[image-220]NASA Catches a Weaker Edouard, Headed Toward Azores
NASA's Aqua satellite passed over the Atlantic Ocean and captured a picture of Tropical Storm Edouard as it continues to weaken. The National Hurricane Center expects Edouard to affect the western Azores over the next two days.
NASA's Aqua satellite flew over Tropical Storm Edouard on Sept. 18 at 1:45 p.m. EDT and the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument took a visible picture that showed the eye had disappeared and the bulk of clouds pushed east of center.
At 5 a.m. EDT on Sept. 19, Edouard's maximum sustained winds had decreased to near 60 mph (95 kph). The storm's center was located near latitude 39.8 north and longitude 38.5 west. That's about 530 miles (855 km) west-northwest of Faval Island in the Western Azores.
Portugal's Azores Islands include nine volcanic islands in the North Atlantic Ocean. They are about 850 miles (1,360 km) west of continental Portugal.
Edouard is expected to become a post-tropical cyclone later on Sept. 19. Then it is forecast to head east and affect the western Azores Islands over the weekend of Sept. 20 and 21 before turning south and weakening to a depression.
NASA's Goddard Space Flight Center
[image-174][image-190][image-93]NASA Sees Hurricane Edouard Enter Cooler Waters
NASA's Tropical Rainfall Measuring Mission or TRMM satellite and Aqua satellite gathered data on Hurricane Edouard's rainfall, clouds and waning power is it continued moving northward in the Atlantic into cooler waters. On Sept. 18, NASA's Global Hawk #872 set out to investigate Edouard again as the storm is expected to weaken to a tropical storm.sept
Edouard, which became the fifth named storm of the season after forming on the night of September 11th (EDT) west of the Cape Verde Islands, continued to strengthen as it made its way through the central Atlantic this past week, reaching hurricane intensity on the 14th before becoming the first major hurricane of the season when it peaked briefly as a category 3 storm on the 16th with sustained winds reported at 100 knots (~115 mph) by the National Hurricane Center (NHC). Fortunately, the storm has not posed a threat to the U.S. East Coast due to the presence of a deep-layer trough along the Eastern Seaboard, which has prevented Edouard from moving further westward and forced it to recurve over the central Atlantic.
TRMM Satellite Peers at Edouard's Eyewall Replacement
This latest overpass of Edouard by the TRMM satellite was taken at 03:39 UTC on Sept. 17 (Sept. 16 at 11:39 p.m. EDT) soon after the storm began to recurve to the northeast well east of Bermuda. By this time Edouard had weakened to a category 1 storm with maximum sustained winds reported at 80 knots (~92 mph) by NHC.
However, the TRMM satellite saw that Edouard still had a very robust and mature circulation as evidenced by the presence of a well-defined eye and two concentric bands of rain surrounding the storm's center.
After tropical cyclones reach their peak intensity and continue to age, it's not uncommon for their wind field (i.e., circulation) to expand. That is the case with Edouard, this can happen as the result of an "eyewall replacement cycle" where a newer outer eyewall forms around the original eyewall creating a double eye-wall structure (i.e., the two concentric rainbands) and another ring of stronger winds around the center but further out.
At that time, Edouard's minimum central pressure was 959 millibars and is nearly as low as it was when Edouard was a category 3 hurricane on the Saffir-Simpson scale, but the pressure gradient is now spread over a larger area, which reduces the storm's peak wind intensity but increase the extent of stronger winds over a larger area.
Getting a 3-D Look at the Storm
At NASA's Goddard Space Flight Center in Greenbelt, Maryland the TRMM team created a 3-D image of Edouard using TRMM Precipitation Radar data. The 3-D image showed that there was little in the way of the tall convective (rising air that forms) thunderstorm towers that can energize the storm's circulation. That's because Edouard was beginning to move over cooler waters. TRMM is a joint mission between NASA and the Japanese space agency JAXA.
NASA's Aqua Satellite Passed Over Edouard
On Sept. 17 at 12:40 p.m. EDT the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA's Aqua satellite took a visible picture of Hurricane Edouard in the Atlantic Ocean. Edouard's eye had become obscured by high clouds. The image revealed bands of thunderstorms spinning into the center from the northern and southern quadrants. The image was created by the NASA Goddard MODIS Rapid Response Team at NASA Goddard.
