Tag Archives: Saipan

Tropical Storm Champi Passing Through the Northern Marianas

Tropical Storm Champi is bringing gusty winds and heavy rain as it moves through the Northern Marianas.  At 11:00 p.m. EDT on Thursday the center of Tropical Storm Champi was centered near latitude 15.9°N and longitude 146.3°E which put it about 80 miles (135 km) east-northeast of Saipan.  Champi was moving toward the west at 19 m.p.h. (31 km/h).  The maximum sustained wind speed was 70 m.p.h. (115 km/h) and there were wind gusts to 85 m.p.h. (135 km/h).  The minimum surface pressure was 980 mb.  A Tropical Storm Warning remains in effect for Rota, Tinian, Saipan, Alamagan, Pagan and Agrihan.  The weather station at the airport on Saipan was reporting southwesterly winds at 46 m.p.h. (74 km/h) with gusts to 78 m.p.h. (126 km/h).

Although an upper level ridge north of Champi continued to cause vertical wind shear over the tropical storm, it slowly intensified on Thursday.  More thunderstorms formed near the center of circulation and those storms are generating more upper level divergence.  The core of the circulation is consolidating and more spiral bands are forming outside the core.  Champi is on the threshold of becoming a typhoon.  It is moving over water where the Sea Surface Temperature is near 29°C.  Champi is likely to move into an area where the upper level winds are lighter during the weekend and it will continue to intensify during the next several days.

A subtropical ridge is steering Champi toward the west and that motion is expected to continue for the next 12 to 24 hours.  After that time Champi will reach the western end of the ridge and turn toward the north.  Champi could be a strong typhoon south of Iwo To in about three days.

Tropical Storm Champi Intensifies, Warnings Issued for Northern Marianas

Tropical Storm Champi intensified on Wednesday and the National Weather Service issued watches and warnings for the northern Marianas.  At 11:00 p.m. EDT on Wednesday the center of Tropical Storm Champi was located at latitude 15.5°N and longitude 151.9°E which put it about 450 miles (730 km) east of Saipan.  Champi was moving toward the west-northwest at 13 m.p.h. (21 km/h).  The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there were wind gusts to 75 m.p.h. (120 km/h).  The minimum surface pressure was 984 mb.  Tropical Storm Warnings have been issued for Rota, Tinian, Saipan, Alamagan, Pagan and Agrihan.  A Typhoon Watch has been issued for Alamagan, Pagan and Agrihan.

The circulation of Tropical Storm Champi is still organizing.  An upper level ridge north of the tropical storm is causing easterly winds to blow over the top of Champi.  The resulting vertical wind shear is causing most of the stronger thunderstorms to form in the western half of the circulation.  Champi is over water where the Sea Surface Temperature is near 29°C.  The vertical wind shear will inhibit intensification on Thursday, but Champi could reach typhoon intensity within 24 hours.  It is expected to move into an area where the upper level winds are lighter on Friday and the rate of intensification could increase.

A subtropical ridge is steering Champi on a track that is a little north of due west.  That general motion is expected to continue for the next several days.  Champi will reach the western end of the subtropical ridge and turn toward the north later in the weekend.  On its anticipated track Champi will approach the northern Marianas in 24 to 30 hours.  It could bring strong winds and heavy rain to those islands.  Since the strongest thunderstorms are west of the center of circulation, conditions could start to deteriorate on some of the islands in less than 24 hours.

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.

Soudelor Almost a Typhoon as It Nears the Marianas

Tropical Storm Soudelor intensified on Saturday and it has almost reached typhoon status.  At 11:00 p.m. EDT on Saturday the center of Tropical Storm Soudelor was located at latitude 14.8°N and longitude 147.7°E which put it about 170 miles (275 km) east-southeast of Saipan.  Soudelor was moving toward the west-northwest at 18 m.p.h. (29 km/h).  The maximum sustained wind speed was 70 m.p.h. (115 km/h) and there were gusts to 85 m.p.h. (135 km/h).  The minimum surface pressure was 978 mb.  A Typhoon Warning has been issued for Saipan and Tinian.  A Tropical Storm Warning has been issued for Rota.  A Typhoon Watch has been issued for Agrihan, Pagan and Alamagan.

