In the Hollywood blockbuster "Twister", a movie about a group of academic storm chasers who put themselves in harm's way to collect valuable scientific data, the team leader is renowned for his ability to predict where and when a tornado will touch down. It is said that he "knows what the storm is thinking".

While factual content is lacking, as we expect from Hollywood blockbusters, there is a kernal of truth in the ability to "know what a storm is thinking".

With some basic education and some field experience, you will be able to identify storm threats with nothing but your own senses.

In a situation where you may find your self with low or no technology, these skills may give you the critical time you need to prepare and may just save your life.

1. Know your Geography

Weather is largely determined by where you live. Awareness of your geography is the first and most important step in understanding what kinds of weather threats to expect, and when to expect them. These can include:

- Hurricanes along gulf and seaboard states

- Blizzards in the northern and eastern states

- Flash flooding in central states, especially along rivers

- Tornadoes in the central and southern plains

Everyone should be well versed in the weather threats for his or her own geography, and have evacuation kits or other prepared resources in advance to deal with them.

2. Time of Day, Time of Year

You don't need to become an expert on weather hazards, but a little knowledge can go a long way in survival situations.

Most thunderstorms, and consequently tornadoes, occur between 2:00 and 6:00 PM during the months of April, May, and June. You should be especially on guard during these times, whatever the threat for your geography.

If you live in Tornado Alley and see towering cumulus on a Spring afternoon, internal warning bells should be sounding.

3. Read the Wind

Fire requires three elements to burn: oxygen, fuel, and an ignition source.

And, like fire, thunderstorms require three essential elements to form: Instability in the atmosphere (cold air over warm air), humidity (the fuel), and "lift" (the ignition source) which usually comes in the form of a cold or warm front.

The key ingredient in all of this is humidity. Thunderstorms can't form without deep levels of moisture in the atmosphere. You've probably noticed that thunderstorms tend to break out on hot, humid days. This is why.

Since most of the humidity in the continental U.S. comes from the Gulf of Mexico, the discerning survivalist will know that days with a steady southerly wind are indications of thunderstorm potential within the next 12-24 hours.

4. Read the Sky

Everyone should be able to read his/her environment and make quick judgements. That includes reading the sky and cloud formations.

Many books and Internet resources exist to teach you how to identify clouds and other sky phenomena. But the general rule is this: vertically growing clouds = bad weather. The taller the cloud, the worse the weather. In the case of severe storms, you should actually be able to see the cloud growing skyward in real-time.

Worth special mention is if rotation is present in the cloud you are observing. Any type of horizontal rotation along the base of a thunderstorm, also known as 'wall cloud', is particularly hazardous because it is the precursor to tornadoes.