Tropical Storm Nari Develops South of Japan

Tropical Storm Nari developed south of Japan on Thursday night.  The Japan Meteorological Agency designated a low pressure system south of Honshu as Tropical Storm Nari when the maximum sustained wind speed reached 40 m.p.h. (65 km/h).  At 11:00 p.m. EDT on Thursday the center of Tropical Storm Nari was located at latitude 30.2°N and longitude 136.9°E which put it about 350 miles (565 km) south of Nagoya, Japan.  Nari was moving toward the north at 14 m.p.h. (22 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.

The circulation around Tropical Storm Nari exhibited more of a hybrid structure than the structure of a pure tropical cyclone.  Tropical Storm Nari developed when an upper level low pressure system stalled south of the Japan.  A surface circulation formed beneath the upper low and then more thunderstorms formed closer to the center of circulation.  The original upper level low was located southwest of the surface low on Thursday night.  The upper level low was producing southwesterly winds which were blowing across the surface low.  Those winds were creating vertical wind shear.  The circulation around Tropical Storm Nari showed evidence of the effect of that wind shear.  The stronger thunderstorms were in a band that curved around north and west of the center of circulation.  Bands south and east of the center consisted primarily of showers and lower clouds.  The wind field around Tropical Storm Nari was also asymmetric.  Winds to tropical storm force extended out about 115 miles (185 km) to the east of the center of circulation, but only extended out about 60 miles (95 km) to the west of the center.

Tropical Storm Nari will move through an environment only marginally favorable for intensification.  Nari will move over water where the Sea Surface Temperature is near 28°C.  The upper low will continue to cause vertical wind shear, which will inhibit intensification.  The upper low will also pull some drier air around the southern side of the circulation.  Nari could strengthen a little during the next 24 hours if more thunderstorms develop closer to the center of circulation.  Tropical Storm Nari will move under stronger westerly winds in about a day or so.  Those winds will cause more vertical wind shear and they should prevent further intensification.

Tropical Storm Nari will be steered by the interaction of the upper low and a subtropical ridge over the western North Pacific Ocean.  Those two features are likely to steer Nari toward the north during the next 24 hours.  On its anticipated track Tropical Storm Nari could approach the coast of Honshu near Nagoya in about 24 hours.  Nari will move more toward the east when it reaches the stronger westerly winds in a day or so.  Tropical Storm Nari could bring gusty winds and locally heavy rain to central Honshu on Saturday.

Tropical Storm Dalila Develops Southwest of Baja California

Tropical Storm Dalila developed southwest of Baja California on Tuesday morning.  More thunderstorms formed to the south of the center of former Tropical Depression Five-E and the circulation produced wind speeds to tropical storm force.  At 11:00 a.m. EDT on Tuesday the center of Tropical Storm Dalila was located at latitude 18.7°N and longitude 117.7°W which put it about 580 miles (935 km) west-southwest of the southern tip of Baja California.  Dalila 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 1006 mb.

Although Tropical Storm Dalila did have a definite low level center of circulation, the center was relatively broad.  In addition, most of the stronger thunderstorms were occurring south of the center of circulation.  Bands in other parts of the tropical storm consisted primarily of showers and lower clouds.  Dalila was moving southwest of a large upper level high pressure system over the western U.S. and Mexico.  Clockwise flow around the high was producing northeasterly winds which were blowing toward the top of Tropical Storm Dalila.  Those winds were causing moderate vertical wind shear and they were a major reason for the asymmetrical distribution of thunderstorms in the southern part of the tropical storm.

Tropical Storm Dalila will move into an environment that will become increasingly unfavorable for intensification.  The upper level high will continue to produce wind shear which will inhibit strengthening.  Dalila is currently over water where the Sea Surface Temperature is near 26°C, but it will move over colder water during the next several days.  Dalila could maintain tropical storm intensity for another 12 to 24 hours, but it is likely to weaken during the next several days.

