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Hurricane Season 2010: Hurricane Earl (North Atlantic Ocean)
09.07.10
 
September 07, 2010

This MODIS image was captured from NASA's Terra satellite on Friday, September 3 of Hurricane Earl off the Mid-Atlantic.> View larger image
This MODIS image was captured from NASA's Terra satellite on Friday, September 3, 2010 at 12:04 p.m. EDT of Hurricane Earl off the Mid-Atlantic.
Credit: NASA/Goddard Direct Readout Lab
Aqua image from Friday, September 3, 2010 at 1: 50 p.m. EDT when Hurricane Earl was still off the Mid-Atlantic.> View larger image
This MODIS image was captured from NASA's Aqua satellite on Friday, September 3, 2010 at 1: 50 p.m. EDT when Hurricane Earl was still off the Mid-Atlantic.
Credit: NASA MODIS Rapid Response Team
MODIS image from Saturday, September 4, 2010 at 1: 15 p.m. EDT when Tropical Storm Earl was over Nova Scotia, Canada.> View larger image
This MODIS image was captured from NASA's Aqua satellite on Saturday, September 4, 2010 at 1: 15 p.m. EDT when Tropical Storm Earl was over Nova Scotia, Canada.
Credit: NASA MODIS Rapid Response Team
NASA's MODIS Instrument Gives 3 Shots of Earl's Progression in 12 Hours

This montage of images of Hurricane Earl's movement north were captured from the Moderate Resolution Imaging Spectroradiometer (MODIS) that flies aboard NASA's Terra and Aqua satellites. MODIS on Terra captured an image of Earl on Sept. 3 at 12:04 p.m. EDT when it was located east of the Virginia coast. MODIS on NASA's Aqua satellite captured an image of Earl as it was parallel to the Maryland coast at 1:50 p.m. EDT. On Saturday, Sept. 4 at 1:15 p.m. EDT, MODIS on the NASA Terra satellite captured Earl when it was a tropical storm over Nova Scotia, Canada.

On Saturday, Sept. 4, the National Hurricane Center noted that Earl was located about 20 miles west-northwest of the Magdalen Islands, near 47.5 North and 62.2 West. Earl's maximum sustained winds were near 60 knots (68 mph) and it was speeding north-northeast at 35 knots (39 mph) moving towards the Gulf of Saint Lawrence.

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





































September 03, 2010

Astronaut Douglas Wheelock noted that (Earl) looks like magnificent chaos from up there on the Space Station and called it incredibly breathtaking.> View larger image
Astronaut Douglas Wheelock aboard the International Space Station (ISS) caught this image of the eye of the storm as the ISS flew over Hurricane Earl just to the east on Sept. 3. Wheelock noted that it looks like magnificent chaos from up there on the Space Station and called it incredibly breathtaking.
Credit: NASA, Douglas Wheelock
This TRMM image of Earl's rainfall showed moderate rainfall (green) mostly to the north of Earl's center.> View larger image
This image of Earl's rainfall was captured by the TRMM satellite on Sept. 3 at 0822 UTC (4:22 a.m. EDT) and showed moderate rainfall (green) mostly to the north of Earl's center.
Credit: NASA/SSAI, Hal Pierce
NASA Satellite and International Space Station Catch Earl Weakening

NASA satellites and the International Space Station are keeping eyes on Hurricane Earl as it heads for New England. Watches and Warnings are posted in the U.S. northeast.

Having felt the effects of both increasing wind shear and cooler waters, Hurricane Earl weakened to a Category 2 storm on the Saffir-Simpson scale with winds still powerful at 90 knots (104 mph) as it neared the North Carolina coast. It was at this time that the Tropical Rainfall Measuring Mission (TRMM) satellite captured the data about TRMM's rainfall rates.

The rainfall pattern associated with Earl and was made using data from the TRMM satellite when it flew over the storm on September 3 at 08:22 UTC (4:22 a.m. EDT). Rainbands from Earl were visible over the outer banks, eastern North Carolina, and southeastern Virginia, but the storm no longer has a well-defined eye. TRMM observed moderate rainfall mostly to the north of Earl's center.

Meanwhile, from a second vantage point in space, at the International Space Station, Astronaut Douglas Wheelock caught an image of the eye of the storm on September 3. As the ISS flew over Hurricane Earl Wheelock noted that it looked like magnificent chaos from up there on the Space Station and called it incredibly breathtaking.

At 11 a.m. EDT on Sept. 3, Hurricane Earl's maximum sustained winds were near 85 mph. It was located about 350 miles south-southwest of Nantucket, Mass. near 36.8 North and 73.1 West. Earl's minimum central pressure was 961 millibars, and he was moving north-northeast at 21 mph.

Because Earl is now forecast to track farther away from the coast, many of the watches and warnings have been discontinued, but new watches and warnings are in place. The current watches and warnings in effect include: a hurricane warning is in effect for Woods Hole eastward around Cape Cod to Sagamore Beach Massachusetts, including Marthas Vineyard and Nantucket Island. In addition a Hurricane Watch is now in effect for Nova Scotia, Canada from Ecum Secum westward to Digby.

Earl is expected to weaken further as it continues northward over cooler waters along the Eastern Seaboard. Updates on Earl are available through the National Hurricane Center at www.nhc.noaa.govand through the NASA Hurricane twitter page.

Text credit: Steve Lang and Rob Gutro, NASA's Goddard Space Flight Center, Greenbelt, Md.



Image showing a huge Hurricane Earl northeast of North Carolina with cloud cover stretching over the northeastern U.S.> View larger image
This image from the GOES-13 satellite at 7:32 a.m. EDT on September 3 shows a huge Hurricane Earl northeast of North Carolina with cloud cover stretching over the northeastern U.S. A disorganized Fiona is located in the bottom right side of this image
Credit: NOAA/NASA GOES Project
GOES-13 Satellite Sees Hurricane Earl's Clouds Covering the U.S. Northeast

Hurricane Earl lashed the North Carolina coast last night and this morning, September 3, and is now headed for Cape Cod, Massachusetts. This morning's image from the GOES-13 satellite saw Hurricane Earl's clouds covering most of the northeastern U.S.

The Geostationary Operational Environmental Satellite known as GOES-13 captured an image of Hurricane Earl at 7:32 a.m. EDT this morning, September 3. The image clearly showed a huge Hurricane Earl northeast of North Carolina with cloud cover stretching over the northeastern U.S. A disorganized Fiona was also seen southeast of Earl near Bermuda. GOES satellites are operated by NOAA, and images and animations are created by the NASA GOES Project at the NASA Goddard Space Flight Center, Greenbelt, Md.

Hurricane Warnings and Watches and Tropical Storm Warnings and Watches were in effect today from North Carolina to Massachusetts. For all warnings, visit: www.nhc.noaa.gov/.

At 8 a.m. EDT today, Earl was a Category 2 hurricane on the Saffir-Simpson scale with maximum sustained winds near 105 with higher gusts. Hurricane force winds extend outward up to 70 miles from the center and tropical storm force winds extend outward up to 205 miles.

