Tag Archives: Okinawa

Typhoon Noru Threatens Southwestern Japan

Typhoon Noru posed an increased threat to southwestern Japan as it slowly moved closer on Thursday.  At 11:00 p.m. EDT on Thursday the center of Typhoon Noru was located at latitude 28.6°N and longitude 131.3°E which put it about 145 miles (235 km) south-southeast of Kagoshima, Japan.  Noru was moving toward the west at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 85 m.p.h. (135 km/h) and there were gusts to 105 m.p.h. (170 km/h).  The minimum surface pressure was 962 mb.

Although Noru is still a powerful and dangerous typhoon, it is not quite as well organized as it was several days ago.  A very large eye with a diameter of 95 miles (150 km) is at the center of circulation.  A broken ring of thunderstorms surrounds the eye.  There are breaks on both the eastern and western sides of the eyewall.  A broad rainband wraps around the southern and eastern sides of the circulation.  Thunderstorms in the core of Noru are generating strong upper level divergence which is pumping mass away from the typhoon.  There are few showers and thunderstorms in the northwestern quadrant and there may be drier air in that part of Typhoon Noru.

Winds to typhoon force extend out about 40 miles (65 km/h) from the center of circulation.  Winds to tropical storm force extend out about 185 miles (295 km/h) from the center.  The Hurricane Intensity Index (HII) for Typhoon Noru is 12.7.  The Hurricane Size Index (HSI) is 16.4 and the Hurricane Wind Intensity Size Index (HWISI) is 29.1

Typhoon Noru will move through an environment that may be somewhat favorable for intensification.  Noru will move over water where the Sea Surface Temperature is near 30°C.  An upper level ridge northwest of Noru is producing northeasterly winds which are blowing toward the top of the typhoon.  Those winds are creating moderate vertical wind shear.  The typhoon could also pull in drier air on the northwestern side of the circulation.  Even though the environmental factors are mixed, some intensification may be possible during the next 24 to 48 hours.

Typhoon Noru is approaching the western end of a subtropical ridge which has been steering the typhoon toward the west.  Noru is forecast to slow as the steering currents weaken.  Typhoon Noru is forecast to turn slowly northward during the next 24 hours.  In about 48 hours westerly winds in the middle latitudes will begin to carry the typhoon more quickly toward the northeast.  On its anticipated track Typhoon Noru could approach the northern Ryukyu Islands on Friday.  It could bring strong winds to Amami-O-Shima.  The center could pass near Yaku-Shima and Tanega-Shima during the weekend.  In a little over two days Typhoon Noru could reach southwestern Kyushu.  Typhoon Noru has the potential to bring strong winds and heavy rain to parts of southwestern Japan during the next few days.  The heavy rain could also cause flash floods.

Typhoon Noru Turns Toward Southwestern Japan

Typhoon Noru turned toward southwestern Japan on Tuesday.  At 11:00 p.m. EDT on Tuesday the center of Typhoon Noru was located at latitude 25.6°N and longitude 136.2°E which put it about 525 miles (850 km) south-southeast of Miyazaki, Japan.  Noru was moving toward the northwest at 6 m.p.h. (10 km/h).  The maximum sustained wind speed was 120 m.p.h. (195 km/h) and there were wind gusts to 150 m.p.h. (240 km/h).  The minimum surface pressure was 942 mb.

Typhoon Noru has a very symmetrical circulation that looks similar to what are sometimes called annular hurricanes.  There is a large circular eye at the center of Typhoon Noru.  The eye has a diameter of 35 miles (55 km).  The eye is surrounded by a wide ring of strong thunderstorms.  There are few bands of showers and thunderstorms outside the core of the typhoon.  The thunderstorms in the core of Noru are generating strong upper level divergence which is pumping mass away from the typhoon.

Typhoon Noru will be moving through a favorable environment during the next several days.  Noru will move over water where the Sea Surface Temperature is near 30°C.  The upper level winds are weak and there is little vertical wind shear.  Typhoons and hurricanes that have an annular structure like that of Typhoon Noru tend to maintain a fairly steady intensity.  Given the favorable environment, Noru could strengthen during the next few days.

