California Long Range Forecast Update, April 15th, 2017

Current Status
It has been a pretty amazing 6 months for much of California. Incredible amounts of rain and snow hit the state. Check out the total liquid precipitation that has occurred during the past 6 months.

The active weather pattern has pretty much eliminated drought for most of California. Granted, the far southern parts of the state are still dealing with drought, but nothing like it was. Great news!

The Oceans and El Niño

The map above shows current sea surface temperature anomalies. Red means warmer than average and blue means colder than average. You can clearly see that the ENSO regions off the west coast of South America are warmer than average. This warmth becomes less pronounced as you go westward, but is still average to slightly above average. The interesting thing here is the cooler than average water off the west coast of Australia, in the Southern Indian Ocean. History tells us that when you have cooler than average water in the Southern Indian Ocean and warmer than average water off the west coast of South America, that an El Niño is brewing. We've been chatting about that for awhile now, and we haven't changed our thinking. Are we in the midst of an El Niño now? Not quite, but most models agree it is coming... Another thing you can take away from the map is that the Pacific basin is still quite warm. Thus, the Pacific Decadal Oscillation is still in a warm/positive state. That USUALLY means average to above average moisture is a pretty good bet.

The yellow line in the above graphic shows the mean of all the different model forecasts. It takes us into weak to moderate El Niño territory by mid to late summer. Given the current state of the oceans and the model forecasts, it is tough to argue against the development of an El Niño. Let's see what the various models are forecasting in terms of temperature and precipitation.

CFSv2 Model Temperature Forecast

May

June

CFSv2 Model Precipitation Forecast

May

June

The CFSv2 Model has average to above average temperatures for most of California, for May and June. No huge tip one way or the other... The model is forecasting average precipitation too, which is not too surprising. As we come out of the wet season and California dries out (as it usually does each late spring and summer), there is no strong signal for a wet or dry May and June.

NMME Model Temperature Forecast

May

June

NMME Model Precipitation Forecast

May

June

The NMME Model looks very similar to the CFSv2 model. Average to above average temperatures and average precipitation. No huge surprises there...

Weather5280 Forecast May and June

May, June Temperature Forecast

May, June Precipitation Forecast

Summary

We are going with above average temperatures and near average precipitation for the state. However, we feel that the southern half of California may end up drier than average for May and June. This is also ahead of the Pacific hurricane season. With the Pacific as warm as it is, and an El Niño brewing, the Eastern Pacific hurricane season is set to be an active one. Some of that moisture will no doubt be deposited in Southern California and the Desert Southwest. However, this will likely occur later in the summer. We'll be watching that trend for you...