Tag Archives: Tropical Storm Estelle

Estelle Weakens to a Tropical Storm

Former Hurricane Estelle weakened to a tropical storm over the Eastern North Pacific Ocean southwest of Baja California on Tuesday morning. At 11:00 a.m. EDT on Tuesday the center of Tropical Storm Estelle was located at latitude 19.0°N and longitude 115.5°W which put it about 450 miles (725 km) southwest of the southern tip of Baja California. Estelle was moving toward the west-northwest at 12 m.p.h. (19 km/h). The maximum sustained wind speed was 65 m.p.h. (105 km/h) and and there were wind gusts to 80 m.p.h. (130 km/h). The minimum surface pressure was 993 mb.

Drier air in the western half of former Hurricane Estelle reached the center of circulation on Tuesday morning and Estelle weakened to a tropical storm. The strongest winds in Tropical Storm Estelle were occurring in bands of thunderstorms in the eastern side of the circulation. Bands in the western half of the circulation consisted primarily of showers and lower clouds. More thunderstorms developed again east of the center of Estelle later on Tuesday morning. Storms near the center generated upper level divergence that pumped mass away from the tropical storm. Winds to tropical storm force extended out 115 miles (185 km) from the center of Estelle’s circulation.

Tropical Storm Estelle will move through an environment only marginally favorable for intensification during the next 24 hours. Estelle will move over water where the Sea Surface Temperatures are near 25˚C. It will move under an upper level ridge over the Eastern North Pacific Ocean west of Mexico. The upper level winds are weak in the ridge and there will be little vertical wind shear. However, the drier air in the western half of Tropical Storm Estelle is likely to continue to inhibit the formation of thunderstorms in that part of the circulation. Estelle could intensify during the next 24 hours, if thunderstorms continue to develop near the center of circulation. However, the drier air is likely to limit any intensification. Tropical Storm Estelle will move over cooler water during the next several days, which is likely to cause it to weaken.

Tropical Storm Estelle will move around the southern side of a high pressure system over the Eastern North Pacific Ocean. The high pressure system will steer Estelle toward the west during the next 24 hours. On its anticipated track Tropical Storm Estelle will move farther to the southwest of Baja California.

Tropical Storm Estelle Forms South of Mexico

Tropical Storm Estelle formed over the Eastern North Pacific Ocean south of Mexico on Friday night. At 11:00 p.m. EDT on Friday the center of Tropical Storm Estelle was located at latitude 13.2°N and longitude 102.0°W which put it about 290 miles (470 km) south-southwest of Acapulco, Mexico. Estelle was moving toward the northwest at 10 m.p.h. (16 km/h). The maximum sustained wind speed was 40 m.p.h. (65 km/h) and and there were wind gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 1006 mb.

An area of low pressure over the Eastern North Pacific Ocean south of Mexico strengthened on Friday night and the National Hurricane Center designated the system as Tropical Storm Estelle. The circulation around Estelle exhibited more organization. More thunderstorms developed near the center of Tropical Storm Estelle. Storms near the center of circulation generated upper level divergence that pumped mass away from the tropical storm. Bands of showers and thunderstorms were revolving around the center of Estelle’s circulation. Winds to tropical storm force extended out 45 miles (75 km) in the northeastern quadrant of Tropical Storm Estelle. The wind in the other parts of Estelle’s circulation were blowing at less than tropical storm force.

Tropical Storm Estelle will move through an environment favorable for intensification during the next 36 hours. Estelle will move over water where the Sea Surface Temperatures are near 28˚C. It will move under an upper level ridge near the west coast of Mexico. The upper level winds are weak in the ridge and there will be little vertical wind shear. Tropical Storm Estelle will intensify during the next 36 hours and it could strengthen to a hurricane.

Tropical Storm Estelle will move around the southern side of a high pressure system over Mexico. The high pressure system will steer Estelle toward the west-northwest during the next 36 hours. On its anticipated track Tropical Storm Estelle will move away from the west coast of Mexico.

Elsewhere, Tropical Storm Darby weakened east-southeast of Hawaii. At 11:00 p.m. EDT on Friday the center of Tropical Storm Darby was located at latitude 17.7°N and longitude 149.4°W which put it about 400 miles (640 km) east-southeast of Hilo, Hawaii. Darby was moving toward the west at 20 m.p.h. (32 km/h). The maximum sustained wind speed was 45 m.p.h. (75 km/h) and and there were wind gusts to 60 m.p.h. (95 km/h). The minimum surface pressure was 1006 mb.

Tropical Storm Estelle Forms As Hurricane Darby Nears Peak Intensity

Tropical Storm Estelle developed late Friday over the Eastern North Pacific as Hurricane Darby neared its peak intensity farther west.  At 11:00 p.m. EDT on Friday the center of Tropical Storm Estelle was located at latitude 15.2°N and longitude 108.3°W which put it about 370 miles (600 km) southwest of Manzanillo, Mexico.  Estelle was moving toward the west-northwest at 12 m.p.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 1005 mb.  Estelle is the fifth tropical storm to form over the Eastern North Pacific during the month of July.

Meanwhile, about 950 miles west of Estelle, Hurricane Darby neared its peak intensity.  At 11:00 p.m. EDT on Friday the center of Hurricane Darby was located at latitude 17.3°N and longitude 122.1°W which put it about 880 miles (1415 km) west-southwest of the southern tip of Baja California.  Darby was moving toward the west-northwest at 9 m.p.h.  The maximum sustained wind speed was 105 m.p.h. (165 km/h) and there were wind gusts to 125 m.p.h. (200 km/h).  The minimum surface pressure was 972 mb.

The large circulation around Tropical Storm Estelle is still organizing.  A primary rainband is wrapping around the western side of the center.  Several spiral bands of thunderstorms are forming farther away from the core of the tropical storm.  Storms near the center are beginning to produce upper level divergence, but it is not currently well developed.

The environment around Estelle is favorable for gradual intensification.  Estelle is moving over water where the Sea Surface Temperature is near 29°C.  An upper level ridge north of Estelle is generating easterly winds which are blowing over the top of the tropical storm.  There is enough vertical wind shear to slow the rate of intensification, but the shear is probably not strong enough to keep Estelle from intensifying.  Storms like Estelle with large initial circulations can intensify slowly as a tighter core develops within the larger circulation.

Hurricane Darby is a well formed mature hurricane.  It has a well developed eye surrounded by a narrow ring of strong thunderstorms.  Several spiral bands are rotating around the core of Darby.  The thunderstorms near the center of circulation are generating upper level divergence which is pumping out mass in all directions.

Hurricane Darby is probably close to its peak intensity.  It is moving over water where the Sea Surface Temperature is near 27°C and Darby will be moving over cooler water during the next few days.  There is not much vertical wind shear, and Darby may have a chance to intensify during the next 12 to 24 hours.  However, Darby will reach cooler water in about a day and then the hurricane will being to weaken.

A subtropical ridge located north of Hurricane Darby and Tropical Storm Estelle is expected to steer both cyclones toward the west during the next few days.