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Typhoon Goni Passing West of Okinawa

The center of powerful Typhoon Goni is passing west of Okinawa.  At 11:00 p.m. EDT on Sunday the center of Typhoon Goni was located at latitude 26.9°N and longitude 126.3°E which put it about 125 miles (200 km) west of Okinawa.  Goni was moving northeast at 18 m.p.h. (29 km/h).  The maximum sustained wind speed 125 m.p.h. (200 km/h) and there were wind gusts to 155 m.p.h. (250 km/h).  The minimum surface pressure was 937 mb.

An upper level trough northwest of Goni contributed to the development of an outflow channel which pumped out mass and allowed the typhoon to intensify on Sunday.  Goni is a strong well organized typhoon with an eye and a well formed eyewall.  Spiral bands of thunderstorms are rotating around the core of the circulation.  A weather station on Ishigaki Jima, Japan reported a wind gust to 97 m.p.h. (155 km/h) when Goni passed over the island.  Goni is moving over warm Sea Surface Temperatures (SSTs) and it could maintain its intensity for another 24 hours.  After that time it will move over cooler SSTs and the upper level trough will generate more vertical wind shear.  Goni will finally start to spin down when it moves west of Kyushu.

The upper level trough will continue to pull Goni toward the northeast.  On its anticipated track Typhoon Goni will approach western Kyushu in about 24 hours.  It could bring strong winds and heavy rain to parts of western Japan.

Wind Shear Weakens Danny to a Tropical Storm

Strong upper level winds sheared the top off of Hurricane Danny on Saturday and it weakened to tropical storm intensity.  At 11:00 p.m. EDT on Saturday the center of Tropical Storm Danny was located at latitude 15.6°N and longitude 54.7°W which put it about 480 miles (775 km) east of the Leeward Islands and about 1760 miles (2840 km) east-southeast of Miami, Florida.  Danny was moving toward the west at 15 m.p.h. (24 km/h).  The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there were wind gusts to 70 m.p.h. (110 km/h).  The minimum surface pressure was 999 mb.  Tropical Storm Watches have been issued for Antigua, Barbuda, Montserrat, St. Kitts, Nevis, Anguilla, Saba, St. Eustatius, St. Maarten, Gudaloupe, St. Barthelemy and St. Martin.

A upper level trough over the eastern Caribbean Sea generated brisk southwesterly winds over the top of Danny and blew the upper portion of the circulation northeast of the low level center.  By late Saturday afternoon the low level center was exposed on satellite imagery.  The vertical wind shear disrupted the vertical circulation of Danny and it weakened fairly quickly.  A few more thunderstorms appear to have developed northeast of the center in recent hours and the wind shear may have decreased just slightly.  Danny will move over slightly warmer water on Sunday, which could add a little more energy to the circulation.  The wind shear is forecast to continue and Danny could weaken further.

As Danny weakened, the lower portion of the circulation was steered more by the winds closer to the surface.  Those winds pushed the center more toward the west.  The subtropical ridge that was steering Danny is expected to strengthen and Danny is forecast to move toward the west for the next day or two.  On its anticipated track Danny could be near the Leeward Islands in about 30 hours and it could be approaching Puerto Rico in 48 hours.

Kilo and Loke Weaken to Tropical Depressions

Both Tropical Storms Kilo and Loke weakened on Saturday and were downgraded to tropical depression status.  At 5:00 p.m. EDT on Saturday the center of Tropical Depression Kilo was located at latitude 14.2°N and longitude 159.4°W which put it about 500 miles (805 km) south-southwest of Honolulu, Hawaii.  Kilo was moving toward the west-northwest at 15 m.p.h. (24 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 m.p.h.).  The minimum surface pressure was 1005 mb.

At 5:00 p.m. EDT on Saturday the center of Tropical Depression Loke was located at latitude 18.1°N and longitude 178.6°W which put it about 700 miles (1130 km) south of Midway Island.  Loke was moving toward the northwest at 8 m.p.h.  The maximum sustained wind speed was 35 m.p.h. (55 km/) and there were wind gusts to 45 m.p.h. (70 km/h).  The minimum surface pressure was 1003 mb.

