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Hurricane Season 2011: Hurricane Dora (East Pacific Ocean)
07.22.11
 
Infrared image from the GOES-13 satellite on July 22 shows Bret, Cindy, Low#1 and Hurricane Dora. › View larger labeled image
› View larger unlabeled image
In this infrared image from the GOES-13 satellite on July 22 at 0845 UTC (4:45 a.m. EDT) Bret and Cindy are in the Atlantic, Low#1 (from a tropical wave) is in the Caribbean and Hurricane Dora is in the eastern Pacific, off the coast of Mexico.
Credit: NASA/NOAA GOES Project, Dennis Chesters
NASA Catches 3 Tropical Cyclones at One Time

It's not often that a satellite can capture an image of more than one tropical cyclone, but the GOES-13 satellite managed to get 3 tropical cyclones in two ocean basins in one image today. Bret and his "sister" Cindy are racing through the North Atlantic, while another area tries to develop far to their south. "Cousin" Dora is still a hurricane in the eastern Pacific.

In infrared image taken on July 22 at 0845 UTC (4:45 a.m. EDT), GOES-13 captured Tropical Depression Bret, Tropical Storm Cindy in the north Atlantic and low pressure area associated with a tropical wave in the Caribbean and Hurricane Dora is in the eastern Pacific, off the coast of Mexico. Cindy is 910 miles west-northwest of the Azores and Bret 295 miles northwest of Bermuda.

NASA's GOES Project issued an infrared image of both Bret and Cindy today from the GOES-13 satellite, which is operated by NOAA. The NASA GOES Project is housed at NASA's Goddard Space Flight Center in Greenbelt, Md. and uses GOES-13 data from NOAA to create images and animations.

Bret Being Battered

During the morning of July 22 Bret has sped up on his track through the north Atlantic and weakened. Bret is being battered by winds and cooler waters.

Bret was a tropical depression at 8 a.m. EDT on July 22, with maximum sustained winds near 35 mph (55 kmh). He was speeding to the northeast near 21 mph (33 kmh). Bret's center was near 36.7 North and 66.5 West. Bret's minimum central pressure was near 1008 millibars.

Bret is now experiencing very strong wind shear and moving into cooler waters, two factors that will help dissipate the depression over the weekend. Those waters that Bret is moving into are cooler than 71 Fahrenheit (22 Celsius), about 9 degrees cooler than the threshold of warmth needed to keep a tropical cyclone going.

Tropical Storm Cindy Racing North

As Bret has sped up in his race across the Atlantic, so has his sister Cindy. Cindy is actually out-racing Bret, as she's moving to the northeast near 29 mph (46 kmh) in the far north Atlantic Ocean. She is expected to continue moving in this direction over the weekend. GOES-13 satellite data showed that her cloud pattern has become ragged overnight.

She was located about 805 miles northwest of the Azores near 44. 5 North and 39.9 West. Her maximum sustained winds were near 50 mph (85 kmh), so she's stronger than her "brother" Bret, who is now down to tropical depression status. Because Cindy is now in very cold water (68F/20C), weakening is forecast and like Bret, she could dissipate over the weekend well to the west of the British Isles.

A Tropical Wave Trying to Get Organized

Far to the south of both Bret and Cindy a low pressure area belonging to a tropical wave in the Caribbean is trying to get organized. As of July 22, the National Hurricane Center noted that there's only a 20 percent chance that the low will get its act together over the weekend.

The low pressure area is located about 425 miles east of the Windward Islands, near 15 N and 50 W, and is kicking up scattered showers and thunderstorms. It is moving almost as fast as Bret, and is headed west-northwest between 15 and 20 mph. During July 22 and 23, that low pressure area is expected to bring locally heavy rainfall and gusty winds to parts of the Lesser Antilles.

Hurricane Dora Weakening Hurricane Dora continues to weaken from northerly wind shear as it moves northwest into cooler waters as cool as 23 Celsius.

