California by the numbers: A billion dollar winter
Wednesday, March 1, 2017, 10:57 - How many times have we heard the term "River of Moisture" or "Pineapple Express" during these past few months? Certainly more times than over the past 6 years, and very likely more than during some of the wettest years on record in the state of California.
The rainy season in California normally extends from about December to March. During an average precipitation year, one would expect to see between 10 to 15 "Atmospheric River" fed storms moving into some portion of the state. But since the official start of the precipitation season on October 1, 2016, the persistent flow of moisture that crosses the Pacific from Hawaii and beyond to account for up to 50% of the state's precipitation, has been tremendously enhanced.
SPRING IS HERE: With La Niña helping shape global patterns what will Americans expect from spring? Find out with The Weather Network’s 2017 Spring Forecast | FORECAST & MAPS HERE
Below: Atmospheric River pattern quick explainer
California has already experienced more than 30 episodes of this kind, and there is still winter left for additional storms to increase the number.
Outstanding Precipitation Values
It is not new, scientists have shown in a variety of studies that future droughts will be more severe in the region, while wet winters will have more flooding episodes. As the oceans become warmer, evaporation is enhanced and more moisture is available to stream into these powerful atmospheric rivers. The latter has actually been the norm this winter, with the west tropical Pacific experiencing positive Sea Surface Temperature (SST) anomalies since last Fall.
So far, this winter has been the wettest ever measured in the northern Sierra Nevada's, with precipitation reaching 230 percent of the historic average.
Adding the latest February 2017 data, since October 1 2016, some mountain observatories in the Lake Tahoe and Mount Shasta area have measured precipitation values well above those registered during El Niño monster winters of 1997-98 and 1982-83.
Reservoirs at Peak capacity
As we approach the end of this Winter, snow melt is expected to add additional water to many of the state's reservoirs. But before that occurs, California's largest reservoirs are collectively already at 122 percent of average and some of the major dams like Oroville, Folsom or Shasta are releasing water at a furious pace to make room for snow melt and other potential storms likely to move through the state before the season is over.
Below: Reservoir conditions in California as of Feb. 26, 2017
Major urban areas in the state have also experienced well above normal precipitation values. From Sacramento, San Francisco, San Jose or Oakland in the north to Los Angeles in the south, values from January and February alone, have already exceed the annual average expected rainfall.
Watch below: The Morning Glory Spillway, called the "Glory Hole" by locals, spilled over for the first time in 10 years in February. The overflow is a result of a month of recent rains filling the river in formerly drought-stricken California.
Ski resorts are also experiencing the best possible snow scenario in many years. For instance, Mammoth Mountain, has already received over 400 inches of snow since January 1, that is 100 inches more than any other combined January-February on record since 1970.
Close to a $1 Billion in Damage
With all this atmospheric action occurring, California weather has made national and international headlines off and on all winter. Floods and evacuations in San Jose and around Oroville Dam have been among the top news, but many other areas of the state from north to south have also been seriously impacted by growing waters, mudslides, heavy snow, strong winds or high surf.
Below: Oroville Dam Spillway - Department of Water Resources
This past week, Governor Jerry Brown's office announced that the bill to repair crumbling roads, dams and other damaged infrastructure will be close to the $1 billion figure mark. Much of this deterioration has occurred between January and February.
A section of mountain highway that runs from Sacramento to South Lake Tahoe has buckled, and repairs alone for this are estimated at $6.5-million. World famous Yosemite National Park has only one of three access roads open do to damage from rain, mudslides and snow. A bridge in the Big Sur area has collapsed, cutting off a frequent route along Highway 1 used by thousands of locals and visitors every year.
Watch below: A car was spotted partially submerged in flood water near Green Valley Road, around 30 miles east of Sacramento, California, on Wednesday, January 11.
The $1-billion value figure also accounts for the clean-up of mudslides and highway repairs, but evacuations or dam repair like in the case of Oroville have yet to be accurately quantified.
Overall, moisture loaded Pacific storms have tampered with more than 350 roads across the state, shutting down at least 35 that will have to wait to be rebuilt.
So, is California done with the drought?
This year has started very dry in many areas of California, with over 50% of the state in a severe to exceptional drought situation. Two months later the value has been reduced to close to 4%.
Experts will say the drought is pretty much over, but … the main question is what about the groundwater?
The intense and prolonged drought has left so many areas with no groundwater at all, that it will be tough to refill all that volume even after the exceptionally wet winter Californians are living this year.Watch Below: The Lake Berryessa reservoir in northern California is set to reach full capacity for the first time in 11 years (animation).
However, in most cases drought is defined mainly by precipitation, so with that in mind, one would think the drought is pretty much over. Jeanine Jones, the interstate resources manager for California's Department of Water Resources, considers that if you look at precipitation, plant health and soil moisture, then yes, the drought looks over for the majority of the state. But if you look closer, you see that while some communities are now well hydrated, others are still struggling to find enough to drink.Below: Drought conditions as of Feb. 21, 2017 (Via: U.S. Drought Monitor)
The importance of groundwater
Groundwater, the water we don´t see flowing down rivers and reservoirs, contributes between 40 to 60% to the state's water supply depending on how dry the year is.
California taps on this resource continuously, especially in the Central San Joaquin Valley, an area that contributes to 8% of the food produced in the US. This is perhaps the big dilemma when it comes to finding and appropriate answer to the drought question.
Yes, surface drought might be almost over in California, but the groundwater supply is far from reaching normal values despite the continuous deluge across much of the state.
Will wet weather continue into Spring? Find out in The Weather Network's official Spring Forecast below:
Sources: U.S. Drought Monitor, California Water Resources Department