Dolly Now a Tropical Storm, Shattered Brownsville Rainfall Records

(NASA) -- After making landfall yesterday afternoon as a Category 2 hurricane, Dolly has weakened into a tropical storm and continues dumping heavy rains inland over Texas and northeastern Mexico. Dolly Parton's song "Steady as the Rain" from her "Grass is Blue" CD is very appropriate for this storm as it broke the record in Brownsville, Texas for the wettest single day ever!

At 8:00 a.m. EDT today, Thursday, July, 24, 2008, Tropical Storm Dolly was located about 50 miles east-southeast of Laredo, Texas. Laredo is a border town on the U.S.-Mexico line, on the Rio Grande.

Dolly's center was near latitude 27.2 degrees north and longitude 98.9 west, over northeast Mexico. Rainbands are currently affecting Eagle Pass, Texas, about 124 miles to the northwest of Laredo.

To See Dolly's Rainfall as it Happens Today, July 24...

For current radar out of Laughlin Air Force Base, Texas, visit: http://radar.weather.gov/radar.php?product=NCR&rid=dfx&loop=yes

Dolly Breaks Rainfall Records for Brownsville

According to the National Weather Service in Brownsville, Texas, "Yesterday's rainfall total in Brownsville was 6.68 inches. It was the wettest single July day in Brownsville history and the 11th wettest day ever. The single day total for July 23 was more than the monthly July totals for all years back to 1878 except for two years."

Dolly is expected to produce total rainfall accumulations of 8 to 12 inches with isolated amounts of 20 inches over portions of south Texas and northeastern Mexico as she continues on her inland track. These rains are very likely to cause widespread flooding.

Dolly Moving Further Into Mexico

At 8:00 a.m. EDT, July 24, Dolly was moving toward the west-northwest near 7 mph. A continued motion toward the west-northwest is expected during the next day or so, with a slight increase in forward speed until the system dissipates on Friday, July 25 over north central Mexico.

Dolly's maximum sustained winds have decreased to near 50 mph with higher gusts. She will continue to weaken as she moves farther inland and is expected to become a tropical depression later today. Estimated minimum central pressure is 995 millibars.

What Do These NASA Satellite Images Show?

These infrared and visible images of Dolly were created by data from the Atmospheric Infrared Sounder (AIRS), an instrument that flies aboard NASA's Aqua satellite. They were created on July 23 at 19:47 UTC (3:47 p.m. EDT) after Dolly made landfall in south Texas. Dolly is clearly seen in a "perfect hurricane shape," especially in the infrared image that shows Dolly in blue and purple.

The AIRS images show the temperature of the cloud tops or the surface of the Earth in cloud-free regions. The lowest temperatures (in purple) are associated with high, cold cloud tops that make up the top of Dolly. 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.

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