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Tropical Storm Bertha Brings Wind and Rain to the Carolinas

Tropical Storm Bertha brought wind and rain to the Carolinas on Wednesday.  Bertha weakened to a tropical depression after it moved inland on Wednesday afternoon.  At 11:00 p.m. EDT on Wednesday the center of Tropical Depression Bertha was located at latitude 36.0°N and longitude 80.5°W which put it about 40 miles (65 km) west of Greensboro, North Carolina.  Bertha was moving toward the north at 23 m.p.h. (37 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 1009 mb.

Flash Flood Watches were in effect for northeast South Carolina, southern and west central North Carolina, southwest Virginia and southwest West Virginia.

Tropical Storm Bertha developed rapidly on Wednesday morning and it was still strengthening when it made landfall on the coast of South Carolina.  The center of Bertha officially made landfall east of Charleston near Mount Pleasant around midday on Wednesday.  NOAA buoy 41004 which is located southeast of Charleston measured a sustained wind speed of 40 m.p.h (65 km/h) and a gust of 58 m.p.h. (94 km/h).  NOAA buoy 41029 (Capers Nearshore) measured a surface pressure of 1005.8 mb when the center of Bertha passed near it.

A weather station at Shaw Air Force Base measured 2.00 inches (51 mm)  of rain.  A weather station in downtown Charleston, South Carolina measured 1.61 inches (41 mm).  Charlotte, North Carolina received 1.64 inches (42 mm), Greensboro received 1.09 inches (28 mm) and Winston Salem received 1.04 inches (26 mm).

Tropical Depression Bertha will move around the western end of a surface high pressure system over the Atlantic Ocean.  The high will steer Bertha toward the north on Thursday.  On its anticipated track Tropical Depression Bertha will move across western Virginia, West Virginia, eastern Ohio and western Pennsylvania.  Bertha will drop rain over those areas on Thursday.  Locally heavy rain could cause flooding in some locations.

Storm Storm Bertha Forms Near South Carolina

Tropical Storm Bertha formed quickly near the coast of South Carolina on Wednesday morning.  At 8:00 a.m. EDT on Wednesday the center of Tropical Storm Bertha was located at latitude 32.7°N and longitude 79.4°W which put it about 30 miles (50 km) east-southeast of Charleston, South Carolina.  Bertha was moving toward the northwest at 9 m.p.h. (15 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 1009 mb.

The National Hurricane Center issued a Tropical Storm Warning for the portion of the coast from Edisto Beach to South Santee River, South Carolina.

The circulation around a low pressure system off the southeast coast of the U.S. organized quickly on Wednesday morning.  A distinct center of circulation was evident on radar.  Radar and satellite images also showed bands of showers and thunderstorms revolving around the center of circulation.  NOAA buoy 41004 southeast of Charleston, South Carolina measured a sustained wind speed of 40 m.p.h. (65 km/h) and a gust to 58 m.p.h. (94 km/h).  Based on all of that information the National Hurricane Center designated the system as Tropical Storm Bertha.

Tropical Storm Bertha will move around the western end of a high pressure system over the Atlantic Ocean.  The high will steer Bertha toward the north during the next 24 hours.  On its anticipated track Tropical Storm Bertha will make landfall on the coast of South Carolina east of Charleston later on Wednesday.  Bertha will move over water where the Sea Surface Temperature is near 24°C.  It will move under the western side of an upper level ridge over the western Atlantic Ocean.  The ridge will produce southerly winds which will blow toward the top of the circulation.  Those winds will cause moderate vertical wind shear.  Based on recent trends Tropical Storm Bertha could strengthen before it makes landfall.  Bertha will drop heavy rain over eastern South Carolina and eastern North Carolina.  The heavy rain could cause floods in some locations.  Waves will cause erosion along the coast of South Carolina and North Carolina.

Tropical Cyclone Mangga Brings Wind and Rain to Cocos Island

Tropical Cyclone Mangga brought wind and rain to Cocos Island on Friday.  At 11:00 p.m. EDT on Friday the center of Tropical Cyclone Mangga was located at latitude 16.3°S and longitude 97.6°E which put it about 270 miles (435 km) south of Cocos Island.  Mangga was moving toward the southeast at 21 m.p.h. (34 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 996 mb.

The center of Tropical Cyclone Mangga passed southwest of Cocos Island on Friday.  The circulation around Mangga was fairly large.  Winds to tropical storm force extended out 150 miles (240 km) to the northeast of the center of circulation.  A weather station on Cocos Island reported a sustained wind speed of 27 m.p.h. (43 km/h) and a wind gust of 38 m.p.h. (61 km/h).  The station measured 1.25 inches (32 mm) of rain during the passage of Tropical Cyclone Mangga.

