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Hurricane Season 2012: Hurricane Carlotta (Eastern Pacific Ocean)
06.18.12
 
TRMM noticed areas within Carlotta where rain was falling heavily, at 2 inches/50 mm per hour (in red).› View larger image
TRMM noticed areas within Carlotta where rain was falling heavily, at 2 inches/50 mm per hour (in red). Areas in blue and green represent light to moderate rainfall. Those heavy rains caused inland flooding and mudslides as Carlotta approached and moved inland. The numbers and white icons represent Carlotta's track and date and time (Z is for Zulu Time, same as Universal Time Coordinate).
Credit: NASA/SSAI, Hal Pierce
NASA's TRMM Satellite Saw Heavy Rainfall in Carlotta's Mexico Approach

Hurricane Carlotta dissipated over inland Mexico over the weekend. NASA's TRMM satellite captured an image of the rainfall it brought with it just before it made landfall.

NASA's Tropical Rainfall Measuring Mission (TRMM) satellite can read rainfall from space and was providing that data to forecasters at the National Hurricane Center, as it was approaching landfall this weekend. On June 15, before it made landfall, TRMM noticed areas within Carlotta where rain was falling heavily, at 2 inches/50 mm per hour. Those heavy rains, mostly in the northern quadrant of the storm, caused inland flooding and mudslides as Carlotta approached and moved inland.

On June 16, Carlotta made landfall near the Mexican beach town of Puerto Escondido, taking down trees and dropping heavy rainfall. On June 16 at 2100 UTC (5 p.m. EDT/2 p.m. PDT), Carlotta was near 17.9 North and 99.8 West, about 70 nautical miles (80.5 miles/129.6 km) north of Acapulco, Mexico. Carlotta had weakened to a depression with maximum sustained winds near 25 knots (28.7 mph/46.3 kph) and was moving to the west-northwest at 4 knots (4.6 mph/7.4 kph). The system was slowing down and brought heavy rainfall with it to inland Mexico. Two fatalities were reported in Oaxaca State.

Text Credit: Rob Gutro
NASA Goddard Space Flight Center, Greenbelt, Md.



June 15, 2012
This animation shows rainfall and cloud heights of Tropical Storm Carlotta as seen from NASA's TRMM satellite on June 13, 2012. The yellow, green and blue areas indicate light-to-moderate rainfall between 20 and 40 millimeters (.78 to 1.57 inches) per hour. The red area is considered heavy rainfall at 2 inches/50 mm per hour. The tallest convective thunderstorm towers reach above 16km (~9.9 miles). (Credit: SSAI/NASA, Hal Pierce)

This image of Carlotta from NASA's TRMM satellite shows the intensity or rainfall within the storm on June 13, 2012.› View larger image
This image of Tropical Storm Carlotta from NASA's TRMM satellite shows the intensity or rainfall within the storm on June 13, 2012. The yellow, green and blue areas indicate light-to-moderate rainfall between 20 and 40 millimeters (.78 to 1.57 inches) per hour. The red area is considered heavy rainfall at 2 inches/50 mm per hour.
Credit: NASA/SSAI, Hal Pierce
A TRMM 3-D analysis of Carlotta's vertical structure from June 13 showed several powerful storms taller  above 15km (~9.3 miles).› View larger image
A 3-D analysis of Carlotta's vertical structure using TRMM data from June 13 showed several powerful storms taller above 15km (~9.3 miles). The tallest convective thunderstorm towers, reaching above 16km (~9.9 miles), are shown in the northwestern side of the developing tropical cyclone. The yellow, green and blue areas indicate light-to-moderate rainfall between 20 and 40 millimeters (.78 to 1.57 inches) per hour. The red area is considered heavy rainfall at 2 inches/50 mm per hour.
Credit: NASA/SSAI, Hal Pierce
NASA Sees Intensifying Hurricane Carlotta Threatening Mexico

NASA's Tropical Rainfall Measuring Mission (TRMM) satellite flew over Carlotta when it was a tropical storm and found areas of heavy rain throughout and powerful high thunderstorms almost 10 miles high, hinting the storm would strengthen into a hurricane. By 8 a.m. EDT on June 15, Carlotta became the first hurricane of the eastern Pacific Ocean season.

