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.
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.
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.
Oct. 31, 2018 -NASA’s CloudSat Gets a Slice of Typhoon Yutu’s Eye
NASA’s CloudSat satellite captured a stunning image of Typhoon Yutu as it passed over the eye of the storm. The storm has since weakened to a tropical storm.
CloudSat flew over the eye of Typhoon Yutu on October 28, 2018 at 12:58 a.m. EDT (0458 UTC) as the storm was approaching the Philippines in the Western North Pacific. At the time of the CloudSat overpass, Typhoon Yutu was beginning a period of weakening as the storm was moving info less favorable atmospheric conditions (lower sea surface temperatures). Typhoon Yutu contained estimated sustained winds of 120 knots (138 mph) with a minimum pressure of 933 millibars (the equivalent of a Category 4 strength storm). Typhoon Yutu left a trail of destruction through Saipan, Tinian and the Mariana Islands on October 24 and 25, 2018 as a Super Typhoon (category 5 strength storm).
Natalie Tourville of Colorado State University who produced the images, said “CloudSat’s 94 GHz cloud profiling radar (CPR) passed directly over the eye of Typhoon Yutu revealing the cirrus free eye with an outward sloping eyewall, a feature typically found in intense tropical systems. The southern portion of the eyewall appears more disorganized as the thicker cloud tops are starting to disintegrate from the top down.
The CloudSat overpass reveals the inner details beneath the storms cloud tops. Intense areas of convection with moderate to heavy rainfall, cloud-free areas (moats) underneath the northern portion of the cirrus canopy and cloud top height’s estimated at 14 kilometers (8.7 miles). Lower values of reflectivity denote smaller ice and water particle sizes typically located at top of the system (in the anvil area). The CloudSat CPR signal attenuates in heavy rainfall when cloud droplets become larger than 3 millimeters (.11 inch) which dampen the strength of the CPR signal. This is evident by the lack of signal typically occurring beneath the melting level when frozen particles transform into liquid.”
On Oct. 31 at 5 a.m. EDT (0900 UTC) Yutu had weakened to a tropical storm with maximum sustained winds near 45 knots (52 mph/83 kph). Tropical storm Yutu was centered near 18.1 degrees north latitude and 117.5 degrees east longitude, about 291 nautical miles northwest of Manila, Philippines.
As Yutu moves toward China, Hong Kong has posted Stand-by signal #1. The Joint Typhoon Warning Center expects Yutu to re-strengthen as it moves north. The storm is forecast to dissipate off the Chinese mainland, east of Hong Kong.
Oct. 30, 2018 – NASA’s Aqua Satellite Captures Typhoon Yutu Exiting the Northern Philippines
Visible satellite imagery from NASA’s Aqua satellite showed that Typhoon Yutu maintained its structure as it exited Luzon, the northern Philippines.
Yutu is known locally as Rosita in the Philippines. On Oct. 30, Yutu moved into the South China Sea after passing through La Union. La Union is a province in the Ilocos Region in the island of Luzon.
Philippines warnings that are in effect on Oct. 30 include Warning signal 3 over the Luzon provinces of La Union and Pangasinan; Warning signal 2 over the Luzon provinces of Abra, Ilocos Sur, Mt Province, Nueva Vizcaya, Nueva Ecija, Tarlac and Zambales; and Warning signal 1 over the Luzon provinces of Ilocos Norte, Apayao, Kalinga, Cagayan, Isabela, Quirino, Aurora, Bulacan, Pampanga, Bataan, Metro Manila, Rizal, Cavite, Laguna and Batangas.
At 1:05 a.m. EDT (0505 UTC) on Oct. 30, the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard Aqua captured a visible image of Yutu as it was exiting then northern Philippines and entering the South China Sea. Visible satellite imagery showed the storm maintained a symmetrical structure despite passing over land.
At 5 a.m. EDT (0900 UTC) on Oct. 30, the center of Yutu was located near latitude 16.8 degrees north and longitude 120.0 degrees east. That’s 144 nautical miles north-northeast of Manila, Philippines. Maximum sustained winds were near 75 knots (86 mph/139 kph).
