Category Archives: Tropical Cyclones

Information about tropical cyclones

Typhoon Ragasa Rapidly Intensifies to Equivalent of Major Hurricane

Typhoon Ragasa rapidly intensified to the equivalent of a major hurricane east of northern Luzon on Saturday.  At 11:00 a.m. EDT on Saturday the center of Typhoon Ragasa was located at latitude 17.4°N and longitude 128.4°E which put the center about 475 miles (765 km) east of Aparri, Philippines.  Ragasa was moving toward the northwest at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 145 m.p.h. (235 km/h).  The minimum surface pressure was 957 mb.

Typhoon Ragasa rapidly intensified to the equivalent of a major hurricane east of northern Luzon on Saturday.  A small circular eye was present at the center of Ragasa’s circulation.  The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the center of Typhoon Ragasa.  Storms near the center of Ragasa generated strong upper level divergence that pumped mass away in all directions from the typhoon.  The removal of large quantities of mass caused the surface pressure to decrease rapidly.

The circulation around Typhoon Ragasa was large.  Winds to typhoon force extended out 70 miles (110 km) from the center of Ragasa’s circulation.  Winds to tropical storm force extended out 275 miles (445 km) in the southern half of Typhoon Ragasa.  Winds to tropical storm force extended out 165 miles (265 km) in the northern side of Ragasa’s circulation.

The Hurricane Intensity Index (HII) for Typhoon Ragasa was 20.6.  The Hurricane Size Index (HSI) was 20.3 and the Hurricane Wind Intensity Size Index (HWISI) was 40.9.  Typhoon Ragasa was similar in intensity to Hurricane Rita when Rita hit southwest Louisiana in 2005.  Ragasa was not as large as Rita was.

Typhoon Ragasa will move through an environment very favorable for intensification during the next 24 hours.  Ragasa will move over water where the Sea Surface Temperatures are near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Typhoon Ragasa will intensify during the next 24 hours.  Ragasa could continue to intensify rapidly.  Typhoon Ragasa could strengthen to the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale.

Typhoon Ragasa will move around the southern side of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Ragasa toward the west-northwest during the next 24 hours.  On its anticipated track, the center of Typhoon Ragasa will be north of Luzon in 48 hours.

Typhoon Ragasa will bring very strong winds and heavy rain to the Batanes Islands and to the Babuyan Islands.  Ragasa could cause a storm surge of up to 16 feet (5 meters.  Typhoon Ragasa could cause catastrophic damage on those islands.  Typhoon Ragasa will also cause strong winds and heavy rain in northern Luzon.  Heavy rain could cause flash floods in some locations.

Elsewhere over the Western North Pacific Ocean, Typhoon Neoguri continued to strengthen southeast of Japan.  At 11:00 a.m. EDT on Saturday the center of Typhoon Neoguri was located at latitude 26.5°N and longitude 154.5°E which put the center about 1100 miles (1775 km) east-southeast of Tokyo, Japan.  Neoguri was moving toward the west-northwest at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 110 m.p.h. (175 km/h) and there were wind gusts to 130 m.p.h. (210 km/h).  The minimum surface pressure was 955 mb.

Ragasa Strengthens to Typhoon East of Luzon

Former Tropical Storm Ragasa strengthened to a typhoon over the Western North Pacific Ocean east of northern Luzon on Friday night.  At 11:00 p.m. EDT on Friday the center of Typhoon Ragasa was located at latitude 16.52°N and longitude 129.3°E which put the center about 530 miles (855 km) east of Aparri, Philippines.  Ragasa was moving toward the west-northwest at 5 m.p.h. (8 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 985 mb.

Former Tropical Storm Ragasa strengthened to a typhoon east of northern Luzon on Friday night.  The inner end of a rainband wrapped around the center of Ragasa’s circulation.  A small circular eye formed at the center of Typhoon Ragasa.  A ring of thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the center of Typhoon Ragasa.  Storms near the center of Ragasa generated upper level divergence that pumped mass away from the typhoon.  The removal of mass caused the surface pressure to decrease.

The circulation around Typhoon Ragasa was large.  Winds to typhoon force extended out 65 miles (105 km) from the center of Ragasa’s circulation.  Winds to tropical storm force extended out 200 miles (325 km) from the center of Typhoon Ragasa.

