Monthly Archives: June 2023

Tropical Storm Bret Strengthens

Tropical Storm Bret strengthened on Wednesday as it moved closer to the Lesser Antilles. At 5:00 p.m. EDT on Wednesday the center of Tropical Storm Bret was located at latitude 13.3°N and longitude 53.9°W which put it about 375 miles (605 km) east of Barbados. Bret was moving toward the west at 15 m.p.h. (24 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 1000 mb.

Tropical Storm Warnings were in effect for St. Lucia and Martinique. Tropical Storm Watches were in effect for Barbados and Dominica.

A U.S. Air Force Reserve Hurricane Hunter aircraft flying into Tropical Storm Bret on Wednesday afternoon found that Bret had strengthened. More thunderstorms developed near the center of Bret’s circulation. Bands of showers and thunderstorms were revolving around the center of Tropical Storm Bret. Storms near the center generated upper level divergence that pumped mass away from the tropical storm. The size of the circulation around Bret increased when it strengthened. The reconnaissance plane found that the strongest winds were occurring northeast of the center of Tropical Storm Bret. Winds to tropical storm force extended out 105 miles (165 km) in the northern side of Bret’s circulation. Winds to tropical storm force extended out 45 miles (75 km) in the southern side of the circulation.

Tropical Storm Bret will move through an environment somewhat favorable for intensification during the next 24 hours. Bret will move over water where the Sea Surface Temperatures are near 28˚C. It will move under the axis of an upper level ridge over the tropical Atlantic Ocean. The upper level winds are weak near the axis of the ridge. There could be slightly stronger winds in the middle troposphere which could cause some vertical wind shear in those levels. Stronger wind shear in the middle troposphere could prevent intensification of Tropical Storm Bret during the next 24 hours. However, if the winds in the middle levels are not too strong, then Bret could strengthen to a hurricane.

Tropical Storm Bret will move south of a subtropical high pressure system over the Atlantic Ocean. The subtropical high will steer Bret toward the west during the next 24 hours. On its anticipated track, Tropical Storm Bret could bring strong winds and locally heavy rain to Barbados on Thursday afternoon. Bret could bring strong winds and locally heavy rain to St. Lucia, Martinique, and Dominica on Thursday night. Locally heavy rain could cause flash floods in some locations.

Tropical Storm Bret Prompts Watch for Barbados

The potential effects of Tropical Storm Bret prompted the issuance of a Tropical Storm Watch for Barbados on Tuesday afternoon. At 5:00 p.m. EDT on Tuesday the center of Tropical Storm Bret was located at latitude 12.2°N and longitude 48.6°W which put it about 835 miles (1350 km) east of the Lesser Antilles. Tropical Storm Bret was moving toward the west at 18 m.p.h. (29 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 Tropical Storm Watch was in effect for Barbados.

The potential effects of Tropical Storm Bret prompted the government of Barbados to issue a Tropical Storm Watch on Tuesday afternoon. The circulation around Tropical Storm Bret strengthened gradually on Tuesday. More thunderstorms formed just to the west of the center of Bret’s circulation on Tuesday afternoon. Bands of showers and thunderstorms were revolving around the center of circulation. Storms near the center generated upper level divergence that pumped mass away from the tropical storm. Winds to tropical storm force extended out 45 miles (75 km) from the center of Tropical Storm Bret.

Tropical Storm Bret will move through an environment favorable for intensification during the next 24 hours. Bret will move over water where the Sea Surface Temperatures are near 28˚C. It will move under the axis of an upper level ridge over the tropical Atlantic Ocean. The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear. Tropical Storm Bret will intensify during the next 24 hours. Bret could strengthen to a hurricane later this week.

Tropical Storm Bret will move south of a subtropical high pressure system over the Atlantic Ocean. The subtropical high will steer Bret toward the west during the next 24 hours. Bret could move more toward the west-northwest later this week. On its anticipated track, Tropical Storm Bret could bring gusty winds and locally heavy rain to Barbados on Thursday. Bret could reach some of the other islands in the Lesser Antilles by Thursday night. Additional watches and warnings are likely to be issued as Tropical Storm Bret moves closer to the Lesser Antilles. Planes are scheduled to start to fly reconnaissance missions into Tropical Storm Bret starting on Wednesday afternoon.

