Category Archives: Tropical Cyclones

Information about tropical cyclones

Tropical Storm Alberto Forms over Western Gulf of Mexico

Tropical Storm Alberto formed over the western Gulf of Mexico on Wednesday morning.  At 11:00 a.m. EDT on Wednesday the center of Tropical Storm Alberto was located at latitude 22.2°N and longitude 95.0°W which put it about 185 miles (300 km) east of Tampico, Mexico and about 295 miles (480 km) south-southeast of Brownsville, Texas.  Alberto was moving toward the west at 9 m.p.h. (15 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 995 mb.

More thunderstorms formed near the center of a low pressure system previously designated as Potential Tropical Cyclone One on Wednesday morning.  A U.S. Air Force Reserve Hurricane Hunter reconnaissance aircraft was able to locate a well defined low level center of circulation and the U.S. National Hurricane Center designated the system as Tropical Storm Alberto.

The structure of Tropical Storm Alberto was beginning to resemble a typical tropical storm.  Thunderstorms were forming near the center of Alberto’s circulation.  A band of thunderstorms wrapped around the southern and eastern side of Tropical Storm Alberto.  Other bands of showers and thunderstorms were revolving around the center of Alberto’s circulation.  Storms near the center of Alberto began to generate upper level divergence that pumped mass away from the tropical storm.  The removal of mass was causing the surface pressure to decrease.

Even though Tropical Storm Alberto was starting to look like a tropical storm, the distribution of winds was still asymmetrical.  The circulation around the northern side of Alberto’s circulation was interacting with the southern part of a strong high pressure system over the eastern U.S.  The interaction of the two pressure systems was causing the strongest winds to occur in the northern side of Tropical Storm Alberto.  Winds to tropical storm force extended out 400 miles (645 km) north of the center of Alberto’s circulation.  An anemometer at Garden Banks 783 (KGBK) measured a sustained wind speed of 45 m.p.h. (75 km/h) and wind gusts of 50 m.p.h (80 km/h).  The anemometer is at a height of 58.2 meters above sea level.  The winds in the southern part of Alberto’s circulation were blowing at less than tropical storm force.

Tropical Storm Alberto will move through an environment favorable for intensification during the next 12 hours. Alberto will move over water where the Sea Surface Temperatures are near 30°C.  It will move under the the center of an upper level ridge over the western Gulf of Mexico.  The upper level winds are weak near the center of the ridge and there will be little vertical wind shear.  Tropical Storm Alberto will intensify during the next 12 hours.  Alberto could undergo a brief period of rapid intensification when it approaches the coast of Mexico.

Tropical Storm Alberto will move south of a strong high pressure system over the eastern U.S.  The high pressure system will steer Alberto toward the west during the next 24 hours.  On its anticipated track, Tropical Storm Alberto will make landfall on the coast of northern Mexico on Wednesday night.  The center of Alberto will make landfall near Tampico, Mexico.

Tropical Storm Forming over Western Gulf of Mexico

A tropical storm is forming over the western Gulf of Mexico on Wednesday morning.  The low pressure system is currently designated as Potential Tropical Cyclone One.  At 8:00 a.m. EDT on Wednesday the center of Potential Tropical Cyclone One was located at latitude 22.7°N and longitude 94.3°W which put it about 235 miles (380 km) east-southeast of La Pesca, Mexico and about 295 miles (475 km) southeast of Brownsville, Texas.  The low pressure system 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 997 mb.

A low pressure system over the western Gulf of Mexico, currently designated as Potential Tropical Cyclone One, on Wednesday morning is beginning to develop a structure more like a tropical cyclone.  Thunderstorms are staring to develop near the center of the low pressure system.  A band of thunderstorms wraps around the southern and eastern side of Potential Tropical Cyclone One.  Other bands of showers and thunderstorms are revolving around the middle of the low pressure system.

The distribution of winds around Potential Tropical Cyclone One is still asymmetrical.  The winds near the middle of the low pressure system are relatively weak.  The strongest winds are occurring in a band of thunderstorms about 400 miles (645 km) north of the middle of Potential Tropical Cyclone One.  Some of the winds in that band of storms are blowing at tropical storm force.  An anemometer at Garden Banks 783 (KGBK) is measuring a sustained wind speed of 45 m.p.h. (75 km/h) and wind gusts of 50 m.p.h (80 km/h).  The anemometer is at a height of 58.2 meters above sea level.  The winds in the rest of the low pressure system are blowing at less than tropical storm force.

