Monthly Archives: September 2020

Marie Rapidly Strengthens Into a Hurricane

Former Tropical Storm Marie rapidly strengthened into a hurricane on Wednesday.  At 5:00 p.m. EDT on Wednesday the center of Hurricane Marie was located at latitude 14.3°N and longitude 115.1°W which put it about 685 miles (1100 km) south-southwest of the southern tip of Baja California.  Marie was moving toward the west at 16 m.p.h. (26 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 988 mb.

The circulation around Hurricane Marie exhibited much greater organization on Wednesday afternoon.  The inner end of a rainband wrapped entirely around the center of Marie.  Other bands of showers and thunderstorms were revolving around the core of Hurricane Marie.  Storms near the core generated upper level divergence which pumped mass away to the west of the hurricane.  The circulation around Marie was small.  Winds to hurricane force only extended out 15 miles (25 km) from the center of circulation.  Winds to tropical storm force only extended out 60 miles from the center.

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

Hurricane Marie will move south of a ridge of high pressure over the southwestern U.S.  The high will steer Marie toward the west-northwest during the next few days.  On its anticipated track Hurricane Marie will move farther away Baja California.

Tropical Storm Marie Forms South of Baja California

Tropical Storm Marie formed south of Baja California on Tuesday.  At 5:00 p.m. EDT on Tuesday the center of Tropical Storm Marie was located at latitude 13.6°N and longitude 109.5°W which put it about 645 miles (1035 km) south of the southern tip of Baja California.  Marie 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 1005 mb.

More thunderstorms developed near the center of a small low pressure system south of Baja California on Tuesday afternoon and the National Hurricane Center designated the system as Tropical Storm Marie.  The circulation around Marie was still organizing.  More thunderstorms were forming around the center of Tropical Storm Marie.  Bands of showers and thunderstorms were also developing and the bands were revolving around the center of the tropical storm.  Storms near the center of Marie started to generate upper level divergence which began to pump mass away to the west of the tropical storm.  The circulation around the Tropical Storm Marie was small.  Winds to tropical storm force extended out 25 miles (40 km) from the center of circulation.

Tropical Storm Marie will move through an environment favorable for intensification during the next two to three days.  Marie 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.  Tropical Storm Marie could intensify into a hurricane within 36 hours.  Marie could strengthen more rapidly once an inner core with an eye and an eyewall forms.  Tropical Storm Marie could intensify into a major hurricane later this week.

Tropical Storm Marie will move south of a ridge of high pressure over the southwestern U.S.  The high will steer Marie toward the west-northwest during the next several days.  On its anticipated track Tropical Storm Marie will move farther away from Baja California.

Tropical Storm Kujira Forms West of Wake Island

Tropical Storm Kujira formed west of Wake Island on Saturday.  At 11:00 p.m. EDT on Saturday the center of Tropical Storm Kujira was located at latitude 21.1°N and longitude 158.5°E which put it about 515 miles (830 km) west of Wake Island.  Kujira was moving toward the northwest at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The maximum sustained wind speed was 1002 mb.

Tropical Storm Kujira was moving around the eastern side of an upper level low.  The upper low was causing vertical wind shear which was causing the distribution of thunderstorms to be asymmetrical.  There were few thunderstorms near the center of the circulation.  Many of the thunderstorms were occurring in bands east and south of the center of Kujira.  Bands in the western half of the circulation consisted primarily of showers and lower clouds. Winds to tropical storm force extended out 200 miles (320 km) in the southeastern quadrant of Tropical Storm Kujjira.  The winds in the other parts of the circulation were blowing at less than tropical storm force.

Tropical Storm Kujira will move through an environment favorable for intensification after it moves away from the upper level low.  When Kujira moves away from the upper low, the vertical wind shear will decrease.  Tropical Storm Kujira will move over water where the Sea Surface Temperature is near 28°C.  Kujira will intensify when the wind shear decreases.   It could strengthen into a typhoon in two or three days.

The upper level low will pull Tropical Storm Kujira toward the northwest during the next 12 to 24 hours.  Then Kujira will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean.  The high will steer Tropical Storm Kujira toward the north for 24 to 36 hours.  Kujira will eventually be steered toward the northeast when it reaches the westerly winds in the middle latitudes.  On its anticipated track Tropical Storm Kujira will pass well to the east of Japan.

