Tag Archives: 08E

Minimal Tropical Storm Gilma Forms Well East of Hawaii

Minimal Tropical Storm Gilma formed well east of Hawaii on Friday.  A scatterometer on a polar orbiting satellite indicated that there were winds to tropical storm force near former Tropical Depression Eight-E and the National Hurricane Center named the system Tropical Storm Gilma.  At 11:00 a.m. EDT on Friday the center of Tropical Storm Gilma was located at latitude 14.9°N and longitude 128.4°W which put it about 1825 miles (2935 km) east of South Point, Hawaii.  Gilma was moving toward the west-northwest at 17 m.p.h. (28 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 1006 mb.

The circulation of Tropical Storm Gilma was poorly organized.  There was a distinct low level center of circulation.  However, the stronger thunderstorms were occurring in bands east of the center.  Bands in the western half of the circulation consisted primarily of low clouds and showers.  A large upper level trough was located west of Tropical Storm Gilma.  The trough was producing strong northwesterly winds which were blowing across the top of the circulation.  Those winds were producing significant vertical wind shear and they were probably the reason why the stronger thunderstorms were occurring east of the center of circulation.

Tropical Storm Gilma will move through an environment unfavorable for intensification during the weekend.  Gilma will move over water where the Sea Surface Temperature is near 28°C.  However, the upper level trough will continue to produce significant vertical wind shear.  Gilma is likely to weaken to a depression and it could dissipate if the upper level winds blow the top of the circulation east of the low level center.

Tropical Storm Gilma will move south of a subtropical high pressure system over the Eastern North Pacific.  The strong wind shear will mean that Gilma will be steered by the winds lower in the atmosphere.  Those winds will push Gilma in a general westerly or west-northwesterly direction.

Tropical Storm Irwin Forms, Greg Gets Larger, Hilary Strengthens

Tropical Depression Ten-E intensified into Tropical Storm Irwin, the circulation of Tropical Storm Greg increased in size and Tropical Storm Hilary strengthened on Sunday.  At 5:00 p.m. EDT on Sunday the center of Tropical Storm Irwin was located at latitude 14.9°N and longitude 116.6°W which put it about 705 miles (1135 km) southwest of the southern tip of Baja California.  Irwin was moving toward the west at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 1003 mb.

At 5:00 p.m. EDT on Sunday the center of Tropical Storm Greg was located at latitude 14.4°N and longitude 130.1°W which put it about 1445 miles (2325 km) west-southwest of the southern tip of Baja California.  Greg 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 1001 mb.

At 5:00 p.m. EDT on Sunday the center of Tropical Storm Hilary was located at latitude 14.9°N and longitude 102.9°W which put it about 410 miles (660 km) south-southeast of Manzanillo, Mexico.  Hilary was moving toward the west-northwest at 9 m.p.h. (15 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 was 999 mb.

A primary rainband wrapped around the western and southern sides of the center of circulation of Tropical Depression Ten-E and the National Hurricane Center upgraded the system to Tropical Storm Irwin.  Several other bands of showers and thunderstorms were developing over the southern half of the circulation.  There were fewer showers and thunderstorms in the northern half of the circulation.  Thunderstorms near the center of circulation were generating some upper level divergence.

Tropical Storm Irwin will move through an environment that will be somewhat favorable for intensification.  Irwin will move over water where the Sea Surface Temperature (SST) is near 28°C.  An upper level ridge northwest of Irwin are generating northeastern winds which are blowing toward the top of the circulation.  Those winds are generating moderate vertical wind shear and the shear may be the cause of the asymmetric distribution of showers and thunderstorms.  Tropical Storm Irwin could intensify during the next 24 to 48 hours.

The circulation of Tropical Storm Greg grew in size on Sunday.  However, Tropical Storm Greg will move into a less favorable environment during the next several days.  Tropical Storm Greg is over water where the SST is near 28°C, but it will move over cooler water in a day or two.  Greg could intensify in the short term, but it will weaken by midweek.

Tropical Storm Hilary is moving through a very favorable environment.  Hilary is moving over water where the SST is near 30°C.  The upper level winds are weak and there is little vertical wind shear.  Tropical Storm Hilary could be beginning a period of rapid intensification.  Hilary is forecast to become a hurricane on Monday and it could be a major hurricane later this week.

A subtropical ridge is steering all three tropical storms in a general west-northwesterly direction.  Tropical Storms Greg, Hilary and Irwin are likely to continue to move a little to the north of due west during the next three days.  On its anticipated track Tropical Storm Hilary is expected to remain west of the west coast of Mexico.