A subtropical ridge is steering Typhoon Noru slowly toward the northwest.  The ridge is forecast to strengthen and to steer Noru more toward the west-northwest during the next several days.  On its anticipated track Typhoon Noru could approach southwestern Japan in about three days.

Noru Rapidly Intensifies Into a Super Typhoon

Typhoon Noru rapidly intensified into a Super Typhoon on Sunday.  At 11:00 p.m. EDT on Sunday the center of Typhoon Noru was located at latitude 22.9°N and longitude 140.3°E which put it about 150 miles (240 km) south-southwest of Iwo To.  Noru was moving toward the west at 5 m.p.h.  The maximum sustained wind speed was 150 m.p.h. (240 km/h) and there were wind gusts to 185 m.p.h. (295 km/h).  The minimum surface pressure was 922 mb.

The circulation of Typhoon Noru is very well organized.  There is a circular eye with a diameter of 20 miles (32 km) in the center of Noru.  The eye is surrounded by a wide ring of strong thunderstorms.  The strongest winds are occurring in this ring.  Bands of showers and thunderstorms are revolving around the core of Typhoon Noru.  Winds to typhoon force extend out about 45 miles (75 km) in all directions.  Winds to tropical storm force extend out about 150 miles (240 km) from the center.

The Hurricane Intensity Index (HII) for Typhoon Noru is 31.6.  The Hurricane Size Index (HSI) is 18.5 and the Hurricane Wind Intensity Size Index (HWISI) is 50.1.

Typhoon Noru is in a very favorable environment.  Noru is moving over water where the Sea Surface Temperature is near 30.5°C.  The upper level winds are weak and there is little vertical wind shear.  Typhoon Noru could maintain its intensity or weaken slowly over the next few days.

Typhoon Noru is moving around the western end of a subtropical ridge which is steering the typhoon slowly toward the west.  Noru is expected to start moving toward the north when it reaches the western end of the ridge.  On its anticipated track Typhoon Noru will remain south of Japan for much of the week.

Tropical Storm Nesat Forms Southeast of Taiwan

Tropical Storm Newsat formed southeast of Taiwan on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Tropical Storm Nesat was located at latitude 18.0°N and longitude 127.5°E which put it about 620 miles (1000 km) southeast of Taipei, Taiwan.  Nesat was moving toward the north at 6 m.p.h. (10 km/h).  The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 80 m.p.h. (130 km/h).  The minimum surface pressure was 988 mb.

A well organized surface circulation formed in an area of thunderstorms southeast of Taiwan on Wednesday.  A strong cluster of thunderstorms formed south of the center of circulation.  Additional bands of showers and thunderstorms developed in the western and southern portions of Tropical Storm Nesat.  There were few thunderstorms in the eastern half of the circulation.  More thunderstorms appeared to be forming near the core of the circulation in recent hours.  The thunderstorms in the core were generating upper level divergence which was pumping out mass.

Tropical Storm Nesat will be moving through an area that is favorable for intensification.  Nesat will move over water where the Sea Surface Temperature is near 31°C.  Tropical Storm Nesat is beneath the northeastern part of an upper level ridge.  The ridge is producing northeasterly winds which are blowing toward the top of the circulation.  Those winds are causing some vertical wind shear and the shear could be the reason for the asymmetrical distribution of thunderstorms.  Tropical Storm Nesat could move under the axis of the upper level ridge where the winds are weaker.  In that case the shear would be less and Nesat could intensify more quickly.  Tropical Storm Nesat is likely to intensify into a typhoon during the next 24 hours.

Tropical Storm Nesat is moving around a weak area in a subtropical ridge, which is allowing the tropical storm to move toward the north.  The ridge is forecast to strengthen and when that happens it will steer Nesat more toward the west.  On its anticipated track Tropical Storm Nesat could approach Taiwan in about three days.  Nesat could be a strong typhoon when it nears Taiwan.

Elsewhere in the Western North Pacific Typhoon Noru has turned back toward the west.  At 11:00 p.m. EDT on Wednesday the center of Typhoon Noru was located at latitude 30.6°N and longitude 151.2°E which put it about 770 miles (1240 km) east-northeast of Iwo To.  Noru was moving toward the west at 19 m.p.h. (31 km/h).  The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 90 m.p.h. (150 km/h).  The minimum surface pressure was 978 mb.

