Nov. 09, 2018 – NASA Satellite Sees Tropical Cyclone Alcide Nearing Madgascar
Tropical Cyclone Alcide continued to linger just northeast of the Island nation of Madagascar in the Southern Indian Ocean when NASA’s Aqua satellite passed overhead and captured an image of the storm.
On Nov. 9 the MODIS instrument aboard NASA’s Aqua satellite captured a visible image of Tropical Cyclone Alcide in the Southern Indian Ocean, located northeast of Madagascar. Credit: NASA Worldview, Earth Observing System Data and Information System (EOSDIS)
On Nov. 9 the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Aqua satellite provided a visible light image of the storm. The MODIS image showed a somewhat elongated storm from northwest to southeast with the bulk of clouds in the western quadrant of the storm.
On Nov. 9, the Joint Typhoon Warning Center or JTWC noted that animated multispectral satellite imagery showed that Alcide has lost much of its deep convection (rising air that forms the thunderstorms that make up a tropical cyclone) but maintained its spiral banding, and convection is newly flaring over the low level circulation center.
On Nov. 9 at 10 a.m. EST (1500 UTC), Alcide’s maximum sustained winds had dropped to 80 mph (70 knots/129.6 kph). It was located approximately 487 nautical miles north-northwest of Port Louis, Mauritius. Alcide is moving southward at 1.1 mph (1 knot1.8 kph) and is expected to curve to the northwest.
Because of the storm’s slow movement, it is bringing up cooler waters from below the ocean’s surface, which will in turn, weaken the storm.
The Joint Typhoon Warning Center now expects Alcide to move to the northwest and pass just north of the northern point of Madagascar over the next several days.
The Global Precipitation Measurement mission or GPM core satellite passed over the Southern Indian Ocean and analyzed the rainfall occurring in pre-season Tropical Cyclone Alcide.
On Nov. 6, the GPM core satellite showed strong convective storms northwest of Alcide’s center of circulation were dropping rain at a rate of more than 44 mm (1.73 inches) per hour. Credit: NASA/JAXA, Hal Pierce
Tropical cyclone Alcide (03S), the first tropical cyclone of the 2018-2019 South-West Indian Ocean tropical cyclone season, has formed in the South Indian Ocean northeast of Madagascar. The Joint Typhoon Warning Center (JTWC) issued its first warning for 03S on Nov. 6, 2018 at 0000 UTC (Nov. 5 at 7 p.m. EST) when the tropical cyclone was located about 1,313 km (709 nautical miles) west of Diego Garcia. This is a little early for a tropical cyclone to develop in that part of the world. The South-West Indian Ocean tropical cyclone season doesn’t officially begin until November 15, 2018.
The GPM core observatory satellite had a good view of tropical cyclone Alcide on November 6, 2018 at 11:09 a.m. EST (1609 UTC). At that time Alcide had maximum sustained winds of about 35 knots (40.3 mph). GPM’s Microwave Imager (GMI) and GPM’s Dual-Frequency Precipitation Radar (DPR) instruments collected data that showed the location and intensity of precipitation within Alcide. GPM’s GMI indicated that strong convective storms northwest of Alcide’s center of circulation were dropping rain at a rate of more than 44 mm (1.73 inches) per hour. GPM’s radar (DPR Ku Band) probed Alcide in a swath through the eastern side of the tropical cyclone. Those data revealed the locations of precipitation within feeder bands spiraling into the southeastern side of the intensifying tropical cyclone.
On Nov. 6, the GPM core satellite showed strong convective storms northwest of Alcide’s center of circulation were dropping rain at a rate of more than 44 mm (1.73 inches) per hour. Credit: NASA/JAXA, Hal Pierce
At NASA’s Goddard Space Flight Center in Greenbelt, Maryland, a 3D animation was created from the data that showed a simulated flyby above Tropical Cyclone Alcide. Measurements of the relative heights of precipitation within tropical cyclone Alcide were made possible using GPM’s radar data (DPR Ku Band). DPR’s Ku Band radar enables three dimensional measurements of precipitation within a 152 mile (245 km) wide swath. The heights of precipitation over a larger area were estimated by blending measurements from GPM’s radar (DPR Ku band) with heights based on the Meteosat satellite’s infrared temperatures. GPM is a joint mission between NASA and the Japan Aerospace Exploration Agency, JAXA.