Typhoon Ragasa will move through an environment favorable for intensification during the next 24 hours.  Ragasa will move over water where the Sea Surface Temperatures are near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Typhoon Ragasa will intensify during the next 24 hours.  Ragasa could intensify rapidly at times.  Typhoon Ragasa is likely to strengthen to the equivalent of a major hurricane during the weekend.

Typhoon Ragasa will move around the southern side of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Ragasa toward the west-northwest during the next 24 hours.  On its anticipated track, Typhoon Ragasa will move closer to northern Luzon.  The center of Typhoon Ragasa will be near northern Luzon in 48 hours.

Elsewhere over the Western North Pacific Ocean, former Tropical Storm Neoguri strengthened to a typhoon southeast of Japan.  At 11:00 p.m. EDT on Friday the center of Typhoon Neoguri was located at latitude 25.7°N and longitude 156.4°E which put the center about 1210 miles (1950 km) east-southeast of Tokyo, Japan.  Neoguri was moving toward the west-northwest at 13 m.p.h. (21 km/h).  The maximum sustained wind speed was 80 m.p.h. (130 km/h) and there were wind gusts to 100 m.p.h. (160 km/h).  The minimum surface pressure was 980 mb.

Tropical Storm Gabrielle Moves Southeast of Bermuda

Tropical Storm Gabrielle moved southeast of Bermuda on Friday.  At 5:00 p.m. EDT on Friday the center of Tropical Storm Gabrielle was located at latitude 22.4°N and longitude 56.6°W which put the center about 850 miles (1360 km) southeast of Bermuda.  Gabrielle was moving toward the west-northwest 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 65 m.p.h. (105 km/h).  The minimum surface pressure was 1004 mb.

Tropical Storm Gabrielle started to exhibit more organization on Friday afternoon.  More thunderstorms formed near the center of Gabrielle’s circulation.  More thunderstorms also developed in bands in the eastern side of Tropical Storm Gabrielle.  Bands in the western side of Gabrielle still consisted primarily of showers and lower clouds.

The distribution of wind speeds in Tropical Storm Gabrielle continued to be asymmetrical.  Winds to tropical storm force extended out 150 miles (240 km) in the eastern side of Gabrielle’s circulation.  Winds to tropical storm force extended out 80 miles (130 km) in the western half of Gabrielle’s circulation.

Tropical Storm Gabrielle will move into an environment that will become more favorable for intensification during the next 24 hours.  Gabrielle will move over water where the Sea Surface Temperatures are near 29°C.  It will move under the eastern side of an upper level low that is south of Bermuda.  The upper level low will produce southerly winds that will blow toward the top of Gabrielle’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 Gabrielle will intensify during the next 24 hours.  Gabrielle is likely to strengthen to a hurricane during the weekend.

Tropical Storm Gabrielle will move around the southwestern part of a subtropical high pressure system over the eastern Atlantic Ocean.  The high pressure system will steer Gabrielle toward the northwest during the next 24 hours.  On its anticipated track, Tropical Storm Gabrielle will make its closest approach to Bermuda on Monday.

Tropical Storm Mitag Brings Wind and Rain to Southeastern China

Tropical Storm Mitag brought wind and rain to southeastern China on Friday morning.  At 5:00 a.m. EDT on Friday the center of Tropical Storm Mitag was located at latitude 23.0°N and longitude 115.1°E which put the center about 85 miles (135 km) east-northeast of Hong Kong.  Mitag was moving toward the north-northwest 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 997 mb.

The center of Tropical Storm Mitag made landfall on the coast of southeastern China east of Hong Kong on Thursday night.  Mitag was bringing wind and rain to parts of Guangdong.

The circulation around Tropical Storm Mitag was small.  Winds to tropical storm force extended out 90 miles (145 km) from the center of Mitag’s circulation.

Tropical Storm Mitag will move around the southern side of a high pressure system over China.  The high pressure system will steer Mitag toward the west during the next 24 hours.  On its anticipated track, Tropical Storm Mitag will move inland over Guangdong.  The center of Mitag’s circulation will pass north of Hong Kong.

Tropical Storm Mitag will weaken gradually as it moves over southern China.  Mitag will continue to bring gusty winds and locally heavy rain to parts of Guangdong during the next 24 hours.  Heavy rain could cause flash floods in some locations.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Ragasa moved slowly toward northern Luzon and Tropical Storm Neoguri strengthened southeast of Japan.

