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Hurricane Season 2009: Azores Low Pressure Area (Atlantic)
June 4, 2009

Azores Low Fades

The area of low pressure that was 425 miles north-northeast of the Azores Islands on June 3 has now dissipated, according to the National Hurricane Center. On June 4, at 8 a.m. EDT, the National Hurricane Center noted that there are currently no tropical cyclones, nor are any expected to form in the next 48 hours in the north Atlantic Ocean, Caribbean Sea or the Gulf of Mexico.

Text credit: Rob Gutro, NASA's Goddard Space Flight Center

June 3, 2009

NASA's Aqua satellite captured some of the Atlantic Low's cold clouds, shown in blue. > Larger image
NASA's Aqua satellite captured some of the Atlantic Low's cold clouds, shown in blue.
Image Credit: NASA/JPL
A Slim Chance for Another Atlantic Tropical Cyclone

If anyone was looking at satellite data or traveling in the northern Atlantic Ocean in the shipping lanes, they would see an area of low pressure about 425 miles north-northeast of the Azores Islands that the National Hurricane Center says has a low probability of becoming tropical or subtropical. Just the same, they're watching it.

On Wednesdat June 3, the non-tropical area of low pressure continues to produce gale force winds, but the National Hurricane Center (NHC), Miami, Fla. says that the showers and thunderstorms that are part of it are sparse.

So how far out at sea is this area of low pressure? Well, the Azores are a Portuguese archipelago in the Atlantic Ocean, about 950 miles from Lisbon, Portugal and about 2,400 miles from the east coast of North America!

Archipelagos are a chain of islands in the open ocean, and they're often volcanic, although there are other ways they can come into being, such as land elevation, deposition and erosion.

The NHC says that "The low is expected to remain over very cold water and gradually weaken as it begins to move eastward later today. There is a low chance...less than 30 percent...of this system becoming a tropical or subtropical cyclone during the next 48 hours."

This infrared image of the low pressure area was created by data from the Atmospheric Infrared Sounder (AIRS), an instrument that flies aboard NASA's Aqua satellite. The image was created on June 3 at 3:29 UTC (June 2 at 11:29 p.m. EDT). The low is the comma-like swirl of clouds (in the left center of the image) to the southwest of the line of clouds associated with a front (the line of blue).

The AIRS image shows the temperature of the cloud tops or the surface of the Earth in cloud-free regions. The coldest cloud temperatures are normally shown in purple, but there aren't any very high thunderstorm clouds associated with this system yet. The second coolest cloud temperatures are in blue. The AIRS data creates an accurate 3-D map of atmospheric temperature, water vapor and clouds, all of which are helpful to forecasters.

The infrared signal of the AIRS instrument does not penetrate through clouds. Where there are no clouds the AIRS instrument reads the infrared signal from the surface of the ocean waters, revealing warmer temperatures in orange and red.

Because this low is moving toward cooler waters, there's only a small chance it could make the transition to a tropical depression or subtropical depression.

Text credit: Rob Gutro, NASA's Goddard Space Flight Center