Fresno Bee Newsroom Blog

It doesn’t rain on June 21 in Fresno — at all

Plan your picnic Friday, you live in Fresno. It’s a good bet you won’t see rain at Woodward Park or anyplace else in the city.

Since weather record-keeping began in the late 1870s, Fresno has never seen rain on June 21.

But that’s not the most interesting part of this trivia. According to the records, June 21 is the only rainless day of the year in Fresno.

In other words, all the torrid, parched days of July and August have seen at least some kind of rain in the last 130 years or so.

“Rain is pretty unusual in the summer for the San Joaquin Valley,” said meteorologist Paul Iniguez of the weather service in Hanford. “But we’ve recorded at least a trace on every day of the season in Fresno, except June 21.”

Iniguez said next month — July — is particularly dry in the Valley. He said there have only been three days since the 1870s when Fresno got more than .10 of an inch of rain. The amounts of rain were .14 of an inch in 1925, .22 in 1992 and .33 in 1913.

“The Valley has a very Mediterranean climate,” he said. “Summers are typically very dry.”

By the way, Friday is the first full day of summer. The solstice happens at 10:04 p.m. Thursday.

2012-2013 wet season might be among Fresno’s 10 driest

Rainfall in Fresno for January through April? It was a kidney stone of a four-month period. It ranks as the sixth-driest on record, according to the National Weather Service in Hanford.

It’s a relief that those four months have just about passed, but we have more than just a dry spell here. If there’s little or no rainfall between now and the end of June, this will go down as one of the 10 driest years on record for Fresno.

Those records date back to 1878.

I’ve talked with a few meteorologists who say California is in a drought, though the state has not declared one.

Paul Iniguez of the National Weather Service says: “As a meteorologist, I will say that large areas of the state are experiencing meteorological drought.”

 The state had a dry year in 2011-2012. It looks like 2012-2013 — water year runs from July 1 through June 20 — will be even drier.

Fresno is a good example. It had 8.15 inches of rain last year, about 75% of average. This year, the city has 5.60 inches, about 52% of average for late April.

The snowpack was a bit of a disaster as well. It was 48% of average on April 1. The year before, it was 54% of average.

With reservoirs still close to average — with the notable exception of San Luis Reservoir in western Merced County — the impact of consecutive dry years could be much worse.

But water managers throughout California already are worrying about next winter.

Irrigation vapor from Central Valley gives Colorado River big bump

Massive water vapor from farm irrigation in California’s Central Valley each year blows over the Sierra Nevada, pumps up rainfall over other states and adds 100 billion gallons of water to the Colorado River, new research shows.

The Colorado gets nearly a 30% bump in stream flow. That’s enough water to fill nearly two-thirds of Millerton Lake near Fresno.

The study, led by climate hydrologist Jay Famiglietti of the University of California at Irvine,  will be published Tuesday in the journal Geophysical Research Letters. This part of the water cycle has not been accurately described before, Famiglietti said.

If irrigation stopped in the Central Valley, there would be a decrease in the stream flow of the Colorado River basin — a supply of water that has been hotly contested for decades.

The Colorado River basin provides water to Los Angeles, Las Vegas, Phoenix and other cities. Nearly 35 million people, as well as more than 3 million acres of farmland, rely on the water.

The study says more than 12 million acres of farmland are irrigated in the Central Valley, which includes the Sacramento and San Joaquin valleys. As water evaporates into the air, it is caught by the wind and taken over the Sierra.

As it moves into the interior of the Southwest, the vapor feeds into the annual monsoon cycle that includes moisture from the Gulf of Mexico, Famiglietti said.

“Adding the moisture from the Central Valley makes storms wetter and more violent,” he said. “It’s like throwing fuel on a fire.”

He said climate computer models make it possible to isolate the contribution from the Central Valley. The research is an effort to account for as many weather influences as possible.

Famiglietti’s study says about 40% of the irrigation in the Central Valley comes from ground-water pumping, and that worries him.

He wonders what it will mean to the Colorado River If land must be taken out of production as the ground water is depleted.

“It raises questions about the future,” he said.

Scientific American: Will California megastorms happen more often?

There’s a riveting online article raising the scary possibility of more frequent megastorms like the siege that struck California in 1861-62.

The Scientific American article says the rain started on Christmas Eve 1861 and continued 43 days, turning the Central Valley into an inland sea 300 miles long and 20 miles wide.

It apparently was not just a freak, the article says. New studies suggest this kind of storm hits every two centuries.

So will climate change increase the frequency? Just raising the question causes anxiety, and you can understand why. The article’s description of the 1860s event is like a script for a disaster flick.

Scientific American said: “Downtown Sacramento was submerged under 10 feet of brown water filled with debris from countless mudslides on the region’s steep slopes. California’s legislature, unable to function, moved to San Francisco until Sacramento dried out — six months later. By then, the state was bankrupt.”

It’s worth a read.

Dry storm suddenly got wet for Kings County

The storm Thursday unexpectedly hammered Kings County and dropped hail on parts of Kern County, said private meteorologist Steve Johnson.

He said he got reports that part of Highway 33 were closed due to flooding.

The storm had been “starved” for moisture until late Thursday when the remnants of a tropical cyclone were drawn into it.

“It changed within about a 12-hour window,” he said. “It happens sometimes in October.”

Johnson, who issues a report for several customers, also said there will be a gradual warmup over the weekend. He predicts temperatures will remain warm until Oct. 20 when a cooling trend will begin.