Tag Archives: AL12

Powerful Hurricane Lorenzo Churns Southwest of the Azores

Powerful Hurricane Lorenzo churned southwest of the Azores on Friday.  At 5:00 p.m. EDT on Friday the center of Hurricane Lorenzo was located at latitude 20.3°N and longitude 43.6°W which put it about 1575 miles (2535 km) southwest of the Azores.  Lorenzo was moving toward the north-northeast at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 125 m.p.h. (200 km/h) and there were wind gusts to 150 m.p.h. (240 km/h).  The minimum surface pressure was 948 mb.

Hurricane Lorenzo weakened slowly on Friday, but it remained a large and powerful hurricane.  Winds to hurricane force extended out 45 miles (75 km) from the center of circulation.  Winds to tropical storm force extended out about 250 miles (400 km) from the center.  The Hurricane Intensity Index (HII) for Hurricane Lorenzo was 23.6.  The Hurricane Size Index (HSI) was 20.7 and the Hurricane Wind Intensity Size Index (HWISI) was 44.3.  Hurricane Lorenzo was capable of causing major damage.

Hurricane Lorenzo weakened on Friday because it moved into a less favorable environment.  Lorenzo continued to move over water where the Sea Surface Temperature was near 27°C.  However, an upper level trough west of Lorenzo was producing southwesterly winds which were causing moderate vertical wind shear.  in addition, Hurricane Lorenzo appeared to be drawing drier air into the western half of the circulation.  The effects of increased vertical wind shear and drier air caused Lorenzo to weaken.

Hurricane Lorenzo will continue to move through a less favorable environment and weaken.  Since Lorenzo is a large hurricane, it will weaken more slowly than a smaller hurricane would.  As a result, Lorenzo will likely remain a hurricane for several more days.

The upper level trough will steer Hurricane Lorenzo toward the northeast during the next few days.  On its anticipated track Hurricane Lorenzo will likely approach the Azores on Tuesday.  Lorenzo is likely to still be a hurricane at that time.

Elsewhere over the Atlantic Ocean, Tropical Depression Karen weakened to a trough southeast of Bermuda on Friday afternoon.  At 5:00 p.m. EDT on Friday the center of former Tropical Depression Karen was located at latitude 29.3°N and longitude 58.5°W which put it about 425 miles (685 km) south-southeast of Bermuda.  Karen was moving toward the northeast at 6 m.p.h. (10 km/h).  The maximum sustained wind sped was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h).  The minimum surface pressure was 1007 mb.

Lorenzo Rapidly Strengthens Into a Major Hurricane

Hurricane Lorenzo rapidly strengthened into a major hurricane west of the Cabo Verde Islands on Thursday.  At 6:00 a.m. EDT on Thursday the center of Hurricane Lorenzo was located at latitude 15.2°N and longitude 39.3°W which put it about 995 miles (1600 km) west of the Cabo Verde Islands.  Lorenzo was moving toward the west-northwest at 15 m.p.h. (24 km/h).  The maximum sustained wind speed was 125 m.p.h. (200 km/h) and there were wind gusts to 150 m.p.h. (240 km/h).  The minimum surface pressure was 955 mb.

Lorenzo was a large well organized a hurricane.  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.  Bands of showers and thunderstorms were revolving around the core of Hurricane Lorenzo.  Storms around the core were generating strong upper level divergence which was pumping mass away from the hurricane.  Winds to hurricane force extended out about 35 miles (55 km) from the center of circulation.  Winds to tropical storm force extended out about 210 miles (335 km) from the center.

Hurricane Lorenzo will move through an environment favorable for intensification during the next day or so.  Lorenzo will move over water where the Sea Surface Temperature is near 27°C.  It will move through an area where the upper level winds are weak and there will be little vertical wind shear.  Hurricane Lorenzo is likely to strengthen to Category 4 on the Saffir-Simpson Scale during the next 24 hours.  Lorenzo will move over cooler water during the weekend, which will cause the hurricane to weaken.

Hurricane Lorenzo will move around the western end of a ridge of high pressure over North Africa and the eastern Atlantic Ocean.  The ridge will steer Lorenzo toward the north during the weekend.  On its anticipated track Hurricane Lorenzo could approach the Azores next week.

