Tropical Storm Barry Strengthens South of Louisiana

Tropical Storm Barry strengthened south of Louisiana on Friday morning.  Hurricane Hunters flying into Barry found that the maximum sustained wind speed had increased to 65 m.p.h. (105 km/h).  At 11:00 a.m. EDT on Friday the center of Tropical Storm Barry was located at latitude 28.2°N and longitude 90.4°W which put it about 115 miles (185 km) south-southeast of Morgan City, Louisiana.  Barry was moving toward the west-northwest at 5 m.p.h. (8 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 998 mb.

A Hurricane Warning is in effect for the portion of the coast from Intracoastal City to Grand Isle, Louisiana. Hurricane Watches have been issued for the portions of the coast from the Mouth of the Mississippi River to Grand Isle, Louisiana and from Intracoastal City to Cameron, Louisiana. Tropical Storm Warnings are in effect for the portions of the coast from the Mouth of the Pearl River to Grand Isle, Louisiana and from Intracoastal City to Cameron, Louisiana. A Tropical Storm Watch has been issued for the portion of the coast from the Mouth of the Pearl River to the Mississippi/Alabama border. A Tropical Storm Warning is in effect for Lake Pontchartrain, Lake Maurepas and New Orleans.

The circulation around Tropical Storm Barry exhibited greater organization on Friday morning.  Thunderstorms developed in a band around the southern side of the center of circulation.  More thunderstorms also formed in bands that stretched around the western, southern and eastern sides of the circulation.  Bands in the northern portion of the circulation consisted primarily of showers and lower clouds, although there were some thunderstorms in the parts of those bands over land.  Winds to tropical storm force extended out about 170 miles (280 km) from the center of circulation.  Storms just south of the center were generating upper level divergence which was pumping mass away to the west of Tropical Storm Barry.  The removal of mass allowed the surface pressure to decrease and it was down to 998 mb on Friday morning.

Tropical Storm Barry will move through an environment that is some what favorable for intensification.  Barry will move south of a narrow upper level ridge that stretches from east Texas to south Alabama.  The ridge will produce northeasterly winds which will cause some vertical wind shear.  The shear is one of the reasons why there are fewer thunderstorms in the northern part of the circulation.  Reconnaissance aircraft reported that the middle level center was a little to the south of the surface center.  The tilt of the circulation with height is also the result of the vertical wind shear.  However, the shear will not be strong enough to prevent intensification.  Tropical Storm Barry will move over water where the Sea Surface Temperature is near 30.5°C.  It will extract a lot of energy from the Gulf of Mexico.  Tropical Storm Barry is forecast to strengthen into a hurricane during the next 24 hours.

Tropical Storm Barry is moving around the southwestern part of a ridge of high pressure over the southeastern U.S.  The ridge will steer Barry slowly toward the west-northwest during the next few hours.  Barry will turn more toward the northwest later on Friday.  On its anticipated track the center of Tropical Storm Barry will approach the coast of Louisiana late Friday night.  Barry is forecast to be a hurricane when it reaches the coast.  The broad circulation will cause mostly minor wind damage over a large area.  There could be widespread power outages.  Barry will also generate a storm surge of 6 to 9 feet (2 to 3 meters near where the center makes landfall.  Tropical Storm Barry will drop heavy rain when it moves slowly inland.  Flooding is a serious risk, since soils are nearly saturated and many creeks and rivers are already high.

Tropical Storm Barry Threatens Louisiana

Tropical Storm Barry threatened Louisiana on Thursday.  A low pressure system formerly designated at Potential Tropical Cyclone Two strengthened into Tropical Storm Barry on Thursday morning.  At 11:00 a.m. EDT on Thursday the center of Tropical Storm Barry was located at latitude 27.8°N and longitude 88.7°W which put it about 95 miles (150 km) south-southeast of the Mouth of the Mississippi River and about 200 miles (320 km) southeast of Morgan City, Louisiana.  Barry was moving toward the west 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 1005 mb.