Teddy Brings Wind and Rain to Nova Scotia

Former Hurricane Teddy brought wind and rain to Nova Scotia on Wednesday.  At 11:00 a.m. EDT on Wednesday the center of Tropical Storm Teddy was located at latitude 46.0°N and longitude 61.3°W which put it about 150 miles (240 km) southwest of Port aux Basques, Newfoundland.  Teddy was moving toward the north-northeast at 26 m.p.h. (43 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 967 mb.

A Tropical Storm Warning was in effect for the portion of the south coast of Nova Scotia from Ecum Secum to Meat Cove.  A Tropical Storm Warning was also in effect for the portion of the coast from Port aux Basques to Francois, Newfoundland.  Tropical Storm Watches were in effect for the portion of the coast from Meat Cove to Brule, Nova Scotia, for the Magdalen Islands and for Prince Edward Island.

The center of former Hurricane Teddy made landfall near Ecum Secum, Nova Scotia on Wednesday morning.  The structure of Teddy made a transition from one typical of a tropical cyclone to one more like an extratropical cyclone as it approached the coast of Nova Scotia.  The area of stronger winds expanded.  Winds to tropical storm force extended out 200 miles (320 km) from the center of Teddy.  The heaviest rain fell over eastern Nova Scotia.  The large circulation around Teddy was producing large waves which caused water level rises and beach erosion as far away as the East Coast of the U.S.

An upper level trough over eastern North America will steer Teddy quickly toward northeast during the rest of today.  On its anticipated track Tropical Storm Teddy will bring gusty winds and heavy rain to parts of southwestern Newfoundland during the next few hours.

Elswhere, former Tropical Storm Beta was dropping heavy rain over parts of Louisiana.  At 11:00 a.m. EDT on Wednesday the center of Tropical Depression Beta was located at latitude 30.2°N and longitude 94.2°W which put it about 60 miles (95 km) west of lake Charles, Louisiana.  Beta was moving toward the east-northeast at 9 m.p.h. (15 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 1007 mb.

Tropical Depression Beta dropped heavy rain over southeastern Texas on Tuesday.  There were numerous reports of flooding around Houston.  Beta was moving over western Louisiana on Wednesday morning and light to moderate rain was falling over many parts of the state.  Flash Flood Watches were in effect for much of Louisiana and western Mississippi.  Beta will move slowly toward the northeast during the next 48 hours.  Moderate to heavy rain could spread over Mississippi, Tennessee, northern Alabama, western North Carolina and western Virginia.

Tropical Storm Dolphin Passes Southeast of Japan

Tropical Storm Dolphin passed southeast of Japan on Wednesday.  At 11:00 a.m. EDT on Wednesday the center of Tropical Storm Dolphin was located at latitude 32.9°N and longitude 141.4°E which put it about 200 miles (320 km) south-southeast of Tokyo, Japan.  Dolphin was moving toward the northeast at 19 m.p.h. (31 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 986 mb.

An upper level trough over eastern Asia steered Tropical Storm Dolphin quickly toward the northeast on Wednesday.  The trough carried Dolphin southeast of Tokyo.  Winds to tropical storm force extended out 175 miles from the center of Dolphin.  The northern periphery of tropical storm Dolphin was bringing gustier winds to parts of the coast of Honshu.  Most of the rain falling in Tropical Storm Dolphin fell southeast of Honshu.

The upper level trough will carry Tropical Storm Dolphin east of Japan.  Although Dolphin is currently over water where the Sea Surface Temperature is near 28°C, the tropical storm will soon move over cooler water.  The upper level trough and the cooler water will cause Tropical Storm Dolphin to make a transition to an extratropical cyclone during the next several days.

Hurricane Teddy Heads for Nova Scotia, Beta Reaches Texas

Hurricane Teddy headed for Nova Scotia on Monday night as Tropical Storm Beta reached the coast of Texas.  At 11:00 p.m. EDT on Monday the center of Hurricane Teddy was located at latitude 35.6°N and longitude 61.5°W which put it about 630 miles (1015 km) south of Halifax, Nova Scotia.  Teddy was moving toward the north at 25 m.p.h. (41 km/h).  The maximum sustained wind speed was 100 m.p.h. (160 km/h) and there were wind gusts to 120 m.p.h. (195 km/h).  The minimum surface pressure was 956 mb.

