In both my early and final winter forecasts, I called for a wetter winter across much of California, particularly in the southern part of the state. In my final forecast, I had reason to extend the wetter region to include almost all of California. Overall, my winter forecast was quite accurate, but unfortunately, I missed the California precipitation/rain forecast. The temperature forecast was spot on though.
What Went Wrong?
That has left many of you scratching your heads asking, why didn’t California get the predicted rain/snow? California has been suffering from drought conditions for four years now, and the state just missed another winter that could have brought some drought relief. Earlier in the winter, there were some hints that California was going to have a stormier and more active pattern, but stormier weather was confined farther to the north over the Pacific Northwest and much farther east. Even with more activity farther north up the coast, much of the West Coast ended up with below average winter precipitation.
Even northern and central California had some rain earlier in the winter, but it was nothing that brought any permanent drought relief. Even during the times that precipitation fell, the snowpack over the mountains didn’t increase much due to unusually warm temperatures.
These last two winter have been very unusual across much of the United States. Sea surface temperatures have been much above average across the northeastern Pacific, causing ridging to build along the West Coast and over Alaska. Warmer water temperatures also extended along the entire West Coast this winter, which would have not necessarily been a bad thing for the state had the overall pattern been more favorable for wetter conditions.
Because these warmer waters have been responsible for this death ridge setting up over the area, the very warm and drought conditions have persisted. For the earlier part of the winter, the ridge was farther east than last winter, allowing a few systems to move up along the western edge of the ridge through northern California and into the Pacific Northwest. By February, the ridge retrograded farther west, keeping the rain/snow chances low even farther north. While the West has been getting record-warmth for a second year in a row, the eastern U.S. has been getting record-cold, breaking century old records in places.
The reds indicate the area with the most severe drought conditions:
The warm West/cold East pattern was something that I predicted at Firsthand Weather, but where I made a mistake was thinking that El Nino conditions would be prevalent enough to allow tropical moisture to pump under the ridge over southern California. This El Nino has been quite unusual anyway, but the death ridge won again this winter. Any system that moved in either dug too far south impacting Mexico and Baja California or moved farther north of the state.
Is There Still Hope?
Unfortunately, California missed their opportunity to truly get a drought-breaking winter. However, there will be a few opportunities here and there that could bring California some rain. Through much of March going into early April, that stubborn ridge is going to likely persist, but some northern parts of California could get some rain/snow during that period.
In the longer term, the ridge will probably start trying to break down into April. Although there’s going to be one last push of winter in the East, reinforced by a building ridge over the West, there may be an opportunity or two arrive later into April for parts of California to get some rain. California generally experiences wetter conditions during El Nino, but the current El Nino is very weak. Also El Nino conditions usually bring the wetter conditions for California during the winter.
I know that this probably wasn’t the clear-cut answer that you were hoping for, but if I see any rain chances coming up for the state later in April, I’ll make you aware of it. Remember, it’s going to take an overall wetter pattern to put a dent in this drought, not just one or two storm systems.
This photo was taken in California earlier this winter. Photo credit: Daniel Griffin