Kilo appeared to be affected by vertical wind shear for much of Saturday.  A reconnaissance aircraft had a difficult time trying to find a surface circulation center and the spiral bands were not well developed.  Upper level easterly winds appeared to be pushing the tops of thunderstorms west of the low level circulation and inhibiting the formation of a warm core in the upper levels.  Recent satellite imagery suggests that more thunderstorms could be forming closer to the center of Kilo.  The vertical wind shear is forecast to decrease and Kilo could strengthen during the next few days.  A subtropical ridge is steering Kilo westward, but the ridge is expected to weaken and the steering currents could become weaker on Sunday.  Eventually, an upper level trough approaching from the northwest is forecast to pull Kilo toward the northeast early next week.

Loke appears to be very well organized for a tropical depression.  A primary rainband wraps around the western and southern side of the center of circulation and there appears to be about three quarters of an eyewall trying to form around the center.  The thunderstorms in the band are generating upper level divergence.  Loke is over warm Sea Surface Temperatures.  However, an upper level trough northwest of Loke is generating some southwesterly winds that are creating some vertical wind shear and are inhibiting upper level divergence south of the center of circulation.  That same upper level trough is expected to steer Loke toward the north-northeast during the next few days.  On it anticipated track Loke could be near Midway Island in about 60 hours.

Typhoon Goni Heading Toward Western Japan

Typhoon Goni turned north-northeastward and began moving toward western Japan on Saturday.  At 5:00 p.m. EDT on Saturday the center of Typhoon Goni was located at latitude 22.7°N and longitude 123.4°E which put it about 270 miles (435 km) southeast of Taipei, Taiwan and about 410 miles (660 km) southwest of Okinawa.  Goni was moving toward the north-northeast at 11 m.p.h. (18 km/h).  The maximum sustained wind speed was 90 m.p.h. (145 km/h) and there were wind gusts to 115 m.p.h. (185 km/h).  The minimum surface pressure was 967 mb.

The circulation of Typhoon Goni continues to be well organized.  It has a small eye with a fairly continuous eyewall surrounding it.  There are multiple spiral bands and the strongest band is about 60 miles east of the center of circulation.  There is upper level divergence pumping out mass.  Goni is moving over warm Sea Surface Temperatures and the upper level winds are relatively light.  The environment is favorable for intensification and modest intensification is possible during the next day or so.

Goni is moving around the western end of a subtropical ridge which is steering it toward the north-northeast.  That steering pattern is expected to continue for another two or three days.  On its anticipated track Goni will be near Ishigaki Jima in about 12 hours.  It could be just west of Okinawa in about 30 hours and it could be approaching Kyushu in about 48 hours.  Goni will bring strong winds and heavy rains to any places in its path.

Typhoon Goni Turning North, May Threaten Okinawa

Typhoon Goni is slowly turning toward the north and moving away from northern Luzon.  At 5:00 p.m. EDT on Friday the center of Typhoon Goni was located at latitude 19.8°N and longitude 122.5°E which put it about 330 miles (530 km) south-southeast of Taipei, Taiwan and about 615 miles (990 km) southwest of Okinawa.  Goni was moving toward the north at 2 m.p.h. (3 km/h).  The maximum sustained wind speed was 105 m.p.h. (120 km/h) and there were wind gusts to 120 m.p.h. (195 km/h).  The minimum surface pressure was 956 mb.

Typhoon Goni will still be moving over warm Sea Surface Temperatures for the next several days and it has a chance to intensify.  The upper level winds are relatively light over the typhoon and there is not much vertical wind shear along its immediate path.  There appears to be an upper level outflow channel to the northeast.  Given the favorable environment Goni could intensify on Saturday.

Goni is moving around the western end of a subtropical high pressure system and it should begin to move toward the northeast a little more quickly.  On its anticipated track Goni could be near Ishigaki Jima in about 36 hours and near Okinawa in about 48 hours.  It could still be a strong typhoon at that time.  Goni could still by a typhoon when it approaches southwestern Kyushu in about three days.

Tropical Storms Kilo and Loke Form Over the Central Pacific

Two tropical storms formed over the Central Pacific Ocean on Friday.  At 5:00 p.m. EDT on Friday the center of Tropical Storm Kilo was located at latitude 13.0°N and longitude 153.3°W which put it about 480 miles (770 km) south-southeast of Hilo, Hawaii.  Kilo was moving toward the west-northwest at 16 m.p.h. (26 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 1004 mb.

