Oct. 15, 2018 – NASA Sees Remnants of Post-Tropical Cyclone Leslie Over Spain
Post-tropical cyclone Leslie made landfall in Portugal bringing heavy rains and hurricane-force winds. On Oct. 14, NASA-NOAA’s Suomi NPP satellite spotted the remnant clouds over northern Spain.
NASA-NOAA’s Suomi NPP satellite passed over Post-tropical Cyclone Leslie on Oct. 13 and the VIIRS instrument provided a visible image of the storm. The VIIRS image showed a disorganized low pressure area over the Iberian Peninsula, covering Portugal and Spain. Credit: NASA
Post-tropical cyclone Leslie made landfall at night on Oct. 13, local time. Leslie’s winds left 300,000 without power in Portugal and brought heavy rain. Lisbon, Leiria and Coimbra received the strongest winds.
Suomi NPP passed over Leslie on Oct. 13 and the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument provided a visible image of the storm. The VIIRS image showed a disorganized low pressure area over the Iberian Peninsula, covering Portugal and Spain.
On Oct. 15, the remnants were bringing downpours to southern Spain and western Italy down to Sicily. The remnants continue to move east through the Mediterranean Sea.
Oct. 12, 2018 – NASA Tracking Hurricane Leslie Toward Southern Spain, Portugal
NASA-NOAA’s Suomi NPP satellite passed over the Eastern Atlantic Ocean and captured a visible image of Hurricane Leslie as it continues to travel toward southern Spain and Portugal.
NASA-NOAA’s Suomi NPP satellite passed over the Eastern Atlantic Ocean and captured a visible image of Hurricane Leslie. Credit: NASA Worldview, Earth Observing System Data and Information System (EOSDIS)/NOAA
A Tropical Storm Warning is in effect for Madeira Island. Interests in Portugal and Spain should monitor the progress of Leslie. Leslie is expected to bring significant rain and wind impacts to portions of Portugal and Spain by Sunday
Suomi NPP passed over Leslie on Oct. 11 and the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument provided a visible image of the storm. The VIIRS image showed Leslie’s cloud pattern continues to feature a central dense overcast, but with only hints of an eye in visible imagery. A large area of clouds extend northeast of Leslie’s center that are associated with an elongated area or trough of low pressure.
At 2p.m. EDT (1800 UTC), the center of Hurricane Leslie was located near latitude 33.3 degrees north and longitude 26.1 degrees west. Leslie is moving toward the east-northeast near 33 mph (54 km/h). A fast motion toward the east-northeastward is expected to continue through Saturday morning, followed by a slower eastward motion late Saturday through Monday.
Maximum sustained winds are near 85 mph (140 kph) with higher gusts. Some weakening is forecast during the next day or so, but Leslie is expected to transition into a powerful post-tropical cyclone by Saturday night, Oct. 13.
On the forecast track, the center of Leslie will pass north of Madeira Island on Saturday, and approach the southwestern portion of the Iberian Peninsula on Saturday night, and move inland over portions of the Iberian Peninsula on Sunday.
Hurricane Leslie had a ragged eye on imagery from NASA-NOAA’s Suomi-NPP satellite when it passed over the Eastern Atlantic.
NASA-NOAA’s Suomi NPP satellite provided a visible image of the very large Hurricane Leslie on Oct. 10 as it continued to linger in the Eastern Atlantic. Credit: NASA Worldview, Earth Observing System Data and Information System (EOSDIS)/ NOAA
On Oct. 10, the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard NASA-NOAA’s Suomi-NPP satellite looked at Leslie in visible light. Leslie is a large storm with a large area of powerful thunderstorms circling the ragged eye. Hurricane-force winds extend outward up to 30 miles (45 km) from the center and tropical-storm-force winds extend outward up to 240 miles (390 km).
On Oct. 11, the National Hurricane Center said that Leslie’s structure has remained steady since the night of Oct. 10. The hurricane has a ragged banding eye surrounded by a somewhat patchy central dense overcast.
