NEQ Friday Review, V.2

The subject of today’s NEQ Friday Review is tornado talk!

Dozens of twisters were spawned this week from violent supercell thunderstorms marching their way across the Great Plains. In the true line of fire was Oklahoma where as many as six EF-3 tornadoes were responsible for leveling houses, flipping cars and dropping hail as big as softballs. Two people (revised from five) were killed and dozens more injured.

But why?! Forecasts warned of tornadoes days in advance. They even predicted almost to the hour when the twisters might strike. How did they do it!?

Supercomputers!!! Years ago computer models were capable of forecasting storms two days in advance and meteorologists needed to rely heavily on radar and storm spotters to confirm the location, size and strength of tornadoes. But nowadays meteorologists use supercomputers that crunch large amounts of atmospheric data well in advance of an imminent threat of severe weather, and therefore provide them the power to warn of oncoming storms long before they strike – even weeks!

So then what went wrong?! In my opinion it’s ignorance. Tornadoes occur frequently in Oklahoma and severe thunderstorm and tornado warnings are almost a weekly occurrence at this time of year. Despite the advance warnings, many people disregarded blaring sirens that indicate a tornado is about to crush them! I mean, television stations even showed motorists clogging roadways as tornadoes were forming, just watching in shear awe – and never knowing what uncanny path the tornado would take. Perhaps the population has become desensitized to the seriousness of these storms. Easily they were in harm’s way.

Well, geez… come to think of it, I would be right there with them! Anything for the shot!

Have a great weekend and stay safe!

Tornadopacalypse 2010

As most have heard by now, a major tornado outbreak took place yesterday in the nation's mid-section. At the center of what I'm dubbing Tornadopacalypse 2010 (the severe weather season's extension to the famed Snowpacalypse of this past winter) were the states of Kansas and Oklahoma. So far there have been over 35 reports of tornadoes, most of which were reported in the Sooner State, where at least 5 people were killed with over 50 injured.

It all began to unfold yesterday morning when the Storm Prediction Center (SPC) in Norman, Oklahoma (which itself was struck by a violent, wedge-like EF3 tornado – the city, not the SPC) had issued a rare 'high risk' warning of violent, large and long tracked tornadoes. Well, that is exactly what happened once they began to develop.

So, what causes a tornado outbreak to occur? To those less versed in tornadic activity and the ingredients that need to come together to cause such an event to take place, here's some helpful information.

First, while there is no single agreed upon definition, generally more than six tornadoes in a day in the same region is defined as an outbreak. These outbreaks typically occur in the Spring months from March through June, and they usually take place in the 'Tornado Alley' section of the Great Plains. May is the most active month, averaging more than 300 tornadoes during the latest 3-year period, which is nearly 25 percent of all tornadoes observed during any given full calendar year.

There are generally three atmospheric criteria that need to come together perfectly (or not so perfectly, depending on how you look at it) for a major tornado outbreak to commence.

• A lifting mechanism, such as an upper level trough, surface cold front, outflow boundary, dry line (or a combination of these), which acts as a focal point for storm initiation.
  
  
• Pronounced wind shear, which is a change of wind speed and direction with height. Fast low-level winds also boost the risk.
  
  
• A deep layer of high moisture content.

Well, yesterday all these ingredients came together at the right time (or not so right time, maybe?)across Kansas and Oklahoma, and the atmosphere became extremely ripe for supercell thunderstorms to form. Supercell thunderstorms are storms with rotating updrafts that can produce extremely large hail, damaging straight-line winds, and violent tornadoes. The result: long-lived twisters with winds up to 150 miles per hour, spouting hail the size of baseballs, toppling stores, flattening schools, ripping up towns and leaving thousands without power!

More severe weather is possible through Wednesday, including parts of Oklahoma and Kansas.

Severe Weather Awareness Week

Severe Weather Awareness Week kicked off this past weekend for the New York metropolitan region, and what better time than now to help explain some of the lingo you’ll often hear from weather forecasters across the nation during one of the most violent weather months of the year.

May is considered the heart of tornado season, but it’s not all about tornadoes, ya know... Over the last 20 years a variety of severe weather events has killed over 100 people in New York state alone, and has caused over three quarters of a billion dollars in damage. On average, the National Weather Service (NWS) issues 400 severe thunderstorm warnings, 17 tornado warnings and about 150 flash flood warnings each year in the Empire State. So, next time you hear word of any of these warnings, remember these definitions:

A severe thunderstorm watch is issued when severe thunderstorms capable of producing winds of at least 58 mph and or hail of at least one inch in diameter, are possible within the next few hours (typically less than six hours).

A severe thunderstorm warning means that severe thunderstorms are imminent or occurring, and could pose a significant threat to life and property.

A tornado watch means conditions are ripe for tornadoes to form and they could do so within the next few hours (typically less than six hours).

A tornado warning means a tornado is imminent or occurring, and has likely been visually spotted or indicated by Doppler radar. A tornado warning implies an immediate threat to life and property and appropriate shelter should be taken immediately.

A flash flood watch means conditions are favorable for flash flooding, which is a rapid rise (typically within six hours) of water along a stream or low lying urban area, most commonly resulting from downpours associated with severe thunderstorms.

A flash flood warning means flash flooding is imminent or occurring and flood waters can rise rapidly, if they have not already.