The circulation around Tropical Cyclone Mangga did not appear to be well organized.  There were not a lot of thunderstorms near the center or circulation.  Bands near the center consisted primarily of showers and lower clouds.  Thunderstorms were occurring to the southeast of the low level center of circulation.  The thunderstorms appeared to be associated with a circulation in the middle and upper troposphere.  Those thunderstorms were generating upper level divergence which was pumping mass away to the southeast of Tropical Cyclone Mangga.

Tropical Cyclone Mangga will move through an environment only marginally favorable for intensification.  Mangga will move over water where the Sea Surface Temperature is near 27°C.  However, an upper level ridge northwest of Australia and an upper level trough west of Australia will produce northwesterly winds which will blow toward the top of the circulation.  Those winds will cause strong vertical wind shear.  The shear is likely to be strong enough to prevent intensification of the current low level center of Tropical Cyclone Mangga.  It is possible that the circulation in the middle and upper troposphere could cause a new low level center to form.  If a new center forms where the thunderstorms and upper level divergence are occurring, then some intensification might be possible.

Tropical Cyclone Mangga will move around the southwestern part of a high pressure system centered over Australia.  The high will steer Mangga quickly toward the southeast.  On its anticipated track the center of Tropical Cyclone Mangga could reach the coast of Western Australia in less than 36 hours.  Mangga could produce winds to tropical storm force along the coast of Western Australia.

Tropical Cyclone Mangga Develops Northwest of Cocos Islands

Tropical Cyclone Mangga developed over the South Indian Ocean northwest of the Cocos Islands on Thursday.  At 11:00 a.m. EDT on Thursday the center of Tropical Cyclone Mangaa was located at latitude 9.4°S and longitude 93.1°E which put it about 320 miles (515 km) northwest of Cocos Island.  Mangga was moving toward the south-southeast at 7 m.p.h. (12 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 996 mb.

The Australian Bureau of Meteorology issued a Warning for the Cocos Islands.

Tropical Cyclone Mangga developed within a trough of low pressure that extended from southwest of Indonesia to western Australia.  The trough had persisted for several days and a center of low pressure gradually formed northwest of the Cocos Islands during the past 24 hours.  The Australian Bureau of Meteorology designated the system as Tropical Cyclone Mangga on Thursday.

The circulation around Tropical Cyclone Mangga was still in the process of organizing.  The strongest thunderstorms were in a band on the western side of the circulation.  Bands on the eastern side of the circulation consisted primarily of showers and lower clouds.  More thunderstorms began to develop near the center of circulation on Thursday.  Storms developing near the center started to generate upper level divergence which was pumping mass away to the west of the tropical cyclone.  Winds to tropical storm force extended out 150 miles (240 km) from the center of Mangga.

Tropical Cyclone Mangga will move through an environment somewhat favorable for intensification during the next 24 to 36 hours.  Mannga will move over water where the Sea Surface temperature is near 27°C.  It will move under the northwestern part of an upper level ridge centered over Indonesia.  The ridge will produce easterly winds which will blow toward the top of the circulation.  Those winds will produce moderate vertical wind shear.  The wind shear may be the reason why the bands on the eastern side of Tropical Cyclone Mangga are weaker.  The shear will also inhibit intensification, but it will probably not be strong enough to prevent Manga from strengthening during the next 24 hours.

Tropical Cyclone Mangga will move around the western end of a high pressure system centered north of Australia.  The high will steer Mangga toward the southeast during the next few days.  On its anticipated track Tropical Cyclone Mangga will pass near the Cocos Islands in about 24 hours.  Manga will bring gusty winds and locally heavy rain to those islands.

Tropical Cyclone Amphan Makes Landfall Near Kolkata

The center of Tropical Cyclone Amphan made landfall on the north coast of the Bay of Bengal near Kolkata, India on Wednesday.  At 11:00 a.m. EDT on Wednesday the center of Tropical Cyclone Amphan was located at latitude 22.7°N and longitude 88.4°E which put it about 30 miles (50 km) south-southwest of Kolkata, India.  Amphan was moving toward the north-northeast at 19 m.p.h. (30 km/h).  The maximum sustained wind speed was 85 m.p.h. (135 km/h) and there were wind gusts to 105 m.p.h. (165 km/h).  The minimum surface pressure was 979 mb.