The low pressure system will move through an environment favorable for the development of a tropical cyclone during the next 24 hours.  Potential Tropical Cyclone One will move over water where the Sea Surface Temperatures are near 30°C.  It will move under the the center of an upper level ridge over the western Gulf of Mexico.  The upper level winds are weak near the center of the ridge and there will be little vertical wind shear.  Potential Tropical Cyclone One is forecast to develop into a tropical storm during the next 24 hours.  In order to be classified as a tropical cyclone, a distinct low level center of circulation will have to form.  Thunderstorms will have to develop and to persist near the low level center.  The strongest winds will need to occur near the low level center of circulation in order for Potential Tropical Cyclone One to be classified as a tropical storm.

Potential Tropical Cyclone One will move south of a strong high pressure system over the eastern U.S.  The strong high pressure system will block Potential Tropical Cyclone One and the high pressure system will prevent the low pressure system from moving toward the north.  The high pressure system will steer the low pressure system toward the west during the next 24 hours.  On its anticipated track, Potential Tropical Cyclone One could approach the coast of northern Mexico and southern Texas on Wednesday evening.  The center of the low pressure system is likely to make landfall between Tampico and La Pesca, Mexico

Tropical Storm Warnings Issued for South Texas and Northern Mexico

Tropical Storm Warnings were issued for the coast of south Texas and northern Mexico early on Tuesday. A low pressure system over the southern Gulf of Mexico was designated as Potential Tropical Cyclone One. At 8:00 a.m. EDT on Tuesday the center of Potential Tropical Cyclone One was located at latitude 21.5°N and longitude 92.8°W which put it about 355 miles (575 km) east-southeast of La Pesca, Mexico and about 420 miles (680 km) southeast of Brownsville, Texas. The low pressure system was moving toward the north 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 999 mb.

A large low pressure system was over the southern Gulf of Mexico on Tuesday morning. The low pressure system did not exhibit the usual structural features of a tropical cyclone. So, the U.S. National Hurricane Center continued to designate the system as Potential Tropical Cyclone One.

The large low pressure system still did not have a well defined, distinct low level center of circulation. There were few thunderstorms in the broad region around the middle of the low pressure system. The surface winds were relatively weak near the middle of the low pressure system. The strongest winds were occurring in a band of thunderstorms about 285 miles (460 km) north of the middle of Potential Tropical Cyclone One. Some winds in that area were blowing at tropical storm force. Elsewhere in the low pressure system, the winds were blowing at less than tropical storm force.

The low pressure system will move through an environment favorable for the development of a tropical cyclone during the next 24 hours. Potential Tropical Cyclone One will move over water where the Sea Surface Temperatures are near 30°C. It will move under the the center of an upper level ridge centered near the Yucatan Peninsula. The upper level winds are weak near the center of the ridge and there will be little vertical wind shear. Potential Tropical Cyclone One could develop into a tropical storm during the next 24 hours. In order to be classified as a tropical cyclone, a distinct low level center of circulation would have to form. Thunderstorms would have to develop and to persist near the low level center. The strongest winds would need to occur near the low level center of circulation in order for Potential Tropical Cyclone One to be classified as a tropical storm.

Potential Tropical Cyclone One will move around the northern part of a large counterclockwise circulation called a Central American Gyre (CAG) during the next 12 hours. The Central American Gyre will steer the low pressure system toward the north-northwest on Tuesday. A strong high pressure system over the eastern U.S. will block Potential Tropical Cyclone One from moving toward the north on Wednesday. The high pressure system will turn the low pressure system toward the west-northwest. On its anticipated track, Potential Tropical Cyclone One could approach the coast of northern Mexico or southern Texas on Wednesday evening.

Tropical Storm Watches Issued for South Texas and Northern Mexico

Tropical Storm Watches were issued for parts of the coast of south Texas and northern Mexico on Monday afternoon. A low pressure system over the Bay of Campeche was designated as Potential Tropical Cyclone One. At 5:00 p.m. EDT on Monday the center of Potential Tropical Cyclone One was located at latitude 20.3°N and longitude 93.2°W which put it about 380 miles (615 km) southeast of La Pesca, Mexico and about 470 miles (755 km) southeast of Brownsville, Texas. The low pressure system was moving toward the north-northwest at 7 m.p.h. (11 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 1001 mb.