At 8 a.m. EDT on July 22, Dora has weakened to a category one hurricane on the Saffir-Simpson scale as it continues to parallel the western coast of Mexico and move in a northwesterly direction about 9 mph (15 kmh). Dora's maximum sustained winds are now near 90 mph (150 kmh). It is centered about 255 miles (415 km) south of Cabo San Lucas, Mexico near 19.2 North and 109.2 West. Minimum central pressure is 977 milibars.

There is a tropical storm warning in effect in Mexico from Agua Blanca to Buenavista including Cabo San Lucas. That means that tropical storm conditions exist somewhere in the warning area or will within 24 hours. Tropical Storm-force winds are likely in the warning area as Dora's center stays off the coast, and hurricane-force winds only extend out 35 miles from her center.

Southwestern Mexico and Baja California beaches and coastal areas will be hit with large and dangerous ocean swells. These swells will likely cause life-threatening surf and rip current conditions.

By Monday, July 25, Bret and Cindy may be off the books while Dora is expected to last through the weekend. As for the tropical wave in the Atlantic, GOES-13 will keep a close eye on it.

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



July 21, 2011

AIRS captured Hurricane Dora's cold cloud temperatures on July 21 at 09:05 UTC (5:05 a.m. EDT). › View larger image
The AIRS instrument on NASA's Aqua satellite captured this infrared image of Hurricane Dora's cold cloud temperatures on July 21 at 09:05 UTC (5:05 a.m. EDT). The strongest thunderstorms and convection (purple) surround the very obvious, cloud-free eye.
Credit: NASA/JPL, Ed Olsen
Animation shows the intensification of Hurricane Dora from tropical storm to major hurricane. › View GOES-11 animation
This animation of GOES-11 imagery shows the intensification of Hurricane Dora from tropical storm status on July 19 at 14:30 UTC to major hurricane status on July 21 at 14:30 UTC.
Credit: NASA/NOAA GOES Project, Dennis Chesters
NASA Satellite Video and Images Show Dora Become a Major Hurricane

A new image and video of major Hurricane Dora were released today from NASA's Goddard Space Flight Center in Greenbelt, Md.

Satellites provide a bird's eye view of a hurricane's eye, and NASA noticed Hurricane Dora's eye from several of them. Infrared imagery from NASA's Aqua satellite provided forecasters with a clear view of a cloud-free eye in hurricane Dora as she strengthens near Category 5 status today. Meanwhile the GOES-11 satellite captured a movie of Dora's intensification over the last two days that clearly shows a developing eye.

The Atmospheric Infrared Sounder (AIRS) instrument on NASA's Aqua satellite captured an infrared image of Hurricane Dora's cold cloud temperatures on July 21 at 09:05 UTC (5:05 a.m. EDT). The strongest thunderstorms and convection totally surrounded the very obvious, cloud-free eye.

The Geostationary Operational Environmental Satellite called GOES-11 provides continuous visible and infrared imagery of the western U.S. and eastern Pacific Ocean basin from its position in space. GOES-11 images were compiled into a movie that runs from July 19 at 14:30 UTC (10:30 a.m. EDT) when Dora was a tropical storm, to July 21 at 14:30 UTC (10:30 a.m. EDT) now that Dora is a major hurricane.

GOES satellites are operated by NOAA, and the NASA GOES Project located at NASA Goddard creates images and compiled them into the video of the storm. The animation includes sped up infrared and visible frames of data that were captured every 15 minutes from the GOES-11 satellite and squeezed down to 26 seconds.

At 11 a.m. EDT on July 21, 2011 Dora's maximum sustained winds were near 155 mph (250 kmh), right on the brink of Category 5 hurricane status. Fortunately, Dora's center is remaining at sea, and will continue to remain at sea as it moves to the northwest near 12 mph (19 kmh). It is expected to continue in that direction for the next couple of days and slow down.

Dora was centered near 17.1N and 106.9W, about 240 miles (390 km) south-southwest of Cabo Corrientes, Mexico. Minimum central pressure is 929 millibars.

