September 8, 2010 by · Comments Off on Kxan 

Kxan, AUSTIN (KXAN) – A tornado warning in place until 19:15 for areas in southeastern Travis County. Residents in areas near Austin-Bergstrom International Airport, Del Valle and nearby towns should take precautions. This is a possible sighting, such as conditions of heavy rain prevented clear vision.

Often tornado warnings are issued during a hurricane or tropical storm. This was the case several times on Tuesday as Tropical Storm Hermine landfall in Texas. If you were to divide a hurricane / tropical storm into quarters like a cake that you consider the upper right side as the more likely it is that the tornado in it. Why?

Conditions for help:

* VERTICAL DIRECTIONAL wind shear – Significant changes in wind direction with height.
* FRICTION – A force of some kind that slows the forward motion and reduces energy.
* LA average levels of the atmosphere – is among the lower and upper levels of the troposphere. This is 6000-25000 feet above the surface, and about as high as an airplane flies.
* Troposphere – The lowest layer of the three main “areas” in our atmosphere. This is the layer over time.

First let me tell you a little about the storm itself. Tropical systems are sometimes viewed as low-pressure large “heat engine.” They need warm, moist air to live. Obviously we are in the northern hemisphere. Our low pressure systems rotate counterclockwise in one way, while in the southern hemisphere the opposite happens.

Part of the reason F1-2 weak tornadoes spin-up is due to increased wind shear in the northeast section. In the northern hemisphere, the right side of the experience of hurricane winds from the ocean to land (because the flow from the left). Wind has a smooth surface on which the water flow and the friction – hills, like, rough terrain, and sometimes even buildings – whichever is less.

As the winds on the right side of the movement of the hurricane inland, the strength of the forces of air friction to turn this inward toward low pressure, thus setting the stage for the vertical wind shear (spin) of the low levels of the troposphere. The wind in the middle levels is not turned as sharply as the wind near the surface. The increase in speed and direction of wind shear the hurricane in this section generates short-lived, small tornadoes also known as “spin-ups.”

Because they generally are small and fast training can be difficult to detect on radar, so it can appear without warning. So we must be especially alert if you are in the northeast section of the tropical storm. And this applies also to ships. Waterspouts are not at all uncommon for a tropical event.