A Hurricane Watch has been issued for the portion of the coast from the Mouth of the Mississippi River to Cameron, Louisiana.  A Tropical Storm Warning is in effect for the portion of the coast from the Mouth of the Pearl River to Morgan City, Louisiana.  A Tropical Storm Watch has been issued for the portion of the coast from the Mouth of the Pearl River to the Mississippi/Alabama border.  A Tropical Storm Watch has also been issued for Lake Pontchartrain, Lake Maurepas and New Orleans.

The circulation around Tropical Storm Barry exhibited more organization on Thursday morning, but there were not a lot of thunderstorms near the center of circulation.  Many of the thunderstorms were occurring in bands wrapping around the western and southern sides of the circulation.  Bands in the northern half of the circulation consisted primarily of showers and lower clouds.  Winds to tropical storm force were occurring in the southeastern part of Tropical Storm Barry.  Winds to tropical storm force extended out about 100 miles (160 km) from the center in that quadrant of Barry.  The winds were weaker in other quadrants of the circulation.

Tropical Storm Barry will move through an environment favorable for intensification during the next 36 hours.  Barry will move over water where the Sea Surface Temperature is near 30.5°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Tropical Storm Barry will intensify slowly until more thunderstorms form near the center of circulation.  If thunderstorms consolidate around an inner core, then rapid intensification would be possible.  Tropical Storm Barry is forecast to strengthen into a hurricane on Friday.

Tropical Storm Barry will move around the southwestern part of a ridge of high pressure over the southeastern U.S.  The ridge is likely to steer Barry slowly toward the west during the next 12 to 24 hours.  Tropical Storm Barry will move more toward the northwest when it moves around the southwestern part of the ridge.  There is still some uncertainty about the timing and location of the turn toward the northwest.  Based on its anticipated track Tropical Storm Barry could approach the coast of Louisiana on Friday night.

Tropical Storm Barry is forecast to strengthen into a hurricane before it makes landfall.  It will bring strong, gusty winds to coastal regions of Louisiana.  Those winds will also push a storm surge toward the coast.  The storm surge could be up to 6 to 8 feet (2 to 3 meters) near where the center makes landfall.  Tropical Storm Barry could drop heavy rain when it moves inland.  Many rivers and streams are already high and locally heavy rain could cause flooding in those locations.

NHC Initiates Advisories on Potential Tropical Cyclone Two

The National Hurricane Center (NHC) initiated advisories on Potential Tropical Cyclone Two on Wednesday morning.  NHC initiated the advisories in order to be able to issue watches for a portion of the coast of Louisiana.  At 11:00 a.m. EDT on Wednesday the center of Potential Tropical Cyclone Two was located at latitude 28.5°N and longitude 86.4°W which put it about 170 miles (270 km) east-southeast of the Mouth of the Mississippi River.  It was moving toward the west-southwest at 8 m.p.h. (13 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 1011 mb.  A Tropical Storm Watch was issued for the portion of the coast from the Mouth of the Mississippi River to Morgan City, Louisiana.

The circulation around Potential Tropical Cyclone Two was not well organized.  There was a large, but relatively weak circulation near the surface.  There was not a well defined center of circulation near the surface.  There was a stronger counterclockwise circulation between about 10,000 feet (3000 meters) and 25,000 feet (7600 meters) above the surface, which was located above the southwestern part of the surface circulation.  Many of the stronger thunderstorms were occurring in bands on the northern and western sides of the circulation above the surface.  There were fewer thunderstorms in the eastern side of the larger, surface circulation.

