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Hurricane Season 2012: Tropical Storm Leslie (Atlantic Ocean)
09.12.12
 
These images show Leslie as it was observed by MODIS (top) and CloudSat (bottom) on August 31, 2012.› View larger image
These images show Leslie as it was observed by MODIS (top) and CloudSat (bottom) on August 31, 2012. The MODIS image has been rotated so that north is toward the left. The yellow line is the north-to-south track that CloudSat took over the storm. The lower image is a radar profile of the storm structure.
Credit: NASA Earth Observatory image by Jesse Allen, using CloudSat FirstLook data provided courtesy of the CloudSat team at Colorado State University.
NASA Gets Two Views of Tropical Storm Leslie

On August 30, 2012, Tropical Depression Twelve turned into Tropical Storm Leslie. The storm further strengthened into Hurricane Leslie days later. When the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite flew over the system on August 31, it appeared as a fairly uniform mass of clouds. But to the CloudSat satellite, the picture was more complex.

These images show Leslie as it was observed by MODIS (top) and CloudSat (bottom) on August 31, 2012. The MODIS image has been rotated so that north is toward the left. The yellow line is the north-to-south track that CloudSat took over the storm. The lower image is a radar profile of the storm structure.

CloudSat sends out pulses of energy, and when that energy bounces off the surface of the ocean or particles in the atmosphere, the echoes provide an internal view of cloud structure. The radar picture shows how the storm would look if it were sliced down the middle and viewed from the side.

CloudSat flies in close formation with the Aqua satellite, so it views storms such as Leslie at almost the same time. In the MODIS imagery, cloud peaks in the storm are hard to discern. In the storm profile from CloudSat, the cloud peaks are clear. CloudSat recorded cloud tops reaching more than 17 kilometers (11 miles) into the atmosphere. In general, higher cloud tops mean cooler clouds, so altitude profiles from CloudSat not only give a picture of the structure but also the temperatures.

As of September 7, Leslie had the potential to affect a NASA-sponsored research cruise taking place in the same region: the Salinity Processes in the Upper Ocean Regional Study (SPURS). Meanwhile, the Hurricane and Severe Storm Sentinel Mission (HS3) flew a Global Hawk robotic plane around the edges of Leslie on September 7.

Text Credit: Michon Scott
NASA's Earth Observatory
NASA Goddard Space Flight Center, Greenbelt, Md.



Sep. 11, 2012

infrared image of Leslie and Michael › View larger image
When NASA's Aqua satellite passed over the Atlantic it caught Tropical Storm Leslie's clouds over Newfoundland and Tropical Storm Michael to its southwest, resembling a peanut shape.
Credit: NASA JPL, Ed Olsen
Leslie › Larger image
NASA's Aqua satellite passed over Tropical Storm Leslie when it was just south of Nova Scotia, Canada on Sept. 10, 2012 and the MODIS instrument captured this visible image at 1:35 p.m. EDT.
Credit: NASA/Goddard/MODIS Rapid Response Team
NASA Infrared Data Reveals Fading Tropical Storm Leslie and Peanut-Shaped Michael

When NASA's Aqua satellite passed over the Atlantic on Sept. 11 it caught Tropical Storm Leslie's clouds over Newfoundland and peanut-shaped Tropical Storm Michael to its southwest. The Atmospheric Infrared Sounder (AIRS) instrument captured infrared data on Tropical Storms Leslie and Michael when it passed overhead on Sept. 11.


Michael Appears Peanut-Shaped on Satellite Imagery

Tropical Storm Michael forecast to become a remnant low later today, Sept. 11, but as of 11 a.m. EDT Michael still had maximum sustained winds near 45 mph (75 kmh). It was located about 1,090 miles (1,755 km) west of the Azores. Michael is moving to the north-northeast 23 mph (37 kmh) and this motion is expected to continue during the next day or so.

In the AIRS infrared image from around 1 a.m. EDT on Sept. 11, the strongest area of convection (and thunderstorms) appeared to be over Michael's north and eastern quadrants making the storm appear peanut-shaped on NASA satellite imagery. An infrared satellite image of Michael later on Sept. 11 showed that most of the convection has disappeared and Michael appeared as tight swirl of low clouds. Michael is over cool waters and in an environment of strong wind shear, two factors that are weakening the storm quickly. The National Hurricane Center forecast notes that Michael's remnants should then become absorbed by a front in the next day or two.


Tropical Storm Leslie Moving Away from Newfoundland

According to the Canadian Hurricane Centre, Leslie made landfall Tuesday, Sept. 10 in Fortune, Newfoundland, at about 8:30 a.m. AST (7:30 a.m. EDT) with maximum sustained winds near 40 mph (65 kmh). The Seattle Post Intelligencer newspaper reports power outages and flight cancellations. Canadian Broadcasting Corporation news reported heavy rainfall and wind gusts up to 82 mph (132 kmh) over the Avalon Peninsula, including St. John's that caused power outages, and downed trees. Leslie became a post-tropical cyclone as it begins to move away from Newfoundland.

The Canadian Hurricane Center discontinued the hurricane watch for southeastern Newfoundland early on Sept. 11, but a tropical storm warning is in effect for Newfoundland from Indian Harbour to Triton.

