Monday, December 28, 2015

Those Tornadoes Were Really Odd, Scary And Tragic

Damage in Garland, Texas, in an image
from Chopper 5, NBC DFW 
Some of the many weather geeks I read and follow online say the tornadoes that have pummeled the nation over the past week are nothing unusual, that there are often December tornado outbreaks.

Don't believe it.

It is true that there are often tornado outbreaks in the United States in December. I can think of some nasty ones in at least five of the past ten years.

But this one, in addition to the obvious tragedy of the deaths and destruction brought by the storms, was by many measures more extensive than most if not all past December tornado swarms.

Tornadoes are most common in the spring, when surges of increasingly warm and humid air from the south feed into large storm systems that still maintain much of their winter strength and size as they move across the country.

In December, such surges of warm, humid air are much more rare, are less intense than in the spring, and don't get as far north.

This time, the air was springlike, bringing record setting, unprecedented Christmas week warmth to the eastern third of the country, and extending all the way into southeastern Canada.

The other key ingredient was a very strong storm organizing and now moving through the middle of the country. It was likely fueled by El Nino, as this type of storm is energized by the El Nino atmospheric patterns.
Large tornado near Hampton,
Arkansas Sunday. 

The result was that terrible week of tornadoes. (not to mention the incredible floods in the Midwest and Southeast, and the blizzard in the southern Plains, AND the ice storm in Oklahoma.)

Here are some of the records and oddities of this December's tornado outbreak:

Deaths:  This stat is the most tragic of them all. At least 25 people died in the tornadoes since December 23. More people died in tornadoes in the United States in the past four days than in the entire rest of the year.

Until this outbreak, the natiion was on pace to have the fewest tornado deaths in a calendar year, with 10.   This is the first time since at least 1975 there were more tornado deaths in December than in the entire rest of the year.

Consecutive Days:  The United States has now had seven consecutive days with tornadoes. That's the most consecutive days in December with twisters. The old record was set in December, 1982, during another super El Nino.

And it apparently continued on this morning. Tornado touch downs were reported in Alabama and the Florida panhandle, and possibly Mississippi today.

Night: Tornadoes are obviously harder to see at night. Also obviously, you should take shelter as soon as you hear a tornado warning. But human nature being what it is, people want a visual confirmation.

Especially if you're out on the road in a car, it's hard to decide how to take shelter, and where. So people get caught.

Days are short this time of year, so a greater proportion of tornadoes in this outbreak happened when it was dark out, as compared to the more traditional springtime tornadoes.

With no visual cues, people were no doubt surprised by how suddenly some of these tornadoes came up to them.

I noticed that all eight of the deaths associated with the tornado in Garland, Texas happened in vehicles. People in vehicles who see a tornado during the day will often stop, or turn around or take a detour to avoid the tornado.

I'm guessing many or all the Garland motorists didn't realize the tornado was near them until it was too late. They just couldn't see it.

Violence I: The tornado that devastated parts of Garland, Texas and surrounding towns Saturday evening was considered "violent" rated as an EF4. Video of the tornado is at the bottom of this post.

Tornadoes rated EF4 and EF5 are regarded as violent and are rare. They're the ones that we hear about because they are obviously the most destructive.

The EF4 Garland tornado had winds of 170 to 180 mph on its 13-mile path through eastern Dallas County, according to the National Weather Service in Dallas-Fort Worth. 

It was only the second EF4 rated tornado in Dallas County since at least 1950, and was the furthest west for an EF4 during December on record. (If you do get an EF4 tornado in December, which is rare, it would tend to be near the Gulf Coast or southeastern United States.

The Garland tornado, which killed at least eight people and damaged or destroyed hundreds of homes,  was the nation's' first EF4 December tornado since 2000.

Violence 2: This one has little if anything to do with meteorology, but it was bizarre. Experienced and reputable storm chaser Jeff Piotrowski was chasing the Garland tornado when he encountered what appeared to be a man injured by the tornado on the roadway.

He stopped to help, but the man was faking the injury and attacked Piotrowski with a knife. Piotrowski thankfully escaped with minor injuries and the attacker was arrested.  At the time of the attack, Piotrowski was live streaming  on Periscope his chase and efforts to help victims, so there were man witnesses to this weird crime.

Early this Monday morning, tornado warnings were still flying in parts of Mississippi and Louisiana.

The outbreak of severe weather will finally wane as the storm heads off toward Canada over the next couple of days.

The weather pattern will mercifully turn much calmer across the nation as we end 2015 and begin a new year.

From Basehunters stormchasers, here's what they saw in Garland as the tornado tore through power lines and neighborhoods Saturday evening:

From USA Today, aerial footage of the Garland, Texas area destruction

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