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Typhoon Maria Rapidly Intensifies to Equivalent of Cat. 5 Hurricane

Typhoon Maria rapidly intensified into the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale on Thursday night.  At 11:00 p.m. EDT on Thursday the center of Typhoon Maria was located at latitude 16.2°N and longitude 141.9°E which put it about 250 miles (405 km) northwest of Guam.  Maria was moving toward the northwest 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 918 mb.

Typhoon Maria continued to intensify rapidly on Thursday night and it reached the equivalent of Category 5 on the Saffir-Simpson Scale.  Maria is a strong, well organized typhoon.  There is a small circular eye at the center of circulation.  The eye is surrounded by a ring of strong thunderstorms and the strongest winds were occurring that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Typhoon Maria.  Storms in the core were generating strong upper level divergence which was pumping large amounts of mass away from the typhoon.  The rapid removal of mass allowed the surface pressure to decrease quickly and the wind speeds to increase rapidly.

Winds to typhoon/hurricane force extended out about 45 miles (75 km) from the center of circulation.  Winds to tropical storm force extended out about 155 miles (250 km) from the center.  The Hurricane Intensity Index (HII) for Typhoon Maria was 43.5.  The Hurricane Size Index (HSI) was 17.8 and the Hurricane Wind  Intensity Size Index (HWISI) was 51.3.

Typhoon Maria will move through an environment favorable for strong tropical cyclones for another day or two.  Maria will move over water where the Sea Surface Temperature is near 30°C.  It will move through an area where the upper level winds are weak and there will be little vertical wind shear.  Typhoon Maria could intensify further on Friday.  However, a rainband could wrap around the existing eye and eyewall.  If that occurs, then an eyewall replacement cycle will begin.  Maria would weaken while the inner eyewall dissipates.  The typhoon could strengthen again if the outer eyewall contracts around the center of circulation.

Typhoon Maria was moving south of a subtropical ridge which was steering Maria toward the northwest.  The northwesterly motion is expected to continue for another 24 to 48 hours.  After that time the ridge is forecast to strengthen and steer Maria more toward the west-northwest.  on its anticipated track Typhoon Maria could approach Okinawa and the Ryukyu Islands in about four days.  Maris is likely to be a powerful typhoon at that time.

Typhoon Maria Rapidly Intensifies Into Equivalent of Major Hurricane

Typhoon Maria rapidly intensified Thursday into the equivalent of a major hurricane as it moved west of the Mariana Islands.  At 5:00 p.m. EDT on Thursday the center of Typhoon Maria was located at latitude 15.7°N and longitude 142.1°E which put it about 210 miles (340 km) northwest of Guam.  Maria was moving toward the northwest at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 125 m.p.h. (205 km/h) and there were wind gusts to 155 m.p.h. (250 km/h).  The minimum surface pressure was 950 mb.

After striking Guam as a tropical storm on Wednesday Maria rapidly intensified into a strong typhoon on Thursday.  A circular eye was evident on satellite imagery.  The eye was surrounded by a ring of strong thunderstorms.  Several bands of showers and thunderstorms were revolving around the core of the circulation.  Storm in the core were generating strong upper level divergence which was pumping mass away from the typhoon in all directions.  Winds to typhoon force extended out about 35 miles (55 km) from the center of circulation.  Winds to tropical storm force extended out about 155 miles (250 km) from the center.

The Hurricane Intensity Index (HII) for Typhoon Maria was 23.6.  The Hurricane Size Index (HSI) was 14.1 and the Hurricane Wind Intensity Size Index (HWISI) was 37.7.

Typhoon Maria will continue to move through an environment favorable for intensification for another day or two.  Maria will move over water where the Sea Surface Temperature is near 30°C.  It will move through a region of weaker winds between an upper level low to the west and an upper level low to the east.  There will be little vertical wind shear.  Typhoon Maria is likely to intensify more on Friday and it could become the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale.  An eyewall replacement cycle could occur if one of the rainbands wraps around existing eye and eyewall.  If an eyewall replacement cycle starts, it will cause Typhoon Maria to weaken at least temporarily.

