Tag Archives: Rota

Strengthening Tropical Storm Maria Brings Wind and Rain to Guam

Tropical Storm Maria strengthened quickly on Wednesday and it brought gusty winds and heavy rain to Guam.  The weather station at Andersen Air Force Base on Guam reported sustained winds to 44 m.p.h. (71 km/h) and wind gusts to 72 m.p.h. (116 km/h).  At 5:00 p.m. EDT on Wednesday the center of Tropical Storm Maria was located at latitude 13.9°N and longitude 144.7°E which put it about 5 miles (10 km/h) south of Andersen Air Force Base.  Maria was moving toward the north-northwest at 11 m.p.h. (17 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 987 mb.  Tropical Storm Warnings remained in effect for Guam and Rota.  Tropical Storm Watches were in effect for Saipan and Tinian.

The circulation of Tropical Storm Maria organized quickly on Wednesday.  A tight center of circulation contracted at the center of Maria.  A partial ring of thunderstorms formed on the east side of the center.  Numerous bands of showers and thunderstorms were revolving around the core of the circulation.  Storms around the core generated well developed upper level divergence which pumped mass away in all directions from the tropical storm.  Winds to tropical storm force extended out about 95 miles (155 km) from the center of circulation.

Tropical Storm Maria will move through an environment very favorable for intensification.  Maria will move over water where the Sea Surface Temperature is near 30°C.  Tropical Storm Maria will move under the western portion of an upper level ridge where the upper level winds are weak.  There will little vertical wind shear.  Upper level lows east and west of the ridge will enhance the upper level divergence.  Tropical Storm Maria will strengthen into a typhoon on Thursday.  Maria could intensify rapidly and it is likely to become the equivalent of a major hurricane.

Tropical Storm Maria was moving around the western end of a subtropical ridge which was steering Maria toward the north-northwest.  The ridge is forecast to steer Maria toward the northwest during the next few days.  On its anticipated track Tropical Storm Maria will move away from the Marianas and toward the Ryukyu Islands.  Tropical Storm Maria will continue to cause gusty winds and drop locally heavy rain on the southern Marianas for a few more hours.  Conditions will improve on Thursday when Maria moves away the Marianas.

Tropical Storm Maria Prompts Warning for Guam

Tropical Depression 10W strengthened into Tropical Storm Maria on Wednesday and a Tropical Storm Warning was issued for Guam.  At 5:00 a.m. EDT on Wednesday the center of Tropical Storm Maria was located at latitude 12.7°N and longitude 145.9°E which put it about 95 miles (155 km) southeast of Guam.  Maria was moving toward the north-northwest at 8 m.p.h. (13 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 1000 mb.  Tropical Storm Warnings were in effect for Guam and Rota.  Tropical Storm Watches were in effect for Saipan and Tinian.

The center of circulation in former Tropical Depression 10W became more well organized on Wednesday and the Japan Meteorological Agency designated the system as Tropical Storm Maria.  The circulation was still increasing in organization.  There was a distinct low level center of circulation.  Numerous bands of showers and thunderstorms were revolving around the center of circulation.  Storms near the center were generating upper level divergence which was pumping mass away from the tropical storm.

Tropical Storm Maria will move through an environment very favorable for intensification during the next few days.  Maria will move over water where the Sea Surface Temperature is near 30°C.  Tropical Storm Maria will move under the western end of an upper level ridge that is between two upper level lows which are east and west of the ridge.  The upper level winds will be relatively weak and there will be little vertical wind shear.  The combination of the ridge and two upper level lows will increase the upper level divergence.  Tropical Storm Maria will continue to strengthen.  Maria will become a typhoon later this week.  It could intensify rapidly once an eye forms and the inner core is well developed.

Tropical Storm Maria is moving around the western end of a subtropical ridge which is steering Maria toward the north-northwest.  On its anticipated track the center of Tropical Storm Maria will move near Guam and Rota later today.  A general motion toward the northwest is forecast for the next several days.  Maria could move in the direction of the Ryukyu Islands at the end of the week.

Tropical Storm Maria will bring gusty winds and heavy rain to the southern Mariana Islands.  The strongest winds and heaviest rain will affect Guam and Rota.  Gusty winds and heavy rain will also affect Saipan and Tinian.  Heavy rain could produce flash floods.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Prapiroon was moving over the Sea of Japan.  Prapiroon was bringing wind and rain to the northern Islands of Japan including Hokkaido and Honshu.  At 5:00 a.m. EDT on Wednesday the center of Tropical Storm Prapiroon was located at latitude 39.6°N and longitude 135.6°E which put it about 360 miles (585 km) west-southwest of Misawa, Japan.  Prapiroon was moving toward the northeast at 25 m.p.h. (40 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were winds gusts to 65 m.p.h. (105 km/h).  The minimum surface pressure was 987 mb.