The Joint Typhoon Warning Center expects Yutu to re-strengthen in the South China Sea and then turn north. It is expected to dissipate in the Taiwan Strait, located between Taiwan and the Chinese mainland.
Typhoon Yutu, known as Rosita in the Philippines, is now threatening the Philippine Island of Luzon. The Global Precipitation Measurement mission or GPM core satellite provided a look at the heavy rainfall the storm is packing.
On Oct. 24, 2018 Yutu devastated the Northern Mariana Islands of Tinian and Saipan as a super typhoon. One death has been attributed to the typhoon in the Mariana with many structures including schools and hospitals being destroyed. Typhoon Yutu weakened as it moved toward the Philippines and had maximum sustained winds of about 90 knots (103.5 mph) when the GPM core observatory satellite passed above the Philippine Sea on Oct. 29, 2018 at 0212 UTC (Oct. 28 at 10:12 p.m. EDT).
By 11 a.m. EDT (1500 UTC) on Oct. 29, Yutu’s maximum sustained winds remained at the same strength as they were earlier. Yutu was located near 16.7 degrees north latitude and 123.6 east longitude. That’s about 224 nautical miles northeast of Manila, Philippines.
At NASA’s Goddard Space Flight Center in Greenbelt, Maryland, a rainfall analysis was developed using data collected by GPM’s Microwave Imager (GMI) and Dual-Frequency Precipitation Radar (DPR) instruments. Those GPM data revealed that heavy rainfall within the typhoon covered an area the size of Luzon. Extreme precipitation falling at a rate of over 178 mm (7 inches) per hour was also revealed by GPM’s radar (DPR Ku Band) within powerful storms in Yutu’s southwestern eye wall.
The GPM mission is managed by both NASA and the Japan Aerospace Exploration Agency, JAXA.
The GPM core observatory satellite passed above the Philippine Sea on Oct. 29, 2018 at 0212 UTC (Oct. 28 at 10:12 p.m. EDT). Those GPM data revealed that heavy rainfall within the typhoon covered an area the size of Luzon. Extreme precipitation falling at a rate of over 178 mm (7 inches) per hour was also revealed by GPM’s radar (DPR Ku Band) within powerful storms in Yutu’s southwestern eye wall. Credit: NASA/JAXA, Hal Pierce
The Joint Typhoon Warning Center (JTWC) predicts that typhoon Yutu will still be a powerful typhoon with winds of about 85 knots (98 mph) when it makes landfall in the Philippines. Interaction with the rugged terrain over Luzon is expected to cause Yutu to weaken to tropical storm intensity. Yutu is then expected to intensify to typhoon again as it moves into the South China Sea. Typhoon Yutu is then expected to re-curve to the east of Hong Kong.
Oct. 26, 2018 – NASA’s Aqua Satellite Tracks Super Typhoon Yutu’s Oblong Eye
Visible satellite imagery from NASA’s Aqua satellite captured powerful Super Typhoon Yutu as it moved through the Philippine Sea. Yutu’s eye appeared oblong on satellite imagery.
On Oct. 25 at 1:30 p.m. CHST (local time, Guam) the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard Aqua captured a visible image of Yutu. The MODIS image showed that large typhoon Yutu continued to remain symmetric with an open 19 nautical-mile-wide eye surrounded by very thick bands of powerful thunderstorms circling the center. At the time of the image, Yutu had passed and cleared Guam.
In satellite imagery on Oct. 26, the eye had become cloud-filled. Infrared satellite imagery revealed cooler cloud tops (indicating the uplift of air had strengthened) and a contracting eye occurring after the storm experienced an eyewall replacement cycle.