Elsewhere over the Atlantic Ocean Tropical Storm Karen moved farther away from Puerto Rico.  At 5:00 a.m. EDT in Thursday the center of Tropical Storm Karen was located at latitude 25.5°N and longitude 63.5°W which put it about 520 miles (835 km) north-northeast of San Juan Puerto Rico.  Karen was moving toward the north-northeast at 15 m.p.h. (24 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 1004 mb.

Tropical Storm Karen Drops Heavy Rain on Puerto Rico and the Virgin Islands

Tropical Storm Karen dropped heavy rain on parts of Puerto Rico and the Virgin Islands on Tuesday.  At 2:00 p.m. EDT on Tuesday the center of Tropical Storm Karen was located at latitude 17.5°N and longitude 66.0°W which put it about 65 miles (105 km) south of San Juan Puerto Rico.  Karen was moving toward the north at 8 m.p.h. (13 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 1005 mb.

Tropical Storm Warnings were in effect for Puerto Rico including Vieques and Culebra, the U.S. Virgin Islands and the British Virgin Islands.

The circulation around Tropical Storm Karen exhibited more organization on Tuesday afternoon.  A new low level center of circulation formed a little farther to the west near a cluster of stronger thunderstorms.  The minimum surface pressure decreased by several millibars.  More thunderstorms formed near the center of circulation and in bands revolving around the center.  Storms near the newly reformed center of circulation were generating more upper level divergence which was pumping mass away from the tropical storm.  The removal of mass was what allowed the surface pressure to decrease.  Winds to tropical storm force extended out about 80 miles (130 km) from the center of circulation.

Tropical Storm Karen will move through an environment favorable for intensification during the next 24 to 48 hours.  Karen will move over water where the Sea Surface Temperature is near 29°C.  Karen has moved under the middle of an upper level ridge over the eastern Caribbean Sea where the upper level winds are weaker.  There will be less vertical wind shear during the next day or two.  The environment around Tropical Storm Karen will support intensification.  However, the center of Karen will pass over Puerto Rico during the next 24 hours.  The mountains in Puerto Rico will disrupt the circulation in the lower levels and Tropical Storm Karen will weaken when it passes over those mountains.  Karen will likely strengthen again when it moves north of Puerto Rico.

Tropical Storm Karen will move around the western end of a subtropical high pressure system over the Atlantic Ocean.  The high will steer Karen toward the north during the next day or two.  On its anticipated track Tropical Storm Karen will move across Puerto Rico during the next 24 hours.  Karen will drop heavy rain on parts of Puerto Rico, the U.S. Virgin Islands and the British Virgin Islands.  Prolonged heavy rain will create a high risk for flash floods in those areas.

Elsewhere over the Atlantic Ocean, Tropical Storm Jerry was moving slowly toward Bermuda and Tropical Storm Lorenzo was strengthening west of the Cabo Verde Islands.  At 2:00 p.m. EDT the center of Tropical Storm Jerry was located at latitude 30.9°N and longitude 69.1°W which put it about 270 miles (435 km) west-southwest of Bermuda.  Jerry was moving toward the north-northeast at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h).  The minimum surface pressure was 992 mb.  A Tropical Storm Warning was in effect for Bermuda.

At 11:00 a.m. EDT on Tuesday the center of Tropical Storm Lorenzo was located at latitude 12.4°N and longitude 29.3°W which put it about 270 miles (435 km) west-southwest of the Cabo Verde Islands.  Lorenzo was moving toward the west-northwest at 16 m.p.h. (26 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 997 mb

Tropical Storm Karen Develops Near Windward Islands

Tropical Storm Karen developed near the Windward Islands on Sunday morning.  At 8:00 a.m. EDT on Sunday the center of Tropical Storm Karen was located at latitude 11.9°N and longitude 60.9°W which put it about 55 miles (90 km) east-southeast of Grenada.  Karen was moving toward the west-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 minimum surface pressure was 1005 mb.

Tropical Storm Warnings were in effect for Trinidad and Tobago, Grenada, and for St. Vincent and the Grenadines.

A center of circulation developed in an area of thunderstorms east of the axis of a strong tropical wave near the Windward Islands on Sunday morning and the National Hurricane Center designated the system as Tropical Storm Karen.  The strongest thunderstorms were forming in bands south and west of the center of circulation.  Bands north and west of the center consisted primarily of showers and lower clouds.   Winds to tropical storm force extended out about 125 miles (200 km) on the eastern side of the tropical storm.