On Nov. 8 at 10 a.m. EST (1500 UTC), Alcide had achieved peak wind speed when maximum sustained winds were near 95 knots (110 mph/178 kph). A weakening trend is now expected, according to the JTWC. Alcide was centered near 12.1 degrees south latitude and 53.6 degrees east longitude, about 528 nautical miles north-northwest of Port Louis, Mauritius. Alcide was moving to the southwest.
Satellite data on Nov. 8 showed that the eye had become ragged and cloud-filled.
The JTWC forecast calls for Alcide to loop. Alcide is expected to remain well northeast of Madagascar. Alcide is then expected to move into an area of increasing vertical wind shear and lower sea surface temperatures causing the tropical cyclone to gradually weaken.
Nov. 07, 2018 – NASA Sees Tropical Cyclone Alcide Reach Hurricane Strength
NASA’s Terra satellite provided a visible image of a more organized Tropical Cyclone Alcide in the Southern Indian Ocean after it reached hurricane-force.
On Nov. 7, the MODIS instrument aboard NASA’s Terra satellite provided a visible image of Tropical Cyclone Alcide in the Southern Indian Ocean after it strengthened to hurricane-force. Credit: NASA Worldview, Earth Observing System Data and Information System (EOSDIS)
On Nov. 7, a visible image of Alcide taken by the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Terra satellite showed an organized storm with a thick band of powerful thunderstorms circling the center. The eye appears ragged on the MODIS imagery and is about 10 nautical miles wide. Satellite data taken after the MODIS image showed that the system continued to strengthen.
The Joint Typhoon Warning Center said that at 10 a.m. EST (1500 UTC) on Nov. 7, Alcide had maximum sustained winds near 75 knots (86 mph/139 kph). It was centered near 10.6 degrees south latitude and 55.7 degrees east longitude. Tropical cyclone Alcide is located approximately 587 nautical miles north of Port Louis, Mauritius, and was moving to the west-southwest.
Alcide is expected to strengthen over the next day or two before starting a weakening trend over cooler ocean waters.
Nov. 06, 2018 – Satellite Finds Tropical Cyclone 03S Develop in Southern Indian Ocean
Tropical Cyclone 03S formed in the Southern Indian Ocean and the NOAA-20 satellite passed overhead and captured a visible image of the storm.
At 5:12 a.m. EDT (0912 UTC) on Nov.6, the VIIRS instrument aboard NOAA’s NOAA-20 satellite captured a visible image of Tropical Cyclone 03S in the Southern Indian Ocean Credit: NASA/NRL
At 5:12 a.m. EDT (0912 UTC) on Nov.6, the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard the NOAA-20 polar orbiting satellite saw fragmented bands of thunderstorms around Tropical Storm 03S’s center of circulation. The VIIRS image revealed that the bulk of clouds and storms were south of the center. The Joint Typhoon Warning Center noted “The bulk of the deep convection remains concentrated southwestward of the low level circulation.”
On Nov. 6 at 11 a.m. EDT (1500 UTC) 03S’s maximum sustained winds were near 35 knots (40 mph/62 mph) making it a tropical storm. It was located approximately 641 nautical miles north of Port Louis, Mauritius near 9.7 south latitude and 58.9 east longitude. 03S was moving west-southwestward and is expected to strengthen over the next several days.
NOAA-20 is the first in the JPSS series of satellites. JPSS is a collaborative program between the National Oceanic and Atmospheric Administration (NOAA) and its acquisition agent, the National Aeronautics and Space Administration (NASA). NOAA is responsible for managing and operating the JPSS program, and developing portions of the ground segment, while NASA is responsible for developing and building the JPSS instruments, spacecraft, and portions of the ground segment and providing launch services.
Nov. 06, 2018 – Weakening Tropical Storm Xavier Observed By NASA
As Tropical Storm Xavier continued to rain on western Mexico, the Global Precipitation Measurement mission or GPM core satellite analyzed the rate in which rain was falling. The next day, Nov, 6, Xavier had weakened to a remnant low pressure area.
On November 4, 2018 at 11:33 a.m. EDT (1533 UTC) the GPM satellite found rain was falling at over 9.5 inches (241.3 mm) per hour in some of the powerful convective storms that were located to the northeast of Xavier’s low level center of circulation. Credit: NASA/JAXA, Hal Pierce
The GPM core observatory satellite passed directly above tropical storm Xavier’s low level center of circulation on November 4, 2018 at 11:33 a.m. EDT (1533 UTC). At that time Xavier was located in the eastern Pacific Ocean less than 150 nautical miles (277.8 km) south of Puerto Vallarta, Mexico. Xavier was experiencing strong southwesterly vertical wind shear.