Potential Tropical Cyclone Two will move through an environment very favorable for development and intensification.  It will move over water where the Sea Surface Temperature is near 30°C.  The system will move through a region where the upper level winds are weak and there will be little vertical wind shear.  It is likely that a center of circulation will form at the surface underneath the counterclockwise circulation above the surface.  Potential Tropical Cyclone Two will strengthen slowly until the surface center is underneath the center higher in the atmosphere.  After the circulation becomes aligned vertically, the system could strengthen more rapidly.  Potential Tropical Cyclone Two is likely to become a hurricane within 48 to 60 hours.

Potential Tropical Cyclone Two will move south of a ridge over the southeastern U.S.  The ridge will steer Potential Tropical Cyclone Two toward the southwest.  It will move more toward the west on Thursday and then turn back more toward the northwest on Friday when it nears the western end of the ridge.  There will be significant uncertainty about the future track of the system until a well defined center of circulation forms at the surface.  On its anticipated track the center of Tropical Cyclone Two could approach the coast of Louisiana and northeast Texas on Friday.  Hurricane Watches and Warnings are likely to be issued for portions of the coast later this week.

Potential Tropical Cyclone Two presents a wide range of hazards.  It will bring hurricane force winds to portions of Louisiana and Texas and it will disrupt operations of offshore facilities in the northwestern Gulf of Mexico.  After the center of the system moves west of New Orleans, southerly winds will force water into the Mouth of the Mississippi River.  The level of the Mississippi River around New Orleans is already near flood stage and any additional rise in the water level could cause serious flooding around the city.  If Potential Tropical Cyclone Two strengthens into a hurricane, as expected, it will cause a significant storm near where the center makes landfall.  The system also has the potential to drop heavy rain and flooding could occur when it moves inland.

Potential Tropical Development Over Northern Gulf of Mexico

The potential exists for the development of a tropical cyclone over the northern Gulf of Mexico this week.  A low pressure system was over Georgia on Monday afternoon.  The low was drifting slowly southward, but it was forecast to move more toward the south-southwest during the next two days.  Several numerical models were predicting that the low pressure system would strengthen into a tropical depression or a tropical storm after it moves over the northern Gulf of Mexico later this week.  The National Hurricane Center was indicating that the low pressure system, currently designated as Invest 92L, had a 30% probability of developing into a tropical cyclone during the next two days and an 80% probability of developing into a tropical cyclone during the next five days.

The low pressure system exhibited a surface circulation on Monday afternoon, but the wind speed was near 15 m.p.h. (25 km/h).  Bands of showers and thunderstorms formed during the daytime heating over land, but they weakened at night.  There was also a counterclockwise rotation in the lower and middle troposphere which may have been the remnants of a mesoscale convective vortex (MCV), which developed over the Middle Mississippi River Valley a few days ago.  The low was not generating upper level divergence on Monday afternoon.

If the low pressure system does move over the northern Gulf of Mexico on Tuesday or Wednesday, it will move into an environment more favorable for the development of a tropical depression.  The Sea Surface Temperature of the water in the northeastern Gulf of Mexico is near 30°C.  The low pressure system will move southeast of an upper level ridge over the southern U.S.  The ridge will produce northeasterly winds, but the winds will be relatively weak and the vertical wind shear will not be too strong.  More thunderstorms are likely to develop when the low pressure system moves over the warm water.  If those thunderstorms generate upper level divergence that pumps mass away, then the surface pressure will decrease and a tropical depression will form.

The upper level ridge is forecast to steer the low pressure system toward the west after it moves over the Gulf of Mexico later this week.  On its anticipated track the low pressure system will move slowly toward the coast of Louisiana and Texas.  The future intensity of the system will be determined by how far the system moves into the Gulf of Mexico.  If the low pressure system takes a track along or near the north coast of the Gulf of Mexico, then it will likely become a tropical depression or a weak tropical storm.  Even if the low only strengthens into a tropical depression, it could drop heavy rain and the potential for flooding exists along the northern Gulf Coast.  If the low pressure system moves farther out into the Gulf of Mexico and remains over warm water for a longer period, then it might intensify into a hurricane.  Residents along the Gulf Coast should monitor this system carefully.

