Wildfire Stories 2012: Fire Weather

There has to be a moment. Imagine the fire nearly out. Your smokejumper or hotshot or engine crew is nearby, each of you working the still burning stumps, the residue on the ground that might still catch a bit of wind and grow again toward fire. Tired, exhausted really, but also proud. The rush of physical work done well. But you get to think a bit now, to look at the forest or hillside in a bit of context. You feel good, but in truth there is nothing happy about this moment. You stand there in the black, a thousand or a million acres still smoldering. Homes turned to charcoal and people dead. “How the hell did this happen?” you wonder. And you look at the sky. Ed Delgado, the Fire Weather Program Manager at NIFC, takes a sip of coffee and moves some paper on his desk at the National Interagency Fire Center in Boise, Idaho. His eyes never leave his computer screen. Short hair, neatly cut and turning grey, glasses, somewhere in his forties, he could just as easily pass as your kids’ principal as the guy who wonders how weather will bring hell to the forests and grasslands. “You have to understand the interactions between weather and fuels. And then how that combination affects fire,” he says. “The better you understand that, the more specific you can be with your forecast, the better you can apply things, what’s important and what’s not. You begin to recognize patterns that have certain effects on fuels. For example, there’s that hurricane in the Pacific. Fabio. When we first saw that was starting to move towards the States, or had the potential, we immediately started to key on what impact that had. And California is always a bad area, so we started thinking lightning. They had dry fuels and a low snow pack. How is this going to affect them this time of year if they get fire? They don’t typically have a lot of fire this time of year, but there are circumstances that make us a little more cautious.” “Typically,” he continues, “we don’t worry about California until September, October, when they get the Santa Ana winds coming out of the interior. But now, because of the extreme conditions down there people pay a little more attention. You’ve probably heard on the news that 61% of the country is in moderate to extreme drought right now, and it’s the worst since the Dust Bowl. To me that’s a little alarmist. It’s not exaggerated, it’s just alarmist because there are different stages of drought. But of course that all ties back into fire.” I ask about lightning strikes. In morning briefings there is always a count, how many positively charged strikes, how many negative. “I don’t buy into that,” he says. “Why not?” “Well, the idea is that positive strikes are hotter than negative strikes.” “And they fall outside the rain shadow.” “Well, yes and no,” he says. “They do tend to have instances where positive strikes strike outside the core of the storm. But I also don’t buy the idea of wet versus dry thunderstorms as being a major difference between fire starting situations and non-fire starting situations, mostly because there are other things people don’t talk about. They say the positive strikes are hotter than negative strikes, but a negative strike is 1500 degrees minimum. That’s going to start a fire. It doesn’t matter. It’s like the difference between a flame thrower and a volcano. They’re both going to start fires. One’s just bigger than the other.” “And the thing with wet versus dry, again, it really depends on the fuel itself. If the fuels are wet they’re not going to burn; if they’re dry they will burn. Now rain will tend to slow it down if it’s a fine fuel. If lightning strikes in grass and it happens to be raining, it may not ignite. But if lightning strikes a dead tree or something, the rain’s not going to put it out. And we don’t get that much rain out here with thunderstorms anyway, so unless you’re dealing with something like a monsoon down in the southwest this time of year, it depends on the fuels.” “The hardest part for us is that we’re in a transition period between El Niño and La Niña,” he continues. “And while those aren’t the only things we think about, they are key drivers of weather patterns and, being in the transition where we’re not at one extreme or the other we have far more outcomes possible. It’s all about timing and when are things going to start transitioning one way or the other.” “So right now anything’s possible.” “Right now anything is possible,” he says. “Last week, back in April we were looking at what we call analog years, where we look at years that have developed similarly to this year in the past and then we try to predict. It’s just a really crude way of getting an idea of what our range of possibilities is. It’s not a forecast. It’s just that past performance is a indication of future. So we try to find out what range of possibilities we’ve had historically. And that narrows down what we need to focus on. We had a situation where if we transition to an El Niño we were going to have a really, really wet year in the west. If we didn’t transition by a certain time it was going to be really hot and dry. So it was going to be hot and dry or it was going to be wet. It’s not easy for a forecaster to resolve that.” “And everyone said thank you, that’s going to be really helpful.” “Oh my God,” he says. “Before I left the weather service, I was working in the Greenville, South Carolina forecast office. I was there in January we had a big storm, or the potential for a big storm. Up and down the east coast all the offices had to coordinate these big, major storms, especially all along the I-95 corridor. A big storm could paralyze that part of the country. Since we were the southernmost office, we were going to be first impacted by the storm. We led the call and we were all pretty much in agreement that the storm was going to move out to sea and it wasn’t really going to affect the east coast very much.” “Uh oh,” I say. “I was the forecaster on duty and we had a zero snow forecast. I was working the night shift. I went home and when I woke up later that afternoon there were sixteen inches of snow in Charlotte. Ended up with twenty. It ended up all up the east coast, all the way to Boston and Philadelphia, two feet of snow.” Ed looks at the many weather maps on his computer screens. “But for now, what we’re dealing with now is this low. We had a little trough, two close lows. The first one is gone, it lifted out, and now we have this one that’s dropped in on northern California. So as the ridge builds over the plains the moisture starts moving back to the west. Right now it’s kind of hanging across the eastern half of the Great Basin. And we’re watching Fabio, to see what that does.” “Right now,” he says, “we’re largely not interested too much in the eastern U.S. They’re basically out of fire season, although it will start to pick up in the southeast around November. Florida, they burn almost all year long. Summer months tend to be sort of a low for their fire season. Georgia and the Carolinas, their fire season will start picking up in the interior part of those states because that’s more where the timber is and more of the deciduous trees and you’re dealing with the leaf litter fires in those areas. And then farther north–a very brief period up here in the Virginias. You might get some fires up there in November after the leaf fall, if it’s been a dry late summer and early fall. The leaves will burn pretty well and it’s a whole different firefighting regime out there. They tend to use leaf blowers instead of shovels and Pulaskis.”

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