San Diego Exceeds Annual Rainfall Average With Potentially Wet March Still Ahead
Tuesday, February 28, 2017
A storm on Monday unleashed record amounts of rain, causing flooding, downed trees, mudslides and power outages. Now, the region has exceeded its average rainfall for the year and the potentially wet month of March is still ahead.
The heavy rains that hit San Diego County on Monday have stopped, but the flood waters are still flowing. The 52-mile-long San Diego River transformed early Tuesday morning into a raging torrent after peaking at 14.2 feet — the third highest level since 1900.
Streets throughout Mission Valley flooded, cars were submerged and a dozen people had to be rescued.
It was an amount of rain not seen in years, said Alex Tardy, meteorologist with the National Weather Service. The deluge was the result of a storm from the north combined with a large plume of subtropical moisture from the south, called an atmospheric river.
“It brought that piece of moisture right into California,” Tardy said. “And since the storm was slow moving, once the two met and once the rain began, it rained literally for 18-24 hours without stopping.”
Downtown San Diego received 2.3 inches; El Cajon, 2.4 inches; Escondido, 4 inches, and Palomar Mountain, 9 inches.
Since October 1, San Diego has received 11.6 inches of rain — more than an inch above the 10.1 inch yearly average.
Tardy said the region’s wet winter is the result of an active pattern of atmospheric river systems and a jet stream that has ushered the storms across the county.
“Each year the atmosphere kind of resets,” Tardy said. “There’s a lot of randomness to what goes on. It’s kind of like throwing a baseball. You don’t throw a baseball in the same spot every time.”
“You can have all the moisture you want in the western Pacific or down in the tropics,” Tardy added, “But if you have no mechanism to bring it, it either rains over the ocean or rains somewhere else. So the key is those ingredients coming together.”
The outlook for spring is a shift in the weather pattern with dryer air and more high pressure systems, Tardy said.
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