Typhoon Prapiroon Brings Wind and Rain to Kyushu

Typhoon Prapiroon brought wind and rain to Kyushu on Monday night.  At 11:00 p.m. EDT on Monday the center of Typhoon Prapiroon was located at latitude 32.8°N and longitude 128.6°E which put it about 110 miles (180 km) southwest of Sasebo, Japan.  Prapiroon was moving toward the north-northeast at 17 m.p.h. (27 km/h).  The maximum sustained wind speed was 80 m.p.h. (130 km/h) and there were wind gusts to 100 m.p.h. (160 km/h).  The minimum surface pressure was 968 mb.

Rainbands on the eastern side of Typhoon Prapiroon were moving over parts of Kyushu.  Those bands were causing gusty winds and they were dropping locally heavy rain.  The circulation of Typhoon Prapiroon was exhibiting the effects of a more midlatitude environment.  Drier air was wrapping around the western and southern portions of the typhoon.  The bands in those parts of Prapiroon consisted primarily of showers and low clouds.  The western portion of the eyewall was also weakening.  There were still strong thunderstorms in the eastern half of the eyewall and that was where the strongest winds were occurring.  Several bands of showers and thunderstorms on the eastern side of the circulation were revolving around the core of Typhoon Prapiroon.

Typhoon Prapiroon will be moving through an environment that will cause it to weaken.  Prapiroon was moving over water where the Sea Surface Temperature was near 26°C.  However, it will move over water where the Sea Surface Temperature is near 24°C when it moves north of Japan.  An upper level trough west of South Korea will produce southwesterly winds which will cause vertical wind shear.  The combination of cooler water and more vertical wind shear will cause Typhoon Prapiroon to weaken to a tropical storm on Tuesday.  Prapiroon could begin a transition to an extratropical cyclone because of the effects of the midlatitude environment.

Typhoon Prapiroon was being steered toward the north-northeast by the upper level trough.  Stronger westerly winds will steer Prapiroon more toward the northeast when it gets north of Japan.  On its anticipated track the center of Typhoon Prapiroon will pass near the northwestern portion of Kyushu.  The center of Prapiroon is forecast to pass between south Korean and Japan and then to move over the Sea of Japan.  Rainbands on the eastern side of Typhoon Prapiroon will cause gusty winds and drop heavy rain over parts of Kyushu.  Heavy could cause flash floods in some locations.  Prapiroon could also bring wind and rain to southeastern South Korea and parts of northern Honshu.

Elsewhere over the Western North Pacific Ocean Tropical Depression 10W formed southeast of Guam.  At 11:00 p.m. EDT on Monday the center of Tropical Depression 10W was located at latitude 10.6°N and longitude 145.7°E which put it about 205 miles (330 km) south-southeast of Guam.  It was moving toward the north-northwest at 6 m.p.h. (10 km/h).  The maximum sustained wind speed was 30 m.p.h. (50 km/h) and there were wind gusts to 40 m.p.h. (65 km/h).  The minimum surface pressure was 1003 mb.  A Tropical Storm Warning was issued for Guam.  A Tropical Storm Watch was issued for Tinian and Saipan.

Tropical Storm Goni Brings Wind and Rain to the Marianas

Tropical Storm Goni brought wind and rain to the Northern Marianas on Saturday.  At 11:00 p.m. EDT on Saturday the center of Tropical Storm Goni was located at latitude 15.1°N and longitude 144.4°E which put it about 60 miles (95 km) west of Tinian.  Goni was moving toward the northwest at 10 m.p.h. (16 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 982 mb.  A Tropical Storm Warning continues for Guam, Rota, Tinian, and Saipan and a Typhoon Watch continues for Saipan and Tinian.

The center of Tropical Storm Goni passed between Rota and Tinian on Saturday.  The tropical storm brought wind and rain to the northern Marianas.  The airport on Saipan reported a wind gust to 56 m.p.h. (90 km/h).  The stormy conditions could have setback the recovery from damage caused by Typhoon Soudelor.