A large low pressure system formed over the Bay of Campeche on Monday. The low pressure system did not exhibit the usual structural features of a tropical cyclone. So, the U.S. National Hurricane Center designated the system as Potential Tropical Cyclone One. Since the low pressure system has the potential to develop into a tropical storm, Tropical Storm Watches were issued for the coast of southern Texas and northern Mexico.

The large low pressure system did not have a well defined, distinct low level center of circulation. There were few thunderstorms in the broad region around the middle of the low pressure system. The surface winds were relatively weak near the middle of the low pressure system. The strongest winds were occurring in a band of thunderstorms about 285 miles (460 km) northeast of the middle of Potential Tropical Cyclone One. Some winds in that area were blowing at tropical storm force. Elsewhere in the low pressure system, the winds were blowing at less than tropical storm force.

The low pressure system will move through an environment favorable for the development of a tropical cyclone during the next 24 hours. Potential Tropical Cyclone One will move over water where the Sea Surface Temperatures are near 30°C. It will move under the the center of an upper level ridge centered near the Yucatan Peninsula. The upper level winds are weak near the center of the ridge and there will be little vertical wind shear. Potential Tropical Cyclone One could develop into a tropical storm during the next 24 hours. A distinct low level center of circulation would have to form. Thunderstorms would have to develop and to persist near the low level center. The strongest winds would need to occur near the low level center of circulation in order for Potential Tropical Cyclone One to be classified as a tropical storm.

Potential Tropical Cyclone One will move around the northeastern part of a large counterclockwise circulation call a Central American Gyre (CAG). The Central American Gyre will steer the low pressure system toward the north-northwest during the next 24 hours. A strong high pressure system over the eastern U.S. will turn the low pressure system toward the west-northwest on Wednesday. On its anticipated track, Potential Tropical Cyclone One could approach the coast of northern Mexico or southern Texas on Wednesday evening.

Potential Tropical Cyclone One could be a tropical storm when it approaches the coast. That is the reason the Tropical Storm Watches were issued. Even if Potential Tropical Cyclone One does not develop into a tropical storm, it will drop heavy rain on parts of northern Mexico and southern Texas. The low pressure system could also cause a storm surge of up to four feet (one meter) where the winds blow the water toward the coast.

Low Pressure System Causes Floods in South Florida

A low pressure system designated as Invest 90L caused floods in parts of South Florida on Wednesday. At 8:00 p.m. EDT on Wednesday the center of Invest 90L was located at latitude 28.6°N and longitude 81.0°W which put it about 10 miles (15 km) northwest of Titusville, Florida. The low pressure system was moving toward the northeast at 5 m.p.h. (8 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 km/h). The minimum surface pressure was 1010 mb.

Even though the center of the low pressure system moved across Central Florida, it produced a band of thunderstorms well to the south of the center of circulation. The band of thunderstorms dropped persistent rain over parts of southwestern and southeastern Florida. Naples reported 3.94 inches (100.1 mm) of rain on Tuesday. There were reports of street flooding in Naples on Wednesday. Ft. Lauderdale reported 6.77 inches (172.0 mm) of rain on Wednesday. Miami reported 2,25 inches (57.2 mm) of rain on Wednesday. West Palm Beach reported 2.38 inches (60.4 mm) of rain on Wednesday. There were reports of urban flooding in Miami, Miami Beach and Hallandale in southeastern Florida.

The low pressure system will move through an environment marginally favorable for the formation of a tropical cyclone during the next 24 hours. The low pressure system will move over water where the Sea Surface Temperatures are near 29°C during the next few hours. An upper level trough over the eastern U.S. will produce westerly winds that will blow across the top of the low pressure system. Those winds will cause strong vertical wind shear. The vertical wind shear will inhibit development of a tropical cyclone, but the wind shear could start to decrease on Thursday. The U.S. National Hurricane Center is indicating that probability is 20% that the low pressure system develops into a tropical cyclone after it moves over the western Atlantic Ocean off the coast of the southeast U.S.

The upper level trough will steer the low pressure system toward the northeast during the next 24 hours. On its anticipated track the low pressure system will move over the western Atlantic Ocean on Thursday. A new center of circulation could develop along the line of thunderstorms in the southern part of the current circulation.

Low Pressure System To Drop Heavy Rain on Central, South Florida

A low pressure system designated as Invest 90L will drop heavy rain over parts of Central and South Florida during the next 24 hours. At 2:00 p.m. EDT on Tuesday the center of Invest 90L was located at latitude 26.9°N and longitude 93.9°W which put it about 75 miles (120 km) west-southwest of Sarasota, Florida. The low pressure system was moving toward the east-northeast at 13 m.p.h. (20 km/h). The maximum sustained wind speed was 25 m.p.h. (40 km/h) and there were wind gusts to 35 m.p.h. (55 km/h). The minimum surface pressure was 1009 mb.