Tropical Storm Dalila will continue to move around the southwestern part of the upper level high over the western U.S. and Mexico.  The high will steer Dalila toward the northwest during the next 12 to 24 hours.  When the remaining stronger thunderstorms weaken, Tropical Storm Dalila will be steered by winds at lower levels in the atmosphere and those winds should steer it more toward the west.  On its anticipated track Tropical Storm Dalila will weaken while it moves farther over the Eastern North Pacific Ocean.

Tropical Depression Three Forms East of Florida

Tropical Depression Three formed east of Florida on Monday.  More thunderstorms developed near the center of a small low pressure system over the Northwestern Bahamas on Monday afternoon and the National Hurricane Center (NHC) designated the system as Tropical Depression Three.  At 5:00 p.m. EDT on Monday the center of Tropical Depression Three was located at latitude 25.6°N and longitude 78.6°W which put it about 120 miles (195 km) southeast of West Palm Beach, Florida.  The depression was moving toward the northwest at 13 m.p.h. (20 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 1013 mb.

More thunderstorms developed around the center of a small low pressure system that was embedded in the northern end of a tropical wave over the Bahamas on Monday.  Most of the thunderstorms were forming in bands on the eastern side of the circulation.  Based on data from satellites NHC determined that a closed circulation had formed at the surface.  There were fewer thunderstorms in the western half of the circulation.  Storms in the eastern half of the depression were exhibiting upper level divergence to the north and east.

Tropical Depression Three will move through an environment somewhat favorable for intensification during the next 24 hours.  The depression will move over water where the Sea Surface Temperature is near 29°C.  It will be in under the western side of an upper level ridge.  The ridge could enhance upper level divergence on Tuesday.  The wind aloft will be relatively weak, although a thin upper trough near the east coast of the U.S. will produce southwesterly winds which will blow toward the top of the circulation.  Those winds will cause some vertical wind shear but the shear will not be strong enough to prevent intensification.  The surface pressure is relatively high and that could slow any intensification.  A larger upper level trough will develop over the eastern U.S. on Tuesday and the trough will produce stronger southwesterly winds.  Those winds will create much more shear on Wednesday.

Tropical Depression Three will move around the western end of a subtropical high pressure system over the western Atlantic Ocean.  The high will steer the depression toward the northwest during the next 12 hours.  Tropical Depression Three is likely to more more toward the north later on Tuesday when it reaches the western end of the ridge.  On its anticipated track the center of Tropical Depression Three could be near the southeast coast of Florida in about 12 hours.  The center is not currently forecast to make landfall, but the depression could bring squally weather and an increased chance for rain to the southeast coast of the U.S. during the next several days.

Tropical Storm Danas Speeds Toward South Korea

Tropical Storm Danas sped toward South Korea on Friday as it moved quickly north-northeast over the East China Sea.  At 11:00 a.m. EDT on Friday the center of Tropical Storm Danas was located at latitude 32.3°N and longitude 125.1°E which put it about 190 miles (305 km) south-southwest of Mopko, South Korea.  Danas was moving toward the north-northeast at 19 m.p.h. (30 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 987 mb.

The distribution of thunderstorms around Tropical Storm Danas remained asymmetrical on Friday.  The strongest thunderstorms were occurring in bands well to the east of the center of circulation.  Bands closer to the center and on the western side of the circulation consisted primarily of showers and lower clouds.  An upper level trough over eastern China was producing southwesterly winds which were blowing toward the top of the circulation.  Those winds were causing moderate vertical wind shear and they were the reason for the asymmetrical distribution of thunderstorms.  The wind field also exhibited the effects of the wind shear.  Winds to tropical storm force extended out about 200 miles (320 km) from the center of Danas on the eastern side of the circulation, but only extended out about 120 miles (195 km) on the western side of the tropical storm.