At 5:00 a.m. EDT on Friday the center of Tropical Storm Ragasa was located at latitude 16.2°N and longitude 130.5°E which put the center about 620 miles (1000 km) east of Aparri, Philippines.  Ragasa was moving toward the west at 6 m.p.h. (10 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 1000 mb.

At 5:00 a.m. EDT on Friday the center of Tropical Storm Neoguri was located at latitude 24.3°N and longitude 159.8°E which put the center about 1450 miles (2340 km) east-southeast of Tokyo, Japan.  Neoguri was moving toward the west-northwest at 12 m.p.h. (19 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 994 mb.

Tropical Storm Gabrielle Spins over the Central Atlantic

Tropical Storm Gabrielle was spinning over the Central Atlantic Ocean on Thursday.  At 5:00 p.m. EDT on Thursday the center of Tropical Storm Gabrielle was located at latitude 20.8°N and longitude 52.7°W which put the center about 700 miles (1125 km) east-northeast of the Northern Leeward Islands.  Gabrielle was moving toward the west-northwest at 13 m.p.h. (21 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 1004 mb.

The appearance of Tropical Storm Gabrielle did not change much on Thursday.  Gabrielle consisted of bands of showers and low clouds revolving around the center of circulation for much of Thursday.  New thunderstorms began to develop late Thursday afternoon in bands northeast of the center of Gabrielle’s circulation.  The bands in the other parts of Tropical Storm Gabrielle still consisted primarily of showers and lower clouds.

The distribution of wind speeds in Tropical Storm Gabrielle was very asymmetrical.  Winds to tropical storm force extended out 290 miles (465 km) in the northeastern quadrant of Gabrielle’s circulation.  Winds to tropical storm force extended out 175 miles (280 km) in the southeastern and northwestern quadrants of Gabrielle.  The winds in the southwestern quadrant of Tropical Storm Gabrielle were blowing at less than tropical storm force.

Tropical Storm Gabrielle will move through an environment that will be only marginally favorable for intensification during the next 24 hours.  Gabrielle will move over water where the Sea Surface Temperatures are near 28°C.  However, an upper level low that is northeast of the Northern Leeward Islands will produce strong southwesterly winds that will blow toward the top of Gabrielle’s circulation.  Those winds will cause strong vertical wind shear.  The strong vertical wind shear will prevent significant intensification during the next 24 hours.  The wind shear is forecast to decrease during the weekend and Tropical Storm Gabrielle is likely to intensify when the shear decreases.

Tropical Storm Gabrielle will move around the southwestern part of a subtropical high pressure system over the eastern Atlantic Ocean.  The high pressure system will steer Gabrielle toward the northwest during the next 24 hours.  On its anticipated track, Tropical Storm Gabrielle will pass northeast of the Leeward Islands on Friday night.

Tropical Storm Mitag Develops Southeast of Hong Kong

Tropical Storm Mitag developed over the South China Sea southeast of Hong Kong on Thursday morning.  At 11:00 a.m. EDT on Thursday the center of Tropical Storm Mitag was located at latitude 20.4°N and longitude 116.5°E which put the center about 225 miles (365 km) southeast of Hong Kong.  Mitag was moving toward the west-northwest at 6 m.p.h. (10 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 1002 mb.

A low pressure system over the South China Sea southeast of Hong Kong strengthened on Thursday morning and the Japan Meteorological Agency  designated the system as Tropical Storm Mitag.

The circulation around Tropical Storm Mitag continued to get better organized on Thursday morning.  More thunderstorms formed near the center of Mitag’s circulation.  Thunderstorms also developed in bands in the eastern side of Tropical Storm Mitag.  Bands in the western side of Mitag’s circulation still consisted primarily of showers and lower clouds.

The strongest winds were occurring in the eastern side of Tropical Storm Mitag.  Winds to tropical storm force extended out 80 miles (130 km) in the eastern side of Mitag’s circulation.  The winds in the western side of Tropical Storm Mitag were blowing at less than tropical storm force.

Tropical Storm Mitag will move through an environment favorable for intensification during the next 24 hours.  Mitag will move over water where the Sea Surface Temperatures are near 29°C.  It will move under the middle of an upper level ridge over eastern China and the South China Sea.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  Tropical Storm Mitag will intensity during the next 24 hours.

Tropical Storm Mitag will move around the southwestern part of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Mitag toward the northwest during the next 24 hours.  On its anticipated track, Tropical Storm Mitag will be near Hong Kong in 24 hours.