At 11 a.m. EDT (1500 UTC), the center of Hurricane Leslie was located near latitude 29.1 degrees north and longitude 38.3 degrees west. That’s about 895 miles (1,440 km) southwest of the Azores Islands. The National Hurricane Center or NHC noted that Leslie is moving toward the east-northeast near 16 mph (26 kph), and this general motion with some increase in forward speed could begin by late Saturday, Oct. 13. Maximum sustained winds are near 80 mph (130 kph) with higher gusts. Little change in strength is forecast during the next 48 hours, but weakening is expected over the weekend.
Leslie is now accelerating east-northeastward on the south side of a mid-latitude trough (elongated area of low pressure) that is moving across the North Atlantic. By 48 hours (Oct. 13) and onward, Leslie will be moving into a far more stable environment and over cooler waters, so steady weakening is anticipated.
Oct. 10, 2018 – NASA Sees Atlantic’s Leslie Become a Hurricane
NASA’s Aqua satellite captured an infrared image of Hurricane Leslie that revealed strong storms circled the center.
At 1:55 a.m. EDT (0555 UTC) on Oct. 3, the MODIS instrument that flies aboard NASA’s Aqua satellite gathered infrared data on Hurricane Leslie. Strongest thunderstorms circled the center and were in a thick band northeast of center where cloud top temperatures were as cold as minus 63 degrees Fahrenheit (minus 53 Celsius). Credit: NASA/NRL
At 1:55 a.m. EDT (0555 UTC) on Oct. 3 the MODIS instrument that flies aboard NASA’s Aqua satellite gathered infrared data on Leslie. Infrared data provides temperature information. Strongest thunderstorms were fragmented as they circled the center and were in a thick band northeast of center where MODIS found cloud top temperatures as cold as minus 63 degrees Fahrenheit (minus 53 Celsius). NASA research has shown that cloud tops with temperatures that cold were high in the troposphere and have the ability to generate heavy rain.
The National Hurricane Center or NHC noted “Deep convection surrounding the center of Leslie has become better organized overnight, with the development of a ragged eye in infrared satellite images.” A microwave image revealed a well-defined low-level eye with a ring of broken convection surrounding it.
At 5 a.m. EDT (0900 UTC), the center of Hurricane Leslie was located near latitude 29.6 degrees north and longitude 56.9 degrees west. That’s about 505 miles (810 km) east-southeast of Bermuda. Leslie is nearly stationary, and little motion is expected today. A northward motion is forecast to begin tonight, and this motion should continue through Friday night. Maximum sustained winds have increased to near 75 mph (120 kph) with higher gusts. Some additional strengthening is forecast during the next day or so.
NHC noted “The hurricane is forecast to remain within favorable environmental conditions consisting of warm water and low vertical wind shear over the next day or two. These conditions should allow for some additional strengthening.”
Oct. 09, 2018 – NASA Gets Tropical Storm Leslie by the Tail
What appears to be a long tail in satellite imagery of Tropical Storm Leslie is in fact clouds associated with a nearby elongated area of low pressure, or a trough.
On Oct. 8, the VIIRS instrument aboard NASA-NOAA’s Suomi satellite provided a visible look at Tropical Storm Leslie that showed a developing eye and clouds associated with an elongated area of low pressure that extends over the United Kingdom. Credit: NASA Worldview, Earth Observing System Data and Information System (EOSDIS)
On Oct. 8, the VIIRS instrument aboard NASA-NOAA’s Suomi satellite provided a visible look at Tropical Storm Leslie that showed a developing eye and a long stretch of clouds associated with an elongated area of low pressure that extends over the United Kingdom.
NOAA’s National Hurricane Center noted “Although the winds have not yet increased, the surface center of the tropical storm has become more embedded within its cold cloud tops and several recent microwave overpasses indicate that the cyclone is beginning to establish an inner-core. Strengthening is therefore still expected, and Leslie is forecast to become a hurricane by tomorrow.”
