Until the 1960s, when satellites began orbiting Earth, meteorologists only knew a hurricane was brewing due to sporadic reports from ships at sea.
But today’s weather experts use sophisticated equipment – including satellites orbiting Earth – to do a good job predicting the paths of hurricanes and tropical storms across the world’s oceans. Satellite technology has driven huge advances in scientists’ ability to predict what hurricanes are going to do.
On the other hand, experts – even those using the world’s most sophisticated technologies – can’t still precisely predict a hurricane’s intensity.
“Our worst nightmare is that a hurricane is approaching a coastal section, and everybody goes to bed thinking they’re going to get a Category 1 hurricane. Then you wake up the next morning and the hurricane has intensified rapidly overnight and now you have a Category 3 coming at you,” he said. “We do very well with storm tracks, but we still have a long way to go on intensity, especially with the rapid changes in intensity associated with hurricanes.”
How does a hurricane or tropical storm choose its path? The storm’s path is determined by the weather environment surrounding the storm, from the ocean surface to the upper atmosphere, according Dennis Feltgen, a meteorologist with the National Oceanic and Atmospheric Administration.
Feltgen said jet stream winds in the upper atmosphere also contribute to a hurricane’s forward speed. For example, the subtropical jet stream will accelerate storms to the northeast.
Speaking of a hurricane’s direction of motion, Feltgen said, “What will typically happen when these storms accelerate is that high pressure along the east coast begins weakening as a big area of low pressure begins advancing across the eastern half of the country.”
Ahead of that low pressure area, the winds are typically accelerating from the southwest to the northeast. A hurricane approaching from the east will get caught up in that flow, turning the storm to the north, and accelerating the storm out towards the northeast, he said.
Feltgen said that because a hurricane is an area of low pressure, an area of high pressure can block it. For example, hurricanes in the Atlantic Ocean are usually steered around a large area of high pressure called the Bermuda High.
Our thanks to:
Dennis Feltgen
Meteorologist
Public Affairs Specialist
NOAA-NWS
