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Green news from the UC Division of Agriculture and Natural Resources
by Bob Smith
on November 19, 2015 at 11:12 AM
This article does not get it quite right. A strong El Nino will deliver higher than average precipitation somewhere along the U.S. West Coast, but that does not necessarily mean CA will receive higher than average precipitation and it certainly does not mean that N. CA (or S. CA) is guaranteed higher than average precipitation this winter. For example, atmospheric blocking can have profound effects on how El Nino may affect CA. During 6 El Nino events CA received higher than average precipitation. Ok, but how about other El Nino events? You are making inferences on less than 60 years of data which is more weather- than climate-related. Even worse, the NCDC/NOAA figure only uses an average period of 30 years. As scientists we need to be more careful when we discuss weather and climate.
by Tapan Pathak
on November 19, 2015 at 12:32 PM
Thanks for commenting on this article. We are not commenting that this El Nino is guaranteed to bring higher than average precipitation. But rather stating that El Nino is LIKELY to bring higher than normal precipitation based on climatology. Of course, 6 strong El Nino events is not ideal, but that is what we have available for comparing strong El Nino years with climate normal (1980-2010). Article from (ño-impacts-0) provides comprehensive view of winter precipitation pattern during strong, moderate, and weak El Nino events since 1950. Thirty-year average is a standard and is widely used for defining climate normal in climate science community.
by Marcia Lewis
on November 19, 2015 at 1:54 PM
I think the first comment was referring to the name of your article, "El Niño expected to drench California," which sure makes it sound like California is going to get plenty of rain this winter because of El Niño. Ask any entry-level weatherman with a slight background in meteorology and they would tell you to take those predictions with a grain of salt. The fact is, California has experienced El Niño before where substantial parts of the state get lower than average precipitation.  
If data is "not ideal," then it is best not to make strong statements that are no more than a best guess, or at least use words suggesting this is your best guess. You make it sound like we should all prepare for a wet winter. You may want to rethink how you present information to your audience. At least when I was in graduate school, we were taught to use caution when using strong statements, especially if there were insufficient data to back them up.
by Sam Sandoval
on November 19, 2015 at 4:47 PM
Dear Bob. Thanks for your comment on the article. The information that we provided in the previous blog was carefully written, it is based on science, and backed up by climatologist experts. Last summer, meteorologist start following the development of El Niño (, and discussions focused on the precipitation effects of a regular or strong El Niño for California ( Strength matter, and this strong El niño is very LIKELY to bring wetter than normal conditions. Once El Niño was established, conversation turned into discussions about the potential persistence the Buoyant Blob (AKA Ridiculous Resilient Ridge) or the predominance of el Niño ( As we have seen, a strong El Niño has prevailed over the Buoyant Blob. Recently, even though there is a slow start of the rainy season, it is predicted a wetter than average conditions for later in the winter season ( This analysis is based on statistical analysis of climate data, as well as model predictions. We are not the only ones mentioning the expected events that can happen due to El Niño, there are other experts mentioning the same events ( As always, Mother Nature can surprise us, but we wanted to share our most informed and science based prediction.
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