At 11 a.m. EDT (1500 UTC) on Oct. 9 the center of Tropical Storm Leslie was located near latitude 31.3 degrees north and longitude 43.5 degrees west. That’s 1,045 miles (1,680 km) west-southwest of the Azores Islands. Leslie is moving toward the south-southeast near 13 mph (20 kph), and this general motion is expected to continue for the next day or so. Maximum sustained winds are near 65 mph (100 kph) with higher gusts. Some strengthening is anticipated, and Leslie is forecast to become a hurricane again on Wednesday.
The National Hurricane Center cites different forecast modeling possibilities for Leslie. It could merge with a trough or elongated area of low pressure or Leslie could remain a tropical cyclone almost indefinitely if it continues meandering over the northern Atlantic.
NASA’s Aqua satellite passed over the Central Atlantic Ocean and obtained infrared data on Leslie, now weakened to a large tropical storm.
The National Hurricane Center or NHC said that Leslie remains a large tropical storm, with tropical-storm-force winds extending outward up to 290 miles (465 km) from the center. Because of the size and strength of Tropical Storm Leslie, waves from Leslie are expected to increase along the coasts of Atlantic Canada and New England today, Oct. 5.
At 1:40 a.m. EDT (0540 UTC) on Oct. 5, the MODIS instrument aboard NASA’s Aqua satellite revealed strongest storms with the coldest cloud top temperatures (yellow) northwest of Leslie’s center with temperatures near minus 63 degrees Fahrenheit (minus 53 degrees Celsius). Credit: NASA/NRL
At 1:40 a.m. EDT (0540 UTC) on Oct. 5, the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Aqua satellite revealed strongest storms with the coldest cloud top temperatures northwest of Leslie’s center. MODIS found coldest cloud tops had temperatures near minus 63 degrees Fahrenheit (minus 53 degrees Celsius). NASA research has found that cloud top temperatures that cold have the capability to generate heavy rainfall.
At 5 a.m. EDT (0900 UTC), the center of Tropical Storm Leslie was located near 35.9 degrees north latitude and 58.3 degrees west longitude. Leslie is moving toward the north-northwest near 14 mph (22 kph). A slower northward motion is expected to occur today, but Leslie will make a sharp turn toward the east and east-southeast over the weekend.
Maximum sustained winds are near 65 mph (100 kph) with higher gusts. Little change in strength is forecast during the next several days.
NHC cautioned, “Large swells generated by Leslie will continue to affect portions of the southeastern coast of the United States, Bermuda, the Bahamas, and the Greater and Lesser Antilles during the next few days. Swells are expected to increase near the coasts of New England and Atlantic Canada today.”
When Tropical Storm Leslie strengthened into a hurricane, the Global Precipitation Measurement mission or GPM core satellite passed overhead and analyzed the rates in which rain was falling throughout the stronger storm.
The GPM or Global Precipitation Measurement mission core observatory satellite passed above Hurricane Leslie on Oct. 3, 2018 at 7:33 a.m. EDT (1133 UTC) and found rain was falling at over 1.8 inches (45.7 mm) per hour within storms located in the northwestern side of the Leslie’s eye wall. Credit: NASA/JAXA, Hal Pierce
Although Leslie is in the Central Atlantic Ocean, it’s strong enough to generate dangerous ocean swells that will continue to affect portions of the southeastern coast of the United States, Bermuda, and the Bahamas during the next few days. Swells are expected to increase near the coasts of New England and Atlantic Canada by the end of the week.
The GPM core observatory satellite passed above Hurricane Leslie on Oct. 3, 2018 at 7:33 a.m. EDT (1133 UTC). GPM is a joint mission between NASA and the Japan Aerospace Exploration Agency or JAXA.