Mature, intense tropical cyclones can and often undergo an eyewall replacement cycle. That’s where a new eyewall or ring of thunderstorms within the outer rain bands forms further out from the storm’s center, outside of the original eye wall. That ring of thunderstorms then begins to choke off the original eye wall, starving it of moisture and momentum. Eventually, if the cycle is completed, the original eye wall of thunderstorms dissipates and the new outer eye wall of thunderstorms contracts and replace the old eye wall. The storm’s intensity can fluctuate over this period, initially weakening as the inner eye wall dies before again strengthening as the outer eye wall contracts.
The National Weather Service (NWS) in Tiyan, Guam continued to issue a small craft advisory on Oct. 26. The NWS noted for Marianas Waters “Winds and seas will remain elevated, then slowly subside over the weekend as Super Typhoon Yutu moves away from the Marianas. A Small Craft Advisory remains in effect through Saturday afternoon.”
At 11 a.m. EDT (1500 UTC) on Oct. 26, the Joint Typhoon Warning Center or JTWC noted that Yutu had maximum sustained winds near 135 knots (155.4 mph/250 kph).
Super Typhoon Yutu was the equivalent of a Category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale. Yutu was centered near 17.3 degrees north latitude and 136.9 east longitude. It was about 465 nautical miles west-northwest of Navsta, Guam. Yutu was moving toward the west-northwest.
The JTWC forecast carries Yutu west toward the northern Philippines through Oct. 31. Yutu is expected to maintain typhoon strength through that time.
NASA’s GPM Core observatory satellite captured an image of Super Typhoon Yutu when it flew over the powerful storm just as the center was striking the central Northern Mariana Islands north of Guam.
Early Thursday, Oct. 25 local time, Super Typhoon Yutu crossed over the U.S. commonwealth of the Northern Mariana Islands. It was the equivalent of a Category 5 hurricane. The National Weather Service in Guam said it was the strongest storm to hit any part of the U.S. this year.
The Global Precipitation Measurement mission or GPM core satellite, which is managed by both NASA and the Japan Aerospace Exploration Agency, JAXA analyzed Yutu on Oct. 24 at 11:07 a.m. EDT (1507 UTC)/ 1:07 a.m. Guam Time, Oct. 25. GPM estimated rain rates within Super Typhoon Yutu fusing data from two instruments aboard: the GPM Dual-frequency Precipitation Radar or DPR, which covered the inner part of the storm, and the GPM Microwave Imager or GMI that analyzed the outer swath, just as the center was passing over the Island of Tinian.
GPM shows the inner eyewall as a near perfect ring of heavy to intense rain. Peak rain rates of up to 269 mm/hr. (~10.6 inches/hr.) were estimated within the DPR swath. The almost perfect symmetry of the inner wall is indicative of an extremely powerful storm. In fact, at the time this image was taken, Yutu’s maximum sustained winds were estimated at 155 knots (~178 mph) by the Joint Typhoon Warning Center, making it the strongest typhoon on record to strike Saipan and Tinian.
For comparison, Hurricane Michael, which devastated the northern Gulf Coast of Florida, had maximum sustained winds reported at 155 mph. At the time of the satellite flyover, GPM showed the northern eyewall passing right over Tinian and the southern tip of Saipan. GPM also reveals another interesting feature common with powerful tropical cyclones, the beginning of an eyewall replacement cycle.
After strong hurricanes and typhoons reach maturity, they often undergo an eyewall replacement cycle wherein a concentric outer eyewall forms outside and around the inner eyewall before contracting and eventually replacing the inner eyewall. This is evidenced by the emerging ring of heavy rain outside of the inner eyewall separated by the area of weaker rain.
At NASA’s Goddard Space Flight Center in Greenbelt, Maryland, a second image was created at the same time as the first and shows a unique 3D perspective of Yutu courtesy of the GPM DPR. In that image the double eyewall structure is readily apparent by the two rings of taller towers evident in the precipitation top heights. The tallest tower is located in the southeast part of the outer eyewall and is 15.7 km (9.7 miles) high.
