California Long Range Forecast Update, June 2nd, 2017

The winter was obviously epic in California, essentially erasing the drought. The last 60 days have also been quite favorable for the Sierras and the northern 1/3 of California. Here is the total precipitation for the last 60 days:

Currently, we aren't seeing any major drought issues for most of California. The far south/southwest part of the state is still dealing with some drought, but the state is in MUCH better shape:

This is important as the dry season sets up for most of California, and the southern part of the state awaits the monsoon season.

El Niño Update
Here is a look at the latest sea surface temperature anomalies:

There is some pretty warm water just northeast of Australia, but most of the Central and Eastern Pacific do not scream El Niño at this time. The one area that I am watching is the Indian Ocean. Areas just west/northwest of Australia are cooler than normal. This may cause high pressure to intensify near that cooler water and create a relative pressure difference across the Pacific...high pressure west with lower pressure east. This may cause the trade winds to weaken or slightly reverse, and allow that warmer water northeast of Australia to push westward. The graph below shows what various models think will happen with El Niño development:

The yellow line is the mean of what the models think will happen, which just reaches weak El Niño criteria through he late summer and winter. Right now, a strong El Niño is not in the forecast. Most models show a weak El Niño developing by late summer and lasting through the winter. While this event will likely not be a strong one, even a weak El Niño will have an impact. What impact will that be? Too early to tell... Every El Niño is different, and it likely won't have an impact on the majority of California during the summer. However, if we can get some Eastern Pacific hurricanes going, it will likely up the odds of a wetter than average summer for far Southern California. This is where rain is needed the most...

In 2004, Gregory McCabe did some brilliant work on the relationship between the PDO (Pacific Decadal Oscillation) and the AMO (Atlantic Multidecadal Oscillation). The map below shows the relationship with each oscillation and phase and how it pertains to drought frequency:

We are currently seeing +PDO and -AMO. The blue in the upper right hand map represents reduced drought frequency. The red shaded areas represent higher than average chances for drought frequency. As of right now, we are dealing with a surplus of moisture for the majority of the state. The current setup does not necessarily favor that continuing for most of California. The southern part of the state stands to benefit the most. Again, this is where the moisture is still needed... Are we worried about a sudden return to dryness for California? Not necessarily... However, if an El Niño does develop it would likely keep Northern California drier and Southern California wetter. But again, every El Niño is different...

June - August Model Forecasts

CFSv2 Temperature Forecast

CFSv2 Precipitation Forecast

NMME Temperature Forecast

NMME Precipitation Forecast

JAMSTEC Temperature Forecast

JAMSTEC Precipitation Forecast

CAS Model (Constructed Analog on Soil Moisture)

Summary
Model consensus dictates that California will be warmer than average with average rainfall through the summer. However, California doesn't receive much rain during the summer, so this isn't saying much. The CAS Model does show a stout dry signal in Northwest California, which would be consistent with what results during an El Niño.

Weather5280 June and July forecast maps

Precipitation

Temperatures