Red Flag Remains In Effect For San Diego County Due To 'Extreme Fire' Conditions

Speaker 1: 00:00 A fire that started in Mexico crossed into the U S early this morning. The copper fire had already burned about 400 acres South of the border. San Diego fire crews jumped on it once it got to this side and were able to stop its forward rate of speed. It burned about 50 acres on the U S side. Meantime, we are still under a red flag warning that's not said to expire until six tonight. Speaking of red flag warnings, the way the national weather service refers to them changed on Wednesday for the first time, it added another word to the current red flag warning, which was extreme. We're now joined by Alex tardy with the San Diego office of the national weather service. Alex, welcome. Thanks for having me on. So can you start by giving us the very latest on Santa Ana winds and humidity levels? Speaker 2: 00:46 Yeah, so the Santa Ana winds continue to blow across San Diego County. We're seeing gusts of 22 as much as 40 miles per hour and that wind continued all night and was blowing across oats, high mountain and along the Mexico border. And those winds help fan the fire, um, that spread across the border. Now the one thing that's really significant is how dry it is. Um, overnight the humidity stayed below 10% along the Mexico border. That's, that's just um, perfect conditions for fire. Not perfect or anything else. Speaker 1: 01:21 I mean, I'm curious what prompted the Oxnard office to use the word extreme to describe this red flag warning? Speaker 2: 01:27 Yeah, that's a good question. So, um, this is our fourth events since October 19th. I'm putting the word extreme before red flag warning is not a standard practice, but I think the messaging of, okay, this is really unusual. It's not just your typical red flag warning. All red flag warnings are bad, but that this one was worse. And what we did see that was much worse was not just the amount of fires or the type of fires, but the air dry us air we've seen in years across the region. And that is that extra ingredient to allow the fires to burn and burn quickly. We saw more than three fires break out overnight last night across Southern California. Speaker 1: 02:09 And that extreme red flag warning did not apply to areas of San Diego County. Speaker 2: 02:15 Is that correct? I mean, that's correct. But the conditions were almost as equal from LA down to San Diego. So in LA it started earlier, the winds were a little bit stronger, but when we're talking about 70 mile per hour winds versus 50 mile per hour winds for a fire, it's not gonna make that much difference. Oh, the fire fields, 2030 miles per hour, it's gonna move that fast. Has the San Diego office every used that term extreme to describe a red flag warning? No. Typically what we do is we describe the conditions of being extreme, um, overall or across the area. But we don't use it as like an adjective with red flag warning. But these are no doubt extreme conditions. And so either way you look at it, it's a red flag warning with extreme fire weather conditions. So here's a question, because many areas woke up to 30 degree temperatures, 34 in some areas. Speaker 2: 03:13 Um, we usually think of Santa Ana winds as hot to be classified as Santa Ana's. Uh, is that true or is that changing now? So the mechanism that drives the Santa Ana winds, and this can be the confusing part of the whole thing, you know, most of us aren't atmospheric scientists or meteorologists, so you can't expect you to to totally get it. But the, the driving mechanism of a Santa Ana wind is cold air over the great basin or Utah. Let's say for example, that cold air is high pressure and the air blows from high to low pressure. If we did not have that cold air, we would not have Santa Ana winds. So scientifically, by definition, the Santana win is a cold win. But by the time it gets to our homes in San Diego, LA, it has to travel thousands of miles across the desert and down the mountains that compresses the air, warms it up. Speaker 2: 04:06 So typically we're much warmer than anywhere across the West, significantly warmer, sometimes 20 degrees. It snowed in Utah, it snowed in Colorado. They were in the teens the past couple of days. So that's our source of that cold air. We're looking at cold temperatures tonight again as well, right? Yeah. So the other thing it does with the Santa Ana, so even if you don't get a lot of cold air coming in that affects your temperatures, is it tries to air out. My lips are really dry right now. I talked about the incredibly dry air. We're looking at dewpoint temperatures, that's a scientific word a little bit, but negative 20 to negative 40 across San Diego County, that's basically the temperature you would have to cool the air down to to have do or fog or anything. We're never going to get down to minus 20 minus 40 so there's a huge spread and that's what creates this low humidity. Speaker 2: 04:55 But at night, if the winds die off and the sky's remained clear, you also have a much greater potential of cooling off or losing that heat to the atmosphere when it's dry like this. And that's why some of us have waking up and we'll do that tomorrow morning to wake up with some actual chilly temperatures, which is more important when it comes to wildfires. The force of the wind or humidity levels? Well that's a great question. He might get a little different answer from everyone. Uh, including firefighters. Um, I think the easy way to answer it would be the wind speeds. We often see aggressive fires even when it's somewhat moist, but if the wind is blowing, that's like having a fan on the fire. Now that said fires can choke, literally have trouble burning when humidity is over 30 or 40%, we're down to 5% at OTI right now. Speaker 2: 05:48 Some places even get down to 3% even in Carlsbad yesterday. So I would say to answer your question, the wind, if I had to choose moving past this week, is there any rain in the extended weather forecast? Nah, I know you'd asked me that. Uh, so it does have a little bit of hope for a little bit of rain in the middle of this month. Like, so the good news is that the next week, the next five to seven days looks like gradual warming. Um, each night will be a little bit warmer, but will remain dry. We'll lose all the wind. So that's great news. The hope for rain is slim. It's not zero. There is a little bit of tropical moisture that might want to sneak up here, um, around November 8th, that timeframe. But I don't see anything real promising other than that. We remain in this Santa Anna like pattern where the storms are going way to our North and then going across the Rockies. I've been speaking with Alex tardy of the national weather service. Alex, thank you. Thanks for out, ma'am. Speaker 3: 06:59 [inaudible].