NASA imagery sees a reawakening of system 98A in the Arabian Sea

Jun 08, 2011
NASA's Aqua satellite AIRS instrument captured an infrared look at System 98A's cloud temperatures and thunderstorms on June 8 at 08:47 UTC (4:47 a.m. EDT) and saw a large area of strong convection (purple). Credit: Credit: NASA/JPL, Ed Olsen

System 98A has been bringing rains, gusty winds and churning up the surf along the Arabian Seacoast of west-central India for days, and NASA satellite imagery confirms that it is getting organized now that it has moved into open waters.

NASA's Atmospheric Infrared Sounder (AIRS) instrument onboard NASA's Aqua satellite captured an image on June 8 at 08:47 UTC (4:47 a.m. EDT) of the hundreds of thunderstorms that make up the low pressure area called System 98A. The low pressure area has now moved to the west-southwest and away from Mumbai, India. In fact, today it is located about 200 miles west-southwest of Mumbai near 17.2 North and 69.8 East.

It appears that the warm waters of the Arabian Sea, and the freedom from land areas has enabled the convection (rapidly rising air that forms the thunderstorms that power a tropical cyclone) to strengthen. AIRS today shows a very large area of high, cold tops mostly on the southwestern side of the center of circulation. That area has temperatures as cold as or colder (it's a benchmark) than -63 Fahrenheit/-52 Celsius. Those cold temperatures in cloud tops mean they're very high in the troposphere and the thunderstorms have a lot of uplift. It also suggests that they're heavy rainmakers.

Despite stronger convection, infrared imagery also showed that the low level circulation center is partially exposed to outside winds. Another factor that's not enabling the low to strengthen into a tropical storm is the presence of dry air that was seen yesterday. Dry air is still present to the northwest of the low, and dry air saps moisture out of the air and suppresses thunderstorm development. That could help explain why most of the convection is in the southern side of the low.

System 98A is drifting slowly to the northwest, and according to the Joint Typhoon Warning Center, its are between 25 to 30 knots (29 to 34/46 to 55 kmh). The Joint Typhoon Warning Center gives System 98A a medium chance of strengthening into a tropical storm in the next 24 hours.

Explore further: Deciphering clues to prehistoric climate changes locked in cave deposits

Related Stories

NASA eyes low in eastern Pacific for tropical development

May 27, 2010

The Atmospheric Infrared Sounder instrument onboard NASA's Aqua satellite captured an infrared image of a low pressure area called "90E" in the Eastern Pacific that forecasters are watching for tropical development. ...

Recommended for you

Location matters in the lowland Amazon

17 hours ago

You know the old saying: Location, location, location? It turns out that it applies to the Amazon rainforest, too. New work from Carnegie's Greg Asner illustrates a hidden tapestry of chemical variation across ...

Quake rattles nerves in Napa Valley after 2014 disaster

May 22, 2015

A magnitude-4.1 earthquake has jolted Napa Valley and became an unwelcome reminder of the wine country's large temblor last summer—the strongest quake to hit Northern California in a quarter-century.

Image: Cambodian rivers from orbit

May 22, 2015

A flooded landscape in Cambodia between the Mekong River (right) and Tonlé Sap river (left) is pictured by Japan's ALOS satellite. The centre of this image is about 30 km north of the centre of the country's ...

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.