The center of Tropical Cyclone Amphan made landfall near Haldia, India which is a little to the south-southwest of Kolkata on Wednesday.  The maximum sustained wind speed in Amphan at the time of landfall was 100 m.p.h. (160 km/h).  Tropical Cyclone Amphan weakened after the center moved over land.  Winds to hurricane/typhoon force extended out 20 miles (30 km) from the center of circulation.  Winds to tropical storm force extended out 160 miles (260 km) to the southeast of the center.  The stronger winds were occurring near the center of circulation and over the northern Bay of Bengal.

When Tropical Cyclone Amphan approached the coast, the heaviest rain occurred in bands in the western side of Amphan.  Heavy rain fell over parts of northern Odisha and West Bengal.  After the center of Amphan made landfall and the tropical cyclone moved inland, the heaviest rain fell in bands in the northeastern part of the circulation.  Heavy rain was falling over parts of Bangladesh.

Strong southerly winds blowing toward the north coast of the Bay of Bengal pushed water toward Bangladesh and the coast of India south of Kolkata.  The coast around the northern Bay of Bengal is very vulnerable to storm surges caused by tropical cyclones.  Tropical Cyclone Amphan likely caused a significant storm surge along that coast.

Tropical Cyclone Amphan will move around the northwestern part of a high pressure system over Southeast Asia.  The high will steer Amphan toward the north-northeast.  On its anticipated track the center of Tropical Cyclone Amphan will move across western Bangladesh and northeastern India.  The circulation around Amphan will continue to weaken as the system moves farther inland.  Tropical Cyclone Amphan will continue to drop locally heavy rain over Bangladesh and northeastern India.  Heavy rain could cause flash floods to occur in some locations.

Large Dangerous Tropical Cyclone Amphan Nears Kolkata and Bangladesh

Large dangerous Tropical Cyclone Amphan neared Kolkata, India and Bangladesh late on Tuesday.  At 5:00 p.m. EDT on Tuesday the center of Tropical Cyclone Amphan was located at latitude 18.8°N and longitude 87.0°E which put it about 310 miles (505 km) south-southwest of Kolkata, India.  Amphan was moving toward the north at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 145 m.p.h. (230 km/h).  The minimum surface pressure was 951 mb.

Tropical Cyclone Amphan was the equivalent of a major hurricane as it neared Kolkata, India and the coast of Bangladesh on Tuesday.  An eyewall replacement cycle caused the circulation around Amphan to expand in size.  Some satellite images showed evidence of the remnants of the original small inner eye inside the larger second eye.  The larger eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Amphan.

Tropical Cyclone Aphan had a large circulation that covered much of the northern Bay of Bengal.  Winds to hurricane/typhoon force extended out 50 miles (80 km) from the center of circulation.  Winds to tropical storm force extended out 230 miles (370 km) from the center.  The Hurricane Intensity Index (HII) for Tropical Cyclone Amphan was 20.6.  The Hurricane Size Index (HSI) was 20.8 and the Hurricane Wind Intensity Size Index (HWISI) was 41.4.  Amphan was capable of causing major damage.

Tropical Cyclone Amphan will move through an environment capable of supporting a large powerful tropical cyclone during the next 12 to 18 hours.  Amphan will move over water where the Sea Surface Temperature is near 30°C.  It will move under the western side of an upper level ridge.  The upper level winds will be weak and there will be little vertical wind shear.  The circulation around Tropical Cyclone Amphan could start to pull in some drier air that is over eastern India when it get closer to the coast.  Amphan will remain a large dangerous tropical cyclone until it makes landfall on the north coast of the Bay of Bengal.

Tropical Cyclone Amphan will move around the western end of a high pressure system over Southeast Asia.  The high will steer Amphan toward the north-northeast during the next 36 hours.  On its anticipated track the center of Tropical Cyclone Amphan will pass near Puri, India in about 12 hours.  The center of Amphan could make landfall south of Kolkata near Haldia, India in about 18 hours.  Tropical Cyclone Amphan could cause major damage.  The wind will blow water toward the coast around the northern Bay of Bengal.  Amphan could generate a storms surge of up to 12 to 15 feet (3 to 4 meters) along past of the Bangladesh coast.  Tropical Cyclone Amphan will also drop heavy rain over parts of northeastern India and Bangladesh when it moves inland.  The heavy rain is likely to cause floods in some locations.