A subtropical ridge north of Typhoon Noru is steering the typhoon toward the west.  A general westerly motion is forecast to continue for several more days.  Noru could reach an area of weaker steering winds in a few days and its motion may slow.  On its anticipated track Typhoon Noru could approach Iwo To in three or four days.

Tropical Storm Nanmadol Brings Wind and Rain to Southern Ryukyu Islands

Tropical Storm Nanmadol brought wind and rain to the southern Ryukyu Islands on Sunday.  At 11:00 a.m. EDT on Sunday the center of Tropical Storm Nanmadol was located at latitude 24.4°N and longitude 124.7°E which put it about 40 miles (65 km) east of Ishigaki, Japan.  Nanmadol was moving toward the north-northwest at 21 m.p.h. (34 km/h).  The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 998 mb.

The core of Tropical Storm Nanmadol continued to organize on Sunday.  A ring of thunderstorms wrapped tightly around the center of circulation.  Additional bands of showers and thunderstorms formed outside the core.  Thunderstorms were beginning to generate more upper level divergence which was pumping out mass in all directions.  The circulation of Tropical Storm Nanmadol was fairly small.  Winds to tropical storm force only extend out about 70 miles (110 km) from the center.

Tropical Storm Nanmadol will be in an environment that is very favorable for intensification for about another 24 hours.  Nanmadol will be moving over water where the Sea Surface Temperature (SST) is near 29°C.  The circulation of Tropical Storm Nanmadol is underneath the center of an upper level ridge and the upper level winds are very weak.  Warm SSTs and almost no vertical wind shear will permit Tropical Storm Nanmadol to intensify during the next day and there could be a period of rapid intensification.  Nanmadol could strengthen into a typhoon before it reaches a less favorable environment.  The tropical storm will move over cooler SSTs and it will move into an area of stronger upper level westerly winds in a couple of days.  Nanmadol will begin to weaken when that happens.

Tropical Storm Nanmadol is moving around the western end of a subtropical ridge which is steering it toward the north.  A general northward motion is expected to continue for about another 24 hours.  Nanmadol will reach the westerly winds in the middle latitudes in about a day and those winds will turn it toward the northeast.  On its anticipated track the center of Tropical Storm Nanmadol will pass west of Okinawa.  Nanmadol could approach Kyushu in about 36 hours.  Tropical Storm Nanmadol will continue to cause gusty winds and locally heavy rain over the southern Ryukyu Islands for another 12 to 24 hours.

Tropical Storm Nanmadol Forms Southeast of Taiwan

Tropical Storm Nanmadol formed southeast of Taiwan on Saturday.  At 8:00 p.m. EDT on Saturday the center of Tropical Storm Nanmadol was located at latitude 20.7°N and longitude 127.1°E which put it about 475 miles (765 km) southeast of Taipei, Taiwan.  Nanmadol was moving toward the northwest at 24 m.p.h. (35 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 1002 mb.

A center of circulation consolidated rapidly on Saturday in an area of thunderstorms southeast of Taiwan.  A primary band of showers and thunderstorms wrapped around the northern and western side of the circulation.  Other bands of showers and thunderstorms developed in the northern half of the circulation.  The thunderstorms near the center began to generate upper level divergence which pumped out mass to the north of the tropical storm.

Tropical Storm Nanmadol will move through an area favorable for intensification during the next 24 hours.  Nanmadol will move over water where the Sea Surface Temperature is near 30°C.  An upper level ridge northeast of Nanmadol is producing southeasterly winds which are blowing toward the top of the tropical storm, but there is little vertical wind shear.  Tropical Storm Nanmadol is likely to intensify on Sunday.  When Nanmadol moves farther north, it will move over cooler water and it will be effected by the upper level westerly winds in the middle latitudes.  Cooler water and more vertical wind shear will cause Nanmadol to start to weaken at that time.