On Oct. 25 at 11 a.m. EDT (1500 UTC), Super Typhoon Yutu had maximum sustained winds near 140 knots (161 mph/259 kph) and was still a Category 5 hurricane on the Saffir-Simpson Hurricane Wind Scale. It was centered near 6.4 degrees north and 141.8 degrees east. Super typhoon Yutu was located approximately 206 nautical miles west-northwest of Tinian and has tracked west-northwestward.
Yutu is expected to remain a very powerful super typhoon for the next few days before gradually weakening as it makes its way westward across the Philippine Sea in the general direction of Taiwan.
Oct. 24, 2018 – Satellite Sees Supertyphoon Yutu’s Eye Pass Over Tinian
On Oct. 24, the National Weather Service or NWS in Tiyan, Guam issued the warning that “Catastrophic winds for Tinian and Saipan are imminent” as the eye of Super typhoon Yutu neared both islands. NASA-JAXA’s GPM satellite and NOAA’s NOAA-20 satellite provided a look at the heavy rainfall and the structure and eye of the storm. Maximum sustained winds in the eye wall are 180 mph or stronger making Yutu a dangerous category 5 super typhoon.
At 10:22 a.m. EDT (1422 UTC) on Oct. 24 or 12:22 a.m. CHST (local time) on Thursday, Oct. 25, the NWS noted “Typhoon warnings remain in effect for Rota, Tinian and Saipan. The strongest winds will occur over the next few hours at Tinian and Saipan. The winds will be much stronger than in Typhoon Soudelor!”
In addition, a Tropical Storm Warning remains in effect for Guam, Alamagan, Pagan, and Agrihan. Typhoon conditions are expected through late this morning (CHST time) at Rota,Tinian and Saipan. Tropical storm conditions are expected for Guam through this evening (CHST time). Tropical storm conditions are expected at Alamagan, Pagan, and Agrihan around midnight tonight through late Thursday evening (CHST time).
Shortly before the NOAA-20 satellite overpass on Oct. 23 (EDT) at 11:51 a.m. EDT (1551 UTC), Super typhoon Yutu hit Tinian Island, one of the three principle islands of the Northern Mariana Islands, just south of Sapian and a U.S. Commonwealth. Tinian is one of the three principal islands of the Commonwealth of the Northern Marianas. The southern part of Saipan was also impacted as well, where Saipan International Airport is located. A NOAA-20 infrared image showed coldest storm top temperatures around the eyewall at 210 kelvin (minus 81.6 Fahrenheit/minus 63.5 degrees Celsius) where storms are dropping extremely heavy rainfall.
NASA and the Japan Aerospace Exploration Agency’s GPM or Global Precipitation Measurement mission core satellite provided a look at heavy rainfall occurring in Super Typhoon Yutu on Oct. 24 at 10:50 a.m. EDT (1450 UTC) as it was battering Tinian and Saipan in the Northwestern Pacific Ocean.
At 11 a.m. EDT (1500 UTC) on Oct. 24 (1 a.m. CHST Oct. 25) the center of Super Typhoon Yutu will be located near Latitude 14.8 degrees North and Longitude 145.7 degrees East. That’s about 15 miles south-southeast of Tinian. Yutu is moving northwest at 13 mph. The eye of Yutu will pass over Tinian over the next couple hours. Maximum sustained winds have increased to 180 mph. Super Typhoon Yutu is a very dangerous Category 5 storm.
Typhoon force winds extend outward from the center up to 85 miles. Tropical storm force winds extend outward from the center up to 240 miles to the northeast and up to 205 miles elsewhere.
NWS said about storm surge and storm tide: Combined seas between 30 and 40 feet near the center of the storm will continue through tonight…resulting in deadly surf conditions. Coastal inundation of 15 to 20 feet is possible on windward exposures. Once Yutu passes to the west of the Mariana Islands…west and southwest swell will build with surf rising to 12 to 16 feet along west facing reefs. Coastal inundation of 5 to 7 feet is possible on west facing exposures. Surf will generate deadly rip currents.
A flash flood warning remains in effect for the entire area. Additional rainfall amounts of 6 to 10 inches are possible today. Isolated total rainfall amounts of up to 15 inches are possible.