An upper level trough northeast of the Lesser Antilles was producing strong westerly winds which were blowing across the northern side of Tropical Storm Karen.  An upper level ridge over the Caribbean Sea was producing strong northeasterly winds which were blowing across the western part of Karen.  The upper level winds were causing moderate vertical wind shear which was inhibiting the development of thunderstorms in those parts of Tropical Storm Karen.  The center of circulation developed in a region between the stronger upper level westerly and northeasterly winds.  Most of the thunderstorms were forming in that area where the upper level winds were not as strong.

Tropical Storm Karen will move through an environment that will be only marginally favorable for intensification during the next day or two.  Karen will move over water where the Sea Surface Temperature  is near 29°C.  However, the upper level trough and upper level ridge will continue to cause moderate vertical wind shear.  If Tropical Storm Karen remains in the zone where the upper level winds are not as strong, it could strengthen.  However, if Karen moves under stronger upper level winds, it could weaken to a depression.  Tropical Storm Karen is forecast to move closer to the center of the upper level ridge in two or three days.  If that happens, then the upper level winds will be weaker and Karen could intensify.

Tropical Storm Karen will move around the western end of a subtropical high pressure system over the Atlantic Ocean.  The high will steer Karen toward the west-northwest during the next 12 hours.  Karen will move more toward the north when reaches the end of the ridge.  On its anticipated track Tropical Storm Karen will move across the Windward Islands on Sunday.  Karen will bring gusty winds and locally heavy rain.  Flash floods are likely.  Tropical Storm Karen could approach Puerto Rico and the Virgin Islands on Tuesday.  Tropical Storm Watches are likely to be issued for those islands.

Elsewhere over the Atlantic Ocean Tropical Storm Jerry was spinning south of Bermuda.  At 5:00 a.m. EDT on Sunday the center of Tropical Storm Jerry was located at latitude 25.0°N and longitude 66.9°W which put it about 520 miles (835 km) south-southwest of Bermuda.  Jerry was moving toward the north-northwest at 12 m.p.h. (19 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 1002 mb.

Tropical Storm Kirk Brings Rain to Lesser Antilles

Tropical Storm Kirk brought rain to some of the Lesser Antilles on Friday.  At 11:00 a.m. EDT on Friday the center of Tropical Storm Kirk was located at latitude 13.8°N and longitude 63.6°W which put it about 360 miles (575 km) south-southeast of San Juan, Puerto Rico.  Kirk was moving toward the west-northwest at 13 m.p.h. (20 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 1007 mb.  All Tropical Storm Warnings and Watches have been discontinued.

An upper level trough over the Caribbean Sea is producing strong westerly winds which is blowing over the top of Tropical Storm Kirk.  Those winds are causing strong vertical wind shear, which is causing the strongest thunderstorms to occur on the far eastern side of the circulation.  Bands west of the center of circulation and near the center consist primarily of showers and lower clouds.  The center of circulation is over the eastern Caribbean Sea and the heavy rain is falling hours after the center passed the Lesser Antilles.  Locally heavy rain could cause flash floods in some locations.

Tropical Storm Kirk will move through an environment that will be unfavorable for intensification during the weekend.  Kirk will move over water where the Sea Surface Temperature is near 29°C.  However, the upper level trough will continue cause strong vertical wind shear for the next several days.  Tropical Storm Kirk will likely weaken to a tropical depression or a tropical wave during the next 24 to 48 hours.

Tropical Storm Kirk will move south of a subtropical high pressure system that is over the Atlantic Ocean.  The high will steer Kirk in a general west-northwesterly direction during the weekend.  On its anticipated track Tropical Storm Kirk should stay south of Puerto Rico and the Dominican Republic.  Kirk or its remnants could be near Jamaica in a few days.

Tropical Storm Kirk Redevelops East of Lesser Antilles, Warnings Issued

Tropical Storm Kirk redeveloped east of the Lesser Antilles on Wednesday morning and Tropical Storm Warnings and Watches were issued for some of those islands.  At 11:00 a.m. EDT on Wednesday the center of Tropical Storm Kirk was located at latitude 12.1°N and longitude 54.3°W which put it about 360 miles (575 km) east-southeast of Barbados.  Kirk was moving toward the west at 18 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 1002 mb.

Tropical Storm Warnings have been issued for Barbados, St. Lucia, Dominica, Martinique and Guadeloupe.  A Tropical Storm Watch has been issued for St. Vincent and the Grenadines.

