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Hurricane Season 2009: Dolores (Eastern Pacific)
07.17.09
 
July 17, 2009

QuikScat saw Dolores' winds on July 16 when her winds were over 46 mph (in purple). > View larger image
QuikScat saw Dolores' winds on July 16 when her winds were over 46 mph (in purple).
Credit: NASA JPL, Pedro Falcon III.
CloudSat shows clouds are over 8 miles high and between -40 and -76F. > View larger image
A top-down combination GOES/Aqua satellite image (top) is compared to a CloudSat image (bottom). CloudSat shows clouds are over 8 miles high and between -40 and -76F.
Credit: NASA/JPL/Colorado State Univ./NRL
Two NASA Satellites See Remnant Low Dolores Go Out Kicking

The remaining clouds and showers that were once tropical storm Dolores are fading at sea, more than 940 miles west of Cabo San Lucas, Mexico. Dolores has now weakened into a remnant low pressure area but continues to kick up 11 foot high waves at sea.

On Friday, July 17 at 6:30 a.m. EDT, Dolores' fragmented showers and thunderstorms were located near 20 degrees north latitude and 125 degrees west longitude moving northwest near 15 knots (17 mph). Sustained winds were still around 20 knots (23 mph) and its minimum central pressure had gone up to 1006 millibars.

Two NASA satellites captured a good view of Dolores before she really started falling apart. NASA's Quick Scatterometer (QuikScat) captured Dolores' fading winds and CloudSat saw what Dolores' clouds looked like from a sideways view.

QuikScat saw Dolores' winds swirling inside her clouds by using microwaves to peer into them. It flew over Dolores and captured an image at 10:01 p.m. EDT on July 15 (0201 UTC July 16). QuikScat can actually determine the speed of a tropical cyclone's rotating winds using microwave technology. QuikScat imagery is false-colored to show different wind speeds, the highest winds are always shown in purple, indicating winds over 40 knots (46 mph). Small barbs are used in the images to indicate wind direction and point to areas of heavy rain.

NASA's CloudSat satellite has the unique capability of seeing a tropical storm from its side. CloudSat's Cloud Profiling Radar captured a sideways look across Dolores on July 16. It took a 3 minute scan across the storm from 4:59-5:02 a.m. EDT (09:59-10:02 UTC) to create an image of the entire storm.

For comparison CloudSat images are combined with other satellite images that show the storm from the top down. The recent CloudSat image was compared with an image from the National Oceanic and Atmospheric Administration's Geostationary Operational Environmental Satellite (GOES-11) combined with NASA's Aqua satellite around the same time.

The colors indicate the intensity of the reflected radar energy. The top of Dolores' clouds are over 14 kilometers (8.7 miles) high.

The blue areas along the top of the clouds indicate cloud ice. The highest clouds in Dolores at the time of the image were as cold as -40 Celsius (-40 Fahrenheit) to -60C (-76 Fahrenheit). CloudSat images show the ground or sea level as a solid line along the bottom. That line disappears where there is strong rainfall exceeding 30mm/hr (1.18 inches/hour).

Dolores is expected to make her final kick over the weekend and fade into the waters of the Eastern Pacific.

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



July 16, 2009

This image is of Tropical Storm Dolores from the NOAA GOES-11 satellite > View video
This movie was created at NASA using images of Tropical Storm Dolores from the NOAA GOES-11 satellite from July 14-16, 2009. Dolores is headed on a northwesterly track further out to sea.
Credit: NASA/NOAA GOES Project
GOES-11 Satellite Captures a Movie of Tropical Storm Dolores

Dolores is holding onto tropical storm status and is heading northwest, staying safely at sea. The GOES-11 satellite captured Dolores' movement over the last couple of days and the GOES Project at NASA created a movie of her tracks.

The GOES Project at NASA's Goddard Space Flight Center in Greenbelt, Md. uses the data from the National Oceanic and Atmospheric Administration's Geostationary Operational Environmental (GOES) satellites to create images and movies. In this case, GOES-11 provided the data to make a movie of Dolores' movements from July 14 to July 16, 2009.

On July 16 at 5 a.m. EDT, Dolores continues moving toward the northwest near 18 mph with maximum sustained winds near 50 mph. The center of Dolores was about 680 miles west-southwest of the southern tip of Baja California near latitude 18.2 north and longitude 119.1 west. Dolores is expected to change her course to the west-northwest by the weekend. Her estimated minimum central pressure was 1000 millibars.

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



July 15, 2009

Tropical Depression 5E's cold clouds as it strengthened into Dolores. > View larger image
NASA's Aqua satellite captured Tropical Depression 5E's cold clouds as it strengthened into Dolores. The coldest clouds in this infrared image appear in purple.
Credit: NASA JPL, Ed Olsen
Introducing Dolores!

It didn't take long for a tropical low pressure area to bloom into tropical depression 5E then further strengthen into the eastern Pacific Ocean's latest Tropical Storm: Dolores.