Dora is far enough off the coast so that there are no watches and warnings over land. However, Dora is sending large ocean swells against the beaches of western Mexico today. Those large, rough, ocean swells will affect the coast over the next couple of days, and will also begin affecting the southern Baja California coast.

The National Hurricane Center expects some weakening by tonight and a rapid weakening on Friday as Dora starts battling wind shear and moves into cooler waters.

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



July 20, 2011

AIRS showed strong thunderstorms all around the center of circulation (purple) where heavy rain was falling. › View larger image
NASA's Aqua satellite passed over Tropical Storm Dora on July 19 at 20:11 UTC (4:11 p.m. EDT). NASA's AIRS infrared imagery showed strong thunderstorms all around the center of circulation (purple) where heavy rain was falling.
Credit: NASA/JPL, Ed Olsen
The TRMM satellite captured rainfall rates in hurricane Dora when it passed overhead on July 20, 2011 at 1015 UTC. › View larger image
The TRMM satellite captured rainfall rates in hurricane Dora when it passed overhead on July 20, 2011 at 1015 UTC. The heaviest rainfall (red) is on the northern and eastern sides of the storm, falling at 2 inches (50 mm) per hour. The yellow and green areas indicate moderate rainfall between .78 to 1.57 inches (20 to 40 mm) per hour.
Credit: NASA/SSAI, Hal Pierce
Frigid Cloud Top Temperatures Show Hurricane Dora's Power

Extremely cold cloud top temperatures in thunderstorms are an indication of the strength they possess, and infrared satellite data from NASA revealed a large area of very cold and powerful thunderstorms around the center of Hurricane Dora.

The Atmospheric Infrared Sounder (AIRS) instrument aboard NASA's Aqua satellite captured an infrared image (false-colored) that revealed strong convection (rapidly rising air that forms thunderstorms) and the strong thunderstorms (purple) around the center of Hurricane Dora. Those areas had cloud-top temperatures as cold as -63F/-52C. Cloud-top temperatures are important because they tell forecasters how high thunderstorms are, and the higher the thunderstorm, the colder the cloud tops and the more powerful the thunderstorms. NASA's Aqua satellite passed over Tropical Storm Dora on July 19 at 20:11 UTC (4:11 p.m. EDT).

At 8 a.m. EDT (5 a.m. PDT) Hurricane Dora was near 14.4 North and 102.3 West. That's about 235 miles (380 km) southwest of Acapulco, Mexico and 250 miles (400 Km) south of Lazaro Cardenas, Mexico. Maximum sustained winds have increased to near 90 mph (140 kmh) with higher gusts. Additional strengthening is forecast during the next 48 hours.

Dora is moving toward the west-northwest near 18 mph (30 kmh) and is expected to gradually turn to the northwest and slow down in the next two days. The National Hurricane Center noted that Dora is expected to move nearly parallel to the coast of southwestern Mexico over the next couple of days.

Dora is expected to brush the southern tip of Baja California on Friday, July 21, so a tropical storm watch is in effect from Lazaro Cardenas to Cabo Corrientes, Mexico. Winds are expected to increase in the watch area tonight, and large ocean swells will affect the coast over the next couple of days.

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







July 19, 2011

Infrared image of Tropical Storm Dora captured by AIRS on July 18, 2011 at 1929 UTC. › View larger image
This infrared image of Tropical Storm Dora was captured from the AIRS instrument on NASA's Aqua satellite on July 18, 2011 at 1929 UTC (3:29 p.m. EDT/12:29 PDT) and it revealed a large area of very cold cloud top temperatures (purple) on strong thunderstorms surrounding the center.
Credit: NASA JPL, Ed Olsen
Infrared image from GOES-11  on July 19 shows Tropical Storm Dora's clouds are reaching western coastal Mexico. › View larger image
This infrared image from the GOES-11 satellite at 1200 UTC (8:00 a.m. EDT) on July 19 shows Tropical Storm Dora's clouds are reaching western coastal Mexico.
Credit: NASA/NOAA GOES Project
Tropical Storm Dora Bringing Rough Surf to Southern Mexico

Tropical Storm Dora was just a depression yesterday. Since then, NASA satellite imagery has watched Dora continue to strengthen as thunderstorm cloud tops have grown much colder. Dora is now stirring up high seas in the eastern Pacific and beach goers in southwestern will encounter warnings because of high surf Dora is kicking up. Warnings are also posted for three western Mexican states.