NASA's HS3 Mission Flying Over Edouard Sept. 18
The remotely piloted Global Hawk aircraft is part of NASA's airborne Hurricane and Severe Storm Sentinel, or HS3 mission that has been investigating tropical cyclones in the Atlantic this summer. The Global Hawk took off from NASA's Wallops Flight Facility, Wallops Island, Virginia, at 7:15 EDT to start Science Flight #8 to Hurricane Edouard
On Sept. 18 at 8 a.m. EDT, the National Hurricane Center noted the Edouard was still a hurricane despite moving over waters near 24 Celsius (75.2 Fahrenheit). Sea surface temperatures of at least 26.6C (80F) are needed for a hurricane to maintain strength, so it's only a matter of time until Edouard weakens below hurricane status.
Where is Edouard?
At 5 a.m. EDT on Sept. 18, the center of Hurricane Edouard was located near latitude 39.6 north and longitude 45.3 west. Edouard was moving toward the east-northeast near 28 mph (44 kph) and is expected to slow down as it moves eastward. Maximum sustained winds remain near 85 mph (140 kph) and weakening is forecast during the next 48 hours.
Edouard continues to move to the northeast away from the U.S. and is expected to begin to weaken and become post tropical before winding up somewhere west of the Azores in the next few days.
Stephen Lang / Rob Gutro
SSAI/NASA Goddard Space Flight Center
[image-142]Sept. 17, 2014 - NASA Sees Hurricane Edouard Far From U.S., But Creating Rough Surf
Although NASA's Aqua satellite showed that Hurricane Edouard is far from U.S. soil, it is powerful enough that it is creating dangerous swells along the U.S. East Coast.
On Sept. 17, the National Hurricane Center noted "Swells from Edouard will affect portions of the east coast of the United States north of Florida beginning today. These swells will likely cause life-threatening rip current conditions along most of the United States east coast for the next couple of days."
When NASA's Aqua satellite passed over Hurricane Edouard on Sept. 16 the MODIS instrument captured a visible image of the storm that it still maintained its eye. Bands of powerful thunderstorms were spinning into the center from the north and south.
At 11 a.m. EDT on Sept. 17, Edouard's maximum sustained winds were near 90 mph (150 kph) and weakening is forecast. The eye of Hurricane Edouard was located near latitude 36.4 north and longitude 53.3 west. Edouard is moving toward the northeast near 24 mph (39 kph) and turn east on Sept. 18. The latest minimum central pressure reported by a NOAA Hurricane Hunter aircraft is 958 millibars.
The National Hurricane Center expects rapid weakening on Sept. 18 with Edouard dropping in intensity to a tropical storm. [image-77]
NASA's Goddard Space Flight Center
[image-110][image-126]Sept. 16, 2014 - NASA's Global Hawk and Satellites Investigating Hurricane Edouard Today
The unmanned Global Hawk aircraft that's part of NASA's airborne Hurricane and Severe Storm Sentinel, or HS3 mission was winging its way to Hurricane Edouard on September 16. In addition to the Global Hawk, various NASA satellites are continually providing data on the Atlantic hurricane.
Scientific instruments aboard NASA's remotely piloted Global Hawk aircraft have been studying the hurricane over the last couple of days, and the Global Hawk returned to Edouard again today, September 16. Two of the instruments aboard the Global Hawk that will study Edouard are the S-HIS and CPL. The S-HIS or Scanning High-resolution Interferometer Sounder will provide continuous sampling of temperature and relative humidity in the clear-air environment, while the CPL or Cloud Physics Lidar will study the aerosols (tiny particles) and the vertical structure of the cloud layers of the hurricane.
"Hopefully Edouard will maintain a clear eye so that S-HIS and CPL can get a good look down into it," said Scott Braun, Principal Investigator of the HS3 mission of NASA's Goddard Space Flight Center in Greenbelt, Maryland. In addition to the S-HIS and CPL, the Advanced Vertical Atmospheric Profiling System (AVAPS) will drop sondes into the hurricane that will measure temperature, humidity and full tropospheric wind (winds in every level of the troposphere from top to bottom as the sonde falls).
