‘Rivers’ Rend Asunder

February 10, 2015

Picasso_bird_goat_dancingCloudy with peek-a-boo sunshine this early Tuesday on California’s northern coast, and from the east, red sky at morning, all the world’s a warning.

Rainfall totals from the NWS shows we received nearly 3.5 inches of rain in five days — that’s semi-non-official, and the real, actual total will probably be higher.
Wind gusts the last 24 hours fairly severe, too. Here in Mckinleyville our strongest measured in at 50 mph, while up the coast in Crescent City, they knocked on 80 mph — this last ‘river’ did pack the wind snap/pop.
Absence of rain, loss of warmth. This morning feels way-colder than the last week or so, and we’re indeed about five/six degrees cooler, according to the NWS.

And what about that drought? Doug Carlson, a spokesman for the state Department of Water Resources: ‘“We are right on par with where we were last year, and last year was a really bad year.”

(Illustration: Pablo Picasso’s ‘Musician, Dancer, Goat & Bird‘ found here).

The major problem with these ‘atmospheric rivers’ (AR) we been seeing lately is the warmth — a lot of rain, but very little snow for the mountain packs, which feed the state’s reservoirs, which keeps the dry from becoming really, really dry. Sort of like it is now.
The last storms did pack an uptick:

Jeffrey Mount, a geologist who studies water and a senior fellow at the Public Policy Institute of California, said while snow has been sparse, the wet start to February was a positive development.
“It would have been nice if we packed in a little snow, but if you’re in a fourth year of drought, you take what you can get,” he said.
“It’s not like this water was lost — it’s being captured as we speak into the reservoirs. These reservoirs do have plenty of space.”

So, there’s that — and what effect does a warming planet have on these ARs?
From Climate Central last week:

The influx of much-needed rain comes courtesy of a feature called an atmospheric river that is a key source of much of the state’s precipitation and water supply.
A relatively recent meteorological discovery, these ribbons of water vapor in the sky are something scientists are trying to better understand.
They are flying research planes into the heart of the current storm to study what fuels it, which could help improve forecasts of the events.
Because the atmospheric rivers are critical for California’s water supply, scientists also want to pin down how they are being affected by climate change.
“We need to understand more about how climate change will change the amounts of precipitation that they will drop in the future,” Michael Dettinger, a research hydrologist with the U.S. Geological Survey who is actively investigating that question, said.

The drought has reached those depths because of record warmth that has increased water use and evaporation, and an atmospheric setup that has kept most storms over the Pacific from reaching the state during the past few winters, typically California’s wet season.
In particular, a tenacious region of high pressure has diverted those storms — and their rains — further north.
“That’s been the culprit these last three winters,” said Allen White, a meteorologist with the CalWater 2015 project, which is using research ships and planes to intensely study the storms.
The pattern has periodically shifted and allowed the atmospheric rivers to flow in, as they did in December when record rains fell on parts of Northern California.
But those record rains were followed by weeks of nothing.
San Francisco marked its first January on record (going back to 1850) with no rainfall — an unbreakable record.

Climate models and basic physics suggest that atmospheric rivers will become moister and more intense in the future, as a warmer atmosphere can hold more water vapor (about 4 percent more for every degree 1°F of warming).
But, as with this storm, that may only mean more rain, not snow.
Winters in California are expected to continue warming, so “it’s pretty likely that the average elevation at which snow falls during [atmospheric rivers] (and at other times) will increase,” Swain said.

Meanwhile, back along the upper US Atlantic coast is another matter — snow. Records for a buried Boston: ‘The 30-day total is even more impressive. At a fraction under 72 inches, it set a record. In an average year, the city gets 47 inches of snow.

Welcome to an extreme world in pieces.

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