Tropical Depression Three Strengthens to Tropical Storm Bret

Former Tropical Depression Three strengthened to Tropical Storm Bret east of the Lesser Antilles on Monday afternoon. At 5:00 p.m. EDT on Monday the center of Tropical Storm Bret was located at latitude 11.3°N and longitude 42.2°W which put it about 1295 miles (2085 km) east of the Lesser Antilles. Tropical Storm Bret was moving toward the west at 21 m.p.h. (33 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 1008 mb.

Satellite images provided evidence that the circulation around former Tropical Depression Three strengthened on Monday afternoon and the National Hurricane Center upgraded the system to Tropical Storm Bret. The inner end of a rainband wrapped part of the way around the center of Tropical Storm Bret. Other bands of showers and thunderstorms were revolving around the center of circulation. Storms near the center of Bret’s circulation generated upper level divergence that pumped mass away from the tropical storm. Winds to tropical storm force extended out 45 miles (75 km) in the eastern side of Tropical Storm Bret. The winds on the western side of the circulation were blowing at less than tropical storm force.

Tropical Storm Bret will move through an environment favorable for intensification during the next 36 hours. Bret will move over water where the Sea Surface Temperatures are near 28˚C. It will move under the axis of an upper level ridge over the tropical Atlantic Ocean. The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear. Tropical Storm Bret will intensify during the next 36 hours. Bret could strengthen to a hurricane later this week.

Tropical Storm Bret will move south of a subtropical high pressure system over the Atlantic Ocean. The subtropical high will steer Bret toward the west during the next 36 hours. Bret could move more toward the west-northwest later this week. On its anticipated track, Tropical Storm Bret could approach the Lesser Antilles on Thursday. Bret could be a hurricane by that time. Planes are scheduled to start to fly reconnaissance missions into Tropical Storm Bret starting on Wednesday afternoon.

Tropical Depression Three Forms East of Lesser Antilles

Tropical Depression Three formed over the Atlantic Ocean east of the Lesser Antilles on Monday morning. At 11:00 a.m. EDT on Monday the center of Tropical Depression Three was located at latitude 11.0°N and longitude 40.3°W which put it about 1425 miles (2295 km) east of the Lesser Antilles. Tropical Depression Three was moving toward the west at 21 m.p.h. (33 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 1009 mb.

A circulation within a tropical wave previously designated as Invest 92L strengthened on Monday morning and the National Hurricane Center designated the system as Tropical Depression Three. More thunderstorms were developing near the center of Tropical Depression Three. Other bands of showers and thunderstorms were revolving around the center of circulation. Storms near the center generated upper level divergence that pumped mass away from the tropical depression.

Tropical Depression Three will move through an environment favorable for intensification during the next 36 hours. The tropical depression will move over water where the Sea Surface Temperatures are near 28˚C. It will move under the axis of an upper level ridge over the tropical Atlantic Ocean. The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear. Tropical Depression Three is likely to strengthen to a tropical storm during the next 24 hours. It could strengthen to a hurricane later this week.

Tropical Depression Three will move south of a subtropical high pressure system over the Atlantic Ocean. The subtropical high will steer the tropical depression toward the west during the next 36 hours. It could move more toward the west-northwest later this week. On its anticipated track, Tropical Depression Three could approach the Lesser Antilles on Thursday. It could be a hurricane by that time.

Potential Development over Tropical Atlantic

A tropical wave over the eastern Atlantic Ocean has the potential to develop into a tropical depression during the next few days. The tropical wave has been designated as Invest 92L. At 2:00 a.m. EDT on Saturday the center of Invest 92L was located at latitude 10.1°N and longitude 26.2°W which put it about 2265 miles (3655 km) east of the Lesser Antilles. The tropical wave was moving toward the west at 10 m.p.h. (16 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 1011 mb.

