National Weather Service Red Flag Warnings

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The National Weather Service has modified the Red Flag Warning to become more in line with what the fire service thinks of as a Red Flag Warning. Public Information Officer Bill Peters with the CAL FIRE San Bernardino Unit explained at the Arrowhead Springs Resort & Conference Center, "In the past, the National Weather Service criteria for the Red Flag Warning consisted of relative humidity in a region that projected to get below 10% or lower for more than 10 hours. Now the fire service, however, has used the criteria of sustained winds of at least 25 miles per hour or frequent gusts of 35, combined with 15% humidity or lower for 6 hours."

This change pertains to the Inland portion of Southern California and the San Diego area. Other areas of the state and parts of the country use different criteria for their warnings, such as topography, vegetation and weather patterns.

"Within the last couple of years, we were just getting overloaded with Red Flag. And just like anything else, when you are running around yelling that the sky is falling, eventually nobody really believes you," explained Peters. With the Red Flag Warnings being issued less often, they should have a greater impact on the public.

The winds that Red Flag Warnings are usually combined with are called Santa Ana winds. Some claim that the name comes from "Santana" or "Devil Winds", but according to Bill Peters, the name goes back to the 1800's and was named after the winds coming out of the Santa Ana Canyon and down into the Santa Ana Basin. However, the winds blow all over Southern California, not just in the Santa Ana Basin.

In 1938, Raymond Chandler wrote a short story called Red Wind where he graphically described them as winds "that come down through the mountain passes and curl your hair and make your nerves jump and your skin itch. On nights like that, every booze party ends in a fight, meek little wives feel the edge of the carving knife and study their husbands' necks. Anything can happen." Local legends associate the winds with homicides, earthquakes and other strange occurrences that happen when they blow.

"Another popular misconception, though, is that the winds are hot only to their desert origin. Actually the Santa Ana Winds develop when the desert is relatively cold," Bill Peters stated. The winds are more prevalent from October through March when the desert is cool, so they do not have to be hot winds.  They can also be cool. PIO Peters said that during the Panorama Brush Fire of 1980, he heard many stories of things freezing at night because it was so cold.

As the season progresses, the Santa Ana Winds will develop about every ten to twelve days and then begin to compress as months go on. It is also possible to have a Santa Ana Condition without wind, where it is just hot and dry. The fires are then driven by topography. Peters remarked, "The combination of these strong, dry winds combined with extremely low humidity and dry vegetation are the prescription for destruction and death particularly in Southern California." One key to minimizing that is that now the Weather Service and the fire service are both using the same criteria to keep the public better informed.

Contributors to this story:
Barbara Brooks - Reporter
Ann Zevely - Camera/Editing
Renee Marquart - Text



Author:B. Brooks, A. Zevely and R. Marquart - FDNNTV.com