Tropical Storm Nanmadol is moving around the western end of a subtropical ridge which is steering it quickly toward the northwest.  Nanmadol will move in a general north-northwesterly direction on Sunday.  It will turn toward the northeast in 24 to 36 hours when it begins to be steered by the mid-latitude westerlies.  On its anticipated track Tropical Storm Nanmadol could approach the southernmost Ryukyu Islands including Ishigaki Jima in about 12 hours.  The center is expected to pass west of Okinawa.  Tropical Storm Nanmadol could approach Kyushu in a couple of days.  An intensifying Tropical Storm Nanmadol will bring gusty winds and locally heavy rain to the southernmost Ryukyu Islands.

Super Typhoon Chaba Threatens Japan and South Korea

Super Typhoon Chaba moved north on Monday and it threatened to bring strong winds and heavy rain to Japan and South Korea.  At 5:00 p.m. EDT on Monday the center of Super Typhoon Chaba was located at latitude 27.5°N and longitude 126.5°E which put it about 100 miles (160 km) west-northwest of Okinawa.  Chaba was moving toward the north at 11 m.p.h. (18 km/h).  The maximum sustained wind speed was 155 m.p.h. (250 km/h) and there were wind gusts to 190 m.p.h. (305 km/h).  The minimum surface pressure was 925 mb.

Typhoon Chaba is a compact well organized storm.  It has a clear circular eye surrounded by a ring of strong thunderstorms.  Winds to typhoon force extend out about 35 miles (55 km) from the center of circulation.  Additional rainbands are rotating around the core of Typhoon Chaba.  Thunderstorms at the core of Chaba are generating upper level divergence which is pumping mass out in all directions.

The Hurricane Intensity Index (HII) for Typhoon Chaba is 33.3.  The Hurricane Size Index (HSI) is 11.6 and the Hurricane Wind Intensity Size Index (HWISI) is 44.9.  These indices indicate that Typhoon Chaba is stronger, but slightly smaller than Hurricane Matthew which is over the Caribbean Sea.

Although Typhoon Chaba is still in a very favorable environment, it has probably peaked in intensity.  Chaba was the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale earlier today.  Chaba is currently moving over water where the Sea Surface Temperature (SST) is near 29°C.  The upper level winds are weak and there is little vertical wind shear.  Typhoon Chaba is likely to weaken gradually during the next 24 hours.  In about a day or so, Chaba will move over cooler SSTs.  In addition, when Chaba moves farther north it will move closer to the upper level westerly winds in the middle latitudes.  A combination of cooler SSTs and more vertical wind shear will increase the rate at which Typhoon Chaba will weaken.

Chaba is moving around the western end of a subtropical ridge which is steering the typhoon toward the north.  That general motion is expected to continue for about another 24 hours.  In about a day or so the westerly winds of the middle latitudes are expected to turn Chaba quickly toward the northeast.  On its anticipated track the core of Typhoon Chaba will pass west of the northern Ryukyu Islands.  Chaba could be near Jeju, South Korea and western Kyushu in 24 hours.

Chaba is a very strong typhoon.  Although it will weaken, Typhoon Chaba will bring strong winds and heavy rain to parts of South Korea and Japan.

Powerful Typhoon Chaba Passing South of Okinawa

Powerful Typhoon Chaba is passing south of Okinawa.  At 11:00 p.m. EDT on Sunday the center of Typhoon Chaba was located at latitude 24.5°N and longitude 127.3°E which put it about 180 miles (290 km) south of Okinawa.  Chaba was moving toward the northwest at 15 m.p.h. (24 km/h).  The maximum sustained wind speed was 145 m.p.h. (230 km/h) and there were wind gusts to 170 m.p.h. (280 km/h).  The minimum surface pressure was 935 mb.

The circulation of Typhoon Chaba is very well organized.  Chaba has a distinct circular eye surrounded by a ring of strong thunderstorms.  Other rainbands are rotating around the core of the circulation.  The thunderstorms in the core are generating upper level divergence which is pumping out mass to the north of Typhoon Chaba.

Typhoon Chaba is moving through a very favorable environment.  Chaba is moving over water where the Sea Surface Temperature (SST) is near 30°C.  The upper level winds are weak and there is little vertical wind shear.  Typhoon Chaba could intensify a little more during the next 12 to 24 hours.  When Chaba moves farther north, an upper level trough over eastern China will cause more vertical wind shear.  Increased wind shear and cooler SSTs will weaken the typhoon.

