ANDOVER — Not a moment too soon.
Right after Essex County Fire Warden Andy Regan climbed to the top of the fire tower on Holt Hill off Route 125 Tuesday, he spotted smoke through his high-powered binoculars.
It was in Tyngsborough, miles away, yet visible from one of the highest points in the region on a clear, dry, sunny day. He called the authorities in that community, and the fire was quickly doused.
A few hours later, at around 5:30 p.m., he spotted another one — in Billerica State Forest. This time, he called the fire warden in the Groton tower, which covers northern Middlesex County, and the warden there responded by calling the Billerica Fire Department and going to the fire himself.
Again, the blaze was successfully doused.
"That's what we're up here for," said Regan, who works for the state Department of Conservation and Recreation's Bureau of Forest Fire Control.
This week, and a few days last week, the National Weather Service declared a so-called "red-flag" alert, meaning conditions were ripe for flare-ups from brush fires. Low humidity, little leaf-cover or greenery in the forests, high winds and plenty of fuel in the form of downed trees, branches and leaves on the forest floor, all conspired to create perfect conditions for dangerous wildfires.
Local cities and towns responded by banning open burning of brush and leaves, which usually is allowed during the open burning season from January to May.
Fire officials from the Merrimack Valley and Southern New Hampshire said they received word early Tuesday from their respective state fire officials regarding the tinder-box threat. Much of the eastern portion of Massachusetts was affected, along with most of Southern New Hampshire and Rhode Island.
As of Tuesday morning, both New Hampshire and Massachusetts were in Class 4 conditions. The scale is from 1 to 5, with 5 the highest threat of fire danger. A classification of 4 makes any open burning extremely hazardous.
"With these weather conditions, a fire could get out of control rapidly and cause extensive damage to woodlands and dwellings," said Haverhill Deputy fire Chief William Laliberty. "We have low humidity, high dryness and extreme drought conditions."
Meanwhile, the Weather Service also issued a "red-flag" warning, which, according to the NWS website, means that "critical fire weather conditions are either occurring now or will shortly. A combination of strong winds and low relative humidity will create an elevated fire-spread potential."
"We are in a heightened state of awareness," said Paul Parisi, assistant fire chief in Salem, N.H. "We will not allow outdoor burning in Class 4 or 5 or with a red flag."
While state fire officials may recommend that open burning be curtailed, it is up to local fire officials to make the final determination. Other Merrimack Valley communities banning open burning yesterday included: Andover, North Andover and Methuen. Open burning is never allowed in Lawrence.
In New Hampshire, in addition to Salem, burning was banned in Derry, Londonderry, Hampstead and Danville.
Regan and other local and state officials expect the fire danger to last the rest of the week.
He noted that usually, brush fire season starts around this time of year. So far in 2012, brush fires have been cropping up since January.
"It came about two months early," he said, adding that the cause of most fires is just carelessness on the part of humans. Other causes include spontaneous combustion, sparks from trains, trucks or dirt bikes, or even, as was the case in one incident last year, overheated mulch that ignites.
The worst time of year for such fires, he said, is early spring because none of the leaves have come out on trees. The result is that the sun heats up the ground cover, making it that much more susceptible to catching on fire.
In Methuen, Deputy fire Chief Dennis Fragala said conditions this year were made worse by the lack of snow.
"The ground cover right now is light, fluffy and brittle," he said. "There's not a lot of groundwater. There was not a lot of snow to melt." The result is perfect conditions for brush fires.
Parisi said the threat isn't just to open or forested spaces.
He noted that anyone with a burn permit needs to be aware that if embers float around and land on a neighbor's property and start a fire there, the people with the fire are liable for any damages.
That also goes for the popular chiminea fire pits people often place on their decks or patios to create an atmosphere while they are sitting outside. Burning wood in chimineas is also banned during outdoor burning bans, he said, while it is permissible to cook with charcoal on a hibachi or barbecue grill.
Small campfires are also prohibited.
He said that at this time of year, "there's a lot of dead fuel sitting on the ground ready to burn. That's what's driving our concern. Once May comes, and things begin to green up, then fire the danger is reduced. Things are alive and green. They have moisture."
He said recent winters have been tough on forests, with a lot of downed trees and fallen branches from ice and windstorms.
"Every year, they just sit there and get dryer and dryer," he said. "There's a lot of fuel."
Andover Fire Department Deputy Chief Al DelDotto said that as in most communities, outdoor burn permits are good for mid-January to May, during which people can burn 7 days a week, as long as they call before they burn.
"When they called today, we told them, 'no burning,'" he said yesterday.
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