Thursday, January 3, 2008

Riding the drought-flood cycle

Well, folks, worries about extended drought conditions in Northern California are easing a bit with the arrival of this energetic series of storms. They're predicting 4 inches at sea level and 8 inches in the bay area hills over the next 3 days. Ten feet of snow at Lake Tahoe and more at higher elevations. Until now, for this rain season (which began measuring last July) we've been at between 40 and 60 of normal. We should make it back to normal by next week.

It's coming down pretty steady right now, with winds gusting up to (my estimate, based on the large eucalyptus trees across the street) 40 mph. We're supposed to see gusts of up to 75 mph tomorrow, especially in the hills.

There's nothing extraordinary about this storm; we've seen at least 2 of these every winter that we've lived here. Sometimes enough storms link together that the sustained rains and ground saturation cause slides and flooding. Ground saturation is not a problem at this point. We'll just wait and see what the skies actually deliver. Weather prediction on the Pacific Coast is still a dicey proposition.

Meanwhile, in Arizona, the downpours of December - in spite of their intensity - have barely made a scratch in the ongoing drought conditions afflicting the state.

Heavy rain and snow earlier this month may have turned streets into rivers and allowed Arizona Snowbowl to open on time, but they did little to stop a 13-year drought.

National Weather Service forecaster Valerie Meyers said it would take numerous storms to replenish aquifers and get river levels back to normal.

To end the drought, Meyers said, "give yourself three good (storm) events like that each month during the winter, then carry that forward to having good precipitation over the summer months, and then let's repeat it for another year or two.
The rain that fell on Arizona replenished reservoirs to their 2006 levels, making it the third wettest December since the state began keeping records 108 years ago.

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