Tropical Storm Mitag will bring strong winds and locally heavy rain to the region around Hong Kong.  Heavy rain could cause flash floods in some locations.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Ragasa formed east of Luzon and Tropical Storm Neoguri formed southeast of Japan.

At 11:00 a.m. EDT on Thursday the center of Tropical Storm Ragasa was located at latitude 16.0°N and longitude 132.7°E which put the center about 755 miles (1220 km) east of Aparri, Philippines.  Ragasa was moving toward the northwest at 5 m.p.h. (8 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 1003 mb.

At 11:00 a.m. EDT on Thursday the center of Tropical Storm Neoguri was located at latitude 23.1°N and longitude 162.5°E which put the center about 1630 miles (2630 km) east-southeast of Tokyo, Japan.  Neoguri was moving toward the west-southwest at 13 m.p.h. (21 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 1003 mb.

Tropical Storm Gabrielle Forms East of Leeward Islands

Tropical Storm Gabrielle formed over the Atlantic Ocean east of the Leeward Islands on Wednesday morning.  At 11:00 a.m. EDT on Wednesday the center of Tropical Storm Gabrielle was located at latitude 17.5°N and longitude 46.6°W which put the center about 1085 miles (1745 km) east of the Northern Leeward Islands.  Gabrielle was moving toward the north-northwest at 22 m.p.h. (35 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 1006 mb.

A low pressure system over the Atlantic Ocean east of the Northern Leeward Islands strengthened on Tuesday morning and the U.S. National Hurricane Center designated the system as Tropical Storm Gabrielle.

The circulation around Tropical Storm Gabrielle was poorly organized on Thursday morning.  Thunderstorms were occurring in bands east of the center of Gabrielle’s circulation.  Bands in the western part of Tropical Storm Gabrielle consisted primarily of showers and lower clouds.  An upper level low northeast of the Leeward Islands was producing strong southwesterly winds that were blowing toward the top of Gabrielle’s circulation.  Those winds were causing strong vertical wind shear.  The strong vertical wind shear was causing the asymmetrical distribution of thunderstorms in Tropical Storm Gabrielle.

The distribution of wind speeds in Tropical Storm Gabrielle was also asymmetrical.  Winds to tropical storm force extended out 175 miles (280 km) in the eastern side of Gabrielle’s circulation.  The winds in the western side of Tropical Storm Gabrielle were blowing at less than tropical storm force.

Tropical Storm Gabrielle will move through an environment that will be only marginally favorable for intensification during the next 24 hours.  Gabrielle will move over water where the Sea Surface Temperatures are near 28°C.   However, the upper level low that is northeast of the Northern Leeward Islands will continue to cause strong vertical wind shear.  The strong vertical wind shear will prevent significant intensification during the next 24 hours.

Tropical Storm Gabrielle will move around the southwestern part of a subtropical high pressure system over the eastern Atlantic Ocean.  The high pressure system will steer Gabrielle toward the northwest during the next 24 hours.  On its anticipated track, Tropical Storm Gabrielle will pass northeast of the Leeward Islands later this week.

 

Tropical Storm Mario Weakens

Tropical Storm Mario weakened on Monday night as it moved over the Eastern North Pacific Ocean west of Baja California.  At 5:00 a.m. EDT on Tuesday the center of Tropical Storm Mario was located at latitude 21.9°N and longitude 115.7°W which put the center about 375 miles (605 km) west of the southern tip of Baja California.  Mario was moving toward the northwest 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 65 m.p.h. (105 km/h).  The minimum surface pressure was 1000 mb.

Tropical Storm Mario weakened on Monday night as it moved over cooler water west of Baja California.  Many of the thunderstorms in Tropical Storm Mario dissipated when Mario moved over the cooler water.  A few thunderstorms were still occurring near the center of Mario’s circulation.  Most of the bands revolving around the center of Tropical Storm Mario consisted primarily of showers and lower clouds.  Since the storms near the center of Mario were not generating much upper level divergence, the surface pressure was increasing.

The circulation around Tropical Storm Mario was still small.  Winds to tropical storm force extended out 45 miles (75 km) from the center of Mario’s circulation.