The circulation around Goni continued to organize on Saturday.  A primary spiral band wrapped around the center of circulation and there have been indications that an eye may be forming in the center.  An upper level ridge east of Goni is causing some easterly winds over the circulation and is creating some vertical wind shear.  The shear is limiting thunderstorm activity on the eastern side of the circulation.  As Goni moves farther west, the wind shear will decrease.  It is moving over water where the Sea Surface Temperature is near 29°C.  The favorable environment will cause intensification and a period of rapid intensification is possible.

A subtropical ridge is steering Goni toward the west-northwest and that general steering pattern is expected to continue for the next few days.  Goni will move farther west of the Marianas on Sunday and conditions there should gradually improve.

Tropical Storm Goni Prompts Watches for Marianas

Tropical Storm Goni formed east of the Marianas on Friday and watches were issued for some of the islands because of the imminent threat it posed.  At 5:00 p.m. EDT on Friday the center of Tropical Storm Goni was located at latitude 13.0°N and longitude 148.0°E which put it about 235 miles (370 km) southeast of Saipan.  Goni was moving toward the west-northwest at 10 m.p.h. (16 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 996 mb.  A Typhoon Watch has been issued for Saipan and Tinian.  A Tropical Storm Watch has been issued for Guam and Rota.

The circulation of Tropical Storm Goni is still organizing.  Most of the thunderstorms are developing in the western half of the circulation.  An upper level ridge is generating easterly winds which are blowing across Goni and those winds are inhibiting the development of convection in the eastern part of the tropical storm.  Goni is moving over water where the Sea Surface Temperatures (SSTs) are near 29°C.  The environment supports intensification and Goni could intensify more rapidly in a day or two when the circulation is more well organized.  Goni could reach typhoon intensity within 48 hours.

A subtropical ridge is steering Goni toward the west-northwest and that general motion is expected to continue during the next few days.  On its anticipated track, the center of Goni could be very near Saipan in about 24 hours.  Goni could be a strong tropical storm on the verge of becoming a typhoon at that time.  Saipan is still recovering from the effects of Typhoon Soudelor.  Strong winds and heavy rain could set back those recovery efforts.

 

Typhoon Soudelor Intensifies Rapidly and Moves Over Saipan

Typhoon Soudelor intensified rapidly during the 12 hours before it moved directly over Saipan.  At 11:00 a.m. EDT on Sunday the center of Typhoon Soudelor was located at latitude 15.3°N and longitude 145.3°E which put it about 25 miles (40 km) west-northwest of Saipan.  It was moving toward the west-northwest at 11 m.p.h. (18 km/h).  The maximum sustained wind speed was 105 m.p.h. (165 km/h) and there were wind gusts to 125 m.p.h. (205 km/h).  The minimum surface pressure was 956 mb.  The airport on Saipan measured sustained wind to 54 m.p.h. (87 km/h) and wind gusts to 91 m.p.h. (147 km/h).  However, there were several observations when no wind speed was reported.  The minimum surface pressure reported was 958 mb.

Typhoon Soudelor organized quickly after the primary band wrapped completely around the center of circulation.  A tiny (4 mile wide) pinhole eye developed at the center of circulation and there are multiple bands of thunderstorms rotating around the center.   Soudelor is over warm Sea Surface Temperatures and there is little vertical wind shear.  Further intensification is likely and Soudelor could reach Super Typhoon status.

A subtropical ridge is steering Soudelor toward the west-northwest and that general motion is expected to continue for the next few days.  On its anticipated track Soudelor could approach the southernmost islands of Japan or Taiwan in four or five days.

Tropical Storm Chan-hom Bringing Wind and Rain to Guam

Tropical Storm Chan-hom is passing through the Marianas and bringing gusty winds and rain to Guam and Rota.  At 11:00 p.m. EDT on Saturday the center of Tropical Storm Chan-hom was located at latitude 14.3°N and longitude 144.8°E which put it about 10 miles (15 km) west of Rota.  Chan-hom was moving toward the west-northwest at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 45 m.p.h. (70 km/h) and there were wind gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 991 mb.

Despite being over warm water Chan-hom did not intensify on Saturday.  The circulation could be pulling in some drier air which is limiting the development of thunderstorms.  More thunderstorms developed near the inner core of Chan-hom late on Saturday.  There is not much vertical wind shear over the tropical storm.  If a well organized inner core forms, then intensification will be possible.  Chan-hom could become a typhoon after it moves west of the Mariana Islands.

The subtropical ridge steering Chan-hom is expected to continue to steer it toward the northwest during the next few days.  On its anticipated track Chan-hom could approach the southern islands of Japan in about four days.