As Carlotta neared the western coast of Mexico, warnings and watches were posted. On Friday, June 15, 2012, a hurricane warning was in effect for the Pacific Coast of Mexico from Salina Cruz to Acapulco. A hurricane watch is in effect for the Pacific Coast of Mexico east of Salina Cruz to Barra De Tonala, and west of Acapulco to Tecpan De Galeana.

A 3-D perspective image was created at NASA's Goddard Space Flight Center in Greenbelt, Md. by Hal Pierce of SSAI, who works on the TRMM mission team. Hal noted that the TRMM Precipitation Radar shows there were several powerful thunderstorms taller than 15km (~9.3 miles). The tallest convective thunderstorm towers, reaching above 16km (~9.9 miles), were seen on the northwestern side of the developing tropical cyclone. Those convective towers or "hot towers" usually indicate strengthening within 6 hours, and Carlotta did, indeed, become a hurricane.

TRMM imagery also showed that the storm was getting better organized with several areas of heavy rainfall located in forming convective rain bands.

At 11 a.m. EDT (8 a.m. PDT) Hurricane Carlotta's maximum sustained winds were near 80 mph making it officially the first hurricane of the Eastern Pacific Ocean hurricane season.

Carlotta was located about 120 miles (195 km) south-southeast of Puerto Angel and 330 miles (530 km) southeast of Acapulco, Mexico. Because tropical-storm-force winds extend out 50 miles (85 kilometer) from Carlotta's center, Puerto Angel was not yet experiencing them at 11 a.m. EDT (8 a.m. PDT), but that will change as Carlotta draws ever closer.

Carlotta's center was near latitude 14.0 north and longitude 96.0 west. Carlotta was moving to the northwest near 12 mph (19 kph) and is expected to continue in that direction over the next 24 hours before turning to the west-northwest and back to sea.

As Carlotta nears the coast, rainfall poses one of the biggest threats. Heavy rains resulting in flooding and landslides are then possible as Carlotta interacts with rugged terrain near the southwestern coast of Mexico. The National Hurricane Center has forecast accumulations of 3 to 5 inches (75 to 125 mm) with isolated maximum amounts of 12 inches (300 mm) over the Mexican states of Guerrero, Oaxaca and Chiapas. Storm surge and hurricane-force winds are also expected.

For updated forecasts over the weekend, visit the National Hurricane Center website: http://www.nhc.noaa.gov. Additional updates will also be available on NASA Hurricane's Facebook and Twitter pages.

Text Credit: Rob Gutro
NASA Goddard Space Flight Center, Greenbelt, Md.



June 14, 2012
On June 14, at 0723 UTC, AIRS showed that Tropical Storm Carlotta's low-level circulation center had consolidated› View larger image
NASA's AIRS instrument data showed on June 14, at 0723 UTC (3:23 a.m. EDT/12:23 a.m. PDT) that Tropical Storm Carlotta's low-level circulation center had consolidated and shows improved convective banding (of thunderstorms).
Credit: NASA/JPL, Ed Olsen
NASA Sees Bitter Cold Cloud Tops in Newborn Tropical Storm Carlotta

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.

Text Credit: Rob Gutro
NASA Goddard Space Flight Center, Greenbelt, Md.



June 13, 2012
TRMM 3-D shows that convective towers within System 94E were reaching heights of over 15km (~9.3 miles).› View larger image
The TRMM 3-D vertical slice though the center of System 94E 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.
Credit: NASA/SSAI, Hal Pierce
TRMM analysis shows that heavy rainfall was occurring in a line of intense convective storms within the potential tropical cyclone.› View larger image
This TRMM analysis shows that heavy rainfall (red) was occurring at a rate of 2 inches/50 mm per hour 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.
Credit: NASA/SSAI, Hal Pierce
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.

Text Credit: Hal Pierce / Rob Gutro
SSAI / NASA Goddard Space Flight Center, Greenbelt, Md.