 

Tropical Cyclone Amphan Intensifies Into Equivalent of Cat. 5 Hurricane

Tropical Cyclone Amphan intensified into equivalent of a Category 5 hurricane on the Saffir-Simpson Scale over the Bay of Bengal on Monday.  At 5:00 a.m. EDT on Monday the center of Tropical Cyclone Amphan was located at latitude 13.9°N and longitude 86.5°E which put it about 635 miles (1025 km) south-southwest of Kolkata, India.  Amphan was moving toward the north at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 160 m.p.h. (260 km/h) and there were wind gusts to 195 m.p.h. (315 km/h).  The minimum surface pressure was 909 mb.

The circulation around Tropical Cyclone Amphan appeared to develop a concentric eyewall structure on Monday.  The inner end of a rainband wrapped around the original small eye and eyewall.  The inner eye had a diameter of 10 miles (16 km).  A ring of strong thunderstorms surrounded the inner eye and the strongest winds were occurring in that ring of storms.  An outer eyewall with a diameter of 50 mile (80 km) surrounded the inner eye.    Bands of showers and thunderstorms were revolving around the concentric eyewalls.  Storms in the core of Amphan were generating strong upper level divergence which was pumping mass away from the tropical cyclone in all directions.

Tropical Cyclone Amphan had a large circulation.  Winds to hurricane/typhoon force extended out 60 miles (95 km) from the center of circulation.  Winds to tropical storm force extended out 200 miles (325 km) from the center.  The Hurricane Intensity Index (HII) for Tropical Cyclone Amphan was 35.0.  The Hurricane Size Index (HSI) was 16.5 and the Hurricane Wind Intensity Size Index (HWISI0 was 51.5.  Tropical Cyclone Amphan was capable of causing catastrophic damage.

Tropical Cyclone Amphan will move through an environment very favorable for a strong tropical cyclone during the next 36 hours.  Amphan will move over water where the Sea Surface Temperature is near 31°C.  It will move under an upper level ridge where the upper level winds are weak.  There will be little vertical wind shear.  The eyewall replacement cycle will stop the intensification of Tropical Cyclone Amphan.  Amphan will weaken, at least temporarily, when the inner eyewall dissipates.  When that occurs the strongest winds will be occurring in the outer eyewall.  The eyewall replacement cycle could cause the circulation to increase in size.

Tropical Cyclone Amphan will move around the western end of a high pressure system over Southeast Asia.  The high will steer Amphan toward the north-northeast.  On its anticipate track the center of Tropical Cyclone Amphan will approach the coast around the northern Bay of Bengal in 36 hours.  Amphan will be a large dangerous tropical cyclone when it approaches the coast.  Tropical Cyclone Amphan will generate a significant storm surge along the coast of Bangladesh.  Amphan will cause major wind damage.  It will drop locally heavy rain over northeast India and Bangladesh.  Freshwater flooding will occur.

Tropical Storm Arthur Brings Wind and Rain to Eastern North Carolina

Tropical Storm Arthur brought wind and rain to eastern North Carolina on Monday.  At 8:00 a.m. EDT on Monday the center of Tropical Storm Arthur was located at latitude 34.5°N and longitude 75.9°W which put it about 50 miles (80 km) south-southwest of Cape Hatteras, North Carolina.  Arthur was moving toward the north-northeast at 15 m.p.h. (24 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 1001 mb.

A Tropical Storm Warning was in effect for the portion of the coast from Surf City to Duck, North Carolina including Pamlico and Albemarle Sounds.

Tropical Storm Arthur began to move more quickly toward the Outer Banks of North Carolina on Monday morning.  The distribution of thunderstorms and winds around Arthur was asymmetric.  The strong thunderstorms were occurring in bands in the eastern half of the circulation.  The strongest winds were occurring in those bands.  Bands in the western half of Tropical Storm Arthur consisted primarily of showers and lower clouds.  Winds to tropical storm force extended out 90 miles (145 km) in the eastern half of Arthur.  The winds in the western half of Arthur were mostly less than tropical storm force.

The asymmetric structure of Tropical Storm Arthur meant that the strongest winds were occurring east of the Outer Banks of North Carolina.  A buoy at Diamond Shoals was reporting a sustained wind speed of 33 m.p.h. (54 km/h) and wind gusts to 47 m.p.h. (76 km/h).  The wind speeds along the coast of North Carolina were much weaker.  Tropical Storm Arthur was dropping moderate rain over eastern North Carolina.   Wind blowing water toward the coast was causing the water level to rise in some locations.  Waves were causing erosion on some beaches.

A large upper level trough will approach Tropical Storm Arthur from the west.  The trough will turn Arthur more toward the east later on Monday.  On its anticipated track, Tropical Storm Arthur should move away from North Carolina on Monday afternoon.  Weather conditions should improve gradually when Arthur moves farther form the coast.