AIRS infrared imagery from 1 a.m. EDT on Sept. 11 showed strong thunderstorms around Leslie's center and in bands to the north of the center. At 11 a.m. EDT on Sept. 11, the center of post-tropical cyclone Leslie was located near latitude 49.4 north, longitude 53.6 west, about 130 miles (210 km) north-northwest of St. Johns Newfoundland. The post-tropical cyclone is moving toward the north-northeast at 45 mph (72 kmh).

By 12 p.m. EDT, satellite imagery showed that Leslie is now part of a cold front and is no longer a tropical cyclone. Post-tropical/extratropical cyclone is still producing a large area of tropical-storm-force winds primarily to the north and east of the center as it continues to move north-northeast at 39 knots. This system is forecast to remain a strong Post-tropical cyclone as it moves rapidly toward the northeast and east over the north Atlantic.

Leslie's remnants are expected to skirt southern Iceland on Thursday, Sept. 12 before heading toward Scotland sometime on Sept. 13.

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



Sep. 10, 2012

Visible image of Tropical Storm Leslie and Hurricane Michael taken by MODIS on Sept. 7 at 11:25 a.m. EDT› View larger image
This visible image of Tropical Storm Leslie and Hurricane Michael was taken by the MODIS instrument aboard both NASA's Aqua and Terra satellites on Sept. 7 at 11:25 a.m. EDT.
Credit: NASA Goddard/MODIS Rapid Response Team
Visible image of Tropical Storm Leslie and Hurricane Michael taken by MODIS on Sept. 9 at 12:50 p.m. EDT› View larger image
This visible image of Tropical Storm Leslie and Hurricane Michael was taken by the MODIS instrument aboard both NASA's Aqua and Terra satellites on Sept. 9 at 12:50 p.m. EDT.
Credit: NASA Goddard/MODIS Rapid Response Team
NASA Catches Tropical Storm Leslie and Hurricane Michael in the Atlantic

Satellite images from two NASA satellites were combined to create a full picture of Tropical Storm Leslie and Hurricane Michael spinning in the Atlantic Ocean. Imagery from NASA's Aqua and Terra satellites showed Leslie now past Bermuda and Michael in the north central Atlantic, and Leslie is much larger than the smaller, more powerful Michael.

Images of each storm were taken by the Moderate Resolution Imaging Spectroradiometer, or MODIS instrument that flies onboard both the Aqua and Terra satellites. Both satellites captured images of both storms on Sept. 7 and Sept. 10. The image from Sept. 7 showed a much more compact Michael with a visible eye. By Sept. 10, the eye was no longer visible in Michael and the storm appeared more elongated from south to north.


Leslie Moves Past Bermuda Heads to North Atlantic

On Sept. 8 at 5 p.m. Leslie was a tropical storm with maximum sustained winds near 55 knots. It was about 240 miles (390 km) south-southeast of Bermuda near 29.4 North latitude and 62.5 West longitude. Leslie was moving north and expected to pass to the east of or close to Bermuda later in the day. A tropical storm warning was in force for Bermuda on Sept. 8 and 9, and forecasters at the National Hurricane Center expected rainfall totals of 1 to 2 inches in Bermuda.

By Sept. 9 at 5 p.m. EDT, Leslie had passed to the east of Bermuda and was centered about 175 miles (280 km) east-northeast of the island, near 33.4 North and 61.2 East. Leslie's maximum sustained winds were near 60 mph (95 kmh) as it continued moving to the north at 14 mph (22 kmh).

By Monday, Sept. 10, Leslie had moved north of Bermuda and was about 805 miles (1,300 km) south-southwest of Cape Race, Newfoundland, Canada, near 36.5 North latitude and 60.8 West longitude. Leslie was moving to the north-northeast at 18 mph (30 kmh) and had maximum sustained winds near 60 mph (95 kmh).

MODIS satellite data shows that Leslie has one main band of powerful thunderstorms and heavy rainfall, located to the northeast quadrant of the storm.

Watches have now been posted for Newfoundland, Canada as Leslie tracks northward. A hurricane watch is now in effect in Newfoundland, from Stones Cove to Charlottetown. A hurricane watch means that hurricane conditions are possible within the watch area, in this case within 24 to 36 hours, according to the National Hurricane Center.

In addition, a tropical storm watch is in effect for Newfoundland, from Indian Harbor to Stones Cove and from Fogo Island to Charlottetown.

Monday, Sept. 10 is expected to be Leslie's last day in warm waters and low-wind shear. After today the storm is forecast to move into cooler waters and the wind shear is expected to kick up. Those are two factors that weaken a tropical cyclone. Leslie is expected to start transitioning from a warm core system to a cold core system later on Sept. 10, which means the storm will be undergoing a change into an extra-tropical storm.


Michael, Once "Wide-Eyed," Now Weakening from Atmosphere and Ocean

Hurricane Michael experienced some adjustments in "vision" over the weekend when the storm's eye grew wider. On Sept. 8, Michael was still a hurricane with maximum sustained winds near 90 knots (150 kmh). Michael was located near 33.1 North latitude and 42.3 West longitude, about 925 miles (1,485 km) west-southwest of the Azores. Michael's tropical-storm-force wind field was about 70 miles (110 km) out from the center, making the storm about 140 miles (220 km) in diameter. Michael was weakening slowly due to atmospheric conditions and cooler waters and by Sept. 9, Michael's maximum sustained winds were still near 90 mph (150 kmh) when it was 990 miles (1,590 km) west-southwest of the Azores islands. On Sunday, Michael's eye widened from 10 miles in diameter to 30 miles in diameter, as was seen in satellite imagery.