On September 15 at 12:47 p.m. EDT when NASA's Aqua satellite passed over the Central Atlantic, several instruments that fly aboard captured information about the storm in visible and infrared light. The Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard captured a visible image of Hurricane Edouard revealing thick bands of thunderstorms spiraling into a clear eye.
At the same time, The Atmospheric Infrared Sounder or AIRS instrument aboard analyzed those bands of thunderstorms in infrared light. Infrared light tells temperature of the cloud tops and surrounding sea surface. AIRS revealed that some of the cloud top temperatures in the band of tightly wound thunderstorms around Edouard's center were near 220 kelvin (-63F/-53C) indicating that they were high in the troposphere, and powerful. NASA research has shown that storms with cloud tops that high and cold have the potential to drop heavy rainfall. Forecaster Berg at the National Hurricane Center noted at 5 a.m. EDT on September 16 that "Convective (thunderstorm) cloud tops within Edouard's eyewall have occasionally been as cold as about -75C, but the eye has actually cooled during the past few hours."
On September 16 at 0614 UTC (2:14 a.m. EDT) NASA's Tropical Rainfall Measuring Mission or TRMM satellite also flew over Edouard and showed that the hurricane's eyewall is partially open on the north side, which means it is exposed to outside winds that can weaken it.
At 5 a.m. EDT Hurricane Edouard's maximum sustained winds were near 110 mph (175 kph)and some slight strengthening is possible over the next day, according to the National Hurricane Center. The hurricane is about 465 miles (765 km) east-southeast of Bermuda, and is moving to the north-northwest at 13 mph (20 kph), however it is expected to turn to the north followed by a turn northeast on September 17.
Edouard is expected to strengthen over the next day before weaken quickly due to colder water and increasing vertical wind shear.
The HS3 mission is funded by NASA Headquarters and overseen by NASA's Earth System Science Pathfinder Program at NASA's Langley Research Center in Hampton, Virginia. It is one of five large airborne campaigns operating under the Earth Venture program.
NASA's Goddard Space Flight Center
[image-63]Sept. 15, 2014 - Satellites Show Edouard's Transition into an Atlantic Hurricane
NASA's Terra satellite passed over Tropical Storm Edouard each day from September 12 through 14 and captured imagery of the storm as it grew into a hurricane. NOAA's GOES-East satellite covers the Atlantic Ocean and takes visible images during the day and infrared images at night to show the movement of weather systems. Those images were compiled into a movie from Sept. 13 through 15 showing movement and intensification of Edouard into a hurricane. NASA's HS3 Mission also investigated the storm.
NASA's Terra satellite captured the three images of Edouard as it transitioned into a hurricane. When Terra flew over the storm, the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument captured visible images on September 12 at 9:10 a.m. EDT, September 13 at 9:50 a.m. EDT, and September 14 at 10:35 a.m. EDT. The three images together show that Edouard consolidated as it strengthened - that is, bands of thunderstorms became more tightly wrapped around the storm. By September 14, the bands of thunderstorms were concentrated over the northern quadrant of the storm and wrapping into the cloud-filled eye.
[image-94]The NASA/NOAA GOES Project at NASA's Goddard Space Flight Center in Greenbelt, Maryland combined NOAA's GOES-East satellite imagery of Edouard taken over several days from September 13 through 15. The showed the storm consolidating. The eye of the hurricane became visible on and off during September 14 in between being obscured by high clouds, and the eye opened again on September 15.
On Sunday morning, September 14, 2014 at 1102 UTC (7:02 a.m. EDT) NASA's Global Hawk 872 took off from NASA's Wallops Flight Facility, Virginia on a flight toward Tropical Storm Edouard for a 24 hour mission. It was the sixth science flight for the Global Hawk during the Hurricane and Severe Storms Sentinel or HS3 mission. For more information about NASA's HS3 mission, visit: www.nasa.gov/hs3
On Sunday at 5 p.m. EDT Edouard's maximum sustained winds had increased to near 85 mph (140 mph) and additional strengthening is forecast. The National Hurricane Center (NHC) noted on Monday, September 15 at 11 a.m. EDT that Edouard's maximum sustained winds increased to 105 mph (165 kph) making it a Category 2 hurricane on the Saffir-Simpson Scale.
NHC forecaster Cangliaosi noted "Satellite images show that the eye of Edouard has become larger and more distinct during the past few hours, with a fairly symmetric inner-core convective pattern."