At 8 a.m. EDT Dare County (North Carolina) regional airport North Carolina reported a wind gust to 70 mph. Estimated minimum central pressure is 955 Millibars.

The National Weather Service forecast for Nags Head, North Carolina for Friday calls for "Tropical storm conditions expected, with hurricane conditions possible. Showers, mainly before 11am with a high near 87. Northwest wind 45 to 55 mph decreasing to between 25 and 30 mph. Winds could gust as high as 75 mph." Nags Head is currently under a hurricane warning.

Earl is about 130 miles east-northeast of Cape Hatteras, North Carolina and 395 miles south-southwest of Nantucket, Mass., near 36.2 North and 73.6 West. It was moving north-northeast near 18 mph and is expected to turn toward the northeast between 8 p.m. EDT tonight and 8 a.m. EDT on Saturday. Earl will approach southeastern New England tonight.

Cameras mounted on the International Space Station captured new views of Hurricane Earl late in the afternoon of Sept. 2 from an altitude of 218 statute miles as the storm churned due east of South Carolina heading north on a track that would skirt the eastern seaboard of the United States. Earl was packing winds of about 115 miles an hour at the time the video was acquired. Credit: NASA Johnson

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



September 02, 2010

Aerial view of Hurricane Earl with overlay of technical data chartFigure 1
Hurricane Earl's eye, as measured by NASA's HAMSR intrument on Sept. 2, 2010. The data reflect the brightness temperatures of the storm with cooler temperatures in shades of blue and green and warmer temperatures in oranges and reds. The pink crosses represent lightning. Image credit: NASA-JPL/Data SIC/NOAA/U.S. Navy/NGA/GEBCO/Google
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Side by side technical images of Hurricane EarlFigure 2
The early evolution of Hurricane Earl is shown in this pair of images from JPL's APR-2 instrument. The left image was taken on August 29, the right image on August 30. The August 30th image shows a more distinct and smaller eye and sharper eye wall. The colors represent the intensity of the precipitation with the most intense shown in shades of red and pink. Image credit: NASA-JPL
› Larger view
Aerial view of Hurricane EarlFigure 3
Hurricane Earl, as seen from a high-definition camera aboard NASA's Global Hawk uninhabited aerial vehicle on Sept. 2. The distortions appearing in the upper part of the images are a result of ice crystals that formed on the outside of the protective lens, not liquid water. Image credit: AMES/HDVIS imager
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NASA Hurricane Researchers Eye Earl's Eye

Hurricane Earl, currently a Category Two storm on the Saffir-Simpson scale with maximum sustained winds of 100 knots (115 miles per hour), continues to push relentlessly toward the U.S. East Coast, and NASA scientists, instruments and spacecraft are busy studying the storm from the air and space. Three NASA aircraft carrying 15 instruments are busy criss-crossing Earl as part of the agency's Genesis and Rapid Intensification Processes mission, or GRIP, which continues through Sept. 30. GRIP is designed to help improve our understanding of how hurricanes such as Earl form and intensify rapidly.

Among the instruments participating in GRIP is the High-Altitude Monolithic Microwave Integrated Circuit Sounding Radiometer, or HAMSR, developed by NASA's Jet Propulsion Laboratory, Pasadena, Calif. The instrument, which flies aboard NASA's Global Hawk uninhabited aerial vehicle, infers the 3-D distribution of temperature, water vapor and cloud liquid water in the atmosphere.

The Global Hawk left NASA's Dryden Flight Research Center, Edwards, Calif., at 9 p.m. PDT on Sept. 1, and emerged off the coast of Florida seven hours later to begin its first-ever flight over a hurricane. The plane spent the day today flying over Earl and is returning to Dryden tonight. An image of Earl as seen the morning of Sept. 2 from a high-definition camera aboard the Global Hawk is shown in Figure 3.

HAMSR has been able to make multiple passes straight across Earl's eye. Figure 1 shows brightness temperature data collected by HAMSR over a half-hour sequence of overpasses around 3 p.m. EDT on Sept. 2. The Global Hawk was flying at an altitude of about 19.2 kilometers (63,000 feet) approximately 1,125 kilometers (700 miles) off Florida's east coast. Earl's eye is visible as the blue-green circular area in the center of the image, surrounded by orange-red. The eye is colored blue-green because the instrument is seeing the ocean surface, which appears cool to the instrument. The surrounding clouds appear warm because they shield the cooler ocean surface from view. Just north of the ring of clouds is a deep blue arch, which represents a burst of convection (intense thunderstorms). The pink crosses in the image represent lightning in the area, as measured by a lightning network. Ice particles and heavy precipitation in the convective storm cell cause it to appear cold.

This image illustrates many of the capabilities of HAMSR, from measuring sea surface and atmospheric temperature to measuring convection and precipitation. For example, since there is a clear view of Earl's eye down to the ocean surface, scientists can determine the change of atmospheric temperatures at different altitudes within the eye, an indication of the strength of convection in the core of the storm. This warming is due to the condensation of water vapor that has been lofted to higher altitudes by the strong convection. This is the engine that powers the storm. That temperature data, in turn, can be used to estimate the intensity of the hurricane. NOAA's National Hurricane Center is currently using this method to determine hurricane intensity.

A second JPL instrument participating in GRIP and flying over Earl is the Airborne Precipitation Radar (APR-2), a dual-frequency weather radar that is taking 3-D images of precipitation aboard NASA's DC-8 aircraft. APR-2 is being used to help scientists understand the processes at work in hurricanes by looking at the vertical structure of the storms.

The two APR-2 images that make up Figure 2 reveal the early evolution of Hurricane Earl from a rather disorganized storm (left) to a better developed hurricane with a more distinct and smaller eye and sharper eyewall (right). The data, taken during southbound passes over Earl's eye on Aug. 29 and 30, respectively, are essentially vertical slices of the storm. They correspond to the intensity of precipitation seen by the radar along the DC-8's flight track. Intense convective precipitation (shown in shades of red and pink) was observed on both sides of the hurricane's eye. The eye is indicated by the dark region near the middle of the images. The yellow-green-colored regions indicate areas of lighter precipitation. The white lines near the bottom are the ocean surface.

The progress of NASA's GRIP aircraft can be followed in near-real-time when they are flying by visiting: http://grip.nsstc.nasa.gov/current_weather.html . "Click to start RTMM Classic" will download a KML file that displays in Google Earth.

Near-real-time images from HAMSR and APR-2 are being displayed on NASA's TC-IDEAS website at http://grip.jpl.nasa.gov . The website is a near-real-time tropical cyclone data resource developed by JPL to support the GRIP campaign. In collaboration with other institutions, it integrates data from satellites, models and direct measurements, from many sources, to help researchers quickly locate information about current and recent oceanic and atmospheric conditions. The composite images and data are updated every hour and are displayed using a Google Earth plug-in. With a few mouse clicks, users can manipulate data and overlay multiple data sets to provide insights on storms that aren't possible by looking at single data sets alone.