At 5:00 p.m. EDT on Friday the center of Tropical Storm Loke was located at latitude 16.4°N and longitude 177.2°W which put it about 815 miles (1310 km) south of Midway Island.  Loke was moving toward the north at 6 m.p.h. (9 km/h).  The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 55 m.p.h. (90 km/h).  The minimum surface pressure was 1000 mb.

Tropical Storm Kilo is not very well organized at the present time.  Strong easterly winds in the upper levels are blowing the tops off of the thunderstorms and the vertical wind shear is keeping Kilo from intensifying.  If the shear decreases as some numerical models forecast, then Kilo could intensify.  On the other hand, if the shear stays strong, then Kilo could weaken to a tropical depression.  If Kilo intensifies as some models suggest, then it could be pushed toward the western Hawaiian Islands.  However, if Kilo stays weaker, then winds lower in the atmosphere could steer more toward the west and keep it south of Hawaii.

Tropical Storm Loke is better organized, although most of the stronger thunderstorms are north of the center.  An upper level trough northwest of Loke could be creating some southwesterly winds around the tropical storm.  Although the vertical wind shear may be slowing the rate of intensification, Loke does appear to be getting stronger.  The upper level trough is expected to steer Loke toward the north and it could approach Midway Island in four or five days.  Loke could be a hurricane at that time.

Danny Becomes a Major Hurricane

Hurricane Danny intensified quickly and a NOAA plane investigating it on Friday afternoon found that Danny had maximum sustained winds of 115 m.p.h.  That made Danny a Category 3 hurricane on the Saffir-Simpson Scale which also made it a Major Hurricane.  At 5:00 p.m. EDT on Friday the center of Hurricane Danny was located at latitude 14.5°N and longitude 49.1°W which put it about 860 miles (1390 km) east of the Leeward Islands and about 2140 miles (3450 km) east-southeast of Miami, Florida.  Danny was moving toward the west-northwest at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 115 m.p.h. (165 km/h) and there were wind gusts to 135 m.p.h. (195 km/h).  The minimum surface pressure was 974 mb.  Danny had a Hurricane Intensity Index (HII) of 20.6, a Hurricane Size Index (HSI) of 6.0, and a Hurricane Wind Intensity Size Index (HWISI) of 26.6

Danny remains a very small hurricane.  It is about two thirds of the size that Hurricane Charley was when it hit southwest Florida in 2004.  Danny may be starting to weaken.  The small eye is no longer visible on satellite images.  Southwesterly winds in the upper levels may be generating some vertical wind shear and those winds may also be inhibiting upper level divergence on the western side of Danny.  The small size of Danny means that it could weaken almost as fast as it intensified, if the shear increases.  Danny will move over warmer water when it passes west of longitude 55°W, which could slow the rate of weakening in about 36 hours.

Danny is being steered toward the west-northwest by a subtropical ridge located north of the hurricane.  The ridge is expected to strengthen in two or three days and steer Danny more toward the west after that time.  On its anticipated track Danny could be approaching the northern Leeward Islands in about two and a half days and it could be near Puerto Rico in about three and a half days.

Tiny Danny Quickly Intensifies Into a Hurricane

Tiny Tropical Storm Danny intensified quickly during the past 12 hours and the National Hurricane Center upgraded it to hurricane status in its 11:00 a.m. EDT advisory on Thursday.  At 11:00 a.m. EDT on Thursday the center of Hurricane Danny was located at latitude 12.5°N and longitude 44.8°W which put it about 1090 miles (1755 km) east of the Windward Islands and about 2480 miles (4000 km) east-southeast of Miami.  Danny was moving toward the west-northwest at 12 m.p.h. (19 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. (145 km/h).  The minimum surface pressure was 992 mb.

The core of Hurricane Danny organized quickly on Thursday.  An eye formed in the center of the circulation and a ring of thunderstorms developed around the eye.  The circulation around Danny is very small.  Hurricane force winds only extend out about 12 miles (19 km) from the center and tropical storm force winds only extend 60 miles (95 km) from the center.  The Hurricane Size Index (HSI) for Danny is only 4.2.