Typhoon Maria was moving south of a subtropical ridge over the Western North Pacific Ocean.  The ridge was steering Maria toward the northwest.  A general motion toward the northwest is expected to continue for another day or two.  The ridge is forecast to strengthen after that time and it will steer Typhoon Maria more toward the west-northwest.  On its anticipated track Maria will pass south of Iwo To.  Typhoon Maria could approach Okinawa and the Ryukyu Islands in four or five days.

TD 2 Quickly Strengthens Into Tropical Storm Beryl

Tropical Depression 2 which was designated earlier on Thursday quickly strengthened into Tropical Storm Beryl.  At 5:00 p.m. EDT on Thursday the center of Tropical Storm Beryl was located at latitude 10.3°N and longitude 42.8°W which put it about 1295 miles (2080 km) east-southeast of the Lesser Antilles.  Beryl was moving toward the west at 16 m.p.h. (26 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 1004 mb.

The circulation of very small Tropical Storm Beryl organized very quickly on Thursday afternoon.  There was evidence of a tiny eye on some microwave satellite images.  A small tight ring of thunderstorms surrounded the center of circulation and the strongest winds were occurring in that ring of storms.  Several short bands of thunderstorms were revolving around the core of the circulation.  Winds to tropical storm force only extended out 35 miles (55 km) from the center of circulation.  Storms near the core of Beryl were generating upper level divergence which was pumping mass away from the tropical storm.

Tropical Storm Beryl will move through an environment somewhat favorable for intensification during the next day or two.  Beryl will move over water where the Sea Surface Temperature is near 26.5°C.  There is cooler water north of the expected track of Beryl, which would limit intensification if the tropical storm wobbles toward the north.  An upper level ridge north of Tropical Storm Beryl will generate easterly winds which will blow toward the top of the circulation.  The wind speed is similar at all level and the vertical wind shear will be modest.  Small tropical cyclones can intensify or weaken rapidly.  Beryl is likely strengthen on Friday and it could intensify into a hurricane.

Tropical Storm Beryl was moving south of the subtropical high over the Atlantic Ocean.  The high was steering Beryl toward the west.  A general motion toward the west-northwest is forecast during the next two to three days.  On its anticipated track Tropical Storm Beryl could be east of the Lesser Antilles on Sunday.

Tropical Depression Two Forms East of the Lesser Antilles

Tropical Depression Two formed east of the Lesser Antilles on Thursday morning.  At 11:00 a.m. EDT on Thursday the center of Tropical Depression Two was located at latitude 10.2°N and longitude 41.4°W which put it about 1385 miles (2230 km) east-southeast of the Lesser Antilles.  It was moving toward the west at 16 m.p.h. (26 km/h).  The maximum sustained wind speed 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 1009 mb.

A distinct area of low pressure developed in the northern end of a tropical wave on Thursday and the National Hurricane Center designated the system as Tropical Depression Two.  The circulation of the depression was quite small.  Several short bands of showers and thunderstorms were revolving around the center of circulation.  Storms near the center were beginning to generate upper level divergence which was pumping mass away from the depression.

Tropical Depression Two will move through an environment somewhat favorable for intensification.  It will move over water where the Sea Surface Temperature is near 26.5°C.  However, there is cooler water to the north of the anticipated track and the depression will not intensify if it moves over the cooler water.  An upper level ridge north of the tropical depression will produce easterly winds which will blow toward the top of the circulation.  The wind speeds will be similar at all levels and there will be little vertical wind shear.  Tropical Depression Two is forecast to strengthen into a tropical storm during the next day or two.

Tropical Depression Two was moving around the southern side of the subtropical ridge over the Atlantic Ocean and the ridge was steering the depression toward the west.  The ridge is forecast to steer the depression toward the west-northwest during the next two or three days.  On its anticipated track Tropical Depression Two could be east of the Lesser Antilles on Sunday.

Strengthening Tropical Storm Maria Brings Wind and Rain to Guam

Tropical Storm Maria strengthened quickly on Wednesday and it brought gusty winds and heavy rain to Guam.  The weather station at Andersen Air Force Base on Guam reported sustained winds to 44 m.p.h. (71 km/h) and wind gusts to 72 m.p.h. (116 km/h).  At 5:00 p.m. EDT on Wednesday the center of Tropical Storm Maria was located at latitude 13.9°N and longitude 144.7°E which put it about 5 miles (10 km/h) south of Andersen Air Force Base.  Maria was moving toward the north-northwest at 11 m.p.h. (17 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 987 mb.  Tropical Storm Warnings remained in effect for Guam and Rota.  Tropical Storm Watches were in effect for Saipan and Tinian.

