This is an El Nino?

2 February 2007

USA — Two months ago scientists detected risingtemperatures along the equator, deep in the Pacific Ocean.

The phenomenon, known as El Niño, usually means several months ofabove-average rainfall in Southern California. It was supposed to mean temporaryrelief in parched area forests and an end to a deadly fire season.

But apart from this week’s teasing drizzle, El Niño effects haven’tmaterialized. The region, experts say, could be on pace for a record dry year.

“These signals in the Pacific almost always mean we’re in for a goodsoaking, but this El Niño is dying,” said Bill Patzert, a climatologist atNASA’s Jet Propulsion Laboratory. “I gave it its last rites.”

The dry rain year is part of a long-term drought cycle, he said. Chartingprecipitation totals for every year dating back a century, Patzert and otherscientists point to a pattern characterized by alternate periods of low rainfalland above average precipitation.

Each period can last two decades or more and, using the past as an indicator,Patzert suggested the anemic rainfall could last another decade.

According to the California Department of Water Resources, snowpack watercontent is averaging only 43 percent of normal over the 400-mile-long SierraNevada Mountains range.

The effects of the current conditions go well beyond dry skin and brown lawns.U.S. Forest Service officials, concerned about the threat of another majorforest fire, received nearly $3 million in emergency grants to keep firefighterstaffing up at a time when it usually is scaled back.The threat has forced firebosses to table prevention measures, including prescribed fires and brushpile-burning projects meant to rid forestland of dead wood that could fuel amajor blaze.

The drought cycle that began in the late 1990s left area forests bone dry andushered in an infestation of bark beetles, which ravaged stands of weakenedpines. By the time the tree-killing beetles slowed their march, in part becausethey ran low on trees to infest, an estimated 12 millions trees were dead in theSan Bernardino National Forest alone.

A massive dead tree removal campaign meant to protect the mostfire-threatened forest communities has met with much success, as tree cuttershave thinned most of the dead trees near those areas.

But tests conducted late last month showed that the living brush andchaparral in the forest is almost as dry as the dead vegetation, Forest ServiceIntelligence Officer Bruce Risher said.

“You’re basically talking about live fuel burning as well as dead fuel,”Risher said. “We’re in a world of hurt.”

Rain Window Closing

With 96,000 wildfires torching some 9.8 million acres across the U.S., the2006 fire season set an all-time record, according to the National Oceanic andAtmospheric Administration.

In Inland Southern California, October’s Esperanza Fire brought a grimreminder of the potential toll of a swirling wildfire. Five firefighters werekilled in the blaze’s first hours when 90-foot flames overtook their engine nearBanning. The Esperanza Fire destroyed 39 homes and blackened more than 40,000acres.

Still reeling from the loss — and the prospect that the dry weather andheavy winds could lead to another blaze — fire officials and experts wererelieved to learn of the approaching El Niño winter.

They’re still waiting.

Years in which scientists detect an elevated sea temperature, SouthernCalifornia has received above average rainfall about 70 percent of the time,Risher and Patzert said.

El Niño effects come in all sizes, but the most significant one in recentyears was the rain year ending in 1998, when rainfall was double the annualaverage and topped 30 inches in some parts of Southern California.

A Forest Service station near UC Riverside has recorded just .86 inches ofrain since July 1, which is recognized as the start of the rain year, accordingto Forest Service meteorologist Matt Shameson.

In an average year, the station would have recorded more than over fiveinches by this time, he said. That places the current rainfall total at around15 percent of normal.

And while a report prepared by the Forest Service’s Predictive Servicesdivision suggested there is a chance of above-average precipitation in theInland area over the next 30 days, experts said the window for substantialrainfall is fast closing.

“Our chances tail off after March and, after April, it’s pretty muchover,” Bureau of Land Management meteorologist Tom Rolinski said.

Both forecasters said the year’s final totals could set an all-time recordlow for the region. The current record is around 3 inches.

The conditions have no known connection to global warming, which would haveno significant impact on Inland precipitation.

Firefighters Kept on Duty

Inland Forest Service officials generally scale back staffing in the wintermonths. They reassign firefighters to work on fire prevention projects,including the burning of piles of dead vegetation that could act as kindling fora large wildfire.

But heightened concern over the lasting dry conditions and continuing windshas kept fire bosses from taking either measure, officials said.

In October, officials from the San Bernardino and Cleveland national forestsbegan asking for emergency funds to keep firefighters, who normally would belaid off, on duty.

For that month, the Forest Service approved spending $378,000 for staffing onthe San Bernardino National Forest and $424,000 for the Cleveland NationalForest, said Gary Biehl, a strategic planner with the Forest Service.

Subsequent requests in each of the next three months brought the totalseverity funding for the two Inland forests to nearly $3 million. Additionalrequests totaling $588,000 for the upcoming month are awaiting approval, Biehlsaid.

“We don’t want to need more money,” Risher said of the emergencyfunds. “But we don’t want to get caught short.”

Despite the high staff levels, crews have been mostly unable to conductplanned pile burning, said Bob Sommer, fuels officer for the San BernardinoNational Forest. About 50 firefighters in that forest have been retained, andfour significant pile-burning operations have been postponed. Sommer expressedconcerns that large-scale prescribed fires planned for the spring might beaffected.

24. November 2017/by GFMCadmin