The National Hurricane Center (NHC) indicated that there was a high probability (70%) a tropical wave over the eastern Atlantic Ocean will develop into a tropical depression during the next seven days. NHC designated the system as Invest 92L. The tropical wave was already exhibiting signs of organization on Saturday morning. Visible satellite images provided evidence of some rotation in the middle levels of the tropical wave. More thunderstorms were forming in bands associated with the tropical wave.

The tropical wave will move through an environment favorable for the formation of a tropical depression during the next few days. Invest 92L will move over water where the Sea Surface Temperatures are near 28˚C. It will move under the axis of an upper level ridge over the tropical Atlantic Ocean. The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear. Invest 92L is likely to develop into a tropical depression during the next few days.

The tropical wave will move south of a subtropical high pressure system over the Atlantic Ocean. The subtropical high will steer Invest 92L toward the west during the next few days. On its anticipated track, Invest 92L will move toward the Lesser Antilles.

Tropical Cyclone Biparjoy Moves Inland near India/Pakistan Border

Tropical Cyclone Biparjoy moved farther inland near the border between India and Pakistan on Friday. At 5:00 a.m. EDT on Friday the center of Tropical Cyclone Biparjoy was located at latitude 23.9°N and longitude 70.0°E which put it about 10 miles (20 km) west of Dholavira, India. Biparjoy was moving toward the northeast at 7 m.p.h. (11 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 991 mb.

Tropical Cyclone Biparjoy continued to bring gusty winds and locally heavy rain to parts of southeastern Pakistan and western India on Friday as it moved slowly inland. The circulation around Tropical Cyclone Biparjoy remained well organized even though the center has been over land for 12 hours. A well defined center of circulation was apparent on both satellite and radar images. The circulation around Biparjoy became more symmetrical after it moved over land. Bands of thunderstorms in all parts of Tropical Cyclone Biparjoy were revolving around the center of circulation. Storms near the center generated upper level divergence that pumped mass away from the tropical cyclone.

Tropical Cyclone Biparjoy will continue to move farther inland during the next 36 hours. Biparjoy will weaken slowly as it moves farther away from the Arabian Sea. Tropical Cyclone Biparjoy will continue to bring gusty winds and locally heavy rain to parts of southeastern Pakistan and western India during the next 36 hours. Heavy rain could cause flash floods in some locations.

Tropical Cyclone Biparjoy Makes Landfall near India/Pakistan Border

Tropical Cyclone Biparjoy made landfall on the coast of the Arabian Sea near the border between India and Pakistan on Thursday. At 5:00 p.m. EDT on Thursday the center of Tropical Cyclone Biparjoy was located at latitude 23.6°N and longitude 69.0°E which put it about 145 miles (235 km) southeast of Karachi, Pakistan. Biparjoy was moving toward the northeast at 7 m.p.h. (11 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 980 mb.

The center of Tropical Cyclone Biparjoy made landfall on the coast of the Arabian Sea near Jakhau Port, India on Thursday. Biparjoy was the equivalent of a strong tropical storm at landfall. Winds to tropical storm force extended out 160 miles (260 km) in the southern half of Biparjoy’s circulation. Winds to tropical storm force extended out 75 miles (120 km) in the northern half of the circulation. Many of the thunderstorms were occurring in bands in the southern part of Tropical Cyclone Biparjoy. Bands in the northern part of the circulation consisted primarily of showers and lower clouds.

Tropical Cyclone Biparjoy will move slowly inland over the Rann of Kutch, which is a salt marsh during the next few hours. Biparjoy will weaken very slowly while it is over the Rann of Kutch. Tropical Cyclone Biparjoy will weaken more rapidly on Friday when it moves into a drier environment. Since the strongest winds and the heaviest rain are in the southern parts of Biparjoy’s circulation, it means that the strongest winds and heaviest rain will occur after the center of circulation passes any given location. Tropical Cyclone Biparjoy will bring strong winds and locally heavy rain to parts of eastern Pakistan and western India. Heavy rain could cause flash floods in some locations.