The National Hurricane Center (NHC) indicated that former Tropical Storm Kirk had weakened to a tropical wave on Monday and NHC ceased issuing advisories on the system.  The remnants of former Tropical Storm Kirk moved quickly westward across the tropical Atlantic Ocean.  More thunderstorms began developing in the system on Tuesday.  NHC determined that sufficient thunderstorms had formed near the center of circulation by Wednesday morning to reclassify the system as a tropical cyclone and it started issuing advisories on Tropical Storm Kirk again.

A cluster of strong thunderstorms developed near the center of Tropical Storm Kirk.  Thunderstorms were also forming in several bands which were revolving around the center of circulation.  Thunderstorms near the core of Kirk were generating upper level divergence which was pumping mass away to the east of the tropical storm.

Tropical Storm Kirk will move through an environment favorable for intensification during the next 24 hours.  Kirk will move over water where the Sea Surface Temperature is near 29°C.  It will move through an area where the upper level winds are not too strong.  There will be some vertical wind shear, but the wind shear will not be strong enough to prevent intensification in the short term.  When Tropical Storm Kirk moves over the eastern Caribbean Sea, it will encounter stronger westerly winds and the vertical wind shear will increase.

Tropical Storm Kirk will move south of the subtropical high pressure system over the Atlantic Ocean.  The subtropical high will steer Kirk on a path a little north of due west.  On its anticipated track Tropical Storm Kirk could be near Barbados on Thursday morning.  Kirk could reach the Lesser Antilles later on Thursday.  Tropical Storm Kirk will bring gusty winds and it could drop locally heavy rain.

Tropical Storm Kirk Forms South of the Cabo Verde Islands

Tropical Storm Kirk formed south of the Cabo Verde Islands on Saturday.  At 11:00 a.m. EDT on Saturday the center of Tropical Storm Kirk was located at latitude 8.3°N and longitude 23.6°W which put it about 450 miles (730 km) south of the Cabo Verde Islands.  Kirk was moving toward the west 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 1005 mb.

The circulation around Tropical Storm Kirk is large and not well organized.  There is a low level center of circulation, but there are not many thunderstorms near the center.  There were thunderstorms in a cluster west of the center and more thunderstorms were in another cluster east of the center.  Some of the thunderstorms appeared to be organizing into bands, but the bands were not well developed.

Tropical Storm Kirk will move through an environment during the next day or two that should be favorable for intensification.  Kirk will move over water where the Sea Surface Temperature is near 27°C.  It will move through an area where the upper level winds are weak and the wind shear will not be strong enough to prevent intensification.  Tropical Storm Kirk is likely to become more organized during the next 24 to 48 hours.  It will move into a region in a couple of days where the lower level easterly winds will be stronger vertical wind shear could increase.

Tropical Storm Kirk will move south of a subtropical high pressure system over the Atlantic Ocean.  The high will steer Kirk toward the west at a fairly quick pace.  On its anticipated track Tropical Storm Kirk could approach the Lesser Antilles by late next week.

Elsewhere over the tropical Atlantic, Tropical Depression Eleven moved slowly toward the Windward Islands.  At 11:00 a.m. EDT on Saturday the center of Tropical Depression Eleven was located at latitude 13.2°N and longitude 53.8°W which put it about 485 miles (780 km) east of the Windward Islands.  It was moving toward the west at 3 m.p.h. (5 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.

Hurricane Maria Moves Away from Puerto Rico

Hurricane Maria moved away from Puerto Rico on Wednesday night after causing significant wind damage and serious flash floods.  At 11:00 p.m. EDT on Wednesday the center of Hurricane Maria was located at latitude 19.2°N and longitude 67.9°W which put it about 55 miles (85 km) northeast of Punta Cana, Dominican Republic.  Maria was moving toward the northwest at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 110 m.p.h. (175 km/h) and there were wind gusts to 130 m.p.h. (210 km/h).  The minimum surface pressure was 959 mb.

Hurricane Warnings are in effect for the Turks and Caicos, the Southeastern Bahamas, and the portion of the coast from Cabo Engano to Puerto Plata, Dominican Republic.  A Hurricane Watch is in effect for the portion of the coast from Cabo Engano to Isla Saona, Dominican Republic.  Tropical Storm Warnings are in effect for the portions of the coast from Puerto Plata to the northern border with Haiti and from Cabo Engano to Punta Palenque, Dominican Republic.

