Sea surface temperatures off the West Coast are warming and most of the Pacific Basin continues to have well above normal sea surface temperatures (Fig 7). Computer models show that these well above normal sea surface temperatures will continue through December (Fig 8).
Thus, strong high pressure is expected to set up off the California Coast bringing above normal temperatures and well below normal precipitation to the region September through December.
Troughs will move up and over the area of high pressure into the Pacific Northwest, causing most of the precipitation to fall north of Central California.
Some of these troughs will drop down into the Great Basin and Desert Southwest bringing a near to above normal amount of Santa Ana wind events to Southern California.
Warm and dry conditions will cause an above normal chance of large fire activity across the mountains as well as the Sierra Foothills and Central Coast Interior in September.
As temperatures cool and nighttime humidity recovery increases, the potential for large fire will become near normal across Central California from October through December.
There will remain an above normal chance of large fire activity across Southern California from the mountains westward due to offshore wind events keeping warm and dry conditions in place.
Source: Predictive Services