Oct. 23, 2018 – NASA-NOAA’s Suomi NPP Satellite Catches Typhoon Yutu Strengthening, Guam on Alert
Tropical Storm Yutu continued strengthening as NASA-NOAA’s Suomi NPP satellite passed overhead. On Oct. 23, Yutu was a strengthening typhoon east of Guam.
On. Oct. 22, the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard NASA-NOAA’s Suomi NPP satellite passed over the western Pacific Ocean and captured a visible image of Yutu. VIIRS revealed a well-organized storm, and showed powerful thunderstorms around the center of circulation and in thick bands spiraling into the center from the northern and southern quadrants. At the time Suomi NPP passed overhead, Yutu was east of Guam and its southern quadrant was affecting the Federated States of Micronesia. The VIIRS image showed that the storm is about 400 miles in diameter.
On Oct. 23, NOAA’s National Weather Service (NWS) in Tiyan, Guam noted several warnings and watches. Typhoon warnings remain in effect for Rota, Tinian and Saipan. A Tropical Storm Warning is now in effect for Guam. A tropical storm watch remain in effect for Alamagan, Pagan, and Agrihan.
At 10 p.m. CHST local time (8 a.m. EDT /1200 UTC) on Oct. 23 the center of Typhoon Yutu was located near latitude 12.0 degrees north and longitude 149.6 degrees east.
That’s about 330 miles east-southeast of Rota and about 335 miles southeast of Saipan. Yutu is moving west at 10 mph. It is expected to maintain this general course and speed over the next 24 hours. Maximum sustained winds have increased to 90 mph. Yutu is forecast to intensify through Wednesday, Oct. 24.Typhoon force winds extend outward from the center up to 60 miles. Tropical storm force winds extend outward from the center up to 200 miles to the northeast and up to 155 miles elsewhere.
Typhoon conditions are expected Wednesday night through Thursday morning (local time) at Tinian and Saipan. Typhoon conditions are expected for Rota Wednesday afternoon through Thursday. Tropical storm conditions are expected for Guam late Wednesday afternoon through Thursday. Tropical storm conditions are possible within the next 24 to 36 hours at Alamagan, Pagan, and Agrihan.
NWS said “The current track has shifted slightly south and now brings Yutu just south of Tinian and Saipan as a 130 mph category 4 storm, late Wednesday night or early Thursday morning.”
NASA-NOAA’s Suomi NPP satellite passed over the Northwestern Pacific Ocean and captured a visible image of Tropical Storm Yutu as warnings were posted. A typhoon watch is in force for Tinian and Saipan and a tropical storm watch is in force for Rota.
The National Weather Service in Tiyan, Guam noted that residents of Guam, Alamagan, Pagan and Agrihan should continue to monitor the progress of Tropical Storm Yutu.
Tropical Depression 31 developed on Monday, Oct. 22 at 2 a.m. CHST (Guam local time) and rapidly intensified into a tropical storm.
On Oct. 22, the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard NASA-NOAA’s Suomi NPP satellite passed over Yutu and captured a visible image of the storm. VIIRS showed an organized storm with strong thunderstorms circling the center and in bands feeding into the center from the south and east.
At 1 a.m. CHST (local time) on Oct. 23 (11 a.m. EDT/1500 UTC on Oct. 22) the center of Tropical Storm Yutu was located near latitude 10.9 degrees north and longitude 153.3 degrees east. That’s about 255 miles north-northeast of Chuuk and about 585 miles east-southeast of Saipan.
Maximum sustained winds have increased to 50 mph. Yutu will continue to intensify through Wednesday, possibly becoming a typhoon later today. Tropical storm force winds extend outward from the center up to 80 miles to the southwest and up to 150 miles elsewhere.
Yutu is moving northwest at 16 mph and is expected to continue its northwest motion through Thursday, but the National Weather Service in Guam said its forward speed will decrease slightly today and tonight. This forecast keeps Yutu on a track that will pass just north of Saipan late Wednesday night or Thursday morning, Oct. 24 local time.