A Tropical Storm Warning was in effect for the south coast of Nova Scotia from Digby to Meat Cove.  Tropical Storm Watches were in effect for the portions of the coast from Meat Cove to Tidnish and from Digby to Fort Lawrence.  Tropical Storm Watches were also in effect for Prince Edward Island, the Magdalen Islands and from Port aux Basques to Francois, Newfoundland.

The circulation around Hurricane Teddy expanded as it began a transition to an extratropical cyclone.  Winds to hurricane force extended out 100 miles (160 km) from the center of Teddy.  Winds to tropical storm force extended out 275 miles (445 km) from the center.  Drier air was wrapping around the southern side of Hurricane Teddy.  The strongest thunderstorms were in bands in the northern half of the hurricane.  Bands in the southern half of the circulation consisted primarily of showers and lower clouds.

An upper level trough over eastern North America will cause strong southerly winds which will blow toward the top of Hurricane Teddy.  Those winds will cause strong vertical wind shear and they will contribute to the extratropical transition of Teddy.  Hurricane Teddy will move over much cooler water when it approaches Nova Scotia.  Teddy will transform into a strong extratropical cyclone.

Hurricane Teddy will be steered rapidly toward the north by the upper level trough over eastern North America.  On its anticipated track Hurricane Teddy will approach Nova Scotia on Tuesday night.  Teddy will bring strong winds and heavy rain to Nova Scotia and southwestern Newfoundland.

Elsewhere, slow moving Tropical Storm Beta reached the coast of Texas on Monday night.  At 11:00 p.m. EDT on Monday the center of Tropical Storm Beta was located at latitude 28.4°N and longitude 96.3°W which put it about 5 miles (10 km) east of Port O Connor, Texas.  Beta was moving toward the northwest at 3 m.p.h. (5 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 999 mb.

A Tropical Storm Warning was in effect for the portion of the coast from Port Aransas, Texas to Morgan City Louisiana.

Tropical Storm Beta weakened gradually on Monday as it moved slowly toward the coast of Texas.  Drier air continued to get pulled into the circulation which limited the development of new thunderstorms.  Without updrafts and downdrafts to transport momentum vertically, the circulation around Beta slowly spun down.

Even though Tropical Storm Beta weakened on Monday, its winds pushed water toward the coast of Texas.  Water levels rose along the coast and there were some reports of damage.  Waves contributed to beach erosion.  Moderate rain was falling over the region between Houston and Victoria, Texas.  The rain could cause flooding in some locations.

Tropical Storm Beta was forecast to move slowly toward the northeast along the coast of Texas during the next 24 to 36 hours.  Beta will continue to weaken, but winds will blow water toward the coast from several more days.  Locally heavy rain will continue to create a risk of floods until Tropical Storm Beta moves away from the area.

Tropical Storm Lowell Forms South of Baja California

Tropical Storm Lowell formed south of Baja California on Monday.  At 5:00 p.m. EDT on Monday the center of Tropical Storm Lowell was located at latitude 17.4°N and longitude 113.6°W which put it about 450 miles (725 km) south-southwest of the southern tip of Baja California.  Lowell was moving toward the west-northwest at 16 m.p.h. (26 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 scatterometer onboard a satellite detected winds to 45 m.p.h. (75 km/h) on the southeast side of former Tropical Depression Seventeen-E on Monday afternoon and the National Hurricane Center upgraded the system to Tropical Storm Lowell.  The circulation around Lowell was not well organized.  The strongest thunderstorms were occurring in bands in the southwestern quadrant of the tropical storm.  Bands in the other parts of Tropical Storm Lowell consisted primarily of showers and lower clouds.  Winds to tropical storm force extended out 85 miles (135 km) on the southern side of Lowell.  Winds on the northern side of the circulation were blowing at less than tropical storm force.

An upper level ridge over the Eastern North Pacific Ocean was producing northeasterly winds which were blowing toward the top of Tropical Storm Lowell.  Those winds were causing moderate vertical wind shear and they were responsible for the stronger thunderstorms being in the southwestern quadrant of Lowell.  The moderate upper level winds also appeared to be tilting the top part of Tropical Storm Lowell toward the southwest of the circulation at the surface.

