Will Tornado Season This Year Make Bad Things Worse?

For what it's worth, AccuWeather is forecasting a busy
tornado season this year, especially in the red zone.

At least two weather outfits and other experts are saying that tornado season in the United States might be rough this spring, especially in March and April.  

Great! Just what we need, more disasters. 

A busy tornado season is by no means guaranteed, of course, but there are signs that the next couple of months could be rough.

The culprit is La Nina, the periodic cooling of Pacific Ocean water off the west coast of South America.  We're in a La Nina pattern now.

Springtimes with La Ninas tend to have heavier tornado activity than years with El Nino, when the water is warm off of South America, and in years where that water is neither particularly hot nor cold. 

During El Nina years, the jet stream is pulled a little further north than usual across the United States. That, in turn allows warm, moist air to flow further north into the nation.  This sets up a bigger temperature contrast between the warm, humid south and the still chilly Great White North along the Canadian border.

This sets up a scenario with frequent storm systems.  

These storms and disturbances riding along that jet stream creates wind shear.  Wind shear is changes in wind direction and speed through different layers of the atmosphere. It's a key ingredient for creating tornadoes. 

When the wind shear interacts with the warm moist air from the south, hot, dry air from the west, and intrusions of chilly air from the north, you get springtime tornadoes.  The consensus seems to be we'll have that kind of pattern fairly frequently this spring.

Though tornadoes in the United States can happen any time of year, spring is the big peak season.  You will see activity ramping up in March and especially April. The question is always, by how much?

So far this year, the nation has seen only 23 tornadoes. On average, there would have been 100 or so twisters by now. Unfortunately two of those tornadoes have already killed four people. 

The Washington Post's Capital Weather Gang is one of the outlets that have jumped onto the busy tornado year train.  Here's one money quote from the Gang:

"'I think you're going to see severe weather return as early as the beginning of March to the Southern Plains and the southeastern United States,' said Victor Gesini, a professor of atmospheric sciences at Northern Illinois University and the creator of Extended-Range Tornado Activity Forecasts or ERTAF.  He's credited with predicting the May, 2019 Great Plains tornado outbreak nearly four weeks in advance."

Now, I'm not dissing or calling into question Gesini's expertise here, but his tornado predicting work is still in the experimental stage. So his March tornado prediction is not something that's cast in stone. 

Long range forecasts into the first ten days of March don't scream "big tornado outbreak" to me. but do suggest the risk of some severe weather. Plus, long range forecasts are notoriously vague and sometimes unreliable, so watch this space. 

The real month to watch, especially with El Nino, is April.  That's when tornado season really ramps up anyway. If these forecasters are correct, there could be some real trouble in a month or two.  Again, we'll see. 

AccuWeather is taking things a step further. Though they disagree with Gesini about early season activity, AccuWeather says meteorologists are "warning of the possibility that severe weather and tornado activity could abruptly fire up and rival one of the most notorious severe weather seasons ever, due to atmospheric similarities current weather patterns bear to that devastating season."

The season they're referencing is 2011, which indeed was among the worst in U.S. history. That year, swarms of tornadoes killed 552 Americans and caused upwards of $25 billion in damage. A  tornado outbreak in late April that year is considered the most widespread and destructive on record. 

Comparing what might happen this year to 2011 might be to an extent hype, as instilling fear of another season like 2011 is good click bait. 

However, you can have an unusually rough, deadly tornado season in the United States without having an extreme year like 2011, and that's what meteorologists seem to be saying now. Basically BOL for busy tornado days or weeks coming up.  Again, not guaranteed, but worth watching. 

These seasonal forecasts have have little practical use, other than the important, good work of raising awareness of the danger of tornadoes.

The location of any given tornado and who is threaten by one can only be predicted minutes or hours in advance. A larger area under threat of tornadoes can only be accurately predicated a few days in advance. 

Still, these seasonal outlooks do give a general heads up. 

Another thing to watch out for this coming spring tornado season is the location of the worst outbreaks.  The forecasts indicate the highest risk areas might be in the Southeast, Gulf Coast states and mid-South, places like Missouri and Tennessee. 

Tornadoes tend to be more dangerous in these locations than in the traditional "tornado alley" Great Plains.

In the southeast quarter of the nation, there's a lot of trees which prevent people from seeing tornadoes coming until it's too late. Humans being what humans are, they like visual confirmation of tornadoes even though the warnings are already blasting on weather radio and on television.

Tornadoes in the East are also more likely to be wrapped in rain, making them even harder to spot.  Most importantly, the south and east are more densely populated than the Great Plains, giving tornadoes more targets to hit upping the chances of damage and death. 

The weather pattern being predicted would emphasize tornadoes in the South and East, so that's not great news.  If this comes to pass, it continues a trend in which tornadoes are becoming more frequent further east and less frequent in the "tornado alley" Plains.