The National Hurricane Center (NHC) uses satellites to watch for tropical storms forming over the ocean that could become hurricanes. When they see a storm forming, they watch it carefully to see how big it is and what direction it is traveling. They also use radar to basically bounce radio waves off the storm to tell how fast the wind is blowing and how much rain there is. Some of the radar monitoring is done from land, but the NHC and the Air Force also fly planes around, over, or even into the storm and drop devices that can send their own radio signals to watch the storm from the inside.

All that information can tell scientists what a storm is doing but not necessarily what it is going to do, so they use computer models to predict what the storm might do. The models use all the information about the storms and other things like the temperature of the ocean and the air pressure to try to figure out where the storm might go and how strong it could be when it gets there. Then, the people using the models warn cities that a hurricane might hit them. This advance warning allows people to get out of the way of the storm. Still, good preparation for a hurricane starts years before the storm ever arrives.

Emergency managers need to know where flooding is likely to occur in cities, so that they can focus on getting people out of those areas when a storm comes. Important things like hospitals and power plants should be located in areas where they are not likely to be damaged. Buildings have to be built strong enough to withstand a storm. Routes need to be planned out so that lots of people can leave the city quickly when a hurricane comes. Actually forecasting a hurricane comes later, but when that happens, it is important for everyone to listen so that they can stay safe.

Hurricanes and other types of weather-related hazards can be seen using weather radar. A transmitter beams microwaves out towards the sky, they bounce off of water droplets (or tiny little microscopic bits of other things in the air), and get beamed back to a machine that "reads" the radar and turns it into a picture people can see!

I've attached a video that shows the radar of Hurricane Katrina as it travels through the Gulf of Mexico. This was taken by a satellite, from space. What else is VERY cool is the different colors of the water - red is warmer, blue is cooler - so you can see how the hurricane picked up heat and grew really fast before it made landfall in New Orleans. Isn't science awesome?!

So meteorologists were able to issue a Hurricane Watch (which means that one is one the way), and then a Hurricane Warning (which means that it's here!), and could see Hurricane Katrina on the radar map. I hope this has answered your question. Hurricanes are really amazing forces of nature!

Hurricanes can be predicted by a number of compounding signs. Meteorologists (scientists who study weather) tend to have little research stations out in the middle of the ocean that send them data about the wind, wave-size, temperature, pressure, humidity, and much more at that location. Things like large waves, high winds, and low pressures can provide warning signs of the possibility of a hurricane.

Because hurricanes form over the ocean, far from land, one of the most important tools for monitoring hurricanes are satellites. Satellites provide real-time images of a storm forming and can tell people about where and when it might be making landfall. This is the critical information for preparing for the arrival of a hurricane.

New Orleans was quite poorly prepared for Katrina, actually. The way that people in New Orleans knew it was coming was because of satellites that could see it from space, and from radars in the Caribbean that could see it from the ground.

This is a good site where I found information for your question. Read here.

"How do you know when a hurricane is coming? Meteorologists track hurricanes using satellites. We take measurements around the storm that tell us what the winds are. A hurricane moves with the winds in the mid level of the atmosphere similar to the way a pine cone would float down a stream."

Scientists predict hurricane directions by modelling. That means that we track how the hurricane is moving right now, and use math to predict how it will move next. We track where it is by measuring wind speeds, and using satellite images (looking and tracking how the clouds are moving from space satellites) This is also how we forecast the weather. The hard part about predicting weather, and hurricanes is that we can see big things easily, but it is hard to predict smaller changes. This is why predictions can be wrong sometimes. For example, we might know a hurricane is coming and predict a hurricane landing tomorrow, but it actually lands a day later.