The center of Hurricane Edouard was near latitude 27.3 north and longitude 55.5 west. That's about 655 miles (1,055 km) east-southeast of Bermuda. Edouard was moving toward the northwest near 14 mph (22 kph) and a movement toward the north is expected on Tuesday, September 16. The estimated minimum central pressure is 966 millibars.
The NHC forecast calls for some strengthening through the end of the day on September 16 while the hurricane remains in favorable conditions. Beyond that time, cooler water, dry air, and a pronounced increase in wind shear is expected to cause Edouard to weaken steadily.
NASA's Goddard Space Flight Center
[image-51]Sept. 12, 2014 - NASA-NOAA Suomi NPP Sees Formation of Tropical Storm Edouard
The sixth tropical depression of the Atlantic Ocean hurricane season formed in the central Atlantic Ocean yesterday, and today, September 12, it strengthened into Tropical Storm Edouard. NASA-NOAA's Suomi NPP satellite flew over Edouard and provided forecasters with an infrared view of what's happening within the strengthening storm.
When Suomi NPP passed over Edouard on September 12 at 04:37 UTC (12:37 a.m. EDT), the Visible Infrared Imaging Radiometer Suite or VIIRS instrument aboard captured an infrared image of the storm. The infrared data shows temperature, an indicated that there were very high thunderstorms with very cold cloud top temperatures surrounding the center of the low level circulation.
VIIRS is a scanning radiometer that collects visible and infrared imagery and "radiometric" measurements. Basically it means that VIIRS data is used to measure cloud and aerosol properties, ocean color, sea and land surface temperature, ice motion and temperature, fires, and Earth's albedo (reflected light).
At 11 a.m. EDT (1500 UTC) the center of Tropical Storm Edouard was located near latitude 18.5 north and longitude 43.0 west. That's about 1,315 miles (2,120 km) east of the Northern Leeward Islands Edouard is moving toward the west-northwest near 16 mph (26 kph) and this motion with a gradual decrease in forward speed is expected during the next couple of days.
Maximum sustained winds have increased to near 45 mph (75 kph) and some slight strengthening is possible during the next two days.
Forecaster Avila of the National Hurricane Center noted that Edouard is moving toward the west-northwest at 14 knots (16 mph/26 kph) steered by the flow around the edge of a large elongated area of high pressure known as the Atlantic subtropical ridge. A gradual turn to the northwest and north is forecast in about 3 to 4 days when the ridge weakens.
The National Hurricane Center expects Edouard to become a hurricane by Monday, September 15 and stay east of Bermuda, curving back to the northeast.
NASA's Goddard Space Flight Center
[image-38]Sept. 11, 2014 - Satellite View of Newborn Atlantic Tropical Depression 6
The sixth tropical depression of the Atlantic Ocean Hurricane Season formed in the Eastern Atlantic Ocean and NOAA's GOES-East satellite captured it.
A visible image of Tropical Depression 6 was taken by NOAA's GOES-East satellite at 7:45 a.m. EDT on September 11 as it developed. The image was created by NASA/NOAA's GOES Project at the NASA Goddard Space Flight Center in Greenbelt, Maryland.
In addition to using GOES imagery and data from other NOAA and NASA satellites, The National Hurricane Center also uses measurements from the Advanced Scatterometer or ASCAT instrument that flies aboard the EUMETSAT METOP satellite. Forecaster Beven at the National Hurricane Center noted "Satellite imagery and a recent ASCAT-B overpass indicate that the low pressure area over the eastern Atlantic has a well-defined circulation and organized convective banding near the center."
At 11 a.m. EDT Tropical Depression Six had maximum sustained winds near 35 mph (55 kph) and the depression could become a tropical storm later in the day. The center of Tropical Depression Six was located near latitude 16.2 north and longitude 37.1 west, about 870 miles (1,400 km) west of the Cape Verde Islands. The depression is moving toward the northwest near 13 mph (20 kph) and is expected to move northwest or west-northwest is expected during the next couple of days. The estimated minimum central pressure is 1007 millibars.
Despite being in an area of wind shear, the NHC noted that computer model guidance forecasts slow but steady strengthening.
NASA's Goddard Space Flight Center