Text Credit:
Alan Buis 818-354-0474
Jet Propulsion Laboratory, Pasadena, Calif.
Alan.buis@jpl.nasa.gov
2010-285





The TRMM satellite observed the high rates (red) rain was falling within Earl, in some areas more than 2 inches per hour.> View larger image
The TRMM satellite observed the high rates (red) rain was falling within Earl, in some areas more than 2 inches per hour.In this image an Infrared GOES-EAST satellite image captured at close to the same time was warped to match the TRMM satellite image in order to show parts of EARL not seen by TRMM.
Credit: NASA/SSAI, Hal Pierce
Hurricane Earl as photographed by an Expedition 24 crew member on the International Space Station.> View larger image
Photographed by an Expedition 24 crew member on the International Space Station, this is an oblique view of the eye (just above center frame) of Hurricane Earl (at this time a category 4), centered just north of the Virgin Islands near 19.3 north latitude and 64.7 west longitude packing 115-kilometer winds. The photo was taken with a digital still camera using a 35mm lens.
Credit: NASA MSFC
NASA Catches Heavy Rainfall Happening in Cat 4 Earl as it Approaches the U.S.

Hurricane Earl is still a powerful category four hurricane on the Saffir-Simpson Scale as it approaches the North Carolina coast today. NASA's Tropical Rainfall Measuring Mission (TRMM) satellite observed the high rates rain was falling within Earl, in some areas more than 2 inches per hour. Today, the Global Hawk unmanned aircraft is also flying into the eye of Hurricane Earl at altitudes of 60,000 feet to gather information about the storm.

Hurricane Earl became the most powerful hurricane of the 2010 Atlantic season early on September 2 when its sustained winds reached 120 kts (~138 mph). It was still intensifying when the TRMM satellite passed near its location on 2 September 2010 at 0602 UTC (2:02 a.m. EDT). The TRMM Microwave Imager (TMI) data were used in the rainfall analysis that showed heavy rainfall, particularly in the northwest quadrant of Earl's very distinct circular eye. TRMM is managed by NASA and the Japanese Space Agency, and images are created at NASA's Goddard Space Flight Center, Greenbelt, Md.

As NASA's Genesis and Rapid Intensification experiment (GRIP) continues to investigate tropical cyclones until Sept. 30, the unmanned Global Hawk aircraft was making fly overs of Hurricane Earl today to gather data from 60,000 feet high, into the lower levels of the stratosphere. This data will help scientists learn about the rapid intensification of Earl, who went from a Category 2 to a Category 4 hurricane earlier this week.

In addition to the GRIP Mission, astronauts aboard the International Space Station are also capturing Hurricane Earl on video and in photographs. These images complement the Global Hawk's view closer to Earth. In addition, NASA satellites, such as the Aqua satellite are capturing views of Earl . The Moderate Resolution Imaging Spectroradiometer (MODIS) instrument has been providing high-resolution views of Earl's clouds since it was born. To see an image from Sept. 1 at 18:01 UTC (2:01 p.m. EDT) of Hurricane Earl as it was moving through the Bahamas, go to: http://rapidfire.sci.gsfc.nasa.gov/gallery/?2010244-0901/Earl.A2010244.1801/.

Today, September 2, Hurricane warnings extend from North Carolina north to Massachusetts, including Cape Cod and the islands, with tropical storm warnings that include Virginia, eastern Maryland, New Jersey, New York, Connecticut and Rhode Island. Hurricane Earl's eye is expected to stay off-shore and eastern North Carolina and eastern Massachusetts have the strongest warnings.

At 11 a.m. EDT on September 2, Hurricane Earl had maximum sustained winds near 140 mph. It was 300 miles south of Cape Hatteras, NC, and 765 miles south-southwest of Nantucket, Mass. near 30.9N and 74.8W. It is moving north at 18 mph and has a minimum central pressure of 932 millibars.

For complete watches and warnings, and forecast track, go to the National Hurricane Center's webpage: www.nhc.noaa.gov.

NASA satellite imagery indicates this is a large storm, with hurricane force winds extend outward up to 90 miles from the center and tropical storm force winds extend outward up to 230 miles.

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



NASA's Global Hawk in the Eye of Hurricane Earl on September 2

This photo of Hurricane Earl's eye was taken from the HDVis camera during the morning of Thursday, Sept. 2.
This photo of Hurricane Earl's eye was taken from the HDVis camera on the underside of the Global Hawk aircraft during the morning of Thursday, Sept. 2 at 13:05 UTC (9:05 a.m. EDT). The Global Hawk captured this photo from an altitude of 60,000 ft. (about 11.4 miles). The Global Hawk is one of three aircraft involved in the Genesis and Rapid Intensification Processes (GRIP) experiment. GRIP a NASA Earth science field experiment from August 15-September 30, 2010 to better understand how tropical storms form and develop into major hurricanes. Credit: NASA/NOAA
> View larger image



September 01, 2010

Temperature scale of Hurricane Earl from satellites instrument› Larger view
Figure 1 - AIRS infrared image of Hurricane Earl on Sept. 1, 2010, shows the temperature of Earl's cloud tops or the surface of Earth in cloud-free regions. The coldest cloud-top temperatures appear in purple, indicating towering cold clouds and heavy precipitation.
Credit: NASA/JPL-Caltech
AIRS visible image of Hurricane Earl› Larger view
Figure 2 - AIRS visible-light image of Hurricane Earl on Sept. 1, 2010.
Credit: NASA/JPL-Caltech
NASA Images Dissect Hurricane Earl

With the peak of the 2010 Atlantic hurricane season still 10 days away, the relative calm of the first half of the season has quickly evaporated. As of Sept. 1, there were three named tropical cyclones in the Atlantic-Hurricane Earl and Tropical Storms Fiona and Gaston.

NASA satellites, instruments and researchers are hard at work, providing the National Oceanic and Atmospheric Administration and other agencies with many kinds of data used to help forecast and track these monster storms.

The NASA imagery presented here depicts Hurricane Earl, currently a Category Four hurricane on the Saffir-Simpson scale with maximum sustained winds of 115 knots (near 135 miles per hour), with higher gusts. As of 5 p.m. EDT on Sept. 1, Earl was located about 1,010 kilometers (630 miles) south-southeast of Cape Hatteras, N.C., moving to the northwest at 28 kilometers per hour (17 mph). Hurricane and tropical storm warnings and watches currently extend up the U.S. East Coast from North Carolina to Massachusetts. Hurricane force winds extend outward up to 150 kilometers (90 miles) from Earl's center, with tropical storm-force winds extending outward up to 325 kilometers (200 miles).

Earl is expected to continue to move northwest, and then make a gradual turn to the north on Thursday, Sept. 2. The core of Earl is expected to approach the North Carolina coast by late Thursday with hurricane-force winds. Tropical-storm-force winds are likely to reach the East Coast from Virginia northward to New Jersey by early Friday, Sept. 3. Earl is expected to fluctuate in intensity through Thursday, then gradually weaken.

Earl's storm surge will raise water levels by 1 to 1.5 meters (3 to 5 feet) above ground level within the hurricane watch level. Elsewhere, the storm surge will raise water levels by as much as 0.3 to 1 meter (1 to 3 feet) above ground level within the tropical storm warning area. The storm surge will be accompanied by large and destructive waves.