Dolores was officially named at 11 a.m. EDT today, July 15 when her maximum sustained winds reached 40 mph, and she's expected to get stronger. She is located near 15.0 north and 115.6 west or about 660 miles southwest of the southern tip of Baja California. She's tracking northwesterly at 13 mph. Minimum central pressure is estimated near 1005 millibars.

The Atmospheric Infrared Sounder (AIRS) instrument on NASA's Aqua satellite captured an infrared image of Dolores when she was just Tropical Depression 5E on July 15 at 5:11 a.m. EDT, and just before she was named as a tropical storm. The image shows a rounded storm coming together.

The AIRS infrared imagery are false-colored to show the heights of thunderstorms in the storm. The coldest clouds have the lowest temperatures and are false-colored in purple. Those temperatures are as cold as or colder than 220 degrees Kelvin or minus 63 degrees Fahrenheit (F). The blue areas are around 240 degrees Kelvin, or minus 27F.

Warm ocean temperatures and low wind shear (winds that can tear a storm apart) will assist Dolores in strengthening over the next 24 hours.

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



Tropical depression #5E's showers and thunderstorms (in blue and purple). > View larger image
Tropical depression #5E's showers and thunderstorms (in blue and purple) are seen as comma shape south of Baja California in this infrared Aqua satellite AIRS image.
Credit: NASA JPL, Ed Olsen
Low Pressure Area Becomes Tropical Depression 5E

The Eastern Pacific Ocean's hurricane season is keeping active, unlike the Atlantic Ocean's which has only seen one tropical depression so far. The fifth tropical depression (TD5E) has now formed in the Eastern Pacific and it's expected to strengthen into a tropical storm at sea.

The area of low pressure that the National Hurricane Center said had more than a 50% chance of developing did become Tropical Depression 5E by Wednesday, July 15 at 5 a.m. EDT. Although TD5E is currently poorly organized, it is expected to track into an area with conditions favorable to let it intensify into a tropical storm.

The depression had sustained winds near 35 mph, and was moving northwest near 10 mph. Its center was located about 675 miles south-southwest of the southern tip of Baja California. That puts it near 14.2 north latitude and 114.6 west longitude. The minimum central pressure was 1006 millibars.

The Atmospheric Infrared Sounder (AIRS) instrument on NASA's Aqua satellite captured an infrared image of the low pressure area on July 14 at 4:59 p.m. EDT, before it strengthened into TD5E. The image shows a storm coming together and taking on the signature comma shape of a developing tropical cyclone.

The AIRS infrared images are false-colored to show the heights of thunderstorms in the storm. The coldest clouds have the lowest temperatures and are false-colored in purple. Those temperatures are as cold as or colder than 220 degrees Kelvin or minus 63 degrees Fahrenheit (F). The blue areas are around 240 degrees Kelvin, or minus 27F.

TD5E is expected to strengthen into a tropical storm and when it does it would be renamed Dolores.

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



July 14, 2009

Eastern half of the low pressure area's cold clouds (in blue and purple). > View larger image
The AIRS instrument on the Aqua satellite captured the eastern half of the low pressure area's cold clouds (in blue and purple) in the Eastern Pacific Ocean on July 14 at 4:29 a.m. EDT (08:29 UTC). The light blue area to the left of the storm was an area outside the satellite's track.
Credit: NASA JPL
Another Eastern Pacific Storm May Join Carlos

Hurricane Carlos may soon have company in the form of another named storm in the Eastern Pacific Ocean. A broad area of low pressure to the east-northeast of Carlos looks like it may get organized over the next day or two and become tropical depression 5E.

Hurricane Carlos is stirring up waters in the open Eastern Pacific Ocean about 1,465 miles southwest of the southern tip of Baja California, while showers and thunderstorms associated with another low pressure area located several hundred miles southwest of Manzanillo, Mexico may come together into a tropical storm.

At 8 a.m. EDT on July 14, the National Hurricane Center said "Conditions remain favorable for further development of this system...and a tropical depression could form in the next day or so as it moves west or west-northwestward at 10 to 15 mph." The Atmospheric Infrared Sounder (AIRS), an instrument that flies aboard NASA's Aqua satellite captured the low pressure area's high cold clouds in the Eastern Pacific Ocean on July 14 at 4:29 a.m. EDT (08:29 UTC).

Infrared imagery is useful to forecasters because it shows the temperature of the clouds. NASA false-colors clouds at different heights in the infrared satellite images, so that in AIRS imagery, the highest clouds appear purple, and the second highest clouds appear in blue. How does infrared imagery know how high clouds are in the sky? The coldest ones are higher in the sky (because in the troposphere, the lowest layer of atmosphere where weather happens, temperatures fall the higher up you go until you get to the stratosphere).

In infrared imagery, NASA's false-colored purple clouds are as cold as or colder than 220 degrees Kelvin or minus 63 degrees Fahrenheit (F). The blue colored clouds are about 240 degrees Kelvin, or minus 27F. The colder the clouds are, the higher they are, and the more powerful the thunderstorms are that make up the cyclone.

The chance for this low to become a tropical depression over the next two days is greater than 50 percent. Forecasters at the National Hurricane Center and NASA satellites are keeping their eyes on it.

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