Tropical Storm Lowell will move over water where the Sea Surface Temperature is near 28°C.  So, there will be sufficient energy in the upper ocean to support intensification.  If the upper level winds weaken, then Lowell could intensify during the next several days.  However, if the upper level winds remain at their current speed, then it will be difficult for the tropical storm to become more organized.  The wind shear is forecast to decrease slowly, which would allow Tropical Storm Lowell to strengthen gradually.

Tropical Storm Lowell will move south of a subtropical high pressure system over the Eastern North Pacific Ocean.  The high is forecast to steer Lowell toward the west during the next few days.  On its anticipated track Tropical Storm Lowell will move farther away from Baja California.

Tropical Storm Dolphin Forms South of Japan

Tropical Storm Dolphin formed south of Japan on Monday.  At 11:00 a.m. EDT on Monday the center of Tropical Storm Dolphin was located at latitude 26.0°N and longitude 135.0°E which put it about 365 miles (590 km) southwest of Tokyo, Japan.  Dolphin was moving toward the north-northeast at 5 m.p.h. (8 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 996 mb.

A distinct low level center of circulation developed near the southern side of an area of thunderstorms south of Japan on Monday and the Japan Meteorological Agency designated the system as Tropical Storm Dolphin.  The circulation around Tropical Storm Dolphin was still organizing.  The strongest thunderstorms were occurring in bands in the northern half of the circulation.  Bands in the southern half of Dolphin consisted primarily of showers and lower clouds.  Storms near the center of circulation generated upper level divergence which pumped mass away to the northeast of the tropical storm.  Winds to tropical storm force extended out 125 miles (200 km) from the center.

Tropical Storm Dolphin will move through an environment somewhat favorable for intensification during the next 36 hours.  Dolphin will move over water where the Sea Surface Temperature is near 28°C.  An upper level trough approaching Japan from the west will produce southwesterly winds which will blow toward the top of Tropical Storm Dolphin.  Those winds will cause moderate vertical wind shear and they will inhibit intensification of Dolphin.  The shear will limit intensification, but Tropical Storm Dolphin is likely to get stronger during the next 36 hours.

Tropical Storm Dolphin will move around the northwestern part of a subtropical high pressure system over the Western North Pacific Ocean.  The high will steer Dolphin toward the north-northeast during the next 24 to 36 hours.  Tropical Storm Dolphin will reach the westerly winds in the middle latitudes after that period and those winds will steer Dolphin more toward the northeast during the middle of the week.  On its anticipated track Tropical Storm Dolphin could approach the coast of Honshu near Tokyo in about 72 hours.

Tropical Storm Beta Moves Toward Texas

Tropical Storm Beta moves slowly toward the coast of Texas on Sunday.  At 11:00 p.m. EDT on Sunday the center of Tropical Storm Beta was located at latitude 29.6°N and longitude 94.5°W which put it about 130 miles (210 km) east-southeast of Port Oconnor, Texas.  Beta was moving toward the west-northwest at 6 m.p.h. (10 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 995 mb.

A Tropical Storm Warning was in effect for the portion of the coast from Port Aransas, Texas to Morgan City, Louisiana.  A Tropical Storm Watch was in effect from Baffin Bay to Port Aransas, Texas.

Tropical Storm Beta exhibited more organization on Sunday afternoon.  Thunderstorms developed near the center of circulation and radar indicated the potential formation of an eye at the center of Beta.  The thunderstorms near the center weakened on Sunday night.  It appeared that drier air over Texas was pulled into the circulation around Tropical Storm Beta.  The drier air mixed into the core of Beta which caused thunderstorms to weaken.  When the thunderstorms near the center weakened, it appeared that the upper part of the circulation drifted northeast of the low level circulation.  Even though the thunderstorms weakened a reconnaissance plane on Sunday night found that the wind speeds had not decreased.  The strongest winds were occurring in the northeastern quadrant of Tropical Storm Beta.  Winds to tropical storm force extended out 200 miles (320 km) in that quadrant of the circulation.  Winds to tropical storm force only extended out 50 miles from the center in the southern half of the circulation.