Hurricane Maria made landfall on the southeast coast of Puerto Rico near Yabucoa on Wednesday morning.  Maria was a Category 4 hurricane on the Saffir-Simpson Scale at the time of landfall.  Hurricane Maria moved northwest across Puerto Rico and the center emerged over the Atlantic Ocean near Arecibo on Thursday afternoon.

Hurricane Maria weakened as the core of the hurricane moved across Puerto Rico.  The mountains on Puerto Rico disrupted the circulation in the lower levels of Maria, but the middle and upper portions of the circulation remained intact.  Hurricane Maria was in the middle of an eyewall replacement cycle when it made landfall in Puerto Rico.  The timing of landfall may have caused Maria to weaken more than it would have if there had not been an eyewall replacement cycle.  The inner eyewall which contained the strongest winds dissipated at Hurricane Maria moved across Puerto Rico.  The strongest winds are occurring in the remaining outer eyewall.  The eyewall replacement cycle contributed to an increase in the size of the circulation of Hurricane Maria.  Wind to hurricane force extend out about 60 miles (95 km) from the center of circulation.  Wind to tropical storm force extend out about 160 miles (260 km) from the center.

Hurricane Maria will move through an environment favorable for intensification on Thursday.  Maria will move over water where the Sea Surface Temperature is near 29°C.  The upper level winds are weak and there is not much vertical wind shear.  It could take another 12 to 24 hours for the lower portions of the circulation to reorganize.   The reorganization could limit the rate of intensification.  In addition the center will pass near the Dominican Republic.  Some of the southern part of the circulation will be over land and that could also limit intensification until Maria moves farther away from Hispaniola.

Hurricane Maria is moving around the southwestern portion of the subtropical high over the Atlantic Ocean.  That high has been steering Maria toward the northwest.  Many of the numerical models are forecasting that the high will weaken and Maria will turn toward the north on Thursday.  If the high remains stronger than the models are forecasting, then Hurricane Maria will move farther toward the west.  Hurricane Maria seems to have moved near the left side of the guidance from the numerical models in recent days.  On its forecast track the center of Hurricane Maria will move north of the Dominican Republic on Thursday.  Hurricane Maria could be near the Turks and Caicos on Friday.

Hurricane Maria is still capable of producing extensive significant damage.  Maria will drop heavy rain on parts of the Dominican Republic and there could be flash floods in some places where there is steeper terrain.

Elsewhere, Tropical Storm Jose move slowly east-northeast southeast of Massachusetts.  At 11:00 p.m. EDT on Wednesday the center of Tropical Storm Jose was located at latitude 39.5°N and longitude 68.2°W which put it about 150 miles (245 km) southeast of Nantucket.  Jose was moving toward the east-northeast at 6 m.p.h. (9 km/h).  The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there were ind gusts to 75 m.p.h. (120 km/h).  The minimum surface pressure was 982 mb.  A Tropical Storm Warning was in effect for the portion of the coast from Woods Hole to Sagamore Beach including Block Island, Martha’s Vineyard, Nantucket and Cape Cod.

Category 5 Hurricane Maria Bearing Down on Puerto Rico

Category 5 Hurricane Maria was bearing down on Puerto Rico on Tuesday night.  The eye was very near St. Croix.  At 11:00 p.m. EDT on Tuesday the center of Hurricane Maria was located at latitude 17.3°N and longitude 64.7°W which put it about 30 miles (45 km) south-southeast of St. Croix and about 120 miles (190 km) southeast of San Juan, Puerto Rico.  Maria was moving toward the west-northwest at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 175 m.p.h. (280 km/h) and there were wind gusts to 215 m.p.h. (345 m/h).  The minimum surface pressure was 909 mb.

Hurricane Warnings were in effect for Puerto Rico, Culebra, Vieques, the U.S. Virgin Islands, the British Virgin Islands, and for the portion of the coast from Cabo Engano to Puerto Plata, Dominican Republic.  Hurricane Watches were in effect for the Turks and Caicos, the Southeastern Bahamas, Saba, St. Maarten, St. Martin, St. Eustatius, St. Barthelemy, and the portion of the coast from Isla Saona to Cabo Engano, Dominican Republic.  Tropical Storm Warnings were in effect for Saba, St. Eustatius, St. Maarten, the portion of the coast from Puerto Plata,, Dominican Republic to the northern border with Haiti and for the portion of the coast from Cabo Engano to Punta Palenque, Dominican Republic,

Hurricane Maria is a very well organized powerful hurricane.  It has a small inner eye and a second outer eyewall extends most of the way around the inner eyewall.  The strongest winds are occurring in the inner eyewall.  Additional spiral bands are revolving around the core of the circulation.  The concentric eyewalls have caused the circulation of Hurricane Maria to increase in size.  Winds to hurricane force now extend out about 60 miles (95 km) from the center of circulation.  Winds to tropical storm force extend out about 160 miles (260 km) from the center.

