for Los Angeles was just set in 2001-2002, when 4.42 inches were recorded. Then in 2004-2005, Los Angeles was deluged with 37.25 inches of rain -- the second wettest on record. During that period, Opids Camp in the San Gabriel Mountains recorded over 100 inches of precipitation! In July of last year Pierce College in Woodland Hills recorded a new all time high temperature for that station of 119°F. This may have been the highest temperature ever recorded in Los Angeles County. In mid January of this year many new record low temperatures for the date were set in the Southern California area. Pierce College plunged to a record low of 20°F (-6.7°C) and a temperature of 10.4°F (-12°C) was recorded at a research site in the Santa Monica Mountains.

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