Disruptions to summer, winter rain made 2017 dry year

Sierra Vista Herald ^ | David Rookhuyzen david.rookhuyzen@myheraldreview.com

[SandRat]

SIERRA VISTA — A combination of bad meteorological luck did more than ensure that 2017 was drier than usual. It made it the least wet year in this millenium.

According to data from the National Weather Service, last year’s rainfall is almost half the annual average and more than six inches below 2016. Information from January 2017 is missing, due to a transfer between computer systems, but the total from February to December show a total of only 7.06 inches.

Ken Drozd, with the weather service in Tucson, said from what the service does know about January’s rainfall it’s highly unlikely the year got close to 8 inches.

The normal average rainfall for the Sierra Vista area is closer to 14 inches, Drozd said. The total for 2016 was 13.33 inches, with 2015 and 2014 coming in at 17.29 inches and 19 inches. The last time rainfall was this low was in 2009, with 8 inches, and 2011, with 8.61 inches. However, nothing under 8 inches has been recorded since at least 2000.

And a similar drop to what the weather service recorded at their gauge in Sierra Vista is something local amateur weather enthusiasts have noticed as well.

Gisela Halley has been keeping a rain gauge at her Sierra Vista home since about 2000. During the past nearly two decades she’s seen two or three years where her annual count has dipped down to 8.4 or 8.5 inches, but never the 7 inches she saw last year.

“The way it rained I knew that it was low, but not that low,” she said.

Halley did say that, given the sporadic nature of monsoon storms, other areas may have had better luck than her own neighborhood of Country Club Estates.

And some areas did, but that didn’t mean they weren’t also down from previous years. That was the case for John Michelich, who lives on the south side of Sierra Vista near the city limits. He said he received 10.23 inches for 2017 at his gauge. That’s higher than the National Weather Service gauge, but down from the nearly 19 inches he saw the previous year. It’s also the second lowest he’s ever recorded, beating out the 7.8 inches he had in 2009.

Richard Smith, who lives in the Chaparral Village area, said he also saw only between six and seven inches of rain. That’s the lowest he’s seen during the 12-plus years he’s been keeping track in Sierra Vista and Hereford.

“Statistically speaking, (it’s) a very low year for our area,” he said.

Smith also said 2018 doesn’t seem to be off to a good start either, as he has seen only trace amounts in his gauge for January, when he should have at least a tenth of an inch by now. There’s also been not a trace of snow, which is an oddity, he said.

Drozd, with the weather service, said there were a couple factors playing into 2017’s rain count. The first is during the monsoon season, where a high pressure system that usually sits north of the area moved south, disrupting normal weather patterns. The area had a decent July, but rainfall in August and September was underwhelming, he said.

“There wasn’t much left of the monsoon after August,” Drozd said.

But while more than half of the average annual rainfall comes from monsoon storms, the rest generally comes during the winter. And that’s where the area was also took a hit, he said.

During both last winter and this one there was a La Niña effect, a period of below-normal ocean temperatures in the Pacific that shifts moisture-bearing weather to the north. Similar conditions existed over the winter of 2010-11 and 2011-12, which caused similar reductions in rainfall, Drozd said.

The bad news is the three-month forecast shows the La Niña conditions continuing, which means rain may continue to be scarce. There is a chance for precipitation Saturday, but it will likely be light and not last long, he said.

“But we’ll take as much as we can get,” Drozd said

[Sacajaweau]

Here in the NE, Upstate NY in particular, we had endless, intense rainstorms...broke all kinds of records...

[moovova]

Yep. All that dryness is probably why it snowed in the Sahara desert the other day...