The Hurricane Intensity Index (HII) for Hurricane Maria is 40.4.  The Hurricane Size Index (HSI) is 19.2 and the Hurricane Wind Intensity Size Index (HWISI) is 59.6.  Those indices indicate that Hurricane Maria is capable of causing regional catastrophic damage.

Hurricane Maria will continue to move through an environment favorable for powerful hurricanes until it reaches Puerto Rico.  Maria will move over water where the Sea Surface Temperature is near 29°C.  The upper level winds are weak and there is little vertical wind shear.  If the outer eyewall completely encircles the inner eyewall, then an eyewall replacement cycle could cause some weakening.  Hurricane Maria will weaken more if the center moves directly over Puerto Rico.  The amount of weakening will depend on the stage of the eyewall replacement cycle at the time of landfall.

Hurricane Maria is being steered toward the west-northwest by the subtropical high pressure system over the Atlantic Ocean.  The western end of the high is forecast to weaken during the next several days.  The weakening of the high will allow Hurricane Maria to move more toward the north.  The core of Hurricane Maria will pass near or over St. Croix during the next few hours.  On its anticipated track Hurricane Maria will reach Puerto Rico on Wednesday morning.

Hurricane Maria is a very dangerous hurricane.  It is capable of causing catastrophic damage.  Maria will also drop very heavy rain over Puerto Rico and there is the potential for significant flash flooding.  Maria could also cause a storm surge of up to 12 feet (4 meters) along the coast.

Elsewhere, Hurricane Jose weakened to a tropical storm east of the U.S.  At 11:00 p.m. EDT on Tuesday the center of Tropical Storm Jose was located at latitude 37.9°N and longitude 70.8°W which put it about 230 miles (375 km) south of Nantucket.  Jose was moving toward the northeast at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were wind gusts to 85 m.p.h. (135 km/h).  The minimum surface pressure was 973 mb.

A Tropical Storm Warning was in effect for the portion of the coast from Woods Hole to Sagamore Beach, Massachusetts including Block Island, Martha’s Vineyard, Nantucket and Cape Cod.  A Tropical Storm Watch was in effect for the portion of Long Island from Fire Island Inlet to Port Jefferson.

Hurricane Maria Strengthens to Cat. 5 Near Leeward Islands

Hurricane Maria quickly strengthened to a Category 5 hurricane on the Saffir-Simpson Scale on Monday.  At 8:00 p.m. EDT on Monday the center of Hurricane Maria was located at latitude 15.3°N and longitude 61.1°W which put it about 15 miles (25 km) east-southeast of Dominica.  Maria was moving toward the west-northwest at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 160 m.p.h. (260 km/h) and there were wind gusts to 190 m.p.h. (305 km/h).  The minimum surface pressure was 925 mb.

Hurricane Warnings were in effect for Puerto Rico, Culebra, Vieques, Dominica, Guadeloupe, St. Kitts, Nevis, Martinique, Montserrat, the U.S. Virgin Islands and the British Virgin Islands.  Hurricane Watches were in effect for Saba, St. Eustatius, St. Maarten, Anguilla, St. Martin, St. Barthelemy and the portion of the coast from Isla Saona to Puerto Plata, Dominican Republic.  Tropical Storm Warnings were in effect for Anguilla, St. Lucia, Antigua, Barbuda, Saba, St. Eustatius and St. Maarten.  Tropical Storm Watches were in effect for St. Vincent, the Grenadines and the portion of the coast from Puerto Plata to the Haiti/Dominican Republic border.

Hurricane Maria has a tight compact circulation.  There is a small eye with a diameter of 10 miles (16 km) at the center of circulation.  The eye is surround by a ring of strong thunderstorms and the strongest winds are occurring in that ring of storms.  Additional bands of showers and thunderstorms are revolving around the core of Maria.  The overall circulation of Hurricane Maria is small.  Winds to hurricane force only extend out about 25 miles (40 km) from the center of circulation.  Winds to tropical storm force only extend out about 125 miles (200 km) from the center.