Tropical Cyclone Biparjoy Nears Indus River Delta

Tropical Cyclone Biparjoy was nearing the Indus River Delta on Wednesday night. At 11:00 p.m. EDT on Wednesday the center of Tropical Cyclone Biparjoy was located at latitude 22.8°N and longitude 67.0°E which put it about 150 miles (245 km) south of Karachi, Pakistan. Biparjoy was moving toward the north-northeast at 5 m.p.h. (8 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 985 mb.

Tropical Cyclone Biparjoy weakened on Wednesday while it moved over the northern Arabian Sea. More drier air was pulled from South Asia into the northern side of Biparjoy’s circulation. In addition, Tropical Cyclone Biparjoy moved under the southern side of an upper level ridge over South Asia. The upper level ridge produced easterly winds that blew toward top of Biparjoy’s circulation. Those winds caused the vertical wind shear to increase. The effects of the drier air and the increased vertical wind shear caused the distribution of thunderstorms to become more asymmetrical. Thunderstorms were still occurring in bands in the southern part of Biparjoy’s circulation. Bands in the other parts of Tropical Cyclone Biparjoy consisted primarily of showers and lower clouds. Winds to tropical storm force extended out 160 miles (260 km) from the center of Biparjoy.

Tropical Cyclone Biparjoy will move through an environment that will be unfavorable for intensification during the next 12 hours. Biparjoy will move over water where the Sea Surface Temperatures are near 30˚C. However, the upper level ridge over the South Asia will continue to cause moderate vertical wind shear. More drier air will be pulled from South Asia into the northern side of Tropical Cyclone Biparjoy. The drier air will continue to inhibit formation of thunderstorms in the that part of Biparjoy. More vertical wind shear and more drier air will prevent intensification of Tropical Cyclone Biparjoy.

Tropical Cyclone Biparjoy will move around the northwestern side of a high pressure system over the Indian Ocean during the next 24 hours. The high pressure system will steer Biparjoy toward the northeast. On its anticipated track, Tropical Cyclone Biparjoy will reach the coast near the border between India and Pakistan in 12 hours. Biparjoy is likely to be the equivalent of a strong tropical storm when it reaches the Indus River Delta. The India Meteorological Department issued a Cyclone Warning for the Saurashtra and Kutch Coasts. Tropical Cyclone Biparjoy will bring strong winds and locally heavy rain to eastern Pakistan and western India. Heavy rain could cause flash floods in some locations. Biparjoy could also cause a storm surge of up to 7 feet (2 meters along the coast).

Tropical Cyclone Biparjoy Continues Toward Indus River Delta

Tropical Cyclone Biparjoy continued to move slowly toward the Indus River Valley on Tuesday. At 11:00 p.m. EDT on Tuesday the center of Tropical Cyclone Biparjoy was located at latitude 21.8°N and longitude 66.3°E which put it about 225 miles (365 km) south of Karachi, Pakistan. Biparjoy was moving toward the north at 4 m.p.h. (6 km/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 951 mb.

Tropical Cyclone Biparjoy remained in equilibrium with the surrounding environment on Tuesday and the intensity did not change much. A microwave satellite image showed a circular eye with a diameter of 40 miles (65 km) at the center of Biparjoy’s circulation. The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms. Thunderstorms were also occurring in bands in the southern and western parts of Tropical Cyclone Biparjoy. Bands in the northern and eastern parts of Biparjoy consisted primarily of showers and lower clouds. Storms near the center of Biparjoy’s circulation generated upper level divergence that pumped mass away to the west of the tropical cyclone.

The size of the circulation around Tropical Cyclone Biparjoy increased on Tuesday. Winds to hurricane/typhoon force extended out 40 miles (65 km) from the center of Biparjoy. Winds to tropical storm force extended out 215 miles (345 km) from the center of circulation. The Hurricane Intensity Index (HII) for Tropical Cyclone Biparjoy was 17.8. The Hurricane Size Index (HSI) was 14.2 and the Hurricane Wind Intensity Size Index (HWISI) was 32.0. Tropical Cyclone Biparjoy was similar in size and intensity to Hurricane Sally when Sally hit South Alabama in 2020.