At the time GPM passed overhead, Leslie had just been upgraded to a hurricane by the National Hurricane Center (NHC). GPM’s Microwave Imager (GMI) instruments collected data that revealed light to moderate convective rainfall in Leslie’s clearly evident eye wall. Very little precipitation was shown by GPM in the center of the hurricane’s nearly circular eye. Algorithms developed by NASA’s Precipitation Measurement Missions (PMM) science team indicated that rain was falling at over 1.8 inches (45.7 mm) per hour within storms located in the northwestern side of the Leslie’s eye wall.
The GPM or Global Precipitation Measurement mission core observatory satellite passed above Hurricane Leslie on Oct. 3, 2018 at 7:33 a.m. EDT (1133 UTC) and found rain was falling at over 1.8 inches (45.7 mm) per hour within storms located in the northwestern side of the Leslie’s eye wall. Credit: NASA/JAXA, Hal Pierce
At NASA’s Goddard Space Flight Center in Greenbelt, Md. a 3D animation of the storm was created that showed the estimated heights of storms within hurricane Leslie at the time of the GPM satellite pass. Storm top heights are based on data observed by GPM’s Dual Frequency Precipitation Radar (DPR Ku Band) blended with estimates based on geostationary satellite cloud top temperatures.
The National Hurricane Center (NHC) noted at 5 a.m. EDT (0900 UTC), the center of Hurricane Leslie was located near latitude 31.4 degrees north and longitude 57.1 degrees west. That’s 455 miles (735 km) east of Bermuda.
Leslie is moving toward the north near 8 mph (13 kph), and this motion with an increase in forward speed is expected through tonight. A reduction in speed is forecast on Friday and Friday night, with Leslie accelerating toward the east or east-southeast over the weekend. Maximum sustained winds are near 80 mph (130 kph) with higher gusts. Gradual weakening is forecast during the next several days.
Oct. 03, 2018 – NASA Sees Atlantic’s Leslie Become a Hurricane
NASA’s Aqua satellite captured an infrared image of Hurricane Leslie that revealed strong storms circled the center.
At 1:55 a.m. EDT (0555 UTC) on Oct. 3, the MODIS instrument that flies aboard NASA’s Aqua satellite gathered infrared data on Hurricane Leslie. Strongest thunderstorms circled the center and were in a thick band northeast of center where cloud top temperatures were as cold as minus 63 degrees Fahrenheit (minus 53 Celsius). Credit: NASA/NRL
At 1:55 a.m. EDT (0555 UTC) on Oct. 3 the MODIS instrument that flies aboard NASA’s Aqua satellite gathered infrared data on Leslie. Infrared data provides temperature information. Strongest thunderstorms were fragmented as they circled the center and were in a thick band northeast of center where MODIS found cloud top temperatures as cold as minus 63 degrees Fahrenheit (minus 53 Celsius). NASA research has shown that cloud tops with temperatures that cold were high in the troposphere and have the ability to generate heavy rain.
The National Hurricane Center or NHC noted “Deep convection surrounding the center of Leslie has become better organized overnight, with the development of a ragged eye in infrared satellite images.” A microwave image revealed a well-defined low-level eye with a ring of broken convection surrounding it.
At 5 a.m. EDT (0900 UTC), the center of Hurricane Leslie was located near latitude 29.6 degrees north and longitude 56.9 degrees west. That’s about 505 miles (810 km) east-southeast of Bermuda. Leslie is nearly stationary, and little motion is expected today. A northward motion is forecast to begin tonight, and this motion should continue through Friday night. Maximum sustained winds have increased to near 75 mph (120 kph) with higher gusts. Some additional strengthening is forecast during the next day or so.
NHC noted “The hurricane is forecast to remain within favorable environmental conditions consisting of warm water and low vertical wind shear over the next day or two. These conditions should allow for some additional strengthening.”
Oct. 02, 2018 – NASA Soaks Up Tropical Storm Leslie’s Water Vapor Concentration
When NASA’s Aqua satellite passed over the Central Atlantic Ocean on Oct. 2 the MODIS instrument aboard analyzed water vapor within Tropical Storm Leslie.