Tropical Storm Danas will remain in an environment only marginally favorable for intensification until it makes landfall in South Korea.  Danas will move over water where the Sea Surface Temperature is near 30°C.  The upper level trough over eastern China will continue to cause moderate vertical wind shear.  Tropical Storm Danas could intensify a little during the next 12 hours, but it will weaken after the center moves over South Korea.

Tropical Storm Danas will move around the western end of a subtropical ridge over the western North Pacific Ocean.  The ridge and the upper level trough will interact to steer Danas rapidly toward the north-northeast.  On its anticipated track the center of Tropical Storm Danas will make landfall on the southwestern coast of South Korea in about 12 hours.  Danas will bring gusty winds and locally heavy rain to South Korea on Saturday.  The heaviest rain will fall over the southeastern half of South Korea.  Locally heavy rain in that region could cause flash floods.  The outer rainbands of Tropical Storm Danas could also drop locally heavy rain over western Kyushu.

Tropical Storm Danas Nears Southern Ryukyu Islands

Tropical Storm Danas moved near the southern Ryukyu Islands late on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Tropical Storm Danas was located at latitude 23.9°N and longitude 124.1°E which put it about 30 miles (50 km) south of Ishigaki, Japan.  Danas was moving toward the north at 21 m.p.h. (34 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 990 mb.

The circulation around Tropical Storm Danas exhibited a little more organization on Wednesday.  More thunderstorms formed near the center of circulation and several bands of showers and thunderstorms formed in the eastern half of the circulation.  The bands north and west of the center consisted primarily of showers and lower clouds.  Storms near the center began to generate upper level divergence which pumped mass away to the northeast of the tropical storm.  Winds to tropical storm force extended out about 125 miles (200 km) from the center of circulation.

Tropical Storm Danas will move into an environment somewhat favorable for intensification.  Danas will move over water where the Sea Surface Temperature is near 30°C.  A small upper level low near Taiwan will produce southwesterly winds which blow toward the top of the circulation around Tropical Storm Danas.  Those winds were the reason why the stronger rainbands were in the eastern half of the circulation.  Those winds will cause moderate vertical wind shear, which will inhibit intensification.  However, the shear will have less of an effect since Danas will move in the same direction as the upper level winds.  Tropical Storm Danas is likely to intensify during the next 24 hours and there is a chance it could strengthen into a typhoon.

Tropical Storm Danas will move around the western end of a subtropical ridge over the western North Pacific Ocean.  The ridge will steer Danas toward the north-northeast.  On its anticipated track Tropical Storm Danas will move through the southern Ryukyu Islands during the next few hours.  Danas will bring gusty winds and locally heavy rain when it passes over those islands.  Tropical Storm Danas will move over the East China Sea toward southwestern Japan and South Korea during the next several days.

Tropical Storm Danas Forms East of Luzon

Tropical Storm Danas formed east of Luzon on Tuesday.  A distinct low level center of circulation developed in an area of low pressure east of Luzon and the Japan Meteorological Agency designated the system as Tropical Storm Danas.  At 5:00 p.m. EDT on Tuesday the center of Tropical Storm Danas was located at latitude 17.5°N and longitude 123.1°E which put it about 80 miles (130 km) east of Tuguegarao, Philippines.  Danas was moving toward the west at 4 m.p.h. (6 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 distribution of thunderstorms around Tropical Storm Danas was highly asymmetrical.  There were a few thunderstorms just to the southwest of the center of circulation, but most of the thunderstorms were occurring in a band on the far western edge of the circulation around Danas.  Bands in other parts of the circulation consisted primarily of showers and lower clouds.  Tropical Storm Danas was moving around the southeastern portion of an upper level ridge over east Asia.  The ridge was producing strong easterly winds which were blowing across the top of the circulation around Danas.  The easterly winds were causing strong vertical wind shear and the wind shear was causing the asymmetric distribution of thunderstorms.  The circulation around Tropical Storm Danas was large.  Winds to tropical storm force extended out about 200 miles (320 km) from the center of circulation.

