This is a weather update from the National Oceanic and Atmospheric Administration.
The Climate Prediction Center recently sent out an update to the El Niño, La Niña, and the Southern Oscillation (ENSO) phase forecast, dropping the La Niña watch for the coming winter season. The gist of the update was that Sea Surface Temperatures (SST’s) have cooled to neutral, and the climate models they use to predict future SST’s have been advertising less cooling (remaining in 0 to -0.5 degree C range). See full technical discussion here.
So, you might be asking, what does that mean for us in CA for this upcoming winter? Well what that means is there are no strong atmospheric signals to indicate strong correlations to winter conditions. i.e. get the dart board out as the seasonal outlooks for precipitation will be Equal Chanced (EC) of 33.3% of below, 33.3% of above and 33.3% of normal precipitation. What about temperatures? Well, given the past several years have trended above average, the outlooks are favoring temperatures trending slightly above average. See images 2,3,4.
We did take a look at precipitation across California during past Neutral ENSO conditions. Of the 24 episodes, what we found is there was a wide range of precipitation outcomes across the state. Everything from well below average to near average to well above average. The main point here is, just like last year, past events do not guarantee a future outcome!
Messages for this upcoming winter season:
- California needs to prepare for flooding during every winter season, regardless of the ENSO phase
- California flooding is typically storm dependent
- Any one storm (Atmospheric River) or a series of storms can result in flooding of small watersheds or communities or regions
- California remains in a drought, therefore conservation efforts should continue
- One normal water year is good for surface water supply conditions; however, not a good indicator of statewide drought improvement