Tornado Environment Browser

Due to the late posting and the slim chance of severe weather, I wanted to post quickly about a neat tool available through the Storm Prediction Center, the Tornado Environment Browser. It can be found here: Storm Prediction Center – Tornado Environment Browser

To find out tornado information in your area, click on the map in the upper left-hand corner. A higher resolution map will appear with an overlay of the tornado tracks from 1962-2011. Beneath each map are some relevant statistics about tornado days, what hours of the day the tornadoes occurred, what month, and so on.

I have provided a screen shot near my home town in Virginia. I Right away, you can see that there have been a number of tornadoes in the mid-Atlantic region. The La Plata, MD tornado stands out like a sore thumb, an F4 that cut across southern Maryland in 2002.

Interestingly enough, there is a second peak to “tornado season” each fall in this region. According to this, tornadoes are slightly more likely in September than May. In this region, tornadoes mostly occur in the evening, between 5:00 pm EDT and 9:00 pm EDT.

Compare these numbers to those in southern Mississippi. There are far more tornadoes in this region and they seem to strike equally at all times of the day. Night time tornadoes are a huge killer in the south.

Compare both of these with north central Oklahoma. The tornadoes occur in the afternoon and evening, but notice the sharp springtime peak in Oklahoma.

Another striking image is one from northern Colorado. The Rocky Mountains are clearly defined by the lack of tornadoes. This is not because of the common myth that tornadoes cannot form in the mountains. There are several other factors; the cooler drier temperatures and dewpoints in the mountains limit convection, air passing over the mountains help to generate “lee side lows” which help form the storms on the lee side of the Rockies that generate the storms, and so on.

If I had included full screen shots of each of these images, you would see statistical information about the meteorological conditions surrounding these storms. In Virginia and Mississippi, storms were forming with low values of Mid-Level Convective Available Potential Energy (MLCAPE). In Oklahoma, the MLCAPE was much higher. What this means is that storms can form at low values, but there are a lot of high value MLCAPE days in the Great Plains.

If you get a chance, play with this tool, it is tremendously powerful.


About highplainschasing

This blog is about my tales in storm chasing. My name is Seth Price and I am an instrumentation instructor at New Mexico Tech. My amateur radio call sign is N3MRA.
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