Tropical Storm Danas will move into an environment that is only marginally favorable for intensification.  Danas will move over water where the Sea Surface Temperature is near 31°C.  So, there is plenty of energy in the upper ocean.  The strong upper level easterly winds are expected to weaken somewhat during the next several days.  If those winds weaken, then there will be less vertical wind shear and Tropical Storm Danas could strengthen.  If the upper level winds remain strong, then Danas will not strengthen and it could weaken to a tropical depression.  The forecast is for very slow intensification during the next 24 to 48 hours.

Since there are not a lot of taller thunderstorms near the center of Tropical Storm Danas, it will be steered by the winds in the lower troposphere.  Danas will move around the western end of a subtropical ridge over the Western North Pacific Ocean.  The ridge will turn Danas toward the north on Wednesday.  On its anticipated track the center of Tropical Storm Danas will remain east of Luzon.  The center of Danas could be near southeastern Taiwan in 24 to 36 hours.  Tropical Storm Danas could be near the east coast of China in about three days.  The primary risks will be locally heavy rain and flash floods.

Tropical Storm Barry Drops Heavy Rain Over Lower Mississippi River Valley

Tropical Storm Barry dropped heavy rain over parts of the Lower Mississippi River Valley on Sunday.  The wind speed gradually decreased as Barry moved farther inland on Sunday and it was classified as a tropical depression on Sunday evening.  At 11:00 p.m. EDT on Sunday the center of Tropical Depression Barry was located at latitude 33.5°N and longitude 93.5°W which put it about 70 miles (110 km) north of Shreveport, Louisiana.  Barry was moving toward the north at 12 m.p.h. (19 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 1008 mb.

Several rainbands in the southern and eastern portions of the circulation around former Tropical Storm Barry dropped persistent heavy rainfall on Sunday.  One rainband developed in an arc that ran from near Beaumont/Port Arthur, Texas to near Alexandria, Louisiana.  A weather station in Beaumont/Port Arthur measured 4.21 inches (10.69 cm) of rain.  A second rainband stretched from south of Abbeville, Louisiana to west of Baton Rouge.  A weather station in Abbeville measured 4.29 inches (10.90 cm) of rain and a station in Lafayette recorded 3.68 inches (9.34 cm).  A third rainband dropped heavy rain over parts of Mississippi.  A weather station in Hattiesburg, Mississippi measured 4.06 inches (10.31 cm) of rain.  A fourth rainband dropped heavy rain over parts of western Alabama.

The center of Tropical Depression Barry is forecast to move north-northeast across Arkansas on Monday.  Bands of showers and thunderstorms in the eastern side of the circulation around Barry are likely to drop heavy rain over parts of Mississippi, eastern Arkansas, eastern Louisiana, western Alabama and western Tennessee on Monday.  Flash flooding could occur in some locations.

Tropical Storm Barry Brings Wind and Water to Central Gulf Coast

Tropical Storm Barry brought wind and water to the central Gulf Coast on Saturday.  At 11:00 p.m. EDT on Saturday the center of Tropical Storm Barry was located at latitude 31.0°N and longitude 93.0°W which put it about 35 miles (55 km) southwest of Alexandria, Louisiana.  Barry was moving toward the north-northwest at 8 m.p.h. (13 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 1002 mb.

Tropical Storm Warnings were still in effect for the portion of the coast from Grand Isle to Cameron, Louisiana, and for New Orleans, Lake Pontchartrain and Lake Maurepas.  Several weather stations on the coast of Louisiana were still reporting sustained winds to tropical storm force on Saturday night.