The circulation of Tropical Storm Maria organized quickly on Wednesday.  A tight center of circulation contracted at the center of Maria.  A partial ring of thunderstorms formed on the east side of the center.  Numerous bands of showers and thunderstorms were revolving around the core of the circulation.  Storms around the core generated well developed upper level divergence which pumped mass away in all directions from the tropical storm.  Winds to tropical storm force extended out about 95 miles (155 km) from the center of circulation.

Tropical Storm Maria will move through an environment very favorable for intensification.  Maria will move over water where the Sea Surface Temperature is near 30°C.  Tropical Storm Maria will move under the western portion of an upper level ridge where the upper level winds are weak.  There will little vertical wind shear.  Upper level lows east and west of the ridge will enhance the upper level divergence.  Tropical Storm Maria will strengthen into a typhoon on Thursday.  Maria could intensify rapidly and it is likely to become the equivalent of a major hurricane.

Tropical Storm Maria was moving around the western end of a subtropical ridge which was steering Maria toward the north-northwest.  The ridge is forecast to steer Maria toward the northwest during the next few days.  On its anticipated track Tropical Storm Maria will move away from the Marianas and toward the Ryukyu Islands.  Tropical Storm Maria will continue to cause gusty winds and drop locally heavy rain on the southern Marianas for a few more hours.  Conditions will improve on Thursday when Maria moves away the Marianas.

Tropical Storm Maria Prompts Warning for Guam

Tropical Depression 10W strengthened into Tropical Storm Maria on Wednesday and a Tropical Storm Warning was issued for Guam.  At 5:00 a.m. EDT on Wednesday the center of Tropical Storm Maria was located at latitude 12.7°N and longitude 145.9°E which put it about 95 miles (155 km) southeast of Guam.  Maria 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 1000 mb.  Tropical Storm Warnings were in effect for Guam and Rota.  Tropical Storm Watches were in effect for Saipan and Tinian.

The center of circulation in former Tropical Depression 10W became more well organized on Wednesday and the Japan Meteorological Agency designated the system as Tropical Storm Maria.  The circulation was still increasing in organization.  There was a distinct low level center of circulation.  Numerous bands of showers and thunderstorms were revolving around the center of circulation.  Storms near the center were generating upper level divergence which was pumping mass away from the tropical storm.

Tropical Storm Maria will move through an environment very favorable for intensification during the next few days.  Maria will move over water where the Sea Surface Temperature is near 30°C.  Tropical Storm Maria will move under the western end of an upper level ridge that is between two upper level lows which are east and west of the ridge.  The upper level winds will be relatively weak and there will be little vertical wind shear.  The combination of the ridge and two upper level lows will increase the upper level divergence.  Tropical Storm Maria will continue to strengthen.  Maria will become a typhoon later this week.  It could intensify rapidly once an eye forms and the inner core is well developed.

Tropical Storm Maria is moving around the western end of a subtropical ridge which is steering Maria toward the north-northwest.  On its anticipated track the center of Tropical Storm Maria will move near Guam and Rota later today.  A general motion toward the northwest is forecast for the next several days.  Maria could move in the direction of the Ryukyu Islands at the end of the week.

Tropical Storm Maria will bring gusty winds and heavy rain to the southern Mariana Islands.  The strongest winds and heaviest rain will affect Guam and Rota.  Gusty winds and heavy rain will also affect Saipan and Tinian.  Heavy rain could produce flash floods.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Prapiroon was moving over the Sea of Japan.  Prapiroon was bringing wind and rain to the northern Islands of Japan including Hokkaido and Honshu.  At 5:00 a.m. EDT on Wednesday the center of Tropical Storm Prapiroon was located at latitude 39.6°N and longitude 135.6°E which put it about 360 miles (585 km) west-southwest of Misawa, Japan.  Prapiroon was moving toward the northeast at 25 m.p.h. (40 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were winds gusts to 65 m.p.h. (105 km/h).  The minimum surface pressure was 987 mb.