By Monday, Sept. 10, Michael's maximum sustained winds at 5 a.m. EDT were near 80 mph (130 kmh). Michael was centered about 1,065 miles (1,715 km) west of the Azores Islands near 33.5 North and 45.2 West. Michael was moving to the west at 7 mph (11 kmh) and is expected to turn northwestward later on Sept. 10, followed by a turn to the north and northeast. Michael could become a tropical storm by the end of the day on Sept. 10, according to the National Hurricane Center.


Another Storm Brewing in the Eastern Atlantic

Satellite imagery showed that another tropical depression may be forming in the eastern Atlantic. The low, called System 90L appears more organized on Monday, Sept. 10. It is located about 855 miles west of the Cape Verde Islands and is being carefully watched. The National Hurricane Center gives it a 90 percent chance of becoming a depression later on Sept. 1 as it moves west-northwestward at 15 to 20 mph.

To see the Sept. 10 MODIS image of Leslie and Michael, visit: http://lance-modis.eosdis.nasa.gov/cgi-bin/imagery/single.cgi?image=LeslieMichael.A2012253.1650.4km.jpg

To see the Sept. 7 MODIS image of Leslie and Michael, visit: http://lance-modis.eosdis.nasa.gov/cgi-bin/imagery/single.cgi?image=LeslieMichael.A2012251.1525.4km.jpg

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



Sep. 7, 2012

MODIS image of Leslie› View larger image"
This visible image of Hurricane Leslie was taken by the MODIS instrument aboard NASA's Terra satellite on Sept. 6 at 10:45 a.m. EDT. Leslie's eye appears cloud covered and the storm weakened to a tropical storm on Sept. 7.
Credit: NASA Goddard/MODIS Rapid Response Team
NASA Sees Hurricane Leslie's Eye Close

Hurricane Leslie appeared to "close its eye" on NASA satellite imagery as the storm heads east of Bermuda, like a little girl shutting her eyes tight on a wild amusement ride. Often when an eye becomes cloud-filled, its a sign that the storm is weakening, and Leslie did drop from a hurricane to a tropical storm on Sept. 7.

The Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard NASA's Terra satellite captured a visible image of Hurricane Leslie on Sept. 6 at 10:45 a.m. EDT and Leslie's eye appeared cloud covered. Leslie went on to weaken to tropical storm on Sept. 7.

At 11 a.m. EDT on Sept. 7, Tropical Storm Leslie's maximum sustained winds were just under hurricane strength, near 70 mph (110 kmh), and the forecasters at the National Hurricane Center expect no change in intensity today, however, Leslie could regain hurricane status over the weekend of Sept. 8 and 9. Leslie was located about 410 miles (660 km) south-southeast of Bermuda near latitude 26.8 north and longitude 62.2 west.

Leslie was sitting still and the NHC doesn't expect much movement on Sept. 7, but expects Leslie to start moving northward on Sat. Sept. 8. The Atmospheric Infrared Sounder (AIRS) instrument that flies aboard NASA's Aqua satellite noticed earlier this week that Leslie's slow movement was causing cooler waters to upwell from below the surface of the ocean, up to the ocean's surface. The waters were cooler than 26.6 degrees Celsius (80 degrees Fahrenheit), which is the threshold needed to maintain a tropical cyclone. When water temperatures drop below that threshold a tropical cyclone weakens, because evaporation (that adds fuel to a storm) cannot happen as much and as quickly.

On Sept. 7 a NOAA aircraft dropped a dropsonde (instrument that measures temperature and other factors) through Leslie, and found that the sea surface temperature was near 24.5 Celsius (76.1 Fahrenheit). NOAA NHC forecaster Lixion Avila noted that "once Leslie moves away from the cool pool it has created for itself the cyclone will have the opportunity to regain hurricane status since the shear is expected to be low."

Leslie is a good-sized storm with tropical storm force winds extending out to 185 miles (295 km) from the center. A tropical storm watch is in effect for Bermuda on Sept. 7, and will become a warning later. Leslie is expected to pass closest to Bermuda on Sunday, Sept. 8.

Even though Leslie isn't close to the U.S. mainland, it is causing rough surf to the U.S. east coast and Bermuda. The NHC noted that ocean swells will affect the U.S. from central Florida all the way north to the Canadian Maritimes, and south to the Northern Leeward Islands and Puerto Rico and the Virgin Islands over the next several days.

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



Sep. 6, 2012 - second update

MODIS image of Leslie› View larger image
This visible image of Hurricane Leslie was captured by the MODIS instrument aboard NASA's Aqua satellite on Sept. 5 at 1:15 p.m. EDT as the storm was approaching Bermuda. Leslie was just becoming a hurricane and its eye became visible.
Credit: NASA Goddard/MODIS Rapid Response Team
AIRS image of Leslie› View larger image
This infrared image of Hurricane Leslie was taken on Sept. 5 at 1:11 p.m. EDT by the AIRS instrument that flies aboard NASA's Aqua satellite. The image was taken just before Leslie intensified into a hurricane. The strongest thunderstorms and coldest cloud top temperatures (purple) around the center of circulation and in a wide band of thunderstorms to the east and south of the center.
Credit: NASA JPL, Ed Olsen
NASA Satellite Captured Hurricane Leslie's Picture Perfect Moment

NASA's Aqua satellite flew over Tropical Storm Leslie on Sept. 5 during a picture perfect moment, just as it was being re-classified as a hurricane, and captured two images of the storm.