Active East Pacific With Fernanda, Greg and TD 8E

The tropical Eastern North Pacific Ocean continued to be very active on Tuesday with Hurricane Fernanda, Tropical Storm Greg and Tropical Depression Eight-E.  At 11:00 p.m. EDT on Tuesday the center of Hurricane Fernanda was located at latitude 16.5°N and longitude 134.4°W which put it about 1375 miles east of Hilo, Hawaii.  Fernanda was moving toward the northwest at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 100 m.p.h. (160 km/h) and there were wind gusts to 120 m.p.h. (195 km/h).  The minimum surface pressure was 976 mb.

At 11:00 p.m. EDT on Tuesday the center of Tropical Storm Greg was located at latitude 14.6°N and longitude 110.1°W which put it about 490 miles (785 km) southwest of Manzanillo, Mexico.  Greg was moving toward the west at 10 m.p.h. (16 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 1003 mb.

At 11:00 p.m. EDT on Tuesday the center of Tropical Depression Eight-E was located at latitude 14.8°N and longitude 119.9°W which put it about 860 miles (1385 km) southwest of the southern tip of Baja California.  It was moving toward the west at 5 m.p.h. (8 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h).  The minimum surface pressure was 1007 mb.

Although Hurricane Fernanda is the strongest of the three tropical cyclones over the Eastern North Pacific Ocean, it is slowly weakening as it moves over cooler Sea Surface Temperatures  (SSTs).  Hurricane Fernanda is over water where the SSTs are near 26.5°C and it will move over cooler water as it moves west toward Hawaii.

Tropical Storm Greg strengthened on Tuesday as it moved over water where the SSTs are near 29°C.  A primary rainband wrapped around the western side of the center of circulation.  Additional showers and thunderstorms formed closer to the center.  Greg is also expected to move west as it moves south of a subtropical ridge.

The future of Tropical Depression Eight-E is less certain.  Upper level divergence from Hurricane Fernanda is creating strong vertical wind shear over the stop of the depression.  The strong wind shear is causing the circulation of the depression to be poorly organized.  There are few showers and thunderstorms in the northern portion of the circulation because of the strong shear.  The stronger upper level winds could shear the top of the circulation away from the lower level circulation of the depression.  It is also possible that Tropical Storm Greg could catch up to the depression and absorb the remnants of the depression into its circulation.

Tropical Storm Frank and Tropical Depression 08E Form

The National Hurricane Center designated two new systems over the Eastern North Pacific Ocean as tropical cyclones on Thursday afternoon.  Tropical Storm Frank was the sixth tropical storm to form over the Eastern North Pacific during the month of July.  The record for tropical storms forming in July is seven.  If Tropical Depression 08E intensifies into a tropical storm then 2016 will tie the record for the most tropical storms to form over the Eastern Pacific during July.

At 5:00 p.m. EDT on Thursday the center of Tropical Storm Frank was located at latitude 14.9°N and longitude 104.0°W which put it about 675 miles (1085 km) southeast of the southern tip of Baja California.  Frank was moving toward the northwest at 14 m.p.h. (22 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 1005 mb.

At 5:00 p.m. EDT on Thursday the center of Tropical Depression 08E was located at latitude 10.8°N and longitude 114.0°W which put it about 880 miles (1415 km) south-southwest of the southern tip of Baja California.  The depression was moving toward the west-northwest at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (70 km/h).  The minimum surface pressure was 1006 mb.

Tropical Storm Frank is the larger and better organized system.  A primary rainband wraps about three-quarters of way around the western side of the center of circulation.  Additional rainbands are spiraling around the outer portion of Frank.  Thunderstorms near the center of circulation are generating upper level outflow which is pumping out mass in all directions.

The circulation of Tropical Depression 08E is smaller and less well organized.  A primary rainband wraps about half way around the western side of the center of circulation.  Other partial rainbands are evident, but most of the thunderstorms are occurring in the western half of the circulation.  If looks like some of the upper level outflow from Tropical Storm Frank could be causing vertical wind shear over Tropical Depression 08E.

The environment around Tropical Storm Frank is favorable for intensification.  Frank is moving over water where the Sea Surface Temperature is near 29°C.  In addition, Tropical Storm Frank appears to be located beneath an upper level anticyclone, which is enhancing the upper level divergence.  Frank is likely to intensify during the next several days and it could intensify rapidly once an inner core forms around an eye.

The environment around Tropical Depression 08E is not as favorable.  It is over water the Sea Surface Temperature is near 28°C.  Upper level outflow from the anticyclone over Tropical Storm Frank is generating easterly winds and moderate vertical wind shear over the depression.  If Tropical Depression 08E and Tropical Storm Frank move farther apart, then the shear could decrease and the depression could strengthen.

A subtropical ridge is steering both Tropical Storm Frank and Tropical Depression 08E toward the west-northwest.  However, a weaker area in the ridge is forecast to develop northwest of Frank and that could allow the tropical storm to move on a more northwesterly track.  On its anticipated track Tropical Storm Frank could move near the southern tip of Baja California on Sunday.