The structure of Tropical Storm Soudelor improved on Saturday.  A long spiral band wrapped almost entirely around the center of circulation and numerous other spiral bands were apparent on satellite imagery.  There are more thunderstorms on the western side of the circulation.  Soudelor is moving over water where the Sea Surface Temperature is near 30°C.  An upper level ridge north of the tropical storm is causing light easterly winds over the circulation.  However, the vertical wind shear is modest and upper level divergence is increasing.  Soudelor is in a favorable environment.  Further intensification is likely and rapid intensification is possible.  Soudelor will very likely be a typhoon when it moves through Marianas.

A subtropical ridge is steering Soudelor toward the west-northwest and that pattern is expected to continue during the next few days.  On its anticipated track Soudelor will be near Saipan and Tinian in about 12 hours.  It could bring strong winds to those locations and other nearby islands.

Nangka Intensifies Rapidly Into a Strong Typhoon

Typhoon Nangka intensified rapidly into a strong typhoon on Monday.  At 11:00 p.m. EDT on Monday the center of Typhoon Nanga was located at latitude 13.2°N and longitude 155.0°E which put it about 670 miles (1080 km) east-southeast of Saipan.  Nangka was moving toward the west-northwest at 13 m.p.h. (21 km/h).  The maximum sustained wind speed was 110 m.p.h. (180 km/h) and there were wind gusts to 130 m.p.h. (210 km/h).  The minimum surface pressure was 952 mb.

The circulation of Typhoon Nangka is very well organized with a strong ring of thunderstorms surrounding a circular eye.  The typhoon is over an area where the Sea Surface Temperature is around 28°C to 29°C.  The upper level winds are relatively light and there appear to outflow channels to the northeast and southwest which are transporting mass away from the center of circulation.  The surface pressure is decreasing rapidly and the wind speeds are increasing quickly.  Nangka is in an environment that is very favorable for further intensification and it could become a very powerful typhoon.

A subtropical ridge is steering Nangka toward the west-northwest and that general motion is expected to continue during the next few days.  On its anticipated track Typhoon Nangka could approach the northern Mariana Islands in about 48 to 72 hours.

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.

Wind Shear Affecting Tropical Storm Chan-hom

Although Tropical Storm Chan-hom briefly reached typhoon intensity on Thursday, strong upper vertical wind shear quickly weakened it back to a tropical storm.  At 11:00 p.m. EDT on Thursday the center of Tropical Storm Chan-hom was located at latitude 10.3°N and longitude 148.0°E which put it about 325 miles (525 km) southeast of Guam.  Chan-hom was moving toward the west 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 981 mb.  A Typhoon Watch has been issued for Guam, Rota, Tinian and Saipan.

The combination of a upper level ridge and an upper level low produced strong northeasterly winds that blew the middle and upper portions of the circulation of Chan-hom west of the low level circulation.  The middle and upper parts of the circulation are about 100 miles (160 km) southwest of the surface center.  There are no thunderstorms currently near the surface center.  The upper level winds and the vertical wind shear they are producing are likely to continue to weaken Chan-hom on Friday.  The upper low is expected to move eastward during the next several days, which would result in a decrease in the wind shear.  If the surface circulation is still intact, it will be over warm Sea Surface Temperatures and reintensification would be possible.

Chan-hom is likely to be steered toward the west on Friday by the winds in the lower levels.  If new thunderstorms develop near the center and the height of the circulation increases, then a subtropical ridge in the middle levels could cause the tropical storm to turn toward the northwest.  If that turn occurs on Friday, it could put Chan-hom on a track toward Guam, Saipan or Tiniana.  If the turn occurs later in the weekend, then Chan-hom could pass to the south of those islands before it turns toward the northwest.

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.