The National Hurricane Center issued the advisory confirming Leslie's hurricane status at 1:45 p.m. EDT after examining visible, infrared, microwave and other data from satellites. Two instruments that fly aboard NASA's Aqua satellite provided infrared and visible imagery of Leslie as it was crossing the threshold from tropical storm to hurricane status on Sept. 5.

The Moderate Resolution Imaging Spectroradiometer (MODIS) instrument provided a visible image of Hurricane Leslie on Sept. 5 at 1:15 p.m. EDT as the storm was approaching Bermuda. The MODIS image showed that an eye had just formed in Leslie.

The Atmospheric Infrared Sounder (AIRS) instrument also aboard Aqua captured infrared data at the same time. The AIRS data showed the strongest thunderstorms and coldest cloud top temperatures were wrapped in a large area around the center of circulation and in a wide band of thunderstorms to the east and south of the center. Cloud top temperatures in both areas were colder than -63 Fahrenheit (-52 Celsius). On Sept. 6, the strongest convection (rising air forming the thunderstorms that make up the cyclone) and coldest cloud top temperatures were east of the center of circulation as a result of westerly wind shear.

On Sept. 6 at 8 a.m. EDT, Leslie had maximum sustained winds near 75 mph (120 kmh). The area of tropical storm force winds now extend outward up to 195 miles (315 km). Leslie's center was about 440 miles (705 km) south-southeast of Bermuda, near latitude 26.3 north and longitude 62.4 west. Leslie is slowly drifting toward the northeast near 1 mph (2 kmh) and is expected to continue drifting in that direction through Friday, Sept. 7.

Leslie continues to cause a lot of rough surf in a large area. Warnings for rough seas, swells and rip tides are in effect for Bermuda, the U.S. east coast from central Florida northward, the Northern Leeward Islands, Puerto Rico and the Virgin Islands for the next couple of days.

Leslie's slow movement continues to bring up cooler waters from below the surface of the ocean, which will be detrimental to its intensification. However, the wind shear is expected to decrease and Leslie is expected to move northward, so the National Hurricane Center expects that Leslie may intensify over the next couple of days. Leslie is forecast to pass east of Bermuda on Sunday, Sept. 9 as a hurricane.

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



Sep. 6, 2012

CloudSat overpass track from August 31.› View larger image
CloudSat overpass track
Credit: CloudSat Data Processing Center)
CloudSat Analyzes Tropical Storm Leslie

CloudSat overpassed Tropical Storm Leslie in the Atlantic Ocean on August 31, 2012 at 1653 UTC (1253 EDT). Leslie contained maximum sustained winds of 65 mph with a minimum central pressure of 999 mb. CloudSat overpassed directly over a developing cumulonimbus cloud with an overshooting cloud top near the center of the storm. FULL CloudSat Update: http://cloudsat.atmos.colostate.edu/news/Tropical_Storm_Leslie.









Sep. 5, 2012

On Sept. 5, AIRS noticed strong convection and cold cloud top temperatures surrounding the center of Leslie's circulation› View larger image
NASA's Aqua satellite flew over Tropical Storm Leslie on Sept. 5 at 0611 UTC (2:11 a.m. EDT) and noticed the strongest convection (purple) and coldest cloud top temperatures in a large area surrounding the center of circulation and in a band of thunderstorms to the east of the center.
Credit: NASA JPL, Ed Olsen
NASA Sees Tropical Storm Leslie Was Causing a Problem for Itself

Infrared data from NASA's Aqua satellite shows that Tropical Storm Leslie has been causing problems for itself.

Tropical Storm Leslie has been on a slow track in the Atlantic, and because of that, the storm is kicking up cooler waters from below the ocean surface. Those cooler waters were seen in infrared imagery on Sept. 5 at 0611 UTC (2:11 a.m. EDT) taken by the Atmospheric Infrared Sounder (AIRS) instrument that flies aboard NASA's Aqua satellite. The cooler waters are responsible for Leslie's slow strengthening. Sea surface temperatures need to be at least as warm as 80 degrees Fahrenheit (26.6 Celsius) to maintain a tropical cyclone. When a tropical cyclone moves slowly, however, it churns up the waters below the surface, which are cooler. That cooler water saps the tropical cyclone's strength.

Infrared satellite data from NASA's AIRS instrument has often seen a "cold water wake" trailing behind a tropical cyclone. That's the cold water drawn up to the ocean's surface as the tropical cyclone passes by. If there's another tropical cyclone behind the one that stirs up the deeper, cooler, ocean water, the second storm tends to weaken in the cold water wake.