The Hurricane Intensity Index (HII) for Hurricane Maria is 35.0.  The Hurricane Size Index (HSI) is 9.1 and the Hurricane Wind Intensity Size Index (HWISI) is 44.1.

Hurricane Maria will continue to move through an environment very favorable for strong hurricanes.  Maria will move over water where the Sea Surface Temperature is near 29°C.  The upper level winds are weak and there is little vertical wind shear.  Hurricane Maria could strengthen further.  Since the eye of Hurricane Maria is so small, it would be easy for a rainband to wrap around the eye.  If that happens, then an eyewall replacement cycle could begin and the cycle could result in a temporary weakening of the hurricane.

Hurricane Maria is being steered to the west-northwest by the subtropical high pressure system over the Atlantic Ocean.  That high is forecast to weaken and Maria is likely to move more toward the northwest during the next several days.  On its anticipate track the center of Hurricane Maria will pass very close to Dominica and Guadeloupe on Monday night.  Maria could pass near Montserrat, St. Kitts and Nevis on Tuesday.  It could be near the U.S. Virgin Islands on Tuesday night and Hurricane Maria will approach Puerto Rico on Wednesday.

Hurricane Maria is a small but very dangerous hurricane.  The winds in the core of Hurricane Maria are capable of causing extensive damage.  In addition, heavy rain falling over steep terrain will likely produce flash floods.  Hurricane Maria will affect some of the same islands that were severely damaged by Hurricane Irma.  Maria will significantly hamper efforts in some places to recover from the effects of Hurricane Irma.

Elsewhere over the Atlantic Ocean, Hurricane Jose has begun the transition to an extratropical cyclone as it moves northward off the east coast of the U.S.  At 5:00 p.m. EDT on Monday the center of Hurricane Jose was located at latitude 34.8°N and longitude 71.1°W which put it about 445 miles (720 km) south of Nantucket, Massachusetts.  Jose was moving toward the north at 10 m.p.h. (16 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 977 mb.

A Tropical Storm Warning was in effect for the portion of the coast from Watch Hill, Rhode Island to Hull, Massachusetts including Block Island, Martha’s Vineyard and Nantucket.  Tropical Storm Watches were in effect for the portion of the coast of Long Island from Fire Island Inlet to Port Jefferson and from New Haven, Connecticut to Watch Hill, Rhode Island.

The structure of Hurricane Jose began to change on Monday from the more circular shape of a purely tropical hurricane to an asymmetrical shape seen more commonly in extratropical cyclones.  Drier air wrapped around the western and southern sides of the circulation.  Most of the strong thunderstorms and heavy rain were occurring in the northern half of Jose.  Winds to hurricane force extended out about 60 miles (95 km) north of the center, but there were few if any winds to hurricane force south of the center.  The circulation of Hurricane Jose is much larger than the circulation of Hurricane Maria.  Winds to tropical storm force extend out about 320 miles (515 km) from the center of Jose.

The Hurricane Intensity Index for Hurricane Jose was 10.4.  The Hurricane Size Index for Jose was 15.6 and the Hurricane Wind Intensity Size Index was 26.0.

Hurricane Jose will move into an environment that is unfavorable for hurricanes on Tuesday.  Jose will stay over warm Sea Surface Temperatures until it moves north of the Gulf Stream.  Once Jose moves north of latitude 38°N, it will start to move over cooler water.  An upper level trough over the eastern U.S. is producing southerly winds which are causing moderate vertical wind shear over Jose.  Cooler water and moderate shear would normally cause a hurricane to weaken.  However, as Hurricane Jose makes the transition to an extratropical cyclone, it will start to be powered by the temperature difference between warm and cold air.  The transition to an extratropical cyclone can sometimes produce a stronger storm when it occurs.

Hurricane Jose is moving around the western end of the subtropical high.  Another surface high pressure system is forecast to move north of Jose when the hurricane approaches the northeastern U.S.  The second high will block the northward motion and it will force Hurricane Jose to move toward the east.  Some models are forecasting that Jose could make a clockwise loop southeast of Cape Cod.  Hurricane Jose could bring gusty winds and high waves to sections of the coast in the northeastern U.S. during the next few days.