The low level center of circulation was located well offshore while the tropical storm’s deep convection had been pushed toward Mexico’s coast. GPM’s Dual-Frequency Precipitation Radar (DPR) revealed that rain was falling at over 9.5 inches (241.3 mm) per hour in some of the powerful convective storms that were located to the northeast of Xavier’s low level center of circulation.
On November 4, 2018 at 11:33 a.m. EDT (1533 UTC) the GPM satellite found rain was falling at over 9.5 inches (241.3 mm) per hour in some of the powerful convective storms that were located to the northeast of Xavier’s low level center of circulation. Strong convective storms north and northeast of Xavier’s low level center of circulation are shown reaching altitudes of about 6.9 miles (11.1 km). Credit: NASA/JAXA, Hal Pierce
At NASA’s Goddard Space Flight Center in Greenbelt, Maryland a 3D image of Xavier’s precipitation structure was created from data collected by the GPM core observatory satellite’s radar (DPR Ku Band). In the 3D image, a view from the south shows that less precipitation was occurring in the southern side of the tropical storm. At the same time the strong convective storms north and northeast of Xavier’s low level center of circulation are shown reaching altitudes of about 6.9 miles (11.1 km). GPM is a joint mission between NASA and the Japan Aerospace Exploration Agency, JAXA.
On November 4, 2018 at 11:33 a.m. EDT (1533 UTC) the GPM or Global Precipitation Measurement Mission core satellite found rain was falling at over 9.5 inches (241.3 mm) per hour in some of the powerful convective storms that were located to the northeast of Xavier’s low level center of circulation. Strong convective storms north and northeast of Xavier’s low level center of circulation are shown reaching altitudes of about 6.9 miles (11.1 km). This animation shows multiple simulated 3D slices through and a simulated flight above tropical storm Xavier using GPM’s radar (DPR Ku Band) reflectivity data. Credit: NASA/JAXA, Hal Pierce
On Nov. 6, Tropical Storm Xavier moved away from Mexico’s coast and weakened into a remnant low pressure area. The National Hurricane Center noted “The remnant low of Tropical Storm Xavier near 19 degrees north latitude and 1089 degrees west longitude at 4 a.m. EDT (1 a.m. PDT) continues to produce minimal gale force winds. Winds will diminish below gale force this morning as the remnant low continues to spin down.”
Nov. 05, 2018 – NASA Sees Tropical Storm Xavier Affecting Western Mexico
Visible from NASA’s Aqua satellite revealed the extent of Tropical Storm Xavier into western Mexico from its position just off-shore from Mexico’s Jalisco state.
On Nov. 4, the MODIS instrument aboard NASA’s Aqua satellite looked at Tropical Storm Xavier just off-shore from western Mexico over the Eastern Pacific Ocean. Thunderstorms were streaming over the Mexican states of Jalisco and Michocan Credit: NASA Worldview, Earth Observing System Data and Information System (EOSDIS)
Tropical Depression Twenty-Five-E (25E) formed on Nov. 3 and strengthened in a tropical storm on by 11 p.m. EDT that day. When it became a tropical storm it was re-named Xavier. Xavier has continued to hug the coast of western Mexico since it formed.
On Nov. 4 a visible image from the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Aqua satellite showed an organized storm with a thick band of powerful thunderstorms circling the center.
On Nov. 5, a Tropical Storm Warning is in effect for Punta San Telmo to Playa Perula, Mexico. A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area.
The National Hurricane Center noted at 11 a.m. EDT the center of Tropical Storm Xavier was located near latitude 18.5 degrees north and longitude 106.2 degrees west. Xavier is moving slowly toward the west-northwest near 3 mph (6 kph), but an increase in forward speed is expected later today. Maximum sustained winds are near 60 mph (95 kph) with higher gusts. Weakening is forecast during the next few days, and Xavier is expected to degenerate into a remnant low by Tuesday night. Tropical-storm-force winds extend outward up to 115 miles (185 km) from the center. The estimated minimum central pressure is 999 millibars from the center. The estimated minimum central pressure is 1006 millibars.
NHC said that Xavier is expected to produce total rain accumulations of 1 to 3 inches over coastal sections of the Mexican states of Colima and Jalisco, with isolated maximum amounts of 4 inches possible. This rainfall may produce flooding. Swells generated by Xavier will affect portions of the coast of southwestern Mexico during the next few days.
