Winter storms sweep California drought and burnished snowpack


California is flooded and its mountains are covered with snow while a stormy winter was still unfolding, which was unimaginable just a few months ago.

The drought has almost been eliminated, the hills blackened by huge forest fires sport layers of lush greenery and the snow has fallen in the usually temperate suburbs of southern California, where the icy conditions have made the jacket and the headscarves rule.

In fact, downtown Los Angeles set a record Thursday for the first of February without reaching at least 70 degrees (21.1 Celsius) in more than 140 years of record keeping.

Also this week, a two-day storm flooded wine regions north of San Francisco and propelled the Russian River to its highest level in more than 20 years.

None of this was expected in October, when the Climate Prediction Center of the National Oceanic and Atmospheric Administration released its forecast for the months of December to February.

The scenario envisioned above-average temperatures in the western United States, continued drought in southern California, and equal chances of a rainy or dry year in the rest of the state.

This abruptly changed the following month, the center said that it was very confident in its forecast of wetter weather than usual in the West and that it provided at least one improvement or even a definitive end to drought in much of California.

Storms, including the "atmospheric rivers" that are aptly named, have begun to arrive.

Snowstorms pounded the Sierra Nevada, burying the huge mountain range in massive amounts of snow. On the east side of the range, for example, the Mammoth Mountain resort has reported nearly 14.5 meters of snow at the summit so far this season.

Although frequently disrupting travel, storms have fed much of the state's water supply – the Sierra snowpack that melts and pours into reservoirs in the spring and summer.

The California Department of Water Resources reported Thursday that Sierra's snowpack is now 153% of the average so far.

A manual measurement at Phillips Station off the United States 50 near Sierra-at-Tahoe revealed a snow depth of 287 centimeters (113 inches) and a snow-water equivalent of 110.5 centimeters (43.5 centimeters). inches), more than double what was recorded in January.

Phillips Station is where then-Gov. Jerry Brown participated in a snowpack study in April 2015 that revealed a field devoid of any measurable snow. Brown then ordered Californians to use less water. Thursday, the department was not able to broadcast live measurement because the storm has cut the connection of cells.

"This winter's snowpack is getting better every month, and it looks like the storms in California are not over yet," Karla Nemeth, the department's director, said in a statement. "It sounds like a great year in the water."

Where it did not snow, there was a lot of rain.

Nearly 53.3 centimeters of rain fell in 48 hours this week near the winegrowing town of Guerneville, in northern California, where the Russian River was slowly retiring Thursday after many floods.

Downtown Los Angeles has recorded nearly 40.1 centimeters of rain this season, nearly 12.7 centimeters above normal to date. A year ago, the total was less than 5 centimeters. San Francisco has a similar total, almost double of last year.

The seasonal rivers of Southern California have been constantly reviving, their normally dry beds filled with rough water.

The water resources department said the six largest state reservoirs held between 84% and 137% of their historical averages so far.

The US drought monitor reported Thursday that more than 87 percent of California was now free of any level of drought or unusual drought. Only 2.3% – along the Oregon border – was in moderate drought, the rest being in a condition called abnormally dry.

Three months ago, nearly 84% of the state was in moderate, severe or extreme drought, and the rest was unusually dry.

In October, NOAA said forecasters were expecting a weak El Nino, the global warming of the Pacific Ocean, to be in place by the end of autumn or early in the summer. winter.

NOAA, however, confirmed the arrival of El Nino only on 14 February.

A study by an agency last week revealed that the heavy rains of the past 30 days were due to a series of atmospheric rivers fed by a combination of El Nino conditions and a lesser known atmospheric phenomenon called Madden- Oscillations. Julian.

An NOAA fact sheet describes it as a "tropical disturbance that spreads to the east around the global tropics with a cycle of the order of 30 to 60 days". One of the most significant impacts of the United States during the winter is the increase in the frequency and intensity of heavy precipitation on the west coast.

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