Other than cool sea surface temperatures, Leslie has been battling wind shear, which has kept the storm below hurricane strength so far. That's changing, though, as the vertical shear has been gradually decreasing today, Sept. 5. As a result of the weaker wind shear, forecasters at the National Hurricane Center noticed a "banding eye feature" in visible satellite imagery. The AIRS data of Tropical Storm Leslie confirmed the visible imagery. AIRS infrared data showed the strongest convection (rising air that forms thunderstorms) and coldest cloud top temperatures were in a large area surrounding the center of circulation and in a band of thunderstorms to the east of the center.

On Sept. 5 at 11 a.m. EDT, Leslie was close to hurricane strength with maximum sustained winds near 70 mph (110 kmh). Leslie is expected to reach hurricane status later in the day as the wind shear eases. Leslie's center was about 470 miles (760 km) south-southeast of Bermuda, near latitude 25.7 north and longitude 62.8 west. Leslie is moving toward the north near 2 mph (4 kmh). Leslie is expected to continue crawling and wobbling to the north and north-northwest over the next couple of days because it is being blocked by a ridge (elongated area) of high pressure to the north and east of the storm. A strong trough (elongated area) of low pressure is expected to move out of southern Canada toward the southeastern U.S. and is expected to push Leslie northward in a couple of days.

The National Hurricane Center noted that Leslie will continue bring rough surf to Bermuda and the U.S. east coast from central Florida northward, the Northern Leeward islands, Puerto Rico and the Virgin Islands over the next couple of days.

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



Sep. 4, 2012

MODIS showed that Tropical Storm Leslie didn't change much in terms of form or strength from Aug. 31 to Sept. 1› View larger image
These visible images from the MODIS instrument onboard NASA's Aqua and Terra satellites showed that Tropical Storm Leslie didn't change much in terms of form or strength from Aug. 31 at 12:55 p.m. EDT to Sept. 1 10:30 a.m. EDT.
Credit: NASA Goddard MODIS Rapid Response Team
NASA Satellites Showed Little Change in Tropical Storm Leslie

Over the weekend of Aug. 31 to Sept. 2, Tropical Storm Leslie's maximum sustained winds were pretty constant and satellite imagery from NASA's Aqua and Terra satellites confirm the steadiness of the storm. That story is expected to change later this week however, as Leslie nears Bermuda and is expected to reach hurricane strength. Meanwhile, Leslie is still about the same strength today, Sept. 4 because of wind shear.

Two visible images from the Moderate Resolution Imaging Spectroradiometer or MODIS instrument that flies onboard both of NASA's Aqua and Terra satellites showed that Tropical Storm Leslie didn't change much in terms of form or strength from Aug. 31 at 12:55 p.m. EDT to Sept. 1 10:30 a.m. EDT. Leslie's shape appeared almost identical in a 22 hour period at a time that its maximum sustained winds were near 60 mph (95 kmh).

On Sept. 4 at 11 a.m. EDT, Tropical Storm Leslie's maximum sustained winds had still not changed much from the time NASA's two satellites passed over it on the weekend. Maximum sustained winds were now up to 65 mph (100 kmh). Leslie is about 410 miles (670 km) in diameter, as tropical-storm force winds extend up to 205 miles (335 km) from the center.

The National Hurricane Center noted that Leslie's path may become somewhat erratic over the next couple od days on its northward journey.

Leslie was located about 525 miles (840 km) south-southeast of Bermuda, near latitude 25.0 north and longitude 62.5 west. Leslie is moving toward the north near 3 mph (6 kmh) and is expected to continue moving slowly in that direction.

Ocean swells from Tropical Storm Leslie may affect the Leeward Islands, Puerto Rico and the Virgin Islands, and those conditions are expected to spread to Bermuda and the eastern U.S.

Satellite data on Sept. 4 showed that the rising air that forms the thunderstorms that make up the storm (convection) has decreased near Leslie's center. Leslie is being battered by wind shear from the northwest at 20 knots, which is pushing the showers and thunderstorms to the southeast. The National Hurricane Center update at 11 a.m. EDT noted that "the convective cloud structure now more resembles a curved band pattern [than a circular tropical cyclone]." In fact, the low-level center of Leslie appears to be 30 miles north of the mid-level center. That's important because the centers of tropical cyclones need to be stacked on top of each other like a coiled spring, in order to rotate and intensify. Basically, it means that Leslie is struggling.

That environment is expected to change, though, as Leslie moves north and wind shear relaxes, giving the storm a chance to organize. That's why the National Hurricane Center expects Leslie to strengthen into a hurricane by the end of the week.

For the Aug. 31 image in high resolution: http://lance-modis.eosdis.nasa.gov/cgi-bin/imagery/single.cgi?image=Leslie.A2012244.1655.2km.jpg.

For the Sept. 1 image in high resolution: http://lance-modis.eosdis.nasa.gov/cgi-bin/imagery/single.cgi?image=Leslie.A2012245.1430.2km.jpg.