A low pressure system developed over the eastern Gulf of Mexico on Tuesday. The low pressure system was designated as Invest 90L. It was approaching the west coast of Florida near Sarasota on Tuesday afternoon. The low pressure system was being steered toward the east-northeast. It will move across the Florida Peninsula during Tuesday night. The low pressure system will drop heavy rain over parts of Central and South Florida.

A well defined low level circulation was visible on satellite images. Thunderstorms were occurring in the eastern and northern parts of the low pressure system. Thunderstorms were also occurring in a band just east of the center of circulation. Bands north and west of the center of the low pressure system consisted primarily of showers and lower clouds.

The low pressure system will move through an environment unfavorable for the formation of a tropical cyclone during the next 24 hours. The low pressure system will move over water where the Sea Surface Temperatures are near 30°C during the next few hours. Then it will move over the Florida Peninsula. An upper level trough over the eastern U.S. will produce westerly winds that will blow across the top of the low pressure system. Those winds will cause strong vertical wind shear. The combination of movement over land and strong vertical wind shear is likely to prevent the development of a tropical cyclone during the next 24 hours.

The low pressure system could move into a more favorable environment when it moves over the western Atlantic Ocean on Friday. The upper level trough could move northeast of the low pressure system which would cause the vertical wind shear to decrease. The U.S. National Hurricane Center is indicating that probability is 20% that the low pressure system develops into a tropical cyclone after it moves over the western Atlantic Ocean northeast of Florida.

The upper level trough will steer the low pressure system toward the east-northeast during the next 24 hours. On its anticipated track the low pressure system will reach the west coast of Florida near Sarasota in a few hours. The center of the low pressure system is likely to pass south of Orlando and Daytona Beach. It will drop heavy rain over parts of Central and South Florida. Some thunderstorms could approach severe criteria.

Maliksi Drops Rain on Southeastern China

Former Tropical Storm Maliksi dropped rain on parts of southeastern China on Saturday. At 5:00 p.m. EDT on Saturday the center of Tropical Depression Maliksi was located at latitude 23.0°N and longitude 112.0°E which put it about 125 miles (200 km) west of Guangzhou, China. Maliksi was moving toward the north-northeast 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. (75 km/h). The minimum surface pressure was 1002 mb.

Former Tropical Storm Maliksi weakened to a tropical depression after it made landfall on the coast of southern China west of Hong Kong late on Friday. Thunderstorms were still occurring in bands in the eastern and southern parts of Maliksi’s circulation. Some of those thunderstorms were dropping heavy rain on parts of southeastern China. Heavy rain was falling in parts of Guangdong. Prolonged heavy rain could cause floods in some locations.

The circulation around Tropical Depression Maliksi will continue to weaken as it moves over southeastern China. Maliksi could dissipate by the end of the weekend.

Tropical Storm Maliksi Forms Southwest of Hong Kong

Tropical Storm Maliksi formed over the South China Sea southwest of Hong Kong on Friday. At 11:00 a.m. EDT on Friday the center of Tropical Storm Maliksi was located at latitude 21.4°N and longitude 111.6°E which put it about 185 miles (300 km) west-southwest of Hong Kong. Maliksi was moving toward the north-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 998 mb.

A low pressure system over the South China Sea southwest of Hong Kong strengthened on Friday and the Japan Meteorological Agency designated the system as Tropical Storm Maliksi. The distribution of thunderstorms in Tropical Storm Maliksi was asymmetrical. Thunderstorms were occurring in bands in the southern half of Maliksi’s circulation. Bands in the northern half of the circulation consisted primarily of showers and lower clouds. Storms near the center of circulation generated upper level divergence that pumped mass away to the south of the tropical storm.

The distribution of wind speeds around Tropical Storm Maliksi was also asymmetrical. Winds to tropical storm force extended out 120 miles (195 km) in the southeastern part of Maliksi’s circulation. Winds to tropical storm force only extended out 60 miles (95 km) in the northwestern side of Maliksi.

