Much of the southeast and south-central portions of the United States are currently in moderate to extreme drought. And the outlook through April is even worse.
Currently Texas, Louisiana, and Florida are in the worst shape but NOAA expects drought to spread extensively across the area over the next three months. In Florida over 400,000 acres were blackened by wildfires last year. If this outlook is accurate that number may be exceeded in 2011.
A new tool is available that predicts the severity of Santa Ana winds in southern California six days in advance. Called the Offshore Flow Severity Index, it combines the relative humidity with the 1:00 p.m. wind speed predicted at the Saugus weather station to rate the events each day on a scale from one to four, with four being the highest. A category four event requires winds in excess of 30 mph with a relative humidity of less than 9%.
The term “offshore” is used because Santa Ana winds usually blow from a high pressure area over the Great Basin to a low pressure area off the southern California coast. These north, northeast, or east winds blow from the land to the ocean, or “offshore”, warming and drying as they move from high elevations to coastal elevations. Many of the larger and most devastating wildfires in southern California have occurred during offshore or Santa Ana wind events.
This forecasting tool will enable wildfire managers to modify their staffing or move fire resources into areas as needed to deal with the potential for large fires.
UPDATE: October 26, 2011. Access to the site now requires a password, which seems very odd.
We have seen recent videos of fire whirls, such as the one HERE, but a video that recently surfaced of wind rotation over a fire near the Pohakuloa Training Area on the Big Island of Hawaii is very impressive. There is no way I would want to be anywhere near a potentially lethal situation like the one in the video below. It was shot on Sunday by the Department of Land and Natural Resources.
When you watch it, click on full screen (the little symbol next to the speaker icon), and also listen to the audio.
Did you notice that the firefighters in the white fire truck got out of there as soon as they saw what was going on? And eventually the photographer did too. Smart move.
We have ranted about San Diego Gas and Electric a number of times for starting numerous wildfires, including the disastrous Witch, Rice, and Guejito fires in eastern San Diego County in 2007. But we have to give them credit for doing two things recently that benefit the wildland fire community.
The second thing they have done is to install a boatload of weather stations in the backcountry areas of San Diego County, including Ramona, Alpine, El Cajon, Valley Center and Fallbrook. So far they have have installed 94, yes 94, weather stations on power poles in wind-prone areas. The solar-powered stations contain sensors and data loggers made by RM Young and Campbell Scientific, respectively, and monitor wind speed, wind direction, temperature, and relative humidity.
The meteorologists in the local National Weather Service office are pretty excited about this massive new source of weather conditions. SDG&E has plans to make the data available to the public through a “dashboard”.
The National Oceanic and Atmospheric Administration has concluded that the first six months of this year were the warmest ever recorded for the combined global land and ocean surface temperatures.
The map below zooms in on North America and shows that areas in the western half of the United States were either one degree C above or below average, while the northeast, Canada, and Alaska were about three to four degrees C above normal for the first six months of this year.