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



Satellite Sees Isaac's Remnants, Tropical Storms Kirk, Leslie and Michael



An animation of satellite observations from Sept. 1-4, 2012, shows Isaac's remnants move from the central to eastern U.S., and tropical storm Leslie nearing Bermuda, Kirk fades in the No. Atlantic on Sept. 2 and tiny Tropical Storm Michael forms on Sept. 4, west of Leslie. This visualization was created by the NASA GOES Project at NASA Goddard Space Flight Center, Greenbelt, Md., using observations from NOAA's GOES-13 satellite. TRT 0:35 Super(s): Courtesy: NASA/NOAA GOES Project Center Contact: Rob Gutro (301) 286-4044



Sep. 2, 2012

GOES satellite image of Isaac, Kirk, Leslie, and Tropical Depression 10E› View larger image
Tropical Depression Isaac's Remnants continued soaking the Ohio Valley and are moving into the Mid-Atlantic, while Kirk became post-tropical in the northern Atlantic, Tropical Storm Leslie is strengthening and headed north. In the Eastern Pacific, Tropical Depression 10E was born.On Sept. 2 at 7:45 p.m. EDT, the NASA GOES Project created this infrared image from NOAA's GOES-13 satellite that showed all four storms.
Credit: NASA GOES Project
This MODIS visible image shows Tropical Storm Leslie in the Atlantic Ocean on Aug. 31› View larger image
This visible image from the MODIS instrument onboard NASA's Aqua satellite shows Tropical Storm Leslie in the Atlantic Ocean on Aug. 31 at 12:55 P.M. EDT.
Credit: NASA Goddard MODIS Rapid Response Team
NASA Sees Atlantic Storms Isaac, Kirk and Leslie, and E. Pacific TD10E

On Sunday, Sept. 2, Tropical Depression Isaac's Remnants continue soaking the Ohio Valley and are moving into the Mid-Atlantic, while Kirk became post-tropical in the northern Atlantic, Tropical Storm Leslie is strengthening and headed north. In the Eastern Pacific, Tropical Depression 10E was born. All of these storms were captured in one panoramic image created by NASA from NOAA's GOES-13 satellite on Sunday, Sept. 2, 2012

On Sept. 2 at 7:45 p.m. EDT, the NASA GOES Project at the NASA Goddard Space Flight Center in Greenbelt, Md. created infrared image from NOAA's GOES-13 satellite that showed all four storms.

Kirk Becomes Post-Tropical

At 5 p.m. EDT on Sept. 2, Kirk became Post-tropical storm Kirk Hurricane Kirk's with maximum sustained winds near 50 mph (85 kmh). Kirk was about 965 miles (1,550 km) east-northeast of Cape Race, Newfoundland near 49.7 North and 30.1 West. It was speeding to the north 47 mph (76 kmh) and had a minimum central pressure of 1002 millibars. That was the last position noted in the final bulletin from the National Hurricane Center. Additional information on this system can be found in high seas forecasts issued by the United Kingdom Meteorological office.


Tropical Storm Leslie Intensifying Again, Turning North

Tropical Storm Leslie weakened and is now expected to intensify as it turns north. The National Hurricane Center expects Leslie to become a hurricane before reaching Bermuda. On Sept. 2 at 5 p.m. EDT Leslie had maximum sustained winds near 60 mph (95 kmh), and was located about 370 miles (590 km) north of the Leeward Islands, near latitude 22.4 north and longitude 61.3 west. Leslie is moving northwest near 10 mph (17 kmh).

The National Hurricane Center noted that Leslie is generating rough surf that is affecting the Leeward Islands and will begin affecting Puerto Rico and the Virgin Islands during the night on Sept. 2, and during Sept. 3. The GOES-13 satellite imagery indicates strong northwesterly wind shear, where clouds and showers are pushed to the southeast of the center of circulation.


Isaac's Remnants Affecting Ohio and Tennessee Valleys

Isaac is merging with a frontal zone and moving through the Ohio Valley. The remnants associated with a low pressure center were located over Illinois on Sept. 2. East of the low pressure center, the frontal boundary was draped over southern West Virginia and into North Carolina. West of the low, a frontal boundary stretched back through the Tennessee Valley. The low pressure center is expected to crawl eastward over southern Indiana on Sept. 3, and over northern Kentucky on Sept. 4, bringing showers and thunderstorms with it as it crawls east.


Eastern Pacific: Tropical Depression 10 E Forms, Ileana Fizzles

Tropical Storm Ileana fizzled early on Sunday, Sept. 2 and Tropical Depression 10E was born.

At 11 a.m. EDT on Sept. 2, Ileana had become a post-tropical depression with maximum sustained winds near 30 mph (45 kmh). The last advisory from the National Hurricane Center was issued at that time, and Ileana was located near latitude 22.6 north and longitude 122.5 west. The remnant low is moving toward the west near 12 mph (19 kmh). Ileana's remnants are expected to turn west-southwest on Sept. 3. Ileana appears as a large area of clouds to the northwest of Tropical Depression 10E on the GOES-13 satellite image.

Tropical Depression 10E formed 320 miles (510 km) south of the southernmost tip of Baja California at 5 p.m. EDT on Sept. 3. It was centered near 18.3 North and 109.6 West. Tropical Depression 10E had maximum sustained winds near 35 mph (55 kmh) and was moving to the west-northwest at 17 mph (28 kmh). The National Hurricane Center noted that the storm could strengthen into a tropical storm on Sept. 3.

