Dry air and cooler waters weakening Tropical Depression LorenzoOctober 24, 2013 by Rob Gutro in Earth / Earth Sciences
NOAA's GOES-East satellite captured a visible image of Tropical Depression Lorenzo that showed very little convection happening throughout the system because of two environmental factors: dry air and cooler sea surface temperatures.
On Oct. 24 at 1415 UTC/10:15 a.m. EDT, a visible image from NOAA's GOES-East satellite showed Lorenzo as a tropical depression with good circulation, but little thunderstorm development around it. Late in the day on Oct. 23, the entire system was devoid of any deep convection (rising air that forms the thunderstorms that make up a tropical cyclone). By the early morning hours (EDT) on Oct. 24, there was one small area of convection flaring southeast of the center.
So what's sapping the strength from Lorenzo? Two things: dry air and cooler sea surface temperatures. Dry air is sapping the moisture and preventing thunderstorms from forming to keep Lorenzo alive. Cooler sea surface temperatures mean reduced evaporation, and less building of thunderstorms.
On Oct. 24 at 0900 UTC/5 a.m. EDT Lorenzo had maximum sustained winds near 35 mpg/55 kph. It was located near 29.8 north and 47.8 west, about 1,020 miles/1,640 km east of Bermuda. It was moving to the east-northeast at 5 mph/7kph.
The National Hurricane Center forecasts Lorenzo will soon become a remnant low and dissipate sometime on Friday, Oct. 25.
Provided by NASA's Goddard Space Flight Center
"Dry air and cooler waters weakening Tropical Depression Lorenzo" October 24, 2013 http://phys.org/news/2013-10-air-cooler-weakening-tropical-depression.html