NASA Sees Bitter Cold Cloud Tops in Newborn Tropical Storm Carlotta
Hurricane Season 2012: Tropical Storm Carlotta (Eastern Pacific Ocean)
Bitter cold cloud tops tell forecasters that a storm has a lot of uplift, and the colder the cloud tops, the higher they are in the atmosphere, and the stronger the thunderstorms. NASA's Aqua satellite data showed that the cloud top temperatures in newborn Tropical Storm Carlotta became colder overnight and continue to grow colder as the low pressure area formely known as System 94E strengthened into a tropical storm. Carlotta is even expected to strengthen further and become a hurricane.
Because Carlotta is expected to continue strengthening, the government of Mexico has issued a hurricane warning for the Pacific coast of Mexico From Salina Cruz to Punta Maldonado. A hurricane watch is also in effect for the Pacific coast of Mexico west of Punta Maldonado to Acapulco and east of Salina Cruz to Barra De Tonala.
Forecasters look at data from the Atmospheric Infrared Sounder (AIRS) instrument that flies on NASA's Aqua satellite. When cloud temperatures get colder, it means that clouds are getting higher. The lowest temperatures in Carlotta were as cold as or colder than 220 degrees Kelvin or minus 63 degrees Fahrenheit (-52 Celsius). The data from AIRS is also used to create an accurate 3-D map of atmospheric temperature, water vapor and clouds, all of which are helpful to forecasters.
At 11 a.m. EDT (8 a.m. PDT) Tropical Storm Carlotta's maximum sustained winds were near 45 mph (75 kph), and further strengthening is expected in the warm waters along the western coast of Mexico. Carlotta is expected to become a hurricane on June 15, according to the National Hurricane Center. Currently, Carlotta is located about 385 miles (620 km) south-southeast of Puerto Angel and 590 miles (950 km) southeast of Acapulco, Mexico. Carlotta is moving northwest near 9 mph (15 kph) and is expected to continue for the next couple of days. The storm should be near the Pacific coast of Mexico on Friday and move near the coast Friday night and Saturday, according to the National Hurricane Center.
That means that hurricane conditions are expected in the warning area by Friday night, June 15 and those conditions will continue on June 16, Saturday. Storm surge, heavy rainfall, flooding and mudslides are also possible. Isolated rainfall totals can reach 10-12 inches (250-300 mm) over the Mexican states of Guerrero, Oaxaca, Chiapas and southern Guatemala.
NASA Goddard Space Flight Center
, Greenbelt, Md.
June 13, 2012
NASA's TRMM Views Forming Tropical Cyclone
System 94E and System 95E are low pressure areas located off the western coast of Mexico that are being watched by forecasters and by satellites. Each of them has the potential for development into a tropical cyclone, although System 95E has a greater chance. That low was recently spotted by NASA's TRMM satellite, which provided rainfall and cloud height data to forecasters.
The National Hurricane Center (NHC) has warned that another tropical cyclone is probably forming from System 94E, located south of Guatemala and El Salvador. The TRMM satellite flew over on June 13, 2012 at 1032 UTC (6:32 a.m. EDT).
TRMM's Microwave Imager (TMI) and Precipitation Radar (PR) data were overlaid on an enhanced infrared image from TRMM's Visible and InfraRed Scanner (VIRS) instrument to create an image of rainfall rates occurring in the low pressure area. This analysis, created at NASA's Goddard Space Flight Center in Greenbelt, Md. showed heavy rainfall was occurring in a line of intense convective storms within the potential tropical cyclone. TRMM PR found that some of these storms were returning high reflectivity values of over 51.675 dBz providing more proof of intense rainfall in that area.
TRMM PR data was also used to create a 3-D vertical image of the storm, showing a slice though the center of the highest storm towers. This cross-section shows that convective towers within this area were reaching heights of over 15km (~9.3 miles). The energy released by heavy rainfall within these towers can hasten the birth of a tropical cyclone.
At 8 a.m. EDT (5 a.m. PDT) on June 13, 2012 the National Hurricane Center noted that System 94E was about 375 miles south of the border of Guatemala and El Salvador. Satellite imagery shows that it has become more organized. System 94E continues to track to the west-northwest at 10 mph and has a 60 percent chance of becoming a tropical depression in the next two days. Meanwhile, System 95E, located west of System 94E and several hundred miles south of Acapulco, Mexico has become less organized in the last day, and has a 20 percent chance of development over the next couple of days.
Hal Pierce / Rob Gutro
SSAI / NASA Goddard Space Flight Center
, Greenbelt, Md.