NASA sees Depression Nine become Gaston then back to a depression

Sep 02, 2010
AIRS infrared image taken Sept. 2 at 0423 UTC (12:23 a.m. EDT) showed that Tropical Depression Gaston seemed to have a compact circulation with some high, cold thunderstorm cloud tops (purple) around its center of circulation. Those clouds reached so high into the troposphere that they were colder than -63 degrees Fahrenheit. It later weakened as it encountered dry, stable air. Credit: NASA/JPL, Ed Olsen

Tropical Depression Nine strengthened yesterday into Tropical Storm Gaston, but today it ran into dry and stable air and weakened back into a depression again.

When NASA's Aqua satellite flew over Gaston early this morning, Sept. 2 at 0423 UTC (12:23 a.m. EDT), the infrared image taken from the Atmospheric Infrared Sounder (AIRS) instrument showed that Tropical Depression Gaston seemed to have a compact circulation with some high, cold thunderstorm cloud tops around its center of circulation. Those clouds reached so high into the troposphere that they were colder than -63 degrees Fahrenheit. Later this morning, Gaston encountered some stable and drier air, weakening it back to a tropical depression.

Visible and late this morning showed deep convection (rapidly rising air that forms thunderstorms that power the cyclone) had decreased considerably since the AIRS image was captured, and convection and is limited to a broken band over the western and northern part of the circulation.

At 11 a.m. EDT today, Gaston's were near 35 mph, although some re- strengthening is possible as it moves into a better environment. The center of Gaston was about 970 miles west of the southernmost Cape Verde Islands, or about 1500 miles east of the Lesser Antilles near latitude 14.0 north and longitude 38.9 west. The depression is moving toward the west-northwest near 7 mph and should continue in that direction for the next couple of days. Estimated minimum central pressure is 1008 millibars.

Even though Gaston is in an area of warm waters and upper level winds that will allow it to develop, the dry and stable air is keeping it weak, so re-strengthening is likely to be a slow process. For now, it is no threat to land.

Explore further: New USGS report: Coastal erosion threatens northern Alaska

Related Stories

Recommended for you

Creating a stopwatch for volcanic eruptions

6 hours ago

We've long known that beneath the scenic landscapes of Yellowstone National Park sleeps a supervolcano with a giant chamber of hot, partly molten rock below it.

Can lightning strike an indoor pool?

17 hours ago

Two swimming pool weather policies have surprised me in recent years. One was when I showed up to swim laps at an outdoor pool as it was beginning to drizzle. "Come on in," I was told; as long as there was no lightning, the ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.