The environment around Danny remains complex.  It is over water where the Sea Surface Temperature (SST) is near 28°C and the upper level winds are very light.  Upper level divergence is being produced by the thunderstorms around the eye.  On the other hand, slightly cooler SSTs and drier air are just to the north of Danny.  In addition, small hurricanes like Danny can be strongly affected by changes in their environment and they can intensify or weaken very quickly.  The environment would seem to support further intensification, but if Danny moves a little farther north, it could move into a more hostile environment.

Danny is being steered toward the west-northwest by the subtropical ridge to its north and that general steering pattern is expected to continue for another two or three days.  Late in the weekend the subtropical ridge is forecast to strengthen and steer Danny more toward the west.  On its anticipated track Danny could be near the Leeward Islands in about four days and near Puerto Rico in about five days.

Typhoon Goni Moving Closer to Northern Luzon and Taiwan

Typhoon Goni moved steadily westward on Wednesday and it got closer to northern Luzon and Taiwan.  At 11:00 p.m. EDT on Wednesday the center of Typhoon Goni was located at latitude 18.9°N and longitude 125.3°E which put it about 350 miles (565 km) southeast of Taipei, Taiwan.  Goni was moving toward the west at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 130 m.p.h. (215 km/h) and there were wind gusts to 160 m.p.h. (260 km/h).  The minimum surface pressure was 937 mb.

Typhoon Goni intensified on Wednesday and it is a very well organized tropical cyclone.  It has a large well formed eye.  The circulation is symmetrical although there are more thunderstorms in the south half of the typhoon.  Upper level divergence is well developed and it is pumping out mass in all directions.  Goni remains over warm Sea Surface Temperatures and the upper level winds are relatively light.  Some further intensification is possible during the next day or so.  Goni could run into stronger upper level winds in two or three days which would create more vertical wind shear and start to weaken the typhoon.

A subtropical ridge has been steering Goni toward the west and it is expected to do so again on Thursday.  However, Goni is nearing the western end of the ridge and it is forecast to turn to the north on Friday.  Goni appears to have moved more slowly during the past few hours, which may be an indication that it is reaching the western end of the ridge.  An upper level trough northwest of Goni is expected to turn Goni toward the northeast during the weekend and then accelerate it toward western Japan.

On its anticipated track, the center of Goni is expected to pass northeast of Luzon.  However, the circulation is large enough that some of northern Luzon could experience strong winds and heavy rain.  The center of Goni is forecast to pass east of Taiwan, but it could also bring strong winds heavy rain to some locations there as well.  The core of Goni could pass very near Ishigaki Jima and bring very strong winds and heavy rain to the islands in that area.

Tropical Storm Danny Heading West

Tropical Storm Danny has moved steadily westward during the past 24 hours.  At 11:00 a.m. EDT on Wednesday the center of Tropical Storm Danny was located at latitude 11.2°N and longitude 41.1°W which put it about 1385 miles (2235 km) east of the Lesser Antilles and about 2740 miles (4410 km) east-southeast of Miami, Florida.  Danny was moving toward the west at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 1000 mb.

The organization of the circulation of Danny has varied during the past day.  It has a visible tight core at the center, but earlier today there was no convection around the core.  Recent satellite images show new thunderstorms developing near the core.  The environment around Danny is complex and it contains both positive and negative factors.  Danny is currently over water where the Sea Surface Temperature (SST) is near 28°C.  However, there is slightly cooler water just to the north of the tropical storm.  Satellite imagery indicates that there could also be drier air north of the circulation and some of that drier air could be pulled into Danny.  The upper level winds are light and upper level divergence is occurring.  However, a surge in the low level trade winds is about 250 miles (400 km) east of Danny.   If the surge in the trade winds reaches the core of Danny, it could push the lower part of the circulation out ahead (to the west) of the upper part of the circulation.  In that case Danny would weaken.

The complexity of the environment around Tropical Storm Danny makes the intensity forecast challenging.  If the trade wind surge does not reach the core of Danny and it stays over warm SSTs, then gradual intensification is possible.  On the other hand, if Danny moves more northward over cooler SSTs and into drier air, or if the trade wind surge creates more vertical wind shear, then Danny could weaken.

A subtropical ridge to the north of Danny is steering Danny toward the west and a generally west or west-northwest motion is forecast for the next few days.  If Danny is a little stronger, it could move a little farther north, and if it is weaker, it could stay farther south.  On its anticipated track, Danny could approach the Lesser Antilles in four or five days.  Interests in those areas should monitor Danny for future developments.