On the forecast track, Xavier’s center is expected to remain offshore the coast of southwestern Mexico and continue to move farther away from the coast today.
Nov. 02, 2018 – NASA Finds Tropical Depression Yutu Fading off China Coast
Once a Super Typhoon, now a ghost of its former self, Tropical Depression Yutu was fading off the coast of southeastern China on Nov.2 when NASA’s Aqua satellite passed overhead.
NASA’s Aqua satellite captured this image of Tropical Depression Yutu fading off the coast of southeastern China on Nov. 2. Credit: NASA Worldview, Earth Observing System Data and Information System (EOSDIS)
The MODIS instrument or Moderate Resolution Imaging Spectroradiometer that flies aboard NASA’s Aqua satellite captured a visible image of Yutu on Nov. 2. Although the storm weakened to a depression, the center of circulation was still apparent on the MODIS imagery. The center was surrounded by wispy clouds and the bulk of clouds and any precipitation was falling north of the center and over China.
On Thursday, Nov. 1 at 11 p.m. EDT (0300 UTC on Nov. 2) Yutu’s maximum sustained winds were near 25 knots (28.7 mph/46.3 kph).
It was centered at 20.7 north latitude and 116.2 east longitude, about 155 nautical miles southeast of Hong Kong, China. Yutu was crawling to the northwest.
The Joint Typhoon Warning Center (JTWC) forecasts Yutu to dissipate by the end of the day.
Typhoon Yutu produced heavy rainfall as it passed over the island of Luzon in the northern Philippines. The Global Precipitation Measurement mission or GPM core satellite provided data on that rainfall. The storm has since weakened to a tropical storm and triggered warnings in China.
The GPM core observatory satellite observed Tropical Storm Yutu on October 31, 2018 at 0210 UTC (Oct. 30 at 10:10 p.m. EDT) as it passed directly above the center of circulation in the South China Sea. GPM showed very little rainfall was occurring near the low level center of circulation. Extremely heavy rainfall was found in powerful storms located northwest and southeast of Yutu’s center where rain was falling at greater than 183 mm (7.2 inches) per hour. Storm top heights were reaching altitudes above 15.5 km (9.6 miles) in the tallest convective storms northwest of Yutu’s center. Credit: NASA/JAXA, Hal Pierce
At least nine deaths have been attributed to the typhoon. Heavy rainfall caused a landslide in the town of Natonin where up to 24 people are still missing. As expected, the typhoon weakened as is passed over the mountainous terrain of northern Luzon.
The GPM core observatory satellite had an excellent view of Tropical Storm Yutu on October 31, 2018 at 0210 UTC (Oct. 30 at 10:10 p.m. EDT) as it passed directly above the center of circulation. At the time GPM passed overhead, Tropical Storm Yutu had maximum sustained winds of about 55 knots (63 mph) and was moving over the South China Sea. A rainfall analysis based on GPM’s Microwave Imager (GMI) and Dual-Frequency Precipitation Radar (DPR) instruments showed that very little rainfall was occurring near the tropical storm’s low level center of circulation. Extremely heavy rainfall was found by the satellite’s radar in powerful storms located northwest and southeast of Yutu’s center of circulation. GPM’s radar (DPR Ku Band) measured precipitation in those areas falling at the exceptional rate of greater than 183 mm (7.2 inches) per hour.
At NASA’s Goddard Space Flight Center in Greenbelt, Md. a 3D view of tropical storm Yutu was constructed using data from GPM’s radar (DPR Ku Band). The image, looking from the south showed the vertical structure of precipitation within the tropical storm. Those data revealed that storm top heights were reaching altitudes above 15.5 km (9.6 miles) in the tallest convective storms that were located well to the northwest of Yutu’s center of circulation. GPM is a joint mission between NASA and the Japan Aerospace Exploration Agency, JAXA.
The GPM core observatory satellite observed Tropical Storm Yutu on October 31, 2018 at 0210 UTC (Oct. 30 at 10:10 p.m. EDT) as it passed directly above the center of circulation in the South China Sea. GPM showed very little rainfall was occurring near the low level center of circulation. Extremely heavy rainfall was found in powerful storms located northwest and southeast of Yutu’s center where rain was falling at greater than 183 mm (7.2 inches) per hour. Storm top heights were reaching altitudes above 15.5 km (9.6 miles) in the tallest convective storms northwest of Yutu’s center. Credit: NASA/JAXA, Hal Pierce
On Nov. 1, the Hong Kong Observatory posted a Tropical Cyclone Warning Bulletin on Yutu 21:45 HKT (9:45 a.m. EDT) and noted that the Strong Wind Signal, No. 3 is in force. This means that winds with mean speeds of 41 to 62 kilometers (25 to 39 mph) per hour are expected.