NASA’s Aqua satellite passed over Tropical Storm Leslie in the Central Atlantic Ocean on Oct. 2 at 1:15 a.m. EDT (0515 UTC). The MODIS instrument showed highest concentrations of water vapor (brown) and coldest cloud top temperatures circled the center with a gap in the north-northeastern quadrant. Credits: NASA/NRL
Water vapor analysis of tropical cyclones tells forecasters how much potential a storm has to develop. Water vapor releases latent heat as it condenses into liquid. That liquid becomes clouds and thunderstorms that make up a tropical cyclone. Temperature is important when trying to understand how strong storms can be. The higher the cloud tops, the colder and the stronger they are.
NASA’s Aqua satellite passed over Tropical Storm Leslie in the Central Atlantic Ocean on Oct. 2 at 1:15 a.m. EDT (0515 UTC) and the Moderate Resolution Imaging Spectroradiometer or MODIS instrument gathered water vapor content and temperature information. The storm continues to have a ragged banded eye.
The MODIS image showed highest concentrations of water vapor and coldest cloud top temperatures circled the center with the exception of the north-northeastern quadrant. MODIS saw coldest cloud top temperatures were as cold as minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius) in those areas. Storms with cloud top temperatures that cold have the capability to produce heavy rainfall.
Leslie remains far enough from land areas so that there are no warnings or watches in effect. At 11 a.m. EDT (1500 UTC), the center of Tropical Storm Leslie was located near latitude 30.9 degrees north and longitude 56.1 degrees west. That’s 520 miles (840 km) east of Bermuda. Leslie is moving toward the southwest near 8 mph (13 kph). Maximum sustained winds remain near 65 mph (100 kph) with higher gusts.
The National Hurricane Center or NHC forecast noted “Gradual strengthening is expected during the next day or two, and Leslie is forecast to become a hurricane tonight or on Wednesday, Oct. 3.”
Oct. 01, 2018 – NASA Finds Bulk of Tropical Storm Leslie’s Storms Northwest of Center
Infrared imagery from NASA’s Aqua satellite showed the location of the strongest storms in reborn Tropical Storm Leslie is it moved through the Central North Atlantic Ocean.
Infrared satellite data at 2:10 a.m. EDT (0610 UTC) on Oct. 1 from NASA’s Aqua satellite revealed strongest storms with the coldest cloud top temperatures (yellow) were northwest of Leslie’s center. MODIS found coldest cloud tops had temperatures near minus 63 degrees Fahrenheit (minus 53 degrees Celsius). Credit: NASA/NRL
Subtropical Storm Leslie formed in the Central North Atlantic Ocean on Sept. 23. It faded out on Sept. 25 but was reborn as a Subtropical storm on Sept. 28. Since then, it has transitioned into a warm-core, tropical storm.
Infrared satellite data captured at 2:10 a.m. EDT (0610 UTC) on Oct. 1 from the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Aqua satellite revealed strongest storms with the coldest cloud top temperatures northwest of Leslie’s center. MODIS found coldest cloud tops had temperatures near minus 63 degrees Fahrenheit (minus 53 degrees Celsius). NASA research has found that cloud top temperatures that cold have the capability to generate heavy rainfall.
At 11 a.m. EDT, the National Hurricane Center or NHC noted, “Leslie is gradually becoming better organized. A large band of deep convection exists on the west side of the circulation and some fragmented bands are beginning to form on the east side. Overall, Leslie appears more symmetric than it has been during the past couple of days due to a decrease in wind shear.”
At 11 a.m. (1500 UTC), on Oct. 1 the center of Tropical Storm Leslie was located near latitude 33.2 degrees north and longitude 54.3 degrees west. That’s about 615 miles (85 km) east of Bermuda. Leslie is moving toward the west-southwest near 5 mph (7 kph). A slow southwestward or southward motion is forecast during the next few days. Maximum sustained winds are near 60 mph (95 km/h) with higher gusts.
The National Hurricane Center said, “Gradual strengthening is expected during the next 48 hours, and Leslie is forecast to become a hurricane on Tuesday (Oct. 2).”