Typhoon Chaba is moving around the western end of a subtropical ridge which is steering it toward the northwest.  Chaba will gradually start to move more toward the north.  In about 36 hours the upper level trough over eastern China will begin to steer Typhoon Chaba toward the northeast.  On its anticipated track Typhoon Chaba will move through the Ryukyu Islands southwest of Okinawa during the next 24 hours.  Chaba would be southwest of Kyushu in about 36 hours.

Chaba is a powerful typhoon and it will bring gusty winds and heavy rain to the Ryukyu Islands including Okinawa.

Typhoon Chaba Rapidly Intensifies Into the Equivalent of a Major Hurricane

Typhoon Chaba intensified rapidly into the equivalent of a major hurricane on Saturday.  At 11:00 p.m. EDT on Saturday the center of Typhoon Chaba was located at latitude 20.1°N and longitude 131.0°E which put it about 530 miles (855 km) south-southeast of Okinawa.  Chaba was moving toward the northwest at 19 m.p.h. (31 km/h).  The maximum sustained wind speed was 120 m.p.h. (195 km/h) and there were wind gusts to 150 m.p.h. (240 km/h).  The minimum surface pressure was 957 mb.

The organization of the circulation of Typhoon Chaba improved significantly on Saturday.  It has a small circular eye which is surrounded by a ring of very strong thunderstorms.  Another primary band of thunderstorms wrapped around the western side of the typhoon.  Thunderstorms in the core of Typhoon Chaba produced strong upper level divergence which pumped out enough mass to allow the pressure at the surface to decrease very rapidly during the past 24 hours.

Typhoon Chaba will continue to move in an environment that is very favorable for intensification.  It is moving over water where the Sea Surface Temperature is near 30°C.  The upper level winds are weak and there is not much vertical wind shear.  Typhoon Chaba should continue to intensify for another 24 hours and it could reach major typhoon status.

Typhoon Chaba is moving around the western end of a subtropical ridge which is steering the typhoon toward the northwest.  Chaba should start to move more toward the north when it reaches the western end of the ridge.  On its anticipated track Typhoon Chaba could reach Okinawa in about 36 hours.  It will be a powerful typhoon when it moves through the Ryukyu Islands.

Tropical Storm Chaba Organizes and Moves Toward Okinawa

Tropical Storm Chaba strengthened on Thursday as it started to move toward Okinawa.  At 5:00 p.m. EDT on Thursday the center of Tropical Storm Chaba was located at latitude 13.8°N and longitude 138.6°E which put it about 1145 miles (1850 km) southeast of Okinawa.  Chaba was moving toward the west at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h).  The minimum surface pressure was 996 mb.

The circulation of Tropical Storm Chaba showed signs of better organization on Thursday.  A primary rainband wrapped around the western and south sides of the circulation.  Additional bands of thunderstorms were forming on the southern and eastern side of Tropical Storm Chaba.  Thunderstorms near the core of Chaba were generating upper level divergence which was pumping mass out to the west, south and east of the tropical storm.

Tropical Storm Chaba is moving into an environment that is favorable for intensification.  It is moving over water where the Sea Surface Temperature (SST) is near 30°C.  An upper level ridge to the north of Chaba is generating easterly winds which are blowing across the northern portion of the tropical storm.  However, those winds are not causing significant vertical wind shear.  The combination of warm SSTs and little vertical wind shear should allow Tropical Storm Chaba to intensify steadily during the next several days.  It could become a typhoon within 24 to 48 hours.  There is a chance that Chaba could become the equivalent of a major hurricane in three or four days.

A subtropical ridge to the north of Chaba is steering the tropical storm toward the west and that general motion is expected to continue in the short term.  When Chaba gets a little closer to the western end of the ridge, it will start to move toward the northwest and when Chaba reaches the western end of the ridge it will turn toward the north.  On it anticipated track Tropical Storm Chaba could be approaching Okinawa and the Ryukyu islands in about three days.  It could be a powerful typhoon at that time.