Tropical Cyclone Biparjoy will move through an environment that will become less favorable for intensification during the next 24 hours. Biparjoy will move over water where the Sea Surface Temperatures are near 30˚C. It will move under the northern part of an upper level ridge over the northern Arabian Sea. The upper level ridge will produce southwesterly winds that will start to blow toward the top of Biparjoy’s circulation. Those winds will cause the vertical wind shear will increase. In addition, more drier air will be pulled from South Asia into the northern side of Tropical Cyclone Biparjoy. The drier air will continue to inhibit formation of thunderstorms in the that part of Biparjoy. More drier air and more vertical wind shear are likely to cause Tropical Cyclone Biparjoy to start to weaken during the next 24 hours.

Tropical Cyclone Biparjoy will move around the northwestern side of a high pressure system over the Indian Ocean during the next 24 hours. The high pressure system will steer Biparjoy slowly toward the north during the next 12 hours. The upper level ridge over the northern Arabian Sea will start to steer Tropical Cyclone Biparjoy toward the northeast on Wednesday. On its anticipated track, Tropical Cyclone Biparjoy will approach the coast near the border between India and Pakistan in 36 hours. Biparjoy is likely to be the equivalent of a hurricane/typhoon when it reaches the Indus River Delta. The India Meteorological Department issued a Cyclone Warning for the Saurashtra and Kutch Coasts. Tropical Cyclone Biparjoy will bring strong winds and locally heavy rain to eastern Pakistan and western India. Heavy rain could cause flash floods in some locations. Biparjoy could also cause a storm surge of up to 8 feet (2.4 meters along the coast).

Tropical Cyclone Biparjoy Churns Toward Indus River Delta

Tropical Cyclone Biparjoy continued to churn toward the Indus River Delta on Monday night. At 11:00 p.m. EDT on Monday the center of Tropical Cyclone Biparjoy was located at latitude 20.8°N and longitude 67.1°E which put it about 285 miles (455 km) south of Karachi, Pakistan. Biparjoy was moving toward the north at 6 m.p.h. (10 km/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 954 mb.

Tropical Cyclone Biparjoy appeared to be in equilibrium with the surrounding environment on Monday and the intensity did not change much. A microwave satellite image showed a small circular eye at the center of Biparjoy’s circulation. The eye was surrounded by a narrow ring of thunderstorms and the strongest winds were occurring in that ring of storms. Thunderstorms were also occurring in bands in the southern half of Tropical Cyclone Biparjoy. Bands in the northern half of Biparjoy consisted primarily of showers and lower clouds. Storms near the center of Biparjoy’s circulation generated upper level divergence that pumped mass away to the west of the tropical cyclone.

The distribution of wind around Tropical Cyclone Biparjoy became more symmetrical on Monday. Winds to hurricane/typhoon force extended out 35 miles (55 km) in all directions from the center of Biparjoy. Winds to tropical storm force extended out 195 miles (315 km) from the center of circulation. The Hurricane Intensity Index (HII) for Tropical Cyclone Biparjoy was 17.8. The Hurricane Size Index (HSI) was 16.9 and the Hurricane Wind Intensity Size Index (HWISI) was 34.7.

Tropical Cyclone Biparjoy will move through an environment that will be somewhat favorable for intensification during the next 24 hours. Biparjoy will move over water where the Sea Surface Temperatures are near 30˚C. It will move under the axis of an upper level ridge over the Arabian Sea. The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear. However, drier air will be pulled from South Asia into the northern side of Tropical Cyclone Biparjoy. The drier air will continue to inhibit formation of thunderstorms in the that part of Biparjoy. Tropical Cyclone Biparjoy could remain in equilibrium with its environment during the next 24 hours if the effects of warm Sea Surface Temperatures and little vertical wind shear balance the effect of the drier air in the northern part of the circulation.

Tropical Cyclone Biparjoy will move around the northwestern side of a high pressure system over the Indian Ocean during the next 24 hours. The high pressure system will steer Biparjoy slowly toward the north. On its anticipated track, Tropical Cyclone Biparjoy could approach the coast near the border between India and Pakistan in 48 hours.