Tag Archives: Tropical Storm Iona

Tropical Storm Gil Forms South of Baja California

Tropical Storm Gil formed over the Eastern North Pacific Ocean south of Baja California on Wednesday night.  At 5:00 a.m. EDT on Thursday the center of Tropical Storm Gil was located at latitude 12.7°N and longitude 115.1°W which put the center about 785 miles (1260 km) south-southwest of the southern tip of Baja California.  Gil was moving toward the west at 15 m.p.h. (24 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 1004 mb.

A low pressure system over the Eastern North Pacific Ocean south of Baja California strengthened on Wednesday night and the U.S. National Hurricane Center designated the system as Tropical Storm Gil.

The circulation around Tropical Storm Gil was organizing quickly on Thursday morning.  Numerous thunderstorms formed near the center of Gil’s circulation.  Thunderstorms also developed in bands revolving around the center of Tropical Storm Gil.  Storms near the center of Gil generated upper level divergence that pumped mass away from the tropical storm.  The removal of mass caused the surface pressure to decrease.

The distribution of wind speed in Tropical Storm Gil was asymmetrical.  Winds to tropical storm force extended out 160 miles (260 km) in the eastern side of Gil’s circulation.  Winds to tropical storm force extended out 60 miles (95 km) in the western side of Tropical Storm Gil.

Tropical Storm Gil will move through an environment very favorable for intensification during the next 24 hours.  Gil will move over water where the Sea Surface Temperatures are near 28°C.   It will move under the southern side of an upper level ridge over the Eastern North Pacific Ocean.  The upper level ridge will produce easterly winds that will blow toward the top of Gil’s circulation.  However, the winds in the lower atmosphere will also blow from the east.  So, there will be little vertical wind shear.  Tropical Storm Gil will intensify during the next 24 hours.  Gil could intensify rapidly,  Tropical Storm Gil could strengthen to a hurricane by Friday.

Tropical Storm Gil will move around the southern side of a high pressure system over the Eastern North Pacific Ocean.  The high pressure system will steer Gil toward the west-northwest during the next 24 hours.  On its anticipated track, Tropical Storm Gil will move away from Baja California.

Elsewhere, Tropical Storm Iona moved quickly away from Hawaii.  At 5:00 a.m. EDT on Thursday the center of Tropical Storm Iona was located at latitude 12.3°N and longitude 166.9°W which put the center about 860 miles (1385 km) southwest of Honolulu, Hawaii.  Iona was moving toward the west at 23 m.p.h. (37 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.

Iona Rapidly Weakens to a Tropical Storm

Former Hurricane Iona rapidly weakened to a tropical storm over the Central Pacific Ocean southwest of Hawaii on Wednesday.  At 5:00 p.m. EDT on Wednesday the center of Tropical Storm Iona was located at latitude 11.7°N and longitude 162.6°W which put the center about 730 miles (1180 km) south-southwest of Honolulu, Hawaii.  Iona was moving toward the west at 22 m.p.h. (35 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 994 mb.

Former Hurricane Iona rapidly weakened to a tropical storm southwest of Hawaii on Wednesday.  Iona moved into a region of drier air.  The drier air caused many of the thunderstorms in Iona’s circulation to dissipate.  A few thunderstorms were still occurring in bands in the southern and eastern periphery of Tropical Storm Iona.  An upper level trough southwest of Hawaii was producing southwesterly winds that were blowing toward the top of Iona’s circulation.  Those winds were causing moderate vertical wind shear.  The vertical wind shear was also contributing to the weakening of Tropical Storm Iona.

The circulation around Tropical Storm Iona was small.  Winds to tropical storm force extended out 80 miles (130 km) from the center of Iona’s circulation.

Tropical Storm Iona will move through an environment that will be mostly unfavorable for intensification during the next 24 hours.  Iona will move over water where the Sea Surface Temperatures are near 27°C.  It will move under the southeastern part of the upper level trough southwest of Hawaii.  The upper level trough will continue to produce southwesterly winds that will blow toward the top of Iona’s circulation.  Those winds will continue to cause moderate vertical wind shear.  In addition, Iona will also continue to move through the region of drier air that is located southwest of Hawaii.  The combination of moderate vertical wind shear and drier air will cause Tropical Storm Iona to start to continue to weaken during the next 24 hours.

Tropical Storm Iona will move around the southern side of a high pressure system over the Central Pacific Ocean.  The high pressure system will steer Iona toward the west during the next 24 hours.  On its anticipated track, Hurricane Iona will move farther away from of Hawaii on Thursday.

Elsewhere over the Central Pacific Ocean, the upper level trough southwest of Hawaii caused former Tropical Storm Keli to weaken to a tropical depression.  At 5:00 p.m. EDT on Wednesday the center of Tropical Depression Keli was located at latitude 13.9°N and longitude 156.6°W which put the center about 520 miles (835 km) south of Honolulu, Hawaii.  Keli was moving toward the west at 17 m.p.h. (28 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 1006 mb.

Depression Strengthens to Tropical Storm Iona

Former Tropical Depression One-C strengthened to Tropical Storm Iona over the Central Pacific Ocean southeast of Hawaii on Sunday.  At 11:00 p.m. EDT on Sunday the center of Tropical Storm Iona was located at latitude 10.9°N and longitude 148.3°W which put the center about 965 miles (1545 km) southeast of Honolulu, Hawaii.  Iona was moving toward the west 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 1005 mb.

Former Tropical Depression One-C strengthened to Tropical Storm Iona over the Central Pacific Ocean southeast of Hawaii on Sunday.  More stronger thunderstorms formed near the center of Iona’s circulation.  Thunderstorms were also occurring in bands revolving around the center of Tropical Storm Iona.  Storms near the center of Iona started to generate upper level divergence that pumped mass away from the tropical storm.

The strongest winds were occurring in the northern half of Tropical Storm Iona.  Winds to tropical storm force extended out 35 miles (55 km) in the northern side of Iona’s circulation.  The winds in the southern half of Tropical Storm Iona were blowing at less than tropical storm force.

Tropical Storm Iona will move through an environment favorable for intensification during the next 24 hours.  Iona will move over water where the Sea Surface Temperatures are near 28°C.  It will move under the southern part of an upper level ridge over the Central Pacific Ocean.  The upper level ridge will produce easterly winds that will blow toward the top of Iona’s circulation.  Those winds will cause some vertical wind shear.  The vertical wind shear will inhibit intensification, but the wind shear will not be enough to prevent intensification.  Tropical Storm Iona will intensify during the next 24 hours.

Tropical Storm Iona will move around the southern side of a high pressure system over the Central Pacific Ocean.  The high pressure system will steer Iona toward the west during the next 24 hours.  On its anticipated track, Tropical Storm Iona will pass south of Hawaii on Tuesday.