While Miami and much of south Florida experienced the coldest December on record, the “other sunny state”, California, has been getting blasted with snow. My family and I experienced this firsthand yesterday on the drive back from Southern California to home on Interstate 5. I kept pushing to “leave now” on Sunday morning, knowing we had a very short window of opportunity left. We made it, but within 20 minutes after we passed the summit, I-5 was closed to traffic, and remains closed now.
Above are some photos (click the arrows) of our trip though the Grapevine and analysis of December weather from one of the leading forecasters in California. These were taken by my lovely wife who was riding shotgun and helping me navigate while photo documenting the trip. Not only was I-5 snowy and high winds over the Tejon Pass, when we reached the base of the mountain in the San Joaquin Valley, we were greeted with gale force+ winds that did some damage by knocking down a stoplight and some small trees in rain soaked ground, and rendered the service area, gas stations and restaurants at Laval Road without power. It also kicked up a dust storm on 99 on the way to Bakersfield too. Snow level was down to 1000 feet by my vehicle altimeter.
Even Las Vegas got snow – more from NWS LV here
My friend Jan Null, former lead forecaster for the National Weather Service in SFO, and now a Certified Consulting Meteorologist running his own service (Golden Gate Weather) has some thoughts on December:
By Jan Null CCM
On a number of fronts, the December weather across California was quite remarkable. Not only was it very wet (duh!), but temperatures were generally quite mild. Both were the result of a prolonged period of a strong low latitude jet steam far enough south to bring the state warm and very moist air from the subtropics. See http://ggweather.com/calif/dec2010.htm
Rainfall anomalies ranged from a paltry 127% of normal for San Jose to a whooping 536% of normal in Los Angeles. The City of Angels ended the month with over 10 inches of rain and locations in the surrounding mountains nearly tripled that amount. Statewide season to date amounts range from near normal to 150% of normal in the north to in excess of 200% of normal over most of the southern half of the state. See: http://www.cnrfc.noaa.gov/awipsProducts/RNOWRKCLI.php .
Note that many locations south of the Tehachapis are within a couple inches of having normal rainfall for entire season, even if another drop did not fall!
In the mountains the Northern and Southern Sierra Nevada Indices and the Snow water content are at or near record values for the end of December. See http://cdec.water.ca.gov/cgi-progs/products/PLOT_ESI.2011.pdf , http://cdec.water.ca.gov/cgi-progs/products/PLOT_FSI.2011.pdf and http://cdec.water.ca.gov/cgi-progs/products/PLOT_SWC.2011.pdf .
This is also reflected in the phenomenal snowpack that ranged from over 150% of normal in the northern Sierra Nevada to over 200% in the south. http://www.water.ca.gov/news/newsreleases/2010/122810snow.pdf .
The low latitude trajectory of the jet stream also contributed to mild monthly temperatures statewide. This was exacerbated by the extensive that kept average overnight monthly minima mostly in a range from 3 to 6 degrees above normal. The warmest minima anomalies were at Redding and Fresno which were 6.2 and 7.1 degrees above normal respectively.
A WORD ABOUT LA NINA
The past month also serves as precautionary reminder that all La Ninas (and El Ninos) are not created equal. While the long term averaging of California rainfall from various warm and cold tropical Pacific Sea Surface Temperature can give a composite look at past events, there are NO absolutes for any given year.
This is true with the current moderate/strong event which doesn’t fit the La Nina stereotype. This was also the case with December 1955 and December 1964 which both saw extensive flooding over much of the state. See http://ggweather.com/enso/2009%20enso/ca%20enso.htm .
UPDATE: Watch this video from AP. fortunately, we got way ahead of this mess!