Rainfall accumulations of 5 to 10 centimeters (2 to 4 inches), with isolated amounts up to 15 centimeters (6 inches) are expected over parts of eastern North Carolina. Large surf swells will continue to affect the Bahamas and U.S. East Coast through Friday, bringing dangerous surf conditions and rip currents.

NASA imagery of Earl from various satellites and aircraft reveal many kinds of information about this impressive storm.

In Figure 1, the Atmospheric Infrared Sounder (AIRS) instrument on NASA's Aqua satellite, built and managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., captured this infrared image of Earl on Sept. 1 at 1:53 p.m. EDT. The AIRS data create an accurate 3-D map of atmospheric temperature, water vapor and clouds, data that are useful to hurricane forecasters. The image shows the temperature of Earl's cloud tops or the surface of Earth in cloud-free regions. The coldest cloud-top temperatures appear in purple, indicating towering cold clouds and heavy precipitation. The infrared signal of AIRS does not penetrate through clouds. Where there are no clouds, AIRS reads the infrared signal from the surface of the ocean waters, revealing warmer temperatures in orange and red.

The view of the storm for AIRS' visible-light camera is seen in Figure 2.

Figure 3 is an animation created from data from NASA's CloudSat spacecraft, which flew over Hurricane Earl on Aug. 31, 2010, at 2:20 a.m. EDT, when the storm had maximum wind speeds of 115 kilometers (approximately 135 mph). At that time, there were three named storms in the Atlantic: Danielle, Earl and Fiona.

The animation begins by depicting global cloud motion for the 72 hours prior to CloudSat's observation of Earl, from NOAA's GOES satellites. It then zooms in to reveal the vertical cross-section of Earl from CloudSat. CloudSat intersected Earl's eastern edge as the hurricane was just beginning an eyewall replacement cycle, during which the outer eyewall band strengthened, while the inner eyewall began to shrink. CloudSat captured Earl's intense cumulonimbus clouds and eye, along with cloud-free regions known as "moats" that contain a thick cirrus cloud canopy between the storm's spiral rain bands. The storm's most intense convection and precipitation are depicted in shades of oranges and reds.

Figure 3 - Animation depicts a vertical cross-section of Hurricane Earl as seen by NASA's CloudSat satellite on Aug. 31, 2010. CloudSat captured Earl's intense cumulonimbus clouds and eye, along with cloud-free regions. The storm's most intense convection and precipitation are shown in shades of orange and red. Credit: NASA/JPL/The Cooperative Institute for Research in the Atmosphere (CIRA), Colorado State University/NOAA


Image of Hurricane Earl from MISR instrument on NASA's Terra satellite› Larger view
Figure 4 - MISR image of Hurricane Earl captured on Aug. 30, 2010. The left panel of the image extends about 1,110 kilometers (690 miles) in the north-south direction and 380 kilometers (236 miles) in the east-west direction. Earl's wind speeds are shown in the right panel. The lengths of the arrows indicate the wind speeds, and their orientation shows wind direction. The altitude of a given wind vector is shown in color.
Credit: NASA/GSFC/LaRC/JPL, MISR Team
Wind speed of Hurricane Earl from Jason-1 and Jason-2 satellites› Larger view
Figure 5 - Hurricane Earl's wind speeds, as measured by a three-day composite of data from NASA's Jason-1 and Ocean Surface Topography Mission (OSTM)/Jason-2 satellites, from Aug. 29 to Sept. 1, 2010.
Credit: NASA/JPL Ocean Surface Topography Team
Wave height of Hurricane Earl from Jason-1 and Jason-2 satellites› Larger view
Figure 6 - Hurricane Earl's wave heights, as measured by a three-day composite of data from NASA's Jason-1 and Ocean Surface Topography Mission (OSTM)/Jason-2 satellites, from Aug. 29 to Sept. 1, 2010.
Credit: NASA/JPL Ocean Surface Topography Team
Figure 4 is from the Multi-angle Imaging SpectroRadiometer (MISR) instrument on NASA's Terra spacecraft, captured at 11 a.m. EDT on Aug. 30, 2010, when Earl was a Category 3 storm on the Saffir-Simpson scale. The image (left panel) extends approximately 1,110 kilometers (690 miles) in the north-south direction and 380 kilometers (236 miles) in the east-west direction. The hurricane's eye is just visible on the right edge of the MISR image swath.

Winds at various altitudes were obtained by processing the data from five of MISR's nine cameras to produce the display shown on the right. The lengths of the arrows indicate the wind speeds, and their orientation shows wind direction. The altitude of a given wind vector is shown in color. Low clouds, less than 4 kilometers (2.5 miles) in altitude (shown in purple), follow the cyclonic (counter-clockwise) flow of air into the hurricane. This warm, moist air is the power source for the hurricane. Mid- and high-level clouds (green and yellow-orange, respectively) move in an anti-cyclonic (clockwise) direction as they flow out from the top of the storm. The very highest clouds, with altitudes around 17 kilometers (10.6 miles), are flowing directly away from the eye of the hurricane.

Figure 5 and Figure 6 were generated with data from NASA's Jason-1 and Ocean Surface Topography Mission (OSTM)/Jason-2 satellites. They depict Earl's wind speeds (top) and wave heights (bottom), respectively. The images were created by compositing three days of data from the two satellites' radar altimeters from Aug. 29 to Sept. 1.

NASA and JPL scientists are currently engaged in the agency's first major U.S.-based hurricane field campaign in nearly a decade. The Genesis and Rapid Intensification Processes mission, or GRIP, is studying hurricanes in the Atlantic and Gulf of Mexico. Three NASA aircraft carrying 15 instruments are being used, including the JPL-developed High-Altitude Monolithic Microwave Integrated Circuit Sounding Radiometer (HAMSR), which is flying aboard NASA's Global Hawk uninhabited aerial vehicle. The instrument infers the 3-D distribution of temperature, water vapor and cloud liquid water in the atmosphere. A second JPL instrument, the Airborne Precipitation Radar (APR-2), is a dual-frequency weather radar that is taking 3-D images of precipitation aboard NASA's DC-8 aircraft. Three NASA satellites are also playing a key role in supplying data about tropical cyclones during the mission, including the JPL- developed and managed CloudSat spacecraft and the Aqua spacecraft, which includes JPL's Atmospheric Infrared Sounder.

The DC-8, with JPL's APR-2 instrument, has already flown over Earl twice, with additional sorties planned for Sept. 1 and 2. NASA's Global Hawk is currently en route to Earl and is expected to fly over Earl for 10 to 12 hours on Sept. 2. The progress of NASA's GRIP aircraft can be followed in near-real-time when they are flying by visiting: http://grip.nsstc.nasa.gov/current_weather.html . "Click to start RTMM Classic" will download a KML file that displays in Google Earth.

Near-real-time images from HAMSR and APR-2 will be displayed on NASA's TC-IDEAS website, available at http://grip.jpl.nasa.gov . The website is a near-real-time tropical cyclone data resource developed by JPL to support the GRIP campaign. In collaboration with other institutions, it integrates data from satellites, models and direct measurements, from many sources, to help researchers quickly locate information about current and recent oceanic and atmospheric conditions. The composite images and data are updated every hour and are displayed using a Google Earth plug-in.