Typhoon Prapiroon Brings Wind and Rain to Kyushu

Typhoon Prapiroon brought wind and rain to Kyushu on Monday night.  At 11:00 p.m. EDT on Monday the center of Typhoon Prapiroon was located at latitude 32.8°N and longitude 128.6°E which put it about 110 miles (180 km) southwest of Sasebo, Japan.  Prapiroon was moving toward the north-northeast at 17 m.p.h. (27 km/h).  The maximum sustained wind speed was 80 m.p.h. (130 km/h) and there were wind gusts to 100 m.p.h. (160 km/h).  The minimum surface pressure was 968 mb.

Rainbands on the eastern side of Typhoon Prapiroon were moving over parts of Kyushu.  Those bands were causing gusty winds and they were dropping locally heavy rain.  The circulation of Typhoon Prapiroon was exhibiting the effects of a more midlatitude environment.  Drier air was wrapping around the western and southern portions of the typhoon.  The bands in those parts of Prapiroon consisted primarily of showers and low clouds.  The western portion of the eyewall was also weakening.  There were still strong thunderstorms in the eastern half of the eyewall and that was where the strongest winds were occurring.  Several bands of showers and thunderstorms on the eastern side of the circulation were revolving around the core of Typhoon Prapiroon.

Typhoon Prapiroon will be moving through an environment that will cause it to weaken.  Prapiroon was moving over water where the Sea Surface Temperature was near 26°C.  However, it will move over water where the Sea Surface Temperature is near 24°C when it moves north of Japan.  An upper level trough west of South Korea will produce southwesterly winds which will cause vertical wind shear.  The combination of cooler water and more vertical wind shear will cause Typhoon Prapiroon to weaken to a tropical storm on Tuesday.  Prapiroon could begin a transition to an extratropical cyclone because of the effects of the midlatitude environment.

Typhoon Prapiroon was being steered toward the north-northeast by the upper level trough.  Stronger westerly winds will steer Prapiroon more toward the northeast when it gets north of Japan.  On its anticipated track the center of Typhoon Prapiroon will pass near the northwestern portion of Kyushu.  The center of Prapiroon is forecast to pass between south Korean and Japan and then to move over the Sea of Japan.  Rainbands on the eastern side of Typhoon Prapiroon will cause gusty winds and drop heavy rain over parts of Kyushu.  Heavy could cause flash floods in some locations.  Prapiroon could also bring wind and rain to southeastern South Korea and parts of northern Honshu.

Elsewhere over the Western North Pacific Ocean Tropical Depression 10W formed southeast of Guam.  At 11:00 p.m. EDT on Monday the center of Tropical Depression 10W was located at latitude 10.6°N and longitude 145.7°E which put it about 205 miles (330 km) south-southeast of Guam.  It was moving toward the north-northwest at 6 m.p.h. (10 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 1003 mb.  A Tropical Storm Warning was issued for Guam.  A Tropical Storm Watch was issued for Tinian and Saipan.

Fabio Strengthens to a Hurricane South of Baja California

Former Tropical Storm Fabio strengthened into a hurricane Monday morning as it moved south of Baja California.  At 11:00 a.m. EDT on Monday the center of Hurricane Fabio was located at latitude 12.8°N and longitude 110.9°W which put it about 700 miles (1125 km) south of the southern tip of Baja California.  Fabio was moving toward the west-northwest at 9 m.p.h. (15 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 989 mb.

The inner core of Hurricane Fabio exhibited signs of greater organization on Monday morning.  Microwave satellite imagery provided evidence of a rainband wrapping around the southern and eastern sides of the center of circulation.  There were intermittent signs that an eye could be forming at the center of circulation.  Several bands of showers and thunderstorms were revolving around the core of the circulation.  The strongest thunderstorms were occurring in bands south and east of the center of Hurricane Fabio.  The bands north and west of the center were weaker, which may indicate that there was some drier air in those parts of the circulation.  Thunderstorms near the core of Fabio were generating upper level divergence which was pumping mass away from the hurricane in all directions.

Hurricane Fabio will be moving through an environment that is very favorable for intensification.  Fabio will move over water where the Sea Surface Temperature is near 28.5°C.  It will move through an area where the upper level winds are weak and there will be little vertical wind shear.  It will continue to strengthen and it could intensify rapidly once an eye forms and persists.  Fabio is forecast to strengthen to a major hurricane on Tuesday.