Tropical Storm Barry strengthened into a hurricane prior to making landfall near Intracoastal City, Louisiana on Saturday afternoon.  Then an upper level ridge centered over Texas strengthened after Barry became a hurricane.  The ridge produced north-northeasterly winds at 25 m.p.h. (40 km/h) which blew over the top of former Hurricane Barry.  Those winds created strong vertical wind shear and they blew the top of the circulation south of the lower part of the circulation.  By Saturday night the lower level circulation was over southwestern Louisiana and the top of the circulation was over the northwestern Gulf of Mexico.  Since the lower part of the circulation did not extend as high in the atmosphere, rain near the center of Tropical Storm Barry was relatively light.  Heavier rain fell in bands on the eastern side of Barry.  Heavy rain caused localized flooding in the area around Mobile, Alabama and along the coast of Mississippi.

Tropical Storm Barry did cause minor wind damage over portions of southern Louisiana.  There were reports of downed trees and widespread power outages.  The wind pushed water toward the coast in the eastern half of the circulation and Barry generated a storm surge of 6 feet (2 meters) in several locations.  There was also a rise in the water level along the northern shore of Lake Pontchartrain.

Tropical Storm Barry is forecast to move northward over western Louisiana on Sunday.  The water level along the coast should gradually decrease while Barry moves farther inland and weakens.  Rainfall could increase in bands in the eastern side of the circulation on Sunday where the wind will transport moist air from the Gulf of Mexico over Louisiana and Mississippi.  Flash Flood Watches continue for parts of Louisiana, Arkansas, Mississippi and Alabama.

Barry Strengthens Into a Hurricane Near the Louisiana Coast

Former Tropical Storm Barry strengthened into a hurricane on Saturday morning.  The National Hurricane Center designated Barry as a hurricane on Saturday morning based on data from surface weather stations and from reconnaissance aircraft.  At 11:00 a.m. EDT on Saturday the center of Hurricane Barry was located at latitude 29.6°N and longitude 92.0°W which put it about 40 miles (65 km) south of Lafayette, Louisiana.  Barry was moving toward the northwest at 6 m.p.h. (10 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 993 mb.

A Hurricane Warning is in effect for the portion of the coast from Intracoastal City to Grand Isle, Louisiana. A Hurricane Watch has been issued for the portion of the coast 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 Sabine Pass, Louisiana. A Tropical Storm Warning is in effect for Lake Pontchartrain, Lake Maurepas and New Orleans.

Former Tropical Storm Barry strengthened on Saturday morning.  Many more thunderstorms developed just south and east of the center of circulation.  The pressure gradient tightened near the center of Hurricane Barry and the wind speeds increased to hurricane force.  The hurricane force winds were occurring in the eastern side of the circulation.  Winds to hurricane force extended out about 45 miles (75 km) from the center on the eastern side of Hurricane Barry.  The winds were weaker on the western side of Barry.  Winds to tropical storm force extended out about 170 miles (280 km) from the center.

Hurricane Barry is unlikely to strengthen significantly before the center moves over the coast of Louisiana.  Almost half of the circulation is over land.  The wind speeds will decrease gradually after the center moves over land.

Hurricane Barry will move around the western end of a ridge of high pressure.  The ridge will steer Barry slowly toward the northwest during the next few hours.  Barry will move more toward the north on Sunday.  On its anticipated track the center of Hurricane Barry will make landfall southwest of Lafayette, Louisiana near Abbeville.  The center of Barry will move northward over western Louisiana on Sunday.

Hurricane Barry will cause mainly minor wind damage over the eastern half of Louisiana.  There also could be widespread power outages.  On the eastern side of Hurricane Barry southerly winds were pushing water toward the coast.  A storm surge of 6 to 9 feet (2 to 3 meters) could occur just to the east of where the center makes landfall.  Southeasterly winds were causing flooding around the western side of Lake Pontchartrain.  Several bands in the eastern side of Hurricane Barry were dropping heavy rain.  Persistent heavy rain is likely to cause flooding in some locations.  Flash Flood Watches were in effect for parts of Louisiana, Arkansas, Mississippi and Alabama.

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.