Sunday, June 5, 2011

California Rainfall Records Smashed

A strong and persistent low pressure area off the Pacific Coast brought record rainfall to the San Francisco Bay area on Saturday, June 4. The 0.66" of precipitation at San Francisco Airport was over 4 times the old record for the date of 0.16" in 1947 and 6 times the long-term average for the entire month of June. Records began at the airport location in 1927.

The 1.07" in downtown San Francisco through 6 pm was more than double the old record of 0.49" in 1939.

Although Oakland Airport observations began only in 1948, the 0.88" there swamped the old June 4 record of 0.04" in 1984.

At San Jose, where records date back over a century to 1893, the 0.88" blew away the old record of 0.18" in 1993.

Because of the persistence of the pattern, much of central and northern California has had at least 600% of normal rainfall this month to date. On the other hand, there has been virtually no precipitation east of the Sierras.

Images (click to enlarge): Surface weather map and satellite image for 11 am PDT, June 4, 2011, from HPC/NCEP/NWS; California percentage of normal precipitation for June, 2011 to date, from NWS


Anna Haynes said...

Out here in Calif we're calling it Junuary. Solar sightings are infrequent & treasured...

Charles said...

I'm reminded of my comment about a friend's wedding in 1995, the last time we had weather approaching this in June. "A Scottish-themed wedding is cool. Scottish-themed weather in June is not."

CapitalClimate said...

According to the historical data at Weather Underground, June 1995 was spectacularly wet at San Francisco. There was no single day with a huge amount of rainfall, but some measurable amount fell on every single day, and the monthly total was 7.76".

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