Typhoon Dolphin Hits Guam and Rota

The core of Typhoon Dolphin moved over Guam and Rota on Friday.  Andersen Air Force Base reported northwesterly winds at 75 m.p.h. with gusts to 106 m.p.h. in one of its hourly observations.  The base also reported a Peak Wind of 86 knots (100 m.p.h.) in another observation.  The international airport on Guam reported a Peak Wind of 70 knots (80 m.p.h.).  At 5:00 p.m. EDT on Friday the center of Typhoon Dolphin was located at latitude 15.1°N and longitude 143.0°E which put it about 120 miles northwest of Guam.  Dolphin was moving toward the northwest at 15 m.p.h.  The maximum sustained wind speed was 125 m.p.h. and there were gusts to 155 m.p.h.  The minimum surface pressure was 941 mb.

Typhoon Dolphin is intensifying rapidly.  It is over water there the Sea Surface Temperature is near 29°C and the upper level winds are light.  It has a well formed eye and thunderstorms around the center are pumping out mass.  Upper level divergence is occurring and their are outflow channels to the northeast and southwest.  Dolphin could continue to intensify rapidly for another 24 hours.

Dolphin is near the western end of a subtropical ridge and it should gradually turn toward the north and then the northeast.  Its anticipated track will take it farther away from Guam, but it could approach Iwo To in about 72 hours as a significant typhoon.

Typhoon Dolphin Nearing Guam

Typhoon Dolphin is bringing wind and rain to Guam and Rota.  At 11:00 p.m. EDT on Thursday the center of Typhoon Dolphin was located at latitude 13.7°N and longitude 146.6°E which put it about 100 miles east of Guam.  Dolphin was moving toward the west-northwest at 16 m.p.h.  The maximum sustained wind speed was 110 m.p.h. and there were gusts to 130 m.p.h.  The minimum surface pressure was 952 mb.  A Typhoon Warning is in effect for Guam, Rota, Saipan and Tinian.  The Hurricane Intensity Index is 19.2, the Hurricane Size Index is 12.8 and the Hurricane Wind Intensity Size Index is 32.0.  The indices suggest that Dolphin is capable of producing regional serious damage.

The circulation of Dolphin became more symmetrical on Thursday and radar images from Guam show a circular eye and eyewall.  The thunderstorms near the center are generating upper level outflow.  Dolphin is moving over warm Sea Surface Temperatures and it is in an area where the upper level winds are relatively light.  The combination of better organization, warm water, little vertical wind shear suggest that further intensification is likely.

A subtropical ridge is steering Dolphin toward the west-northwest and that steering pattern is likely to continue for another day or so.  As Dolphin moves near the western end of the subtropical ridge, it is likely to turn more toward the north.  Eventually, when the typhoon moves farther north, westerly winds will turn it toward the northeast.

The core of Typhoon Dolphin will pass near Guam and Rota during the next few hours.  The northern portion of Guam and Rota will experience the strongest winds and heaviest rainfall, although much of Guam will experience the effects of Dolphin.  The core of the typhoon will likely pass south of Saipan and Tinian, but those islands will still get hit by rainbands rotating around the northern half of the circulation.

 

Typhoon Dolphin Still Moving Toward Guam

Typhoon Dolphin continued to moved toward the west-northwest in the direction of Guam on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Typhoon Dolphin was located at latitude 11.6°N and longitude 151.6°E which put it about 510 miles east-southeast of Guam.  Dolphin was moving toward the west-northwest at 15 m.p.h.  The maximum sustained wind speed was 105 m.p.h. and there were gusts to 125 m.p.h.  The minimum surface pressure was 956 mb.  A Typhoon Warning has been issued for Guam and Rota.  A Typhoon Watch and a Tropical Storm Warning has been issued for Saipan and Tinian.

Although the overall circulation of Dolphin remains well organized, many of the thunderstorms are located in a long spiral band that is trying to wrap around the center.  Some drier air may be wrapping around the western and southern sides of the circulation outside this band.  Dolphin is moving over warm Sea Surface Temperatures.  It is moving near the axis of an upper level ridge and the core of the typhoon is in an area with little vertical wind shear.  Except for the possible dry air, the conditions are favorable for further intensification.

Dolphin is being steered to the west-northwest by a subtropical ridge north of the typhoon.  The ridge is likely to continue to steer Dolphin in this direction for another day or two.  On the anticipated track Dolphin would approach Guam in 24 to 30 hours.  It could be a significant typhoon at that time.  After it passes Guam, Dolphin is expected to turn more toward the northwest as it moves around the western end of the subtropical ridge.