We had viewers submit their questions for Dallas to answer. Here's what the award-winning meteorologist had to say about the weather, storms and his career.
With LA's microclimates, why can it be 85 and sunny in the Valley while it's foggy and 65 in Santa Monica? - Amie, Woodland Hills
This happens in Southern California a lot because we have a really cold ocean and a Mediterranean climate.
Santa Monica has a cool sea breeze, and if you swim in the ocean around Santa Monica, you know just how chilly it is. When that cold air comes in off the ocean and makes its way inland, it starts to warm up.
Many times, we have a nice marine layer that comes in too. Sometimes that marine layer hangs on during the afternoon in Santa Monica, so it will stay cloudy all day while the inland valleys heat up.
Our Mediterranean climate is really beautiful!
Dallas frequently talks about the unique "Mediterranean climate" in Los Angeles. What other cites in the world are similar in that regard to Los Angeles? - Bill, Burbank
That's a great question. First, I want to point out how limited the Mediterranean climate is in the U.S.
As a matter of fact, if you go all the way from the equator to the North Pole in our part of the hemisphere, this region on the coast of California is the only Mediterranean climate. It extends from San Francisco down into Los Angeles.
This type of climate gets its name from the Mediterranean Sea, but there's a huge difference between our climate and the climate around the Mediterranean Sea.
We have a cold-water Mediterranean climate, so during the summertime, we don't see a lot of humidity. The Mediterranean Sea, on the other hand, gets really warm.
If you're in southern Italy during the summer, for example, the water temperatures can get up to 82 degrees. That releases moisture into the atmosphere, so their Mediterranean climate can be very sticky.
Why do they call them the "Santa Ana winds"? - Bennie
The "Santa Ana winds" actually received their name from a writer at the LA Times. Back in the day, he happened to be in Santa Ana during a strong wind.
They should actually be called the "Santana winds" because that's the "devil wind." The Santana winds occur all over Southern California, not just Santa Ana.
The winds come from the northeast through the mountain passes. As they blow through the mountain passes, the air is compressed and heats up, so they are usually very warm.
Now, once you get into wintertime, they can actually be cold "Santana winds." And once they come down from the mountain passes, they can produce winds of hurricane velocity. We had that, of course, back in January in the horrific fires.
High pressure builds over the Colorado Plateau, and there's low pressure out over the ocean, causing the winds to blow and howl through the canyons out to sea.
Why is the Midwest so humid in the summer months even though it's not considered a tropical climate? - Samantha, Menifee
If you draw a line right down the middle of the United States, the regions east of Denver get tremendously humid. I grew up in Florida and Georgia, and I never got used to it. Humidity is really tough.
The reason why these regions are more humid is that the ocean waters around the East Coast, the Gulf of Mexico and the Atlantic are really warm. In the summertime, the Gulf is sometimes 90 degrees, believe it or not.
On the West Coast, though, we have nice cold water; it's called the California current. Cold water doesn't release as much water vapor into the atmosphere, resulting in lower humidity.
We have some of the most beautiful climates out here in the west. If you head to the Midwest or anywhere east of Denver, however, you get more humidity. It gets particularly bad down in Texas and Florida where the water temperatures are warm.
On the East Coast that moisture builds into thunderstorms and heavy rain.
Summer is so hot. Is that because we are closer to the sun? - Philip, Hollywood
You would think that we would be closer to the sun during the summer, but we're actually a little further - like 3 million miles further from the sun in July. It's called the "Aphelion" at that time.
The reason for the heat is that Earth is tilted more toward the sun, 23.4 degrees to be exact. That's why, even though we are 3 million miles further away from the sun in July, the temperatures are hotter.
When you go to tornado alley for the extreme weather, is it fun, scary or scientifically interesting? - Mark, Rancho Cucamonga
It's all three of those actually!
When you get out there, it's amazing because you see Mother Nature in action. You can study this in a textbook, but until you're standing under a supercell that's rotating, and there's a funnel cloud coming down, and it touches down really close to you, there's nothing like that.
It's also a little frightening. The first time that I was really close to a tornado was out in southeastern Colorado in the rear flank downdraft, which is a very strong current that comes down wrapping around the vortex. I thought it was actually the tornado, so I really got on the throttle to get out of the way.
Where I go tornado chasing, from northern Texas all the way up to the Dakotas, is called "Tornado Alley." In the springtime there, warm moist air from the gulf comes northbound. At the same time, cold air is coming down out of the arctic.
Where these two air masses come together, it's like a battle zone. The air is lifted very violently ahead of the cold front, which can cause tornados to form. It takes some strong winds along with that, like a jet stream, kind of whipping around and spinning these tornados up.
More tornadoes occur in Tornado Alley than anywhere else in the world.
Something always seems to happen when you get warm and cold air merging together. Even if you don't have the other ingredients, like a strong jet stream in the mid parts of the atmosphere and what we call a low-level jet that comes up from the south, you normally get powerful thunderstorms that can cause heavy rain and hail.
Once you get into late June and July, this all goes away for the most part because the cold air is limited. That's when we shift our focus to hurricanes.
You've given me inspiration to go into weather. What got you into weather? - Dakota, Anza
It was a tornado that first got me into weather.
I was in the sixth grade in Georgia, where I grew up, and they issued a tornado warning for our little town. Now, my class had this big window that looked out to the west, and I decided in the sixth grade that it would be a good idea to hide, not go downstairs.
I thought, "okay, I'm going to hide in the closet." When everyone had gone down to the basement, I came out and went over to the window, and I looked out. You could see this funnel cloud rotating just above the trees, and the trees were crackling and popping.
And then, all of a sudden, I was lifted up.
It was just the football coach, though. He grabbed me by the back and he said, "you are one crazy little kid." That day, I went home and told my mom and dad, "this is the most incredible thing."
I had the World Book Encyclopedias, and I started studying about the weather, and it just became an obsession.
What drives you to teach us about the importance of the weather? - Teddy, Norwalk
I think that we're always learning; it doesn't matter how much we know in any subject. We're always learning more about the situation with the atmosphere and the climate system.
I just have a really great passion for meteorology and Earth sciences, and I like to teach others about it. What I love about our audience is that they can watch the weather show on a nightly basis and see a little bit of science beyond just the temperatures. We get to teach about the weather systems and why the climate system is doing what it's doing.
Sometimes I have to be careful because I'll get all excited and start talking about thermodynamics and things like that. Sometimes, we just need to know what the weather patterns are going to be, but I still enjoy every bit of teaching.
Many times, parents will come up to me and say, "Dallas, my son or daughter got interested in science because they watched you do the weather and do a little teaching about the dynamics of the Earth science system." And that's the best compliment.