Tropical Storm Cosme Forms Southwest of Baja California

Tropical Storm Cosme formed southwest of Baja California on Saturday.  At 11:00 a.m. EDT on Saturday the center of Tropical Storm Cosme was located at latitude 15.6°N and longitude 115.7°W which put it about 630 miles (1015 km) southwest of the southern tip of Baja California.  Cosme was moving toward the west-northwest at 14 m.p.h. (22 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.

The National Hurricane Center (NHC) determined on Saturday that a distinct center of circulation had developed in a broader area of lower pressure and NHC designated the system as Tropical Storm Cosme.  The distribution of thunderstorms around Tropical Storm Cosme was asymmetrical.  The stronger thunderstorms were occurring in bands in the eastern half of the circulation.  Bands in the western half of the circulation consisted primarily of showers and lower clouds.  An upper level trough near Baja California was producing strong southwesterly winds which were blowing across the top of the circulation.  Those winds were causing strong vertical wind shear and they were probably the reason for the asymmetrical distribution of thunderstorms.  Winds to tropical storm force extended out about 150 miles (240 km) from the center of circulation.

Tropical Storm Cosme will move through an environment that is not favorable for significant intensification.  Cosme will move over water where the Sea Surface Temperature is near 26°C.  The upper level trough will continue to produce southwesterly winds that will blow toward the top of Tropical Storm Cosme.  The upper level winds are likely to weaken somewhat, but they will continue to cause vertical wind shear.  Tropical Storm Cosme could intensify a little during the next 24 hours, but it is not likely to strengthen significantly.

Tropical Storm Cosme will move south of a subtropical high pressure system over Eastern North Pacific Ocean.  The high will steer Cosme toward the west-northwest.  On its anticipated track Tropical Storm Cosme is forecast to remain well to the west of Baja California.

Elsewhere over the Eastern North Pacific Ocean, Tropical Storm Barbara continued to weaken as it moved toward Hawaii.  At 11:00 a.m. EDT on Saturday the center of Tropical Storm Barbara was located at latitude 18.7°N and longitude 139.2°W which put it about 1040 miles (1670 km) east of Hilo, Hawaii.  Barbara was moving toward the west at 17 m.p.h. (28 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 1000 mb.

Barbara Weakens to a Tropical Storm

Former Hurricane Barbara weakened to a tropical storm on Friday.  At 5:00 p.m. EDT on Friday the center of Tropical Storm Barbara was located at latitude 18.6°N and longitude 134.7°W which put it about 1330 miles (2145 km) east of Hilo, Hawaii.  Barbara was moving toward the west-northwest at 13 m.p.h. (20 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 997 mb.

The effects of vertical wind shear and cooler Sea Surface Temperatures caused former Hurricane Barbara to weaken quickly to a tropical storm on Friday.  An upper level trough northeast of Hawaii produced strong southwesterly winds which blew the upper portion of the circulation north of the remainder of the tropical storm.  In addition, Tropical Storm Barbara moved over water where the Sea Surface Temperature was near 25°C which meant there was less energy to support the development of taller thunderstorms.  Tropical Storm Barbara still had a well formed circulation in the lower levels of the atmosphere.  However, as a result of the strong shear and cooler water, bands consisted primarily of showers and lower clouds.  Winds to tropical storm force extended out about 140 miles (220 km) from the center of circulation.

Tropical Storm Barbara will continue to move over cooler water and through a region of strong vertical wind shear during the next several days.  Barbara will continue to weaken and it could be a tropical depression on Saturday.

Since Tropical Storm Barbara contains few tall thunderstorms, it is being steered by winds closer to the surface.  A subtropical high pressure system north of Barbara will steer the tropical storm toward the west.  On its anticipated track Tropical Storm Barbara will move toward Hawaii.