With a few mouse clicks, users can manipulate data and overlay multiple data sets to provide insights on storms that aren't possible by looking at single data sets alone. The data can be animated and downloaded on demand. TC-IDEAS is a component of JPL's Tropical Cyclone Information System (TCIS) website, located at: http://tropicalcyclone.jpl.nasa.gov/hurricane/ . Researchers can use the TCIS to better understand hurricane processes, improve hurricane models and plan future satellite missions.

#2010-282
Alan Buis 818-354-0474
Jet Propulsion Laboratory, Pasadena, Calif.
Alan.buis@jpl.nasa.gov



September 01, 2010

AIRS shows Hurricane Earl with high, powerful thunderstorms circling the center (purple).> View larger image
This infrared image from NASA's AIRS instrument onboard the Aqua satellite shows Hurricane Earl on Sept. 1 at 06:53 UTC (2:53 a.m. EDT). It shows high, powerful thunderstorms circle the center (purple) providing the heat engine for the hurricane. Note that Earl's eye is not visible in this image.
Credit: NASA/JPL, Ed Olsen
TRMM satellite captured very heavy rainfall (red) of over 50 mm/hr (2 inches) in Earl on Aug. 31.> View larger image
NASA's TRMM satellite captured very heavy rainfall (red) of over 50 mm/hr (2 inches) in Earl on Aug. 31 that clearly defined the location of Earl's eye wall.
Credit: NASA/SSAI, Hal Pierce
Hurricane Warnings Posted on U.S. East Coast, NASA Sees Earl's Heavy Rainfall

NASA's Tropical Rainfall Measuring Mission, or TRMM satellite looked at the rate rain was falling in Hurricane Earl yesterday, and it was intense.

The TRMM satellite passed close to Hurricane Earl's position early on August 31 at 0439 UTC (12:39 a.m. EDT) collecting data used in the TRMM Microwave Imager (TMI) rainfall analysis. At that time, TRMM observed a band of rain drenching Puerto Rico as it spiraled into the powerful hurricane. At the time Earl had become a powerful category four hurricane with wind speeds of about 115 knots (~132 mph). Very heavy rainfall of over 50 mm/hr (2 inches) clearly defined the location of Earl's eye wall. TRMM is managed by NASA and the Japanese Space Agency.

Another NASA satellite analyzed Hurricane Earl's cloud temperatures and thunderstorms. High, cold thunderstorm cloud tops indicate powerful storms. NASA's Atmospheric Infrared Sounder (AIRS) instrument flies aboard the Aqua satellite and captured an infrared image of Hurricane Earl today, Sept. 1 at 06:53 UTC (2:53 a.m. EDT). It showed high, powerful thunderstorms circle the center providing the heat engine for the hurricane. Earl's eye was not visible in the image, possibly because it was going through eyewall replacement, which usually occurs in major hurricanes.

On September 1 at 1500 UTC (11 a.m. EDT), Earl was a Category 3 hurricane with maximum sustained winds near 125 mph. Earl's center was located about 725 miles south-southeast of Cape Hatteras, N.C. near 25.1 North and 72.1 West. It is moving to the northwest near 17 mph, and had a minimum central pressure of 943 millibars.

Earl is a large storm, with tropical storm-force winds extending out from the center to 200 miles, and hurricane-force-winds extending out 90 miles from the center. The extent of hurricane-force winds has increased since yesterday.

A Hurricane warning is in effect from Bogue Inlet,N.C. to the N.C./V.A. border, including Pamlico and Albemarle Sounds. That means that hurricane conditions expected within 36 hours. A Hurricane watch has been posted from the North Carolina/Virginia border to Cape Henlopen, Delaware. That means Hurricane conditions expected within 48 hours. Tropical storm warning is in effect from Cape Fear, N.C. to west of Bogue Inlet, N.C. and San Salvador Island, Central Bahamas. That means Tropical storm conditions expected within 36 hours.

The eye of Hurricane Earl in the Atlantic Ocean is captured by a videographer aboard NASA’s DC-8 research aircraft on Monday, Aug. 30, 2010. The DC-8 passed through the eye of the storm six times just as Earl was intensifying from a Category 2 to a Category 4 hurricane. The flights are part of the Genesis and Rapid Intensification Processes (GRIP) mission.
Credit: National Suborbital Education and Research Center (NSERC)

What can be expected? A storm surge of 3 to 5 feet above normal tidal levels expected in the warning area, with large and destructive waves. Large swells should affect the Bahamas and southeastern U.S. today. In terms of rainfall, the Bahamas and extreme eastern North Carolina, including Outer Banks, can expect 1 to 2 inches, locally up to 4 inches of rain.

Earl is expected to maintain intensity for the next few days, as it moves northwest, then north.

Residents from New Jersey to New England should monitor Earl's progress. For updated information, visit: http://www.nhc.noaa.gov/, or your local National Weather Service forecast webpage.

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



ISS024-E-012815 -- Hurricane Earl
ISS024-E-012815 (30 Aug. 2010) --– Photographed by an Expedition 24 crew member on the International Space Station, this is an oblique view that shows the eye (just left of center) of Hurricane Earl (at this time a category 4 but later downgraded to a category 3), centered just north of the Virgin Islands near 19.3 north latitude and 64.7 west longitude packing 115-kilometer winds. A Russian Soyuz vehicle is docked to the station (foreground). The photo was taken with a digital still camera using a 55mm lens.

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ISS024-E-012947 -- Hurricane Earl› View high resolution
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ISS024-E-012947 (30 Aug. 2010) --– Photographed by an Expedition 24 crew member on the International Space Station, this is an oblique view of the eye (center) of Hurricane Earl (at this time a category 4 but later downgraded to a category 3), centered just north of the Virgin Islands near 19.3 north latitude and 64.7 west longitude packing 115-kilometer winds. The photo was taken with a digital still camera using a 50mm lens.



ISS024-E-012920 -- Hurricane Earl› View high resolution
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ISS024-E-012920 (30 Aug. 2010) --- Photographed by an Expedition 24 crew member on the International Space Station, this is an oblique view of the eye (just above center frame) of Hurricane Earl (at this time a category 4 but later downgraded to a category 3), centered just north of the Virgin Islands near 19.3 north latitude and 64.7 west longitude packing 115-kilometer winds. The photo was taken with a digital still camera using a 35mm lens.



ISS024-E-012894 -- Hurricane Earl› View high resolution
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ISS024-E-012894 (30 Aug. 2010) --– Photographed by an Expedition 24 crew member on the International Space Station, this is an oblique view that shows the eye (just above center) of Hurricane Earl (at this time a category 4 but later downgraded to a category 3), centered just north of the Virgin Islands near 19.3 north latitude and 64.7 west longitude packing 115-kilometer winds. A Russian Soyuz vehicle is docked to the station (foreground). The photo was taken with a digital still camera using a 22mm lens.