Tropical Cyclone Amphan Rapidly Intensifies Into Equivalent of Major Hurricane

Tropical Cyclone Amphan rapidly intensified into the equivalent of a major hurricane over the Bay of Bengal on Sunday night.  At 11:00 p.m. EDT on Sunday the center of Tropical Cyclone Amphan was located at latitude 13.3°N and longitude 86.4°E which put it about 675 miles (1090 km) south-southwest of Kolkata, India.  Amphan was moving toward the north at 5 m.p.h. (8 km/h).  The maximum sustained wind speed was 150 m.p.h. (240 km/h) and there were wind gusts to 185 m.p.h. (295 km/h).  The minimum surface pressure was 919 mb.

Tropical Cyclone Amphan rapidly intensified into a large powerful tropical cyclone on Sunday night.  A small circular eye was 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.  Bands of showers and thunderstorms were revolving around the core of Amphan.  Storms near the core were generating strong upper level divergence which was pumping mass away from the tropical cyclone in all directions.

The circulation around Tropical Cyclone Amphan grew in size on Sunday.  Winds to hurricane/typhoon force extended out 40 miles (65 km) from the center of circulation.  Winds to tropical storm force extended out 210 miles (335 km) from the center.  The Hurricane Intensity Index (HII) for Tropical Cyclone Amphan was 31.6.  The Hurricane Size Index was 16.8 and the Hurricane Wind Intensity Size Index (HWISI) was 48.4.  Tropical Cyclone Amphan was capable of causing widespread significant damage.

Tropical Cyclone Amphan will remain in an environment capable of supporting a strong tropical cyclone during the next 36 to 48 hours.  Amphan will move over water where the Sea Surface Temperature is near 31°C.  It will move under an upper level ridge.  The upper level wind will be weak and there will be little vertical wind shear.  The ridge will actually enhance the upper level divergence.  If a rainband wraps around the existing eye and eyewall, then an eyewall replacement cycle could cause Tropical Cyclone Amphan to weaken.  Tropical Cyclone Amphan is likely to remain a large, powerful tropical cyclone during the next 48 hours.

Tropical Cyclone Amphan will move around the western end of a high pressure system over Southeast Asia.  The high will steer Amphan toward the north.  On its anticipated track Tropical Cyclone Amphan could approach the coast of Bangladesh in 48 hours.  Amphan is could still be the equivalent of a major hurricane when it reaches Bangladesh.  Tropical Cyclone Amphan could generate a significant storm surge at the coast.  Amphan will cause major wind damage and heavy rain could cause freshwater flooding.

Tropical Cyclone Amphan Strengthens to Equivalent of Hurricane/Typhoon

Tropical Cyclone Amphan strengthened to the equivalent of a hurricane/typhoon on Sunday.  At 11:00 a.m. EDT on Sunday the center of Tropical Cyclone Amphan was located at latitude 12.3°N and longitude 86.4°E which put it about 695 miles (1120 km) south-southwest of Kolkata, India.  Amphan was moving toward the north at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 85 m.p.h (135 km/h) and there were wind gusts to 105 m.p.h. (165 km/h).  The minimum surface pressure was 969 mb.

Tropical Cyclone Amphan continued to intensify on Sunday.  A small circular eye with a diameter of 10 miles (16 km) developed at the center of circulation.  A ring of strong thunderstorms surround the eye and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Amphan.  Storms near the core were generating strong upper level divergence which was pumping mass away from the tropical cyclone in all directions.  Wins to hurricane/typhoon force extended out 30 miles (50 km) from the center of circulation.  Winds to tropical storm force extended out 140 miles (225 km) from the center.

Tropical Cyclone Amphan will move through an environment favorable for intensification during the next 36 to 48 hours.  Amphan will move over water where Sea Surface Temperature is near 31°C.  It will move under an upper level ridge over the Bay of Bengal.  The winds in the upper level ridge are weak and there will be little vertical wind shear.  Tropical Cyclone Amphan will continue to intensify and it is likely to strengthen into the equivalent of a major hurricane.

Tropical Cyclone Amphan will move around the western end of a high pressure system over Southeast Asia.  The high will steer Amphan toward the north during the next 48 hours.  On its anticipated track Tropical Cyclone Amphan will approach the coast around the northern Bay of Bengal in less than 72 hours.  Amphan will bring strong winds and locally heavy rain to northeast India and to Bangladesh.  Tropical Cyclone Amphan is likely to generate a significant storm surge along the northern coast of the Bay of Bengal.