Hurricane Barbara Starts to Weaken

Hurricane Barbara started to weaken on Wednesday when it moved over cooler water well to the east of Hawaii.  At 5:00 p.m. EDT on Wednesday the center of Hurricane Barbara was located at latitude 14.3°N and longitude 127.5°W which put it about 1860 miles (2990 km) east of Hilo, Hawaii.  Barbara was moving toward the west-northwest at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 140 m.p.h. (220 km/h) and there were wind gusts to 170 m.p.h. (275 km/h).  The minimum surface pressure was 941 mb.

The circulation around Hurricane Barbara remained very well organized.  There was a circular eye at the center of circulation.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Several bands of showers and thunderstorms were revolving around the core of Hurricane Barbara.  Storms near the core of the circulation were generating strong upper level divergence which was pumping mass away from the hurricane.  Winds to hurricane force extended out about 45 miles (75 km) from the center of circulation.  Winds to tropical storm force extended out about 185 miles (295 km) from the center.

Hurricane Barbara still rated at Category 4 on the Saffir-Simpson Scale.  The Hurricane Intensity Index (HII) for Barbara was 28.3.  The Hurricane Size Index (HSI) was 16.5 and the Hurricane Wind Intensity Size Index (HWISI) was 44.8.

Hurricane Barbara will gradually move into an environment less capable of supporting a strong hurricane during the next few days.  Barbara will move over water where the Sea Surface Temperature is near 26°C.  As a result, Hurricane Barbara will extract less energy from the upper ocean and it will gradually weaken.  Barbara will move closer to an upper level trough located northeast of Hawaii.  When Hurricane Barbara gets closer to the trough later this week, stronger upper level southwesterly winds will create more vertical wind shear and the hurricane will weaken more quickly.

Hurricane Barbara will move south of a subtropical ridge over the Eastern North Pacific Ocean.  The ridge will steer Barbara toward the west-northwest during the next 24 to 36 hours.  The ridge is forecast to strengthen on Friday and it will steer Hurricane Barbara more toward the west when that happens.  On its anticipated track Barbara could approach Hawaii in about five days.  It will be much weaker by that time.

Tropical Storm Mun Develops Near Hainan Island

Tropical Storm Mun developed near Hainan Island on Tuesday when the Japan Meteorological Agency designated an area of low pressure as a tropical storm.  At 5:00 p.m. EDT on Tuesday the center of Tropical Storm Mun was located at latitude 19.4°N and longitude 109.8°E which put the center over Hainan Island and it was about 225 miles (365 km) east-southeast of Hai Phong, Vietnam.  Mun was moving toward the west at 12 m.p.h. (19 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 994 mb.

The circulation around Tropical Storm Mun was very large but it did not have a well developed inner core.  Winds to tropical storm force extended out several hundred miles from the center of circulation.  However, there were few thunderstorms near the center.  The strongest thunderstorms were in two bands in the western periphery of the circulation.  Other bands around Tropical Storm Mun consisted primarily of showers and lower clouds.

Tropical Storm Mun will move through an environment that is not favorable for intensification.  After Mun moves west of Hainan Island the tropical storm will move over water where the Sea Surface Temperature is near 30°C.  So, there is plenty of energy in the upper ocean to support intensification.  However, Tropical Storm Mun will move south of an upper level ridge over eastern Asia.  The ridge will produce strong northeasterly winds which will cause strong vertical wind shear.  The wind shear will prevent significant intensification of Tropical Storm Mun.

Since Tropical Storm Mun does not have a well developed inner core with tall thunderstorms, it will be steered by the winds at lower levels in the atmosphere.  Southeasterly winds blowing as part of the monsoonal circulation will push Mun toward the border between Vietnam and China.  On its anticipated track the center of Tropical Storm Mun will move inland within 24 hours.  Mun will bring some gusty winds and locally heavy rain to portions of northeastern Vietnam and southeastern China.  Heavy rain could cause flash floods in some locations.

