It doesn’t take a climatologist to explain what’s going on in California’s weather. There’s a deep ridge of high pressure parked over the western U.S., and it looks a lot like last year.
Where the weather is— The jet stream that brings all this country’s prevailing wet weather from the equatorial Pacific is entrenched north of California, dips southward over the Great Plains then dives again over the northeast and New England. That pattern translates to mostly sunny and dry for California with patchy fog in the valleys, fluctuations in temperature in the Montana-Colorado Rockies, bitter Arctic chill in the upper Midwest, and record snowfall in the northeast and New England.
The Pacific is a few degrees warmer than normal so the jet stream is doing what it always does, transporting plenty of moisture to the U.S. Where there are cold temperatures when those moisture-laden clouds reach the lower altitudes, they dump snow.
There is so much snow this year in Boston, in fact, they have nowhere left to pile it. So now Boston civic officials are pondering dumping all that dirty snow into the rivers and the bay. Environmentalists are saying an emphatic no because all that road filth and oily runoff would spell disaster for local waterways already under siege from population and development.
Warm days and wildflowers— While Three Rivers will bask in sunny upper-70-degree temperatures during the Valentine’s Day weekend, Boston and the northeast is bracing for yet another blizzard. Unfortunately, there is no rain in the 10-day Kaweah Country forecast but the one to two inches that the local foothills received last weekend certainly helped.
The warm storms, the typical pattern predicted for this climate change era, filled the Kaweah drainage with runoff for a few hours but only brought snow to elevations above 10,000 feet. The California Department of Water Resources released its February 1 snowpack statistics and announced that the Sierra-wide pack is only 25 percent of what it should be; 18 percent of the benchmark April 1 total.
California is not the only parched state. Most of the West is in what the National Drought Mitigation Center calls a range from “abnormally dry” to “exceptional drought.”
Lake Kaweah outlook— Phil Deffenbaugh, general manager at Lake Kaweah, likes to look at the water glass as half full.
“Thanks to those storms last weekend, we’re in better shape than last year,” he reported.
As of Thursday, Feb. 12, there was a gradually rising 35,000 acre feet in the basin; one year ago there was only 14,175 acre feet, less than half of the current pool.
The February 12 mean inflow from the Kaweah River to the reservoir was 458 cubic feet per second with an outflow of just 6 cfs.
The inflow one year ago was 102 cfs. The highest average inflow was 826 cfs, and that occurred May 1.
The maximum lake level last year was 83,277 acre feet on June 1. The storage capacity of the Lake Kaweah basin that was enlarged in 2004 is 185,000 acre.
“Barring any sudden storms, we’ll continue to go up,” Phil said. “There’s just not much water in the 25 percent snowpack so we’re going to hold onto to whatever we can get.”
Recent rainfall— Three Rivers, at 1,000 feet elevation, received a total of 1.42 inches of rainfall in the storms that occurred on February 7 and February 9. That brings the season total to approximately eight inches depending on location, and that’s right at or slightly above what was recorded for the entire 2013-2014 season.
There are still about 10 weeks left in which this area could receive precipitation that might make a difference. In the past, there have been some healthy precipitation events from warm and cold storms during this period.