A Stormy End to April, But a Very Warm Start to May!

Believe it or not, here in WC Ohio the month of March will end up being warmer than the month of April this year! We did have the warmest March in recorded history, but still, that’s pretty impressive if you ask me! So here we are on our last day of April, and almost right on cue, we will begin quite the warm up for May. We’ll have to endure the possibility of a few storms later this afternoon though as a warm front and an area of low pressure usher in some very warm and moist air out of the South. Here is surface map showing dew-point (moisture) and my crude attempt at drawing a surface low and warm frontal position around 11:30 AM Monday.

The darker green colors indicate a surge of 60+ degree dew-point mainly for the Southern half of the state by later this afternoon. Couple that with warming temperatures and an area of low pressure passing through and you have a recipe for developing thunderstorms. The good news is that the area of low pressure is relatively weak and there isn’t much wind shear in the atmosphere with the low. Basically that means there will be a very low threat for rotating storms and the potential for tornadoes, but we have the chance at seeing a few strong to severe storms capable of producing hail and damaging winds late this afternoon and evening.

After this system passes through later tonight, the flood gates will be open for some very warm air to work in by midweek. By late Wednesday a strong upper high will develop over the SE United States and that means temperatures likely surging into the low 80’s for highs! Here is a look at the upper high at about 8 PM Wednesday. The high pushes the main jet stream flow indicated by the blue colors well to our North.

With the warm and moist air in place, there will be chances for scattered showers and thunderstorms through the period but they will be very hit or miss. It looks like this pattern holds up into the upcoming weekend until a cold front swings through to bring us cooler weather once again.

Welcome to May!

Kyle

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Is Tornado Alley Expanding?

A recent article in the USA Today really got me thinking about tornadoes in the United States. Popularity seems to be at an all time high with these storms with more and more people taking an interest in both spotting and chasing severe weather. The report in the USA today claims that a new Tornado Alley should be extended much further east covering all of Illinois, Indiana and even here in Western Ohio. Here is the link to the story:

http://www.usatoday.com/weather/storms/tornadoes/story/2012-04-09/tornado-alley/54157872/1

This “expanding” of tornado alley doesn’t really come as news though, tornadoes have always been prevalent in these parts of the country. This is the way it’s always been! We know that the best conditions year after year for the most powerful tornadoes are in the plains, but that doesn’t mean these storms can’t develop in other places (Xenia F-5 tornado, Van Wert EF-4 tornado).

But what the public needs to consider here is that people and technology are looking for tornadoes now more than ever, which is leading to this “expansion” of tornado alley! For example, fifty years ago a weak EF-0 tornado in the middle of a corn field wouldn’t have gotten reported because nobody cared, or no one was there to see it. Today with technology and more eyes to the sky, these tornadoes get reported and recorded into the system. Don’t get me wrong, this is a great thing that there is more awareness and recognition of these storms. But don’t let the hype fool you into thinking that the increase in tornadoes doesn’t have anything to do with increased reporting in this digital age where everyone has a easy access to things like cell phone cameras and the internet to spread the word quickly. Here is a graphic from the National Weather Service (NWS) showing a steady increase in tornadoes over the years.

If you only saw this graphic you would think, “Uh Oh! This doesn’t look good!” But before jumping to conclusions, consider this graph also from the NWS showing an increase in reported EF-0  tornadoes through the years.

What is very obvious to me based on the data provided in these two graphs is that the  correlation between the number of total tornadoes over the years has risen in part because a greater number of smaller tornadoes being reported due to recent advances in technology. While the overall number of tornadoes has gone up, the total number of more powerful storms has basically stayed the same. The overall strength of tornadoes has shown little change over the years.

Below is a graphic of strong to violent tornadoes in the US since 1950. (EF-3 to EF-5 tornadoes)

The trend is pretty steady with the highest point being in 1974 for the Super Outbreak.  The point I want to reiterate is that tornado alley has always consisted of a larger area than depicted in most maps, however, this recent development comes in large part due to increased reporting and new technologies.

Kyle

Experimental Tornado Warning System Begins Today

It was a very busy severe weather season in 2011, and in the wake of that the National Weather Service is testing out a new method for issuing warnings. The NWS has found that many times when a tornado warning is issued people won’t actually take shelter until they actually see or hear the storm. And because the majority of tornado warnings actually don’t produce tornadoes, people have stopped taking warnings seriously.

Beginning on April 2nd, five National Weather Service offices in the heart of tornado alley will begin a new experimental warning system that will try to better portray to the public the severity of a particular storm. For example, when the NWS issues a tornado warning there will be three different possible tiers of warnings issued. The differences in the warnings will be found in what the NWS is calling “tags” at the end of the warning text. The first tier would be the standard tornado warning with no tag. These warnings would be the majority and usually are the ones that are radar indicated with no spotter confirmation on the ground. The second tier would be a tornado warning with the tag “tornado damage threat, significant”. This tag would be used when the NWS feels that the particular storm has a greater risk of significant damage in the area it is impacting. The third tier of warning would be with the tag “tornado threat, catastrophic”. This term would rarely be used but would convey to the public that a confirmed tornado is on the ground and poses a severe threat to the loss of life or property. In this case the NWS may also decide to issue a completely new warning calling it a “Tornado Emergency”. The NWS will also use wording like “mass devastation” and “unsurvivable” to further try to promote how dangerous the storm is.

After the warning goes out, it’s up to broadcast media and other emergency management agencies to further communicate the risks. For example, if there were multiple tornado warnings in effect for a viewing area, this method could help the meteorologist to better focus on one storm and not another. But then again, it will be interesting to see how the new method has an effect on the standard tornado warning. Will people take a warning less seriously when the new wording like “significant damage possible” isn’t attached? This could even further propagate the “cry wolf” phenomena associated with some warnings.

Again, this new warning method WILL NOT impact WC Ohio. It’s only being tested at five NWS offices in the plains. If they find that it has worked well over the course of the upcoming Spring and Summer it may be implemented for the rest of the country in the coming years. We’ll have to wait and see. What are your thoughts???

Kyle