On Nov. 1 at 11 a.m. EDT (1500 UTC), the Joint Typhoon Warning Center noted that satellite imagery shows disorganized deep convection (developing thunderstorms) becoming displaced to the northeast of a poorly defined low-level circulation center.” At that time, Tropical Storm Yutu had maximum sustained winds near 40 knots (46 mph/74 kph). It was centered near 20.7 degrees north latitude and 116.3 degrees east longitude. Tropical storm Yutu was located approximately 160 nautical miles southeast of Hong Kong, China and was moving north.
The bulk of clouds and precipitation is being pushed to the northeast from strong wind shear. In general, wind shear is a measure of how the speed and direction of winds change with altitude. In order to understand how it affects a tropical cyclone or hurricane, think of a tropical cyclone as a vertical rotating cylinder. The different levels of rotating winds in the center of Tropical cyclones need to be stacked on top each other for the storm to strengthen. If there are outside winds pushing against the cylinder near the top, it affects the balance of the entire cylinder and that’s what happens when vertical wind shear pushes against a storm. It pushes the center and weakens (or wobbles) the rotation of the entire cylinder (storm).
The Joint Typhoon Warning Center (JTWC) predicts that Tropical Storm Yutu will turn toward the northwest, gradually weaken and dissipate as it moves toward Hong Kong.
Nov. 01, 2018 – NASA Sees Hurricane Oscar Transitioning To Extratropical Low
Hurricane Oscar has transitioned into an extra-tropical low pressure area in the northeastern Atlantic Ocean. The Global Precipitation Measurement mission or GPM core satellite provided a look at rainfall occurring within the storm.
On October 31, 2018 at 8:43 a.m. EDT (1243 UTC) the GPM core observatory satellite showed the heaviest convective rainfall was located well northwest of Oscar’s low level center of circulation. Rain was falling at a rate of about 2 inches (50.8 mm) per hour in that area. On the western side, few storm tops were reaching heights above 5.6 miles (9.0 km) but contained heavy downpours. Credit: NASA/JAXA, Hal Pierce
When a storm becomes extra-tropical, it means that a tropical cyclone has lost its “tropical” characteristics. The National Hurricane Center defines “extra-tropical” as a transition that implies both poleward displacement (meaning it moves toward the north or south pole) of the cyclone and the conversion of the cyclone’s primary energy source from the release of latent heat of condensation to baroclinic (the temperature contrast between warm and cold air masses) processes. It is important to note that cyclones can become extratropical and still retain winds of hurricane or tropical storm force.
On October 31, 2018 at 8:43 a.m. EDT (1243 UTC) the GPM core observatory satellite had a pass over hurricane Oscar. The hurricane had maximum sustained winds of about 74.8 mph (65 knots) and was moving toward the northeast while becoming more extratropical in appearance. GPM’s Microwave Imager (GMI) showed that the heaviest convective rainfall was located well northwest of the low level center of circulation. Rain was falling at a rate of about 2 inches (50.8 mm) per hour in that area.
On October 31, 2018 at 8:43 a.m. EDT (1243 UTC) the GPM core observatory satellite showed the heaviest convective rainfall was located well northwest of Oscar’s low level center of circulation. Rain was falling at a rate of about 2 inches (50.8 mm) per hour in that area. On the western side, few storm tops were reaching heights above 5.6 miles (9.0 km) but contained heavy downpours. Credit: NASA/JAXA, Hal Pierce
At NASA’s Goddard Space Flight Center in Greenbelt, Md. a simulated 3-D view was created from GPM data looking from the east toward the storm. The image was derived from GPM’s radar (DPR Ku Band) data. GPM’s radar swath (DPR Ku Band) passed through storms on Oscar’s western side. GPM’s DPR found that very few storm tops were reaching heights above 5.6 miles (9.0 km) but heavy downpours were returning strong radar reflectivity values to the GPM satellite. Radar reflectivity values were frequently observed in the 3D cross-section through heavy rainfall in the northwestern side of the hurricane. GPM is a joint mission between NASA and the Japan Aerospace Exploration Agency, JAXA.
Oscar is now an extra-tropical low pressure area and is expected to pass northwest of Ireland over the weekend of Nov. 3 and 4 and will bring winds and rain to the country.
