Thursday, April 28, 2016

No Gigantic Tornado Outbreak On Tuesday Defied Forecast, But Don't Complain

A tornado near Howe, Texas Tuesday night.
There were far fewer tornadoes Tuesday than
expected, and that's a good thing. 
I suppose you can say the forecasts for the central and southern Plains was wrong for Tuesday.

I, and NOAA's Storm Prediction Center and lots and LOTS of other forecasters said there was a good possibility of strong, long-tracked tornadoes for that region Tuesday afternoon and evening.

There were none.

Oh sure, there were some smaller tornadoes, And lots of big hail and thunderstorms with destructive winds. And flash flooding.

For the record there were 13 preliminary reports of tornadoes Tuesday, 388 reports of damaging winds and 273 hail reports, so it was definitely a stormy day out there.

But there were none of the expected huge, photogenic but unwanted tornadoes that literally tear communities apart. If a forecast is going to be inaccurate, this is the type of inaccuracy I like.

True, municipalities closed schools and made other emergency preparations that might not have been necessary, but that's good practice.

Hordes of storm chasers looking for their dream tornadoes came away disappointed, and wasted money and time chasing nonexistent storms.

But those are the breaks! And there will be other tornadoes to chase. Possibly in the next few days, in fact.

Look at this way. Communities are not in ruins. Families are not mourning dead fathers, mothers, children, aunts, uncles.

As noted, there is the possibility of dangerous thunderstorms, and tornadoes daily for the next week in different parts of the country. Don't let your guard down in those areas.

In fact, on Wednesday, there was an outbreak of tornadoes. Not the worst ever, but still bad. There were 19 reports of tornadoes in an arc from Iowa through Illinois into western Kentucky.  One tornado touched down in the Omaha, Nebraska metro area Wednesday and caused damage.

So it wasn't all good news on the tornado front this week.

The lack of enormous tornadoes on Tuesday, while definitely a very good thing, highlights the fact that we still have a lot to learn about forecasting severe weather.

Forecasts have gotten much, much better, but we still can't forecast precisely where tornadoes will hit more than a few minutes or at most, an hour, before they strike.

And overall storm systems sometimes "over perform" dropping more, and more dangerous tornadoes than expected. And sometimes we get days like Tuesday, where it's not as bad as feared.

One preliminary look at what made Tuesday's forecast gratefully wrong was a subtle feature in the air mass over places like Oklahoma and Kansas.

You need massive updrafts as one important ingredient in the formation of supercell thunderstorms that produce tornadoes. That was certainly in place Tuesday. But there was a subtle layer in the atmosphere where the updraft wasn't as violently upward as expected. In fact, there was a little layer of sinking air in spots.

That might be one reason that tornadoes were stifled. And another lesson learned for forecasters.

The lack of tornadoes Tuesday just might have made forecasting future tornado outbreaks just a tiny, tiny bit better in the future.

Here's a video of a funnel cloud/tornado lurking behind a building in the Omaha, Nebraska area Wednesday:

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