Tropical Storm Beta will move through an environment only marginally favorable for intensification on Monday.  Beta will move over water where the Sea Surface Temperature is near 30°C.  It will continue to be surrounded by drier air, which will inhibit intensification.  Tropical Storm Beta could maintain its intensity if new thunderstorms develop near the center of circulation.  If thunderstorms do not develop near the center, then Beta will slowly weaken.

Tropical Storm Beta will move around the southwestern part of a large high pressure system over the eastern U.S.  The high will steer Beta toward the west-northwest.  On its anticipated track Tropical Storm Beta will approach the coast of Texas near Matagorda Bay on Monday evening.  Winds blowing water toward the coast will cause a storm surge of 3 to 6 feet (1 to 2 meters).

Elsewhere, Hurricane Teddy was moving closer to Bermuda.  At 11:00 p.m. EDT on Tuesday the center of Hurricane Beta was located at latitude 29.4°N and longitude 63.6°W which put it about 210 miles (340 km) south-south east of Bermuda.  Teddy was moving toward the north-northwest 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 963 mb.

A Tropical Storm Warning was in effect for Bermuda.  A Tropical Storm Watch was issued for the portion of the coast from Lower East Pubnico to Canso, Nova Scotia.

Tropical Storm Beta in Holding Pattern

Tropical Storm Beta was in a holding pattern on Saturday afternoon.  At 5:00 p.m. EDT on Saturday the center of Tropical Storm Beta was located at latitude 26.6°N and longitude 92.4°which put it about 320 miles (510 km) east-southeast of Corpus Christi, Texas.  Beta was stationary.  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 994 mb.

A Hurricane Watch was in effect for the portion of the coast from Port Aransas to High Island, Texas.  A Tropical Storm Warning was in effect for the portion of the coast from Port Aransas to Intracoastal City, Louisiana.  Tropical Storm Watches were in effect for the portions of the coast from the Mouth of the Rio Grande River to Port Aransas and from Intracoastal City to Morgan City, Louisiana.

The intensity of Tropical Storm Beta held steady and it moved little on Saturday afternoon.  An upper level trough over Texas produced southwesterly winds which blew across the top of Tropical Storm Beta.  Those winds caused strong vertical wind shear and they blew the tops off thunderstorms near the center of Beta on Saturday morning.  The shear may have decreased later because new thunderstorms formed near the center of circulation on Saturday afternoon.  A reconnaissance flight found that the winds around Tropical Storm Beta had maintained their speed.  Winds to tropical storm force extended out 175 miles (280 km) on the northern side of Beta.  Tropical storm force winds only extended out 50 miles (80 km) in the southern half of the circulation.

Tropical Storm Beta will move through an environment somewhat favorable for intensification during the next 36 hours.  Beta will move over water where the Sea Surface Temperature is near 30°C.  The upper level trough over Texas is forecast to weaken and if that happens, then the vertical wind shear will decrease.  There is drier air over Texas and Tropical Storm Beta could pull some of that air into the southern part of the circulation.  Beta could strengthen on Sunday if the wind shear decreases.  However, if Tropical Storm Beta remains stationary for too long, its winds will mix cooler water to the surface, which would inhibit intensification.

A large cool high pressure system is over the eastern U.S.  The high blocked the northward movement of Beta, which is why the tropical storm became stationary.  The high pressure system will move slowly eastward during the next few days.  As the high moves east, it will steer Tropical Storm Beta slowly toward the west-northwest.  On its anticipated track Tropical Storm Beta could approach the Central Texas coast on Monday.  Beta could be a hurricane when it approaches the coast.

The figure below shows the factors affecting Tropical Storm Beta on Saturday afternoon.

Elsewhere, Hurricane Teddy continued to move in the direction of Bermuda.  At 5:00 p.m. EDT on Saturday the center of Hurricane Teddy was located at latitude 26.7°N and longitude 60.2°W which put it about 475 miles (765 km) southeast of Bermuda.  Teddy was moving toward the northwest at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 120 m.p.h. (195 km/h) and there were wind gusts to 140 m.p.h. (220 km/h).  The minimum surface pressure was 958 mb.  A Tropical Storm Warning was in effect for Bermuda.