August 31, 2010

In this image are Hurricane Earl (lower left), Tropical Storm Fiona located to Earl's east, and Tropical Storm Danielle far in the Northern Atlantic.> View larger image
The GOES-13 satellite captured an image of the busy Atlantic Ocean at 1145 UTC (7:45 a.m. EDT) on August 31. In the visible image, was the large and powerful Hurricane Earl (lower left) passing Puerto Rico, Tropical Storm Fiona located to Earl's east, and Tropical Storm Danielle far in the Northern Atlantic.
Credit: NASA/GOES Project
This infrared image from NASA's AIRS instrument on Aug. 30 at 2010 UTC shows the powerful thunderstorms and high, cold clouds in Earl.> View larger image
This infrared image from NASA's AIRS instrument on Aug. 30 at 2010 UTC shows the powerful thunderstorms and high, cold clouds in Earl. The highest clouds are in purple. Note one band of blue around the center, suggesting eyewall replacement occurring in Earl.
Credit: NASA/JPL, Ed Olsen
GOES-13 Catches 3 Tropical Cyclones Thrashing Through the Atlantic

Powerful Hurricane Earl, growing Tropical Storm Fiona and fading Danielle were all captured in today's visible image from the GOES-13 satellite. The Geostationary Operational Environmental Satellite called GOES-13 captured an image of the busy Atlantic Ocean at 1145 UTC (7:45 a.m. EDT) on August 31. In the visible image, was the large and powerful Hurricane Earl passing Puerto Rico, Tropical Storm Fiona located to Earl's east, and Danielle far in the Northern Atlantic. Hurricane Earl's eye appear to be covered with high-clouds in the GOES-13 image, while Fiona appeared somewhat disorganized with no apparent center. Farther north in the North Atlantic Ocean, Danielle appeared more "U" shaped on the satellite imagery, although her maximum sustained winds were still near 70 mph at that time.

GOES satellites are operated by NOAA, and the NASA GOES Project at NASA's Goddard Space Flight Center in Greenbelt, Md. provides images and animations of satellite data.


DANIELLE NOW A LOW IN THE NORTHERN ATLANTIC

Danielle has already transitioned into a cold-core low pressure area in the Northern Atlantic Ocean today. Tropical cyclones are warm-core systems, so when the core temperatures change, the dynamics of the system also changes. The final warning for Danielle was issued today (August 31) at 0300 UTC (Aug. 30 at 11 p.m. EDT). At that time, Danielle was about 475 miles southeast of Cape Race, Newfoundland, Canada near 41.3 North and 47.1 West and headed east-northeast at 15 mph. Her sustained winds were near 70 mph, but waning.

Danielle's effects are being felt along the shores of Newfoundland with heavy surf and waves up to 3 meters (10 feet).


EARL STILL A POWERFUL HURRICANE THREATENING THE U.S.

Hurricane Earl is a storm that's about 400 miles in diameter and the hurricane force winds are about 140 miles in diameter from side-to-side of the storm's eye. Earl is still a Category Four hurricane on the Saffir-Simpson scale, one category stronger that Hurricane Katrina was when she made landfall in Mississippi in 2005.

At 11 a.m. EDT on August 31, Hurricane Earl was located about 205 miles east of Grand Turk Island. That's about 1070 miles south-southeast of Cape Hatteras, North Carolina. Earl's center was located at 21.2 North and 67.9 West. Earl's maximum sustained winds were near 135 mph and he is moving west-northwest near 14 mph. Minimum central pressure is 939 millibars.

Earl's eye has become obscured in the latest imagery from the GOES-13 satellite, and the central pressure has increased. Forecasters believe that it's because Earl is undergoing "eyewall replacement." What that means is a new eye begins to develop around the old eye. The new eye gradually decreases in diameter and finally replaces the old eye.

Currently there is a warning and a watch in effect. A tropical storm warning is in effect for Turks and Caicos Islands and a tropical storm watch is in effect for the southeastern Bahamas. Meanwhile, residents from the Carolinas northward to New England should monitor the progress of Earl. A hurricane watch could be required for portions of the mid-Atlantic coast later today.


FIONA CAUSES WARNINGS AND WATCHES IN THE ISLANDS

Tropical Storm Fiona is battering the same areas that Hurricane Earl swept through days ago. A tropical storm warning is in effect for St. Martin and St. Barthelemy. A tropical storm watch is in effect for, Antigua, Barbuda, Montserrat, St. Kitts, Nevis, and Anguilla and St. Maarten, Saba, and St. Eustatius. The National Hurricane Center noted in its forecast this morning, August 31, Tropical storm conditions could spread over portions of the Northern Leeward Islands tonight or early Wednesday.

At 11 a.m. EDT, Tropical Storm Fiona had maximum sustained winds near 40 mph and some strengthening is possible. It was located about 440 miles east of the Leeward Islands near 15.9 N and 55.3 W. Fiona is moving west-northwest near 24 mph and is expected to slow down.

Estimated minimum central pressure is 1006 millibars. Fiona's forecast track does not take her behind Earl, so she does not appear to be a threat to the U.S. mainland at this time.

Earl and Fiona are two storms keeping NASA satellites busy this week, and providing the scientists on NASA's Hurricane Genesis and Rapid Intensification Processes (GRIP) experiment with a lot of data. To see what's happening with GRIP, visit: www.nasa.gov/grip/.

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



August 30, 2010

MODIS captured this visible image of hurricanes Danielle (top) and Earl (bottom)  in the Atlantic Ocean.> View larger image
At 14:20 UTC (10:20 a.m. EDT on August 29, 2010 the MODIS instrument on NASA's Terra satellite captured this visible image of hurricanes Danielle (top) and Earl (bottom) in the Atlantic Ocean.
Credit: NASA/MODIS Rapid Response Team
A very large area of powerful convection and strong, high thunderstorms that took up most of Hurricane Earl's center.> View larger image
NASA's AIRS instrument captured this infrared image on August 30 at 0535 UTC (1:35 a.m. EDT) that shows a very large area of powerful convection and strong, high thunderstorms (as cold as -63 Fahrenheit) that took up most of Hurricane Earl's center as it was moving through the Northern Leeward Islands and headed to Puerto Rico. Earl became a major hurricane later that morning.
Credit: NASA/JPL, Ed Olsen
This image from August 30 at 0523 UTC (1:23 a.m. EDT) shows cold areas (yellow-green) that indicate cold, high thunderstorms.> View larger image
Microwave images are created when data from NASA's Aqua satellite AIRS and AMSU instruments are combined. This image from August 30 at 0523 UTC (1:23 a.m. EDT) shows cold areas (yellow-green) that indicate where there is precipitation or ice in the cloud tops. The microwave image suggests cold, high thunderstorms.
Credit: NASA/JPL, Ed Olsen
Danielle and Earl Dueling in the Atlantic: Earl Threat to U.S. East Coast

Danielle and Earl are both spinning around in the Atlantic Ocean and NASA's Terra satellite captured one image of both storms at the same time, one in the Caribbean and the other approaching the North Atlantic Ocean. Both are expected to impact land.

Danielle is transitioning to an extra-tropical storm in the northern Atlantic and may impact southern Greenland. Before Earl reached hurricane status NASA's GRIP Hurricane Mission researchers flew out to analyze the storm. Earl is now threatening the U.S. east coast and earlier today, August 30, he became a major hurricane.