Hurricane Fabio is moving south of a subtropical ridge which is steering the hurricane toward the west-northwest.  The west-northwesterly motion is forecast to continue during the next several days.  On its anticipated track Hurricane Fabio will move away from Baja California.

Typhoon Prapiroon Brings Winds and Rain to Okinawa

Typhoon Prapiroon brought wind and rain to Okinawa on Sunday.  At 5:00 p.m. EDT on Sunday the center of Typhoon Prapiroon was located at latitude 26.8°N and longitude 126.8°E which put it about 65 miles (100 km) west-southwest of Okinawa.  Prapiroon 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 978 mb.

The circulation of former Tropical Storm Prapiroon became much more well organized on Sunday.  A circular eye formed at the center of circulation and Prapiroon strengthened into a typhoon.  A ring of thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms.  Several bands of showers and thunderstorms in the eastern half of the typhoon were revolving around the center of circulation.  Bands northwest of the center consisted mostly of showers and low clouds.  Storms in the core of the circulation were generating upper level divergence which was pumping mass away to the east of the typhoon.

Typhoon Prapiroon will move through an environment favorable for intensification during the next 12 to 24 hours.  Prapiroon 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.  Typhoon Prapiroon could intensify during the next 12 to 24 hours.  Prapiroon will move over cooler water in a day or so.  It will also reach a location where an upper level trough west of South Korea will cause more vertical wind shear.  An environment of cooler water and more wind shear will cause Typhoon Prapiroon to weaken at that time.

Typhoon Prapiroon is moving around the western end of a subtropical ridge which is steering it toward the north.  On its anticipated track the center of Typhoon Prapiroon will pass west of Okinawa and the northern Ryukyu Islands.  Winds to typhoon force extend out about 30 miles (50 km) east of the center of circulation.  Winds to tropical storm force extend out about 150 miles (240 km) east of the center.  So, even though the center of Typhoon Prapiroon will pass west of the northern Ryukyu Islands, it will bring gusty winds and heavy rain.  Typhoon Prapiroon could approach western Kyushu in 24 hours.  When Prapiroon moves farther north the trough west of South Korea will start to steer the typhoon more toward the northeast.

Tropical Storm Fabio Develops West of Mexico

Tropical Storm Fabio developed west of Mexico on Sunday.  At 11:00 a.m. EDT on Sunday the center of Tropical Storm Fabio was located at latitude 12.0°N and longitude 107.4°W which put it about 770 miles (1240 km) south-southeast of the southern tip of Baja California.  Fabio was moving toward the west-northwest at 13 m.p.h. (20 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 1000 mb.

The circulation of Tropical Storm Fabio was still organizing.  There was a broad low level center of circulation, but it did not have a well developed inner core.  Multiple bands of showers and thunderstorms were revolving around the broad low level center.  The storms in the rainbands were generating some upper level divergence which was starting to pump mass away from the tropical storm.

Tropical Storm Fabio will move through an environment that is very favorable for intensification.  Fabio will move over water where the Sea Surface Temperature is near 28.5°C.  An upper level ridge northeast of Tropical Storm Fabio will produce easterly winds which will blow toward the top of the circulation.  However, the wind speed will be similar at all levels and there will not be much vertical wind shear.  Tropical Storm Fabio will continue to intensify in the favorable environment.  Once a primary rainband wraps around the center of circulation, an inner core will develop.  Tropical Storm Fabio could intensify rapidly when an eye starts to form.  Fabio could strengthen into a major hurricane in two or three days.

Tropical Storm Fabio was moving south of a subtropical ridge which was steering the tropical storm toward the west-northwest.  A general west-northwesterly motion is expected to continue during the next few days.  On its anticipated track the center of Tropical Storm Fabio will pass well to the south of Baja California.

Elsewhere over the Eastern North Pacific Ocean Tropical Depression Emilia continued to weaken over cooler water.  At 11:00 a.m. EDT on Sunday the center of Tropical Depression Emilia was located at latitude 19.3°N and longitude 123.0°W which put it about 880 miles (1415 km) west-southwest of the southern tip of Baja California.  Emilia was moving toward the west-northwest 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 1006 mb.