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



Aug. 31, 2012

This visible image of Isaac over moving over the Mississippi Valley, and Kirk and Leslie in the central Atlantic Ocean.› View larger image
This visible image of Tropical Storm Isaac over moving over the Mississippi Valley, Hurricane Kirk and Tropical Storm Leslie in the central Atlantic Ocean. The image was taken from NOAA's GOES-13 satellite on Aug. 31 at 4:45 a.m. EDT.
Credit: NASA GOES Project
NASA Sees Atlantic Storms Isaac, Kirk and Leslie

Tropical Depression Isaac is weakening and dropping heavy rainfall along its slow path through the center of the U.S., while Hurricane Kirk is spinning in the central Atlantic, and Tropical Storm Leslie is strengthening on a westward track toward the Caribbean. All of these storms were captured in one panoramic image created by NASA from NOAA's GOES-13 satellite.

On Aug. 31 at 4:45 a.m. EDT, a visible image from NOAA's GOES-13 showed Tropical Depression Isaac centered over Arkansas and moving into Missouri. Hurricane Kirk and Tropical Storm Leslie were moving through the central Atlantic Ocean. The image was created by the NASA GOES Project at the NASA Goddard Space Flight Center in Greenbelt, Md.


Hurricane Kirk Staying at Sea

At 5 a.m. EDT on Aug. 31, Hurricane Kirk's maximum sustained winds were near 105 mph (165 kmh). Kirk was about 835 miles (1,345) east of Bermuda near 30.1 North and 50.9 West. It was moving to the north-northwest 12 mph (19 kmh) and had a minimum central pressure of 970millibars. Kirk is a Category two hurricane on the Saffir-Simpson Scale.

The GOES-13 image showed that Kirk continued to be a compact hurricane, and hurricane force winds extend just 15 miles (30 km) from the center. The National Hurricane Center forecasts Kirk to move in a northeasterly direction over the next four days on an approach to Ireland. As Kirk tracks northward and runs into cooler waters, it will weaken and transition into an extra-tropical storm.


Tropical Storm Leslie Intensifying, Moving West

Tropical Depression 12 formed on Aug. 30, and quickly strengthened into Tropical Storm Leslie. The National Hurricane Center expects Leslie to become a hurricane over the weekend of Sept. 1-2 and move northwest and turn north on Sunday, Sept. 2. Leslie is expected to stay to the north of the Leeward Islands and turn toward Bermuda. At this time, it is expected to pass east of Bermuda.

On Aug. 31 at 6 a.m. EDT Leslie had maximum sustained winds near 65 mph (100 kmh), and was located about 940 miles (1,510 km) east of the Leeward Islands, near latitude 15.2 north and longitude 47.8 west. Leslie is moving west-northwest near 16 mph (26 kmh). Because Leslie continues to move in a favorable environment of low wind shear and warm waters, it could become a major hurricane over the weekend of Sept. 1-2, according to the National Hurricane Center.


Tropical Depression Isaac Over Arkansas and Missouri

At 5 a.m. EDT on Aug. 31, Tropical Depression Isaac had maximum sustained winds are near 25 mph (40 kmh). Isaac is expected to weaken over the weekend of Sept. 1-2 and become a post-tropical remnant low pressure area.

Isaac's center was about 95 miles (155 km) west of Little Rock, Ark. near latitude 34.7 north and longitude 93.9 west. Isaac is moving north near 12 mph (19 km). Isaac is expected to move over Arkansas today and Missouri tonight. Rainfall totals of 3 to 6 inches with isolated maximum amounts of 8 inches possible across Arkansas and into southern Missouri through Friday, Aug. 31. Tornado watches are posted central and southern Mississippi in addition to extreme eastern Arkansas.

Isaac is expected to turn northeast and track over the mid-Mississippi Valley, and into the Ohio Valley on Labor Day, Monday, Sept. 3 as it continues to crawl to the Mid-Atlantic.

Flooding has been widespread in Louisiana, as a result of the heavy rainfall. Following are rainfall totals from Hurricane Isaac, according to the National Hurricane Center:

RAINFALL TOTALS
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SELECTED STORM TOTAL RAINFALL IN INCHES THROUGH 7 PM CDT


ALABAMA
Grand Bay 0.6 Nw 11.07
Mobile/Bates Field 9.67
Wilmer 7.9 Se 8.75
Fairhope 2.3 N 6.42
Daphne 1.8 Ese 5.87
Theodore 8.0 Sse 5.12
Point Clear 1.6 Ssw 5.04
Silverhill 0.9 Sse 4.34
Foley 2.0 Ssw 3.71

ARKANSAS
Monticello Airport 2.91
Pine Bluff/Grider Field 2.63
El Dorado/Goodwin Field 1.71

FLORIDA
Vero Beach 5.2 S 16.60
Royal Palm Beach 5.0 W 16.29
Boynton Beach 1.9 Nnw 14.41
Port St Lucie 1.5 Ne 13.04
Aberdeen 4.2 Nnw 12.41
Palm City 4.0 Sw 11.69
Homestead Afb 9.37
Fort Pierce/St Lucie 9.18
West Palm Beach Intl Arpt 8.64
Vero Beach Muni Arpt 7.66
Fort Lauderdale Executive Apt 7.02
Miami/Opa Locka 6.64
Pompano Beach Airpark 5.33
Winter Haven Gilbert Arpt 5.19
Orlando/Herndon 5.12
Hollywood/North Perry Arpt 5.12

