Dry Terrain Boosts Monstrous Growth of California Wildfires

The smoke plume from the fire has been able to surge over 20,000 feet high.

Station Fire - Mount Wilson last night Courtesy: CalFireBlogspot

(LOS ANGELES) - Though extreme heat and low humidity have been playing a role, it has largely been excessive drought and steep terrain that have allowed the Station fire burning north of Los Angeles to spread so rapidly without Santa Ana winds.

The fire has exploded from covering 5,500 acres Friday to over 100,000 acres of the Angeles National Forest by the end of the day Monday. By Tuesday evening, the blaze grew to over 127,000 acres.

Unlike most California wildfires, this blaze has been able to grow at an astounding rate without the help of Santa Ana winds.

Instead, it has been the combination of an excessive three-year-long drought and steep terrain that has allowed for the rapid spread. Extreme heat and low humidity have only made it worse.

Rainfall has been below normal the past three years straight in the Los Angeles area with the 2006-2007 rainfall season being the worst. During that season, Los Angeles received the least amount of rain ever on record.

The excessive drought has made vegetation across Southern California extremely dry. In addition, the Angeles National Forest has been untouched by flames for the past 40 to 60 years, so there is plenty of "dead, dry fuel to burn quick and hot" says AccuWeather.com Expert Senior Meteorologist Ken Clark.

Some of the trees have also succumbed to disease in recent years, adding even more dry fuel for the fire.

The steep terrain of Angeles National Forest is also playing a role. Fire burns more quickly uphill rather than downhill. This AccuWeather.com headline has more information.

To top things off, the fire happened to ignite just as the hottest, driest weather of the summer started kicking in over Southern California.

Temperatures have been in the 100s even in the mountains since late last week, while relative humidity has been dropping into the single digits during the afternoons.

While broad-scale winds have not been much of a factor in fanning the Station Fire, wildfires this large can actually create their own local, gusty winds. This AccuWeather.com headline has more information.

Relative humidity levels were slightly higher this morning than recent mornings. A few showers even started bringing some light rain to the areas where the fires are burning. However, these factors are not expected to aid firefighters significantly today.

Slightly cooler, more humid air will continue spilling into the immediate coast this week with a weak sea breeze. Meanwhile, highs will still climb into the 90s and low 100s away from the coast.

While temperatures will start trending downward in the mountains by midweek, the change may be too subtle to aid firefighters battling the massive wildfire. There were hopes that moisture associated with Hurricane Jemina, which remains a major hurrciane near Baja California, would spread into the L.A. Basin. However, it appears that moisture will likely remain well south and east, not bringing any relief to the burn areas. It will likely take weeks to contain this blaze.

In addition to homes, the Station fire is also threatening numerous Los Angeles radio and television towers, as well as an observatory on Mount Wilson. The observatory is home to two giant telescopes and several multi-million-dollar university programs.

The combination of a lack of air circulation and smoke from fires that have been burning across Southern California since early last week have created very poor air quality in Los Angeles County and others in the state, posing health hazards to people spending extended periods of time outdoors.

The smoke plume from the fire has been able to surge over 20,000 feet high. Visible satellite imagery Tuesday morning showed the smoke from this fire reaching all the way to Las Vegas and even parts of Utah and Colorado.

Heather Buchman is a meteorologist with AccuWeather.com.