Golden Gate Weather Services

Rain and snow in the past 72 hours across California have pushed precipitation amounts in the Sierra Nevada watersheds to above normal through March 6th. This the highest they have been on this date in five years. The Northern Sierra Nevada 8-Station index picked up over 6 inches of rain, while the Central Sierra 5-Station Index and the Tulare Basin 6-Station Index received 3.86 and 2.20 inches respectively.

For the Northern Sierra this brings the rainfall season precipitation to date to 107% of normal, the Central Sierra to 106% and the Tulare Basin to 100%. 


Note: There will be a minor discrepancies between these figures and those published by Calif. DWR which uses the Oct. 1 Water Year instead of the historical rainfall season of July 1 to June 30. DWR also does not use the standard 30-year climatological normal (1981-2010) but rather non-standard average period of 1922-1998 for the 8-Station Index and 1961-2010 for the 5 and 6-Station Indices.   

Jan Null, CCM
Golden Gate Weather Services
http://ggweather.com

See http://ggweather.com/calif/feb2016.htm

Average maximum temperatures across California for February 2016 ranged from "just" well above normal (i.e., Eureka at +2.5 deg F) to downright toasty with average monthly maxima anomalies of between +6.1 and +9.4 degrees.  Four of the eight major stations set records for all-time warmest maxima for the month. 
                                       2016    Prev record
    San Jose                    69.0    67.8 in 2015
    Sacramento Ex AP    67.6    67.1 in 1988
    Los Angeles - City     77.5    75.6 in 1954
    San Diego                 74.4    72.1 in 1954

At the same time, rainfall across the Golden State was paltry at best, with values ranging mostly between 10 and 20% of normal.  The exceptions were at opposite ends of the state with 58% of normal in Eureka and only 2% of normal in San Diego.

This allowed rainfall season (Jul - Jun) totals to drop below normal for most of California, though prog charts for the next two weeks should produce  very strong upward movement to back above normal.  Currently: http://ggweather.com/seasonal_rain.htm 

Likewise, snowfall totals have slipped below normal, but should also show a strong recovery in coming weeks. Currently: http://cdec.water.ca.gov/cgi-progs/snow/COURSES

Jan Null, CCM
Golden Gate Weather Services  

Among the mantras from the past year by myself, SF State Professor Dr. John Monteverdi and many other responsible meteorologists, are that 1) each El Niño is unique, 2) the number of past events is statistically very small for comparison, and 3) that there are "no guarantees". To date many of the blogs, webpages and associated articles have look at the similarities to previous strong and very strong El Niño events.

However, as the El Niño 2015-2016 and its impacts continue to unfold, Dr. Monteverdi and I felt it's important to look at how this year is dissimilar in many ways to previous events.  To that end we have co-authored the following page: Differences Between 2015-16 El Niño and Previous Strong and Very Strong  Events.   

Below is one of the figures from that page, which breaks down the Sea Surface Temperature Anomalies (SSTAs) for each of the strong and very strong El Niños for all four of the Niño sampling regions in the tropical Pacific. Other data includes how the circulation patterns are different along with how the November through January precipitation and temperature patterns don't match very well with previous events, 



Coming soon, will be a separate page with how the second half of the winter during these events has looked.

Jan Null, CCM
Golden Gate Weather Services

Dr. John Monterverdi, CCM
San Francisco State University

In the major cities across California the January 2016 rainfall ranged from "just" 102% of normal in Los Angeles to over 200% of normal at Redding (213%) and Fresno (202%). Rain in the critical Sierra Nevada watersheds ranged from 175% of normal in the Northern Sierra 8-Station Index  to 119% of normal in the Tulare Basin 6-Station Index. (See http://ggweather.com/calif/jan2016.htm)

 

The rainfall season- (July 1 to June 30) to-date totals and percentages of normal for 46 California stations are available at: http://ggweather.com/seasonal_rain.htm.

Monthly temperatures were generally warmer than normal though maxima in Redding and LA slipped in as cooler than normal.  (See http://ggweather.com/calif/jan2016.htm)

Jan Null, CCM
Golden Gate Weather Services
http://ggweather.com

Maybe More Soupy Than Super

The first week of February 2016 will see the eyes of the world focused on the San Francisco Bay Area for Super Bowl 50 on February 7, 2016.  If past Februarys, and the recent impacts of El Niño, are any indication, the odds are pretty high of that some of the outside activities will be wet.

During the first week of February, over the past 49 years, it has rained on average two days with an average rainfall amount of 0.81 inches at San Jose Airport, just 3 miles away from Levi Stadium in Santa Clara, CA. That rained occurred on 37 of the 49 weeks, or 76% of the time.  It is also interesting to note that the two wettest Super Bowl Weeks were during the strong El Nino events of 1997-98 (6.76") and 1972-73 (2.23").

Over the past 49 February 7ths it has rained 20 times, or 41% of the time.  And on those occasions the average rainfall has been 0.22 inches. 

The last time the Super Bowl was played in the San Francisco Bay Area was Super Bowl 19 on January 20, 1985.  That day was clear, cool and crisp with a high temperatures of only 52 degrees.  And the San Francisco 49ers beat the Miami Dolphins,  38-16.

The average high temperature during the 1st week of February is 61 degrees and the average low is 43.


Jan Null, CCM
Golden Gate Weather Services
http://ggweather.com