Tropical Storm Maliksi will move through an environment somewhat favorable for intensification during the next few hours. Maliksi will move over water where the Sea Surface Temperatures are near 29°C. It will move under the eastern part of an upper level ridge over China. The ridge will produce northerly winds that will blow toward the top of Maliksi’s circulation. Those winds will also cause moderate vertical wind shear. The wind shear will inhibit intensification. Tropical Storm Maliksi could intensify a little during the next few hours.

Tropical Storm Maliksi will move around the western side of a high pressure system over the Western North Pacific Ocean. The high pressure will steer Maliksi toward the north during the next 24 hours. On its anticipated track, Tropical Storm Maliksi will make landfall in southern China in a few hours. Maliksi will drop heavy rain over parts of southern China. Heavy rain could cause floods in some locations.

Tropical Storm Ewiniar Weakens South of Japan

Tropical Storm Ewiniar weakened south of Japan on Thursday. At 11:00 a.m. EDT on Thursday the center of Tropical Storm Ewiniar was located at latitude 30.8°N and longitude 137.7°E which put it about 400 miles (645 km) south-southwest of Tokyo, Japan. Ewiniar was moving toward the northeast at 17 m.p.h. (28 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 995 mb.

Strong vertical wind shear and cooler Sea Surface Temperatures caused Tropical Storm Ewiniar to weaken south of Japan on Thursday. No thunderstorms were occurring in Tropical Storm Ewiniar. Bands revolving around the center of Ewiniar’s circulation consisted primarily of showers and lower clouds. Winds to tropical storm force extended out 90 miles (145 km) from the center of Ewiniar.

Tropical Storm Ewiniar will move through an environment that will be unfavorable for intensification during the next 24 hours. Ewiniar will move over water where the Sea Surface Temperatures are near 24°C. An upper level trough northwest of Japan will produce strong westerly winds that will blow across the top of Ewiniar’s circulation. Those winds will cause strong vertical wind shear. The cooler water and strong vertical wind shear will cause Tropical Storm Ewiniar to continue to weaken during the next 24 hours.

Tropical Storm Ewiniar will move around the northern side of a high pressure system over the Western North Pacific Ocean. The high pressure system and the upper level trough northwest of Japan will steer Ewiniar toward the northeast during the next 24 hours. On its anticipated track, Tropical Storm Ewiniar will remain south of Japan. Ewiniar will pass south of Tokyo in 12 hours.

Ewiniar Weakens to a Tropical Storm

Former Typhoon Ewiniar weakened to a tropical storm south of Japan on Wednesday. At 11:00 a.m. EDT on Wednesday the center of Tropical Storm Ewiniar was located at latitude 26.9°N and longitude 133.5°E which put it about 120 miles (195 km) northeast of Minamidaitojima, Japan. Ewiniar was moving toward the northeast at 18 m.p.h. (30 km/h). The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were wind gusts to 85 m.p.h. (135 km/h). The minimum surface pressure was 981 mb.

After bringing strong winds and heavy rain to Minamidaitojima, former Typhoon Ewiniar weakened to a tropical storm on Wednesday. An upper level trough northwest of Japan was producing strong southwesterly winds that were blowing toward the top of Ewiniar’s circulation. Those winds were causing strong vertical wind shear. The wind shear caused former Typhoon Ewiniar to weaken.

The strong vertical wind shear was also affecting the structure of Tropical Storm Ewiniar. The strong upper level southwesterly winds were causing the upper part of Ewinar’s circulation to tilt toward the northeast. Thunderstorms were still occurring in bands in the northern and eastern parts of Tropical Storm Ewiniar. Bands in the southern and western parts of Ewiniar consisted primarily of showers and lower clouds.

The circulation around Typhoon Ewiniar was still small. Winds to tropical storm force extended out 100 miles (160 km) from the center of circulation.

Tropical Storm Ewiniar will move through an environment that will be unfavorable for intensification during the next 24 hours. Ewiniar will move over water where the Sea Surface Temperatures are near 25°C. The upper level trough northwest of Japan will continue to cause strong vertical wind shear. The cooler water and strong vertical wind shear will cause Tropical Storm Ewiniar to weaken during the next 24 hours. If the upper level winds get stronger, they could blow the top off of Ewiniar’s circulation. The cooler water and strong vertical wind shear will also cause Tropical Storm Ewiniar to begin to make a transition to an extratropical cyclone.

Tropical Storm Ewiniar will move around the northern side of a high pressure system over the Western North Pacific Ocean. The high pressure system and the upper level trough northwest of Japan will steer Ewiniar toward the northeast during the next 24 hours. On its anticipated track, Tropical Storm Ewiniar will remain south of Japan.