Tropical Storm Mario will move through an environment that will be unfavorable for intensification during the next 24 hours.  Mario will move over water where the Sea Surface Temperatures are near 24°C.  It will move under the southeastern part of an upper level trough that is near the west coast of the U.S.  The upper level trough will produce southerly winds that will blow toward the top of Mario’s circulation.  Those winds will cause moderate vertical wind shear.  The combination of moderate vertical wind shear and cooler Sea Surface Temperatures will cause Tropical Storm Mario to continue to weaken during the next 24 hours.

Tropical Storm Mario will move around the around the southwestern part of a high pressure system over the southwest U.S. and northwest Mexico.  The high pressure system will steer Mario toward the northwest during the next 24 hours.  On its anticipated track, Tropical Storm Mario will move west of Baja California.

Tropical Storm Mario Strengthens

Tropical Storm Mario strengthened during Sunday night as it moved over the Eastern North Pacific Ocean south of Baja California.  At 5:00 a.m. EDT on Monday the center of Tropical Storm Mario was located at latitude 19.4°N and longitude 112.3°W which put the center about 285 miles (460 km) south-southwest of the southern tip of Baja California.  Mario was moving toward the west-northwest at 12 m.p.h. (19 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 995 mb.

Tropical Storm Mario strengthened during Sunday night.  The distribution of thunderstorms in Mario became more symmetrical.  Thunderstorms continued to develop near the center of Mario’s circulation.  Thunderstorms were also occurring in bands revolving around the center of Tropical Storm Mario.  Storms near the center of Mario generated upper level divergence that pumped mass away from the tropical storm.  The removal of mass caused the surface pressure to decrease.

Even though Tropical Storm Mario strengthened, the size of Mario’s circulation remained small.  Winds to tropical storm force extended out 35 miles (55 km) from the center of Tropical Storm Mario.

Tropical Storm Mario will move through an environment that will become unfavorable for intensification during the next 24 hours.  Mario will move over water where the Sea Surface Temperatures are near 26°C.  It will move under the southeastern part of an upper level trough  that is near the west coast of the U.S.  The upper level trough will produce southwesterly winds that will blow toward the top of Mario’s circulation.  Those winds will cause the vertical wind shear to increase.  The combination of more vertical wind shear and cooler Sea Surface Temperatures will cause Tropical Storm Mario to start to weaken during the next 24 hours.

Tropical Storm Mario will move around the around the southern part of a high pressure system over the southwest U.S. and northwest Mexico.  The high pressure system will steer Mario toward the west-northwest during the next 24 hours.  On its anticipated track, Tropical Storm Mario will remain southwest of Baja California.

Tropical Storm Mario Re-develops South of Baja California

Tropical Storm Mario re-developed over the Eastern North Pacific Ocean south of Baja California on Sunday morning.  At 11:00 a.m. EDT on Sunday the center of Tropical Storm Mario was located at latitude 18.5°N and longitude 110.2°W which put the center about 305 miles (490 km) south of the southern tip of Baja California.  Mario was moving toward the west-northwest at 8 m.p.h. (13 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 1004 mb.

After almost dissipating during Friday night, Tropical Storm Mario re-developed south of Baja California on Sunday morning.  A distinct low level center of circulation re-formed on Sunday morning.  More thunderstorms started to develop near the low level center of circulation.  Bands of showers and thunderstorms were revolving around the center of Tropical Storm Mario.  Storms near the center of Mario began to generate upper level divergence that pumped mass away from the tropical storm.

The circulation around Tropical Storm Mario was still small.  Wind to tropical storm force extended out 25 miles (40 km) in the northeastern quadrant of Mario’s circulation.  The winds in the other parts of Tropical Storm Mario were blowing at less than tropical storm force.

Tropical Storm Mario will move through an environment that will be somewhat favorable for intensification during the next 24 hours.  Mario will move over water where the Sea Surface Temperatures are near 28°C.  It will move under the southeastern part of upper level ridge over the southwest U.S. and northwest Mexico.  The upper level ridge will produce northeasterly winds that will blow toward the top of Mario’s circulation.  Those winds will cause moderate vertical wind shear.  The moderate vertical wind shear will inhibit intensification, but the wind shear will not be enough to prevent intensification.  Tropical Storm Mario is likely to intensify during the next 24 hours.

Tropical Storm Mario will move around the around the southern part of a high pressure system over the southwest U.S. and northwest Mexico.  The high pressure system will steer Mario toward the west-northwest during the next 24 hours.  On its anticipated track, Tropical Storm Mario will southwest of Baja California.