Barbara Rapidly Intensifies Into a Major Hurricane

Hurricane Barbara rapidly intensified into a major hurricane on Tuesday as it moved over the Eastern North Pacific Ocean between Baja California and Hawaii.  At 11:00 a.m. EDT on Tuesday the center of Hurricane Barbara was located at latitude 12.5°N and longitude 122.2°W which put it about 1080 miles (1740 km) southwest of the southern tip of Baja California.  Barbara was moving toward the west-northwest at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 130 m.p.h. (215 km/h) and there were wind gusts to 150 m.p.h. (240 km/h).  The minimum surface pressure was 948 mb.

Hurricane Barbara continued to intensify rapidly on Tuesday.  A circular eye became more evident on satellite imagery.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Storms near the core of Barbara were generating strong upper level divergence which was pumping mass away from the hurricane in all directions.  Multiple bands of showers and thunderstorms were revolving around the core of Hurricane Barbara.  Winds to hurricane force extended out about 25 miles (40 km) from the center of circulation.  Winds to tropical storm force extended out about 200 miles (320 km) in the southeastern quadrant of the circulation.  Tropical storm force winds extended out about 120 miles (195 km) from the center in the other three quadrants.

Hurricane Barbara was at Category 4 on the Saffir-Simpson Scale.  The Hurricane Intensity Index (HII) for Barbara was 25.1.  The Hurricane Size Index (HSI) was 11.0 and the Hurricane Wind Intensity Size Index (HWISI) was 36.1.

Hurricane Barbara will move through an environment very favorable for strong hurricanes for another 12 to 24 hours.  Barbara will move over water where the Sea Surface Temperature is near 28°C.  It will move through an area where the upper level winds are weak and there will be little vertical wind shear.  Hurricane Barbara is likely to intensify further during the next 12 hours.  If a rainband wraps around the existing eye and eyewall, then an eyewall replacement cycle could cause Barbara to weaken.  Hurricane Barbara will approach cooler water on Wednesday and it is likely to start to weaken by that time.  Barbara will move into an area where the upper level winds are stronger later this week and it could weaken more quickly when the wind shear increases.

Hurricane Barbara will move south of a subtropical ridge over the Eastern North Pacific Ocean.  The ridge will steer Barbara in a west-northwesterly direction during the next several days.  On its anticipated track Hurricane Barbara will move in the general direction of Hawaii.

Barbara Rapidly Intensifies Into a Hurricane

Former Tropical Storm Barbara rapidly intensified into a hurricane over the Eastern North Pacific Ocean on Monday.  At 5:00 p.m. EDT on Monday the center of Hurricane Barbara was located at latitude 11.5°N and longitude 118.5°W which put it about 970 miles (1560 km) southwest of the southern tip of Baja California.  Barbara was moving toward the west at 16 m.p.h. (26 km/h).  The maximum sustained wind speed was 85 m.p.h. (135 km/h) and there were wind gusts to 100 m.p.h. (160 km/h).  The minimum surface pressure  was 983 mb.

Hurricane Barbara intensified rapidly on Monday.  An eye formed at the center of circulation and a ring of strong thunderstorms surrounded the eye.  The strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of the circulation.  Storm near the core of Barbara were generating strong upper level divergence which was pumping mass away from the hurricane.  Winds to hurricane force extended out about 25 miles (40 km) from the center of circulation.  Winds to tropical storm force extended out about 160 miles (260 km) from the center.

Hurricane Barbara will move through an environment very favorable for intensification during the next 36 to 48 hours.  Barbara will move over water where the Sea Surface Temperature is near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Hurricane Barbara will continue to intensify rapidly and it is expected to strengthen into a major hurricane on Tuesday.

Hurricane Barbara will move south of a subtropical ridge over the Eastern North Pacific Ocean during the next few days.  The ridge will steer Barbara toward the west-northwest.  On its anticipated track Hurricane Barbara will move farther away from Baja California and the rest of Mexico.