The Moderate Resolution Imaging Spectroradiometer (MODIS) instrument that flies aboard NASA's Terra satellite captured a stunning image of the large Hurricane Danielle and the smaller, less organized Hurricane Earl, far to Danielle's south. In the image, Danielle's eye can be seen, despite some high clouds filling in most of it. An eye is not visible in Earl, however. The image shows the western edge of Earl affecting the Leeward Islands when this image was captured on August 29 at 10:20 a.m. EDT.

Danielle started causing problems for U.S. east coast residents this weekend with large waves and dangerous surf conditions. News reports indicated that more than 100 people were rescued from dangerous currents in beaches from Maryland to New Jersey over the weekend. Large waves and dangerous surf conditions are diminishing around Bermuda today, and will gradually subside along the U.S. east coast over the next couple of days. Waves near 10 feet however are expected to develop this afternoon along parts of Newfoundland, Canada as Danielle tracks northward.

At 11 a.m. EDT on August 30, Danielle's maximum sustained winds were near 75 mph, and it is expected to weaken in the next 48 hours and become extratropical. The center of Hurricane Danielle was located near latitude 40.9 north and longitude 50.7 west. Danielle is moving toward the northeast near 16 mph and is expected to speed up in this direction. The National Hurricane Center noted that Danielle will still remain a large and powerful cyclone over the far north Atlantic for the next two days. Tropical Storm force winds extend out from Danielle's center up to 310 miles, making this monster storm up to 620 miles in diameter!

As Danielle continues north and heads toward Greenland, Hurricane Earl has the residents of the U.S. East coast on watch. Earl reached hurricane strength as it approached the northern Leeward Islands on August 29 and NASA researchers were there collecting data.

NASA's Genesis and Rapid Intensification Processes (GRIP) experiment is a NASA Earth science field mission that's happening now out of Fort Lauderdale, Florida using three aircraft, 15 instruments and NASA satellites to better understand how tropical storms form and develop into major hurricanes.

NASA's DC-8 aircraft left Fort Lauderdale at 10:05 a.m. EDT on Saturday heading for St. Croix for a multi-day deployment that targeted (at that time) Tropical Storm Earl. Science missions to Earl were planned for Sunday and Monday in close support of operations being flown by NOAA aircraft. On Sunday, August 29, the DC-8 completed an 8.5-hour science flight over (then) Hurricane Earl west of St. Croix. The research aircraft flew at altitudes of 33,000 feet and 37,000 feet and descended to 7,000 feet northwest of the storm area to collect measurements of atmospheric aerosols. The flight originated in St. Croix but diverted to land in Fort Lauderdale, Fla., due to the degrading weather forecast for St. Croix associated with the approaching hurricane.

Early on August 30 at 0535 UTC (1:35 a.m. EDT), NASA's Atmospheric Infrared Sounder (AIRS) that flies on the Aqua satellite captured an infrared image that showed a very large area of powerful convection and strong, high thunderstorms (as cold as -63 Fahrenheit) that take up most of Hurricane Earl's center as it was moving through the Northern Leeward Islands and headed to Puerto Rico.

Later in the morning after NASA's Aqua satellite passed over Earl, it became a major hurricane (Category 3) with maximum sustained winds near 120 mph. Hurricane Earl was already impacting many islands and hurricane warnings are in effect. Earl's center was about 95 miles east-northeast of St. Thomas and 165 miles east of San Juan, Puerto Rico near 18.7 North and 63.6 West. It was moving west-northwest near 15 mph, and had a minimum central pressure of 960 millibars.

A hurricane warning is in effect for Anguilla, Saint Martin and Saint Barthelemy, St. Maarten, Saba, and St. Eustatius, the British Virgin Islands, the U.S. Virgin Islands and the Puerto Rican Islands of Culebra and Vieques. A Hurricane Watch is in effect for Puerto Rico. A tropical storm warning is in effect for Antigua, Barbuda, Montserrat, St. Kitts, and Nevis and Puerto Rico. A tropical storm watch is in effect for Turks and Caicos Islands.

The National Hurricane Center noted this morning, "Hurricane conditions will be spreading across the northern Virgin Islands during the next few hours. Tropical storm conditions will spread over portions of Puerto Rico this afternoon with Hurricane conditions possible this evening and tonight. Storm surge will raise water levels by as much as 3 to 5 feet above ground level primarily near the coast in areas of onshore wind within the hurricane warning area...and 1 to 3 feet in the tropical storm warning area. The surge will be accompanied by large and dangerous battering waves. Earl is expected to produce total rainfall accumulations of 4 to 8 inches over the Leeward Islands, The Virgin Islands and Puerto Rico with possible isolated maximum amounts of 12 inches especially over higher elevations."

Interests along the U.S. East coast should closely monitor the approach of Hurricane Earl. Beachgoers should be aware of dangerous surf and riptides developing as Earl approaches the U.S. coast later this week.

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



August 27, 2010

GOES-13 captured a visible image of Tropical Storm Earl on August 27 at 1745 UTC spinning in the central Atlantic Ocean.> View larger image
GOES-13 captured a visible image of Tropical Storm Earl on August 27 at 1745 UTC (1:45 p.m. EDT) spinning in the central Atlantic Ocean
Credit: NASA/GOES Project
GOES-13 Sees Earl Moving Over Tropical Atlantic

Tropical Storm Earl is still making its way westward through the tropical Atlantic Ocean, and the GOES-13 satellite captured a visible image of today.

GOES-13 captured a visible image of Tropical Storm Earl on August 27 at 1745 UTC (1:45 p.m. EDT) spinning in the central Atlantic Ocean and it appeared to be developing the signature tropical cyclone shape. GOES is operated by the National Oceanic and Atmospheric Administration, and NASA's GOES Project, located at NASA's Goddard Space Flight Center, Greenbelt, Md. creates some of the GOES satellite images.

At 11 a.m. EDT, Earl's maximum sustained winds were near 45 mph. It was about 1,300 miles east of the Northern Leeward Islands, near 15.7 North and 43.6 West. It was moving west near 17 mph, and had a minimum central pressure of 1003 millibars. There were no watches or warnings in effect at that time, but residents of the Northern Leeward Islands should monitor the progress of Earl over the weekend.

Because of low wind shear and warm sea surface temperatures ahead of Earl, the National Hurricane Center forecasts strengthening over the weekend. Some models even call for Earl to become a major hurricane. For updates on the storm track and intensity, visit: www.nhc.noaa.gov/. Earl is definitely a tropical cyclone to watch over the weekend.