Dora reached tropical storm strength at 2 p.m. EDT yesterday, July 18 and is now nearing hurricane strength. The National Hurricane Center expects Dora to strengthen into a hurricane later today.

That forecast coincides with infrared satellite imagery coming from the Atmospheric Infrared Sounder (AIRS) instrument that flies on NASA's Aqua satellite. AIRS captured an infrared image of Dora's cloud top temperatures on July 18 at 1929 UTC (3:29 p.m. EDT/12:29 PDT) and it revealed a large area of very cold cloud top temperatures on thunderstorms surrounding Dora's center.

On the morning of July 18, AIRS infrared imagery showed that the strong convection (rapidly rising air that creates the thunderstorms that power the tropical cyclone) have increased near the center of the tropical storm.

Those cloud tops were so high into the troposphere that the temperatures were as cold as -63 Fahrenheit (-52 Celsius). AIRS infrared imagery also revealed that Dora has the signature "comma" shape of a hurricane.

As a result of the power of Dora's increasing winds, large ocean swells are expected to begin affecting the southern coast of mainland Mexico today. These swells are likely to cause life-threatening surf and rip current conditions.

The Mexican Weather Service has posted weather warnings for the Mexican states of Chiapas, Oaxaca and Guerrero. Residents in those states can expect heavy rains, gusty winds, and some local flooding. According to weather reports from the National Oceanic and Atmospheric Administration, Oaxaca was already reporting rain at 9 a.m. EDT on July 19. Winds were from the east-northeast near 5 mph (4 knots) and it was 62 degrees Fahrenheit (17C). For weather advisories in Spanish from the Mexican Weather Service, go to: http://smn.cna.gob.mx/.

At 5 a.m. EDT (2 a.m. PDT), Tropical Storm Dora's winds were near 65 mph (100 kmh) and are expected to continue strengthening today. It was located about 300 miles (485 km) south of Puerto Angel, Mexico near 11.4 North and 95.9 West. It was moving to the west near 16 mph (26 kmh). Tropical storm-force winds extend out 125 miles from the center, making the storm about 250 miles in diameter.

Dora is expected to continue tracking off-shore from western Mexico and strengthen to hurricane status later today.

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



July 18, 2011

Tropical Depression 4E as taken from GOES-11 on July 18 shows the storm south of Guatemala. › View larger image
This visible image of Tropical Depression 4E was taken from the GOES-11 satellite on July 18 at 15:00 UTC (11:00 a.m. EDT/8 a.m. PDT) and shows the storm south of Guatemala.
Credit: NRL/NASA/NOAA GOES Project
GOES-11 Takes First "Baby Picture" of Fourth Eastern Pacific Tropical Depression

The fourth tropical depression of the Eastern Pacific ocean hurricane season was born today south of Guatemala in waters. Its baby picture was taken by the GOES-11 satellite, a veteran photographer of tropical cyclones.

The GOES-11 satellite monitors weather over the western U.S. took recorded the birth of Tropical Depression 4E (TD4E) today at 8 a.m. PDT (11 a.m. EDT).

TD4E was born about 265 miles southeast of San Salvador, El Salvadore, near 10.6 North and 91.5 West. It was moving to the west as 12 mph (19 kmh) and had maximum sustained winds near 35 mph (55 kmh). Minimum central pressure was 1006 millibars.

It looks like Mother Nature will soon give her newborn Tropical Depression a name as it strengthens into a tropical storm later today - as the forecasters at the National Hurricane Center noted that in the storm's "baby records." Once it matures, it will get the name Dora. In fact, Dora may grow up quickly and become a hurricane in the next day or two as conditions are right for her development and "personal growth."

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