27 June 2011
Posted in WFTV Severe Weather Center 9

Wildfires are a product of temperature, wind and moisture. High temperatures, high winds and low humidity are conditions that are of concern, especially to those in the West now. These are what can be called red flag conditions. Conditions like these contribute to intense fire behavior and rapid fire growth much like what has been seen recently with the Arizona and New Mexico wildfires.

High temperatures are what serve to induce the first spark to the fire. The ground, including plants, sticks and underbrush, absorbs radiant heat from the sun, which serves to heat and dry potential fuels. Warmer temperatures combined with low humidity or dry air allow for fuels to ignite and burn faster, adding to the rate that wildfires spread. For this reason, wildfires tend to rage in the afternoon, when temperatures are hotter. In New Mexico, the Las Conchas wildfire grew to cover over 43,000 acres in a little less than a day.

Note: This is the first in a three part article describing the recent wildfirs in the Western US and what causes wildfires in general.  Check back for the second part on how wind adds to the dangerous mix.

20 June 2011
Posted in WFTV Severe Weather Center 9

Did you know that simply listening to a cricket could tell you more about the weather than you might think?! Mother Nature offers its own built-in thermometer-the cricket.  Simply listening to the frequency of a cricket’s chirp and counting the number of chirps in 15 seconds and adding 37 will provide you with a rough estimate of the outside temperature.

The reason these crickets are such adept thermometers is because they are cold-blooded creatures. The warmer it is, the faster the crickets are able to rub their legs together. The colder it is, the slower crickets move. That means temperature is the determining factor of their movement and sound-making abilities. All you have to do is use your ears to determine the temperature relative to the cricket’s activity level.

So when you go to bed tonight, listen closely to the crickets chirp outside your window and try figuring out the temperature it is outside.

31 May 2011
Posted in WFTV Severe Weather Center 9

Planes are built to endure the most extreme weather conditions including lightening strikes.

Let us dispel the myth that if your plane gets struck by lightning it could spell disaster. This is not true. In fact, a plane getting struck by lightning is a common occurrence in aviation and has little effect on the flight. As far as anyone knows, the odds are that each airliner in the USA will be hit by lightning roughly once a year.

Because most airplanes are made of aluminum, a good natural conductor of electricity, lightening is able to flow along the airplanes outer skin and back into the atmosphere. This coupled with the fact that, all airplanes are required to have a built-in system ensuring that a spark will not ignite fuel or fuel vapor in tanks or fuel lines, makes airplanes adapt well to lightning strikes. During a 1980s lightning research project, NASA flew an F-106B jet into 1,400 thunderstorms and lightning hit it at least 700 times, without any cause for concern. Still, this led to requirements to have built-in lightning protection for electronics as an extra precaution.

Although lightning striking an airplane may seem extreme and potentially disastrous, it really is quite an uneventful phenomena in the aviation community. Planes are designed with many extra precautions to prevent lightening from ruining your travel experience. Rest assured, next time you fly through a lightning storm, just remember, you are flying high and dry through some of the safest front-row seats to one of nature’s most fearsome phenomena.

24 May 2011
Posted in WFTV Severe Weather Center 9

Have you ever wondered if it is possible to see a rainbow at night? After all, rainbows are generally made from sunlight shining through raindrops. Although seeing a rainbow at night may seem like an odd thing to contemplate, it is possible.

Night rainbows are incredibly rare and often difficult to see, but not impossible. If the moon is bright enough and the atmosphere offers the right conditions, night rainbows, also called moonbows or lunar rainbows, can occur.

Just like a normal rainbow, this phenomenon happens when light is split up into the different colors of the spectrum. When the light bounces off the back of a raindrop, it causes the colorful display of light to streak across the sky.

However, because moonlight is not nearly as bright as the sun, the moonbow appears much dimmer. Without much light for our eyes to take in, moonbows can appear muted and grayish or even ghostly white. Only a full moon, or nearly full moon can produce enough light to make a night rainbow. Even with enough light from a full moon, there still needs to be the right conditions to produce a rain-shower while still having enough breaks in the clouds to allow light through. If you ever get a chance to see one, be sure to take in the beauty the night has to offer and snap a photo.

Image courtesy of Starry Night Skies Photography