GEORGIA
Guyton 1.9 S 5.60
Brooklet 13.1 Se 4.60
Rincon 1.2 Nnw 4.03
Monroe 5.6 Nne 3.11
Augusta/Bush Field 2.53
Alma/Bacon Co. Arpt 2.49
Savannah Muni Arpt 2.47
Fort Stewart/Wright Aaf 2.06
Augusta/Daniel Field 1.95
Moody Afb/Valdosta 1.50

LOUISIANA
New Orleans 20.08
Reserve 0.5 Sse 13.46
Livingston 13.16
Hammond 2.3 Wsw 11.93
Terrytown 3.3 S 10.56
Slidell 10.40
Abita Springs 1.9 Ne 10.15
Baton Rouge/Ryan Muni Arpt 4.57
Boothville 4.20
Monroe Rgnl Arpt 2.37
Patterson Memorial Arpt 2.00
Lafayette Rgnl Arpt 1.55
Alexandria/Esler 1.50

MISSISSIPPI
Kiln 3.3 N 17.04
Marion Raws/Columbia 15.02
Saucier 1.7 Nne 12.78
Picayune 5.6 Ene 12.17
Diamondhead 1.5 Ne 12.04
Long Beach 0.7 S 11.95
Mccomb/Lewis Field 10.93
Gulfport-Biloxi 10.85
Pascagoula 10.67
Keesler Afb/Biloxi 10.17
Hattiesburg/Chain Muni Arpt 9.44
Hattiesburg/Laurel 7.93
Jackson/Hawkins Field 4.03
Meridian/Key Field 4.00
Jackson Wfo 3.93
Meridian Nas/Mccain 1.72

NORTH CAROLINA
Wilmington/New Hanover Co. Arpt 4.07
Jacksonville/Ellis Airport 1.50

SOUTH CAROLINA
Mount Pleasant 5.5 Nne 9.08
Pawleys Island 5.6 Nne 8.36
Charleston 2.8 Ne 7.36
Johns Island 9.0 Se 6.44
Meggett 1.8 W 4.85
Beaufort Mcas 3.59
Rock Hill-York Co. Arpt 2.89
Darlington 1.75

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



Aug. 30, 2012

GOES visible image of Hurricane Kirk and Tropical Depression 12 in the central Atlantic Ocean on Aug. 30› View larger image
This visible image of Tropical Storm Isaac over the U.S. Gulf coast, Hurricane Kirk and Tropical Depression 12 in the central Atlantic Ocean. The image was taken from NOAA's GOES-13 satellite on Aug. 30 at 7:45 a.m. EDT.
Credit: NASA GOES Project
NASA Spies Fifth Atlantic Hurricane and Twelfth Tropical Depression

Tropical Storm Kirk intensified into a hurricane today, Aug. 30, while another tropical depression was born. Satellite imagery revealed Hurricane Kirk and newborn Tropical Depression 12 romping through the central Atlantic Ocean today, while Tropical Storm Isaac continues to drench the U.S. Gulf coast and Mississippi Valley. Kirk became the Atlantic Ocean season's fifth hurricane today, Aug. 30.

On Aug. 30 at 7:45 a.m. EDT, a visible image from NOAA's GOES-13 satellite captured all three tropical cyclones in a panoramic shot of the Atlantic Ocean basin. The visible image showed Tropical Storm Isaac over the U.S. Gulf coast, Hurricane Kirk and Tropical Depression 12 in the central Atlantic Ocean. Isaac was by far the largest of the three systems, with cloud cover extending from east Texas to the Carolinas. Hurricane Kirk appeared as a small, rounded , compact storm, located northwest of newborn Tropical Depression 12, which appeared larger than Kirk. The image was created by the NASA GOES Project at the NASA Goddard Space Flight Center in Greenbelt, Md.


Hurricane Kirk

At 11 a.m. EDT on Aug. 30, Kirk became the fifth hurricane of the Atlantic Ocean season. Its maximum sustained winds were near 75 mph (120 kmh). It was far from land, however, about 1.065 miles (1.715) northeast of the Northern Leeward Islands near 27.2 North and 49.5 West. It was moving to the northwest at 12 mph (19 kmh) and had a minimum central pressure of 989 millibars. The GOES-13 image showed that Kirk was a compact hurricane, and hurricane-force winds only extend 10 miles (20 km) from the center, while tropical-storm-force winds extend up to 70 miles (110 km).


Tropical Depression 12 Expected to Become Tropical Storm Leslie

On Aug. 30 at 11 a.m. the warm summertime waters of the Atlantic Ocean gave birth to the twelfth tropical depression on the season. Tropical Depression 12 (TD12) had maximum sustained winds near 35 mph (55 km/h), and is expected to become a tropical storm later on Aug. 30 and could become a hurricane over the weekend, according to the National Hurricane Center.

TD12 was also far from land areas, located about 1,185 miles (1,905 km) east of the Windward Islands, near latitude 14.1 north and longitude 43.4 west. TD12 is moving quickly to the west near 20 mph (32 kmh). TD12's estimated minimum central pressure is 1007 millibars.

Satellite data shows a well-defined curved band of thunderstorms wrapping around the western side of the circulation center.TD12 is expected to move over warm waters which will help it strengthen, and it could become Tropical Storm Leslie later on Aug. 30,or Hurricane Leslie by the weekend of Sept. 2.

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