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



August 26, 2010

The TRMM satellite showed rainfall in Tropical Storm Earl was moderate (yellow and green), between .78 to 1.57 inches per hour with some heavy rain (red) at almost 2 inches per hour. > View larger image
The TRMM satellite showed rainfall in Tropical Storm Earl was moderate (yellow and green), between .78 to 1.57 inches per hour with some heavy rain (red) at almost 2 inches per hour. Credit: NASA/SSAI, Hal Pierce



NASA's Aqua satellite instrument created a microwave image of Earl on August 26 at 12:17 a.m. EDT and the cold areas in this image (yellow-green) indicates where there is precipitation or ice in the cloud tops. > View larger image
NASA's Aqua satellite instrument created a mcrowave image of Earl on August 26 at 12:17 a.m. EDT and the cold areas in this image (yellow-green) indicates where there is precipitation or ice in the cloud tops. The microwave image suggests cold, high thunderstorms. Credit: NASA JPL, Ed Olsen
NASA's TRMM satellite Sees Moderate to Heavy Rainfall in Tropical Storm Earl

Tropical Depression 7 became Tropical Storm Earl around 5 p.m. EDT on August 25. Since then, the rain has been falling within Tropical Storm Earl in a moderate to heavy fashion according to data from NASA's TRMM satellite.

The Tropical Rainfall Measuring Mission (TRMM) Satellite passed over Tropical Storm Earl on August 26 at 0430 UTC (12:30 a.m. EDT) collected rainfall data. At that time, Earl appeared slightly better organized than it was on August 25 and TRMM's rainfall analysis showed that Earl was dropping scattered moderate to heavy rainfall in the storm. There were some isolated areas of heavy rainfall where rain was falling at about 2 inches per hour. However, most of the rain was moderate, falling at rates between 20 and 40 millimeters (.78 to 1.57 inches) per hour.

TRMM images are pretty complicated to create. They're made at NASA's Goddard Space Flight Center in Greenbelt, Md. At Goddard, rain rates in the center of the swath (the satellite's orbit path over the storm) are created from the TRMM Precipitation Radar (PR) instrument. The TRMM PR is the only space borne radar of its kind. The rain rates in the outer portion of the storm are created from a different instrument on the satellite, called the TRMM Microwave Imager (TMI). The rain rates are then overlaid on infrared (IR) data from the TRMM Visible Infrared Scanner (VIRS). For more information about TRMM, visit: http://trmm.gsfc.nasa.gov/.

On August 26 at 04:17 UTC (12:17 a.m. EDT) NASA's Aqua satellite flew over Earl, and the Atmospheric Infrared Sounder (AIRS) instrument on Aqua captured infrared, visible and microwave imagery of the hurricane. AIRS data was coupled with data from the Advanced Microwave Sounding Unit (AMSU) that flies with AIRS on Aqua to create a microwave image of Earl. The AMSU image uses the radiances of the 89 GHz channel, and the cold areas in those images indicated where there was precipitation or ice in the cloud tops. The microwave image did show a center of circulation and suggested strong thunderstorms around Earl's center.

At 11 a.m. EDT on August 26, Tropical Storm Earl had maximum sustained winds near 45 mph. It was located about 1.735 miles east of the Northern Leeward Islands, near 14.9 North and 37.1 West. It was moving west near 17 mph, and is expected to move to the west-northwest in the next 2 days. Minimum central pressure was near 1004 millibars.

National Hurricane Center forecasters noted that the visible and microwave satellite imagery they referenced this morning indicated that Earl had not become any better organized since early morning today. Some of the convection (rapidly rising air that forms thunderstorms that make up the tropical cyclone) has eroded since this morning because of dry air that has made its way into the center.

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



August 25, 2010

This image of TD7 shows some strong convection in the northwestern and southwestern quadrants of the storm.> View larger image
This infrared image of Tropical Depression 7's cloud temperatures was captured on August 25 at 0335 UTC (Aug. 24 at 11:35 p.m. EDT) and shows some strong convection (purple) in the northwestern and southwestern quadrants of the storm. The warm sea surface temperatures are over 80F (orange) which are helping it strengthen. Africa's west coast is pictured on the far right.
Credit: NASA/JPL, Ed Olsen
NASA AIRS Instrument Sees Strong Convection as Tropical Depression 7 Forms in Atlantic

Infrared satellite data gives scientists clues about the height and power of thunderstorms that make up tropical cyclones, and the latest infrared imagery from NASA's AIRS satellite noticed some high, strong thunderstorms in the newly developed Tropical Depression 7 and some warm sea surface temperatures to power it.

At 11 a.m. EDT, System 96L strengthened and was designated the Atlantic Ocean Hurricane Season's seventh tropical depression (TD7). At that time, TD7 had maximum sustained winds near 35 mph, and is expected to strengthen into a tropical storm. If TD7 does strengthen, it would become Tropical Storm Earl.

TD7 is still in the far eastern Atlantic Ocean, about 430 miles west of the southernmost Cape Verde Islands, near 14.3 North and 30.8 West. It is moving west near 17 mph, and has a minimum central pressure of 1007 millibars.

When NASA's Aqua satellite passed over Tropical Depression 7 on August 25 at 0335 UTC (Aug. 24 at 11:35 p.m. EDT) the infrared data from the Atmospheric Infrared Sounder (AIRS) instrument showed some strong convection (purple) in the northwestern and southwestern quadrants of the storm. Those high cloud tops were as cold as or colder than -63 degrees Fahrenheit, indicating strong convection and well-developed thunderstorms.

By this morning, August 25, TD7 has "well-defined cyclonically-curved convective bands...and an established upper-level outflow in the western semicircle," according to the National Hurricane Center. That means that the depression is getting organized.

TD7 is expected to become Tropical Storm Earl later today, especially because there are unusually warm waters in the tropical Atlantic that will help fuel its development. AIRS data showed that the waters are over the 80 degree Fahrenheit threshold needed to power tropical cyclones.

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



August 24, 2010

The AIRS instrument on NASA's Aqua satellite captured this infrared image of System 96L's clouds on August 24.> View larger
The AIRS instrument on NASA's Aqua satellite captured this infrared image of System 96L's clouds on August 24 at 15:23 UTC (11:23 a.m. EDT). It shows strongest convection (and thunderstorms) in the northeast quadrant of the storm in purple, which indicates highest cloud tops as cold as or colder than -63 Fahrenheit. The islands near the top part of the image are the Cape Verde Islands.
Credit: NASA/JPL, Ed Olsen
NASA's AIRS Instrument Sees Potential in Developing Depression

System 96L in the far eastern Atlantic had a 90 percent chance of becoming the seventh tropical depression at 2 p.m. EDT today, August 24. Infrared satellite data from NASA's Atmospheric Infrared Sounder, or AIRS instrument shows it has the potential.

The AIRS instrument on NASA's Aqua satellite captured an infrared image of System 96L's clouds today, August 24 at 15:23 UTC (11:23 a.m. EDT). It showed that the strongest convection (and thunderstorms) were in the northeast quadrant of the storm where the highest cloud tops as cold as or colder than -63 Fahrenheit. The infrared data didn't show a well-defined center of circulation yet, which is one reason why System 96L hasn't been classified as a tropical depression yet.

At 2pm EDT, the low pressure system known as System 96L was about 150 miles south-southwest of the Cape Verde Islands. It was producing heavy showers and gusty winds to that group of islands today and those are expected to taper off on Wednesday. System 96L was moving west-northwest near 15 mph.

The National Hurricane Center (NHC)in Miami, Fla. noted that it continues to show organization. The NHC said that System 96L could become a tropical depression at any time as it continues on its journey far behind Hurricane Danielle.

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