Tag Archives: HWISI

Tropical Cyclone Gelena Strengthens to Equivalent of a Major Hurricane

Tropical Cyclone Gelena strengthened into the equivalent of a major hurricane on Friday.  At 4:00 p.m. EST on Friday the center of Tropical Cyclone Gelena was located at latitude 16.8°S and longitude 56.9°E which put it about 265 miles (425 km) north of Port Louis, Mauritius.  Gelena was moving toward the southeast at 15 m.p.h. (24 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. (205 km/h).  The minimum surface pressure was 953 mb.

The circulation around Tropical Cyclone Gelena strengthened and grew larger on Friday.  An eye appeared intermittently at the center of Gelena on satellite imagery.  A ring of strong thunderstorms surrounded the eye and the strongest winds were occurring in the ring of storms.  More bands of showers and thunderstorms were revolving around the core of the circulation.  Winds to hurricane/typhoon force extended out about 50 miles (80 km) from the center of circulation.  Winds to tropical storm force extended out about 175 miles (280 km) from the center.

The Hurricane Intensity Index (HII) for Tropical Cyclone Gelena was 23.6.  The Hurricane Size Index (HSI) was 17.3 and the Hurricane Wind Intensity Size Index (HWISI) was 40.9.  Those indices indicated that tropical Cyclone Gelena was capable of causing major regional damage.

Tropical Cyclone Gelena will move through an environment somewhat favorable for intensification for another 12 to 24 hours.  Gelena will move over water where the Sea Surface Temperature is near 29°C.  An upper level trough near Madagascar will produce westerly winds which are blowing toward the top of Tropical Cyclone Gelena.  Those winds will produce some vertical wind shear and they will inhibit upper level divergence toward the western periphery of Gelena.  The wind shear will inhibit intensification, but Tropical Cyclone Gelena could strengthen on Saturday.

Tropical Cyclone Gelena will move south of a subtropical ridge.  The ridge will steer Gelena in a southeasterly direction.  On its anticipated track Tropical Cyclone Gelena will pass north of Mauritius.  However, Gelena could approach Rodrigues within 36 hours.  Tropical Cyclone Gelena could bring strong winds and heavy rain to Rodrigues.

Elsewhere over the southern Indian Ocean, Tropical Cyclone Funani was speeding toward colder water.  At 4:00 p.m. EST on Friday the center of Tropical Cyclone Funani was located at latitude 26.3°S and longitude 73.4°E which put it about 805 miles (1295 km) east-southeast of Rodrigues.  Funani was moving toward the southeast at 28 m.p.h. (45 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. (170 km/h).  The minimum surface pressure was 977 mb.

Powerful Tropical Cyclone Cilida Strengthens to Equivalent of Cat. 4 Hurricane

Powerful Tropical Cyclone Cilida strengthened to the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale on Friday.  At 4:00 p.m. EST on Friday the center of Tropical Cyclone Cilida was located at latitude 15.9°S and longitude 57.8°E which put it about 310 miles (505 km) north of Port Louis, Mauritius.  Cilida was moving toward the south at 6 m.p.h. (10 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 931 mb.

The circulation of Tropical Cyclone Cilida was very well organized.  A 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.  Several bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Cilida.  Storms around the core were generating strong upper level divergence which was pumping mass away from the tropical cyclone.

The circulation around Tropical Cyclone Cilida was relatively small.  Winds to hurricane/typhoon force extended out about 35 miles (55 km) from the center of circulation.  Winds to tropical storm force only extended out about 95 miles (155 km) from the center.  The Hurricane Intensity Index (HII) for Tropical Cyclone Cilida was 31.6.  The Hurricane Size Index (HSI) was 11.0 and the Hurricane Wind Intensity Size Index (HWISI) was 42.6.

Tropical Cyclone Cilida may have peaked in intensity, but it will move through an environment capable of supporting a strong tropical cyclone for another 24 to 36 hours.  Cilida will move over water where the Sea Surface Temperature is near 28°C for about another 24 hours.  Then it will start to move over colder waters.  Tropical Cyclone Cilida will move toward the upper level westerly winds in the middle latitudes and the vertical wind shear will increase in about 36 hours.  When Cilida moves over colder water and under stronger upper level winds, it will weaken more quickly.

Tropical Cyclone Cilida is moving around the western end of a subtropical ridge over the South Indian Ocean.  The ridge will start to steer Cilida toward the southeast on Saturday.  On its anticipated track, the center of Tropical Cyclone Cilida could be a little northeast of Mauritius in about 24 hours.  It will still be a powerful tropical cyclone at that time.

Elsewhere over the South Indian Ocean, Tropical Cyclone Kenanga continued to weaken well to the southeast of Diego Garcia.  At 4:00 p.m. EST on Friday the center of Tropical Cyclone Kenanga was located at latitude 16.3°S and longitude 78.5°E which put it about 760 miles (1225 km) southeast of Diego Garcia.  Kenanga was moving toward the west at 7 m.p.h. (11 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 982 mb.

Typhoon Yutu Brings Wind and Rain to Luzon

Typhoon Yutu brought wind and rain to Luzon on Monday.  At 5:00 p.m. EDT on Monday the center of Typhoon Yutu was located at latitude 16.8°N and longitude 122.4°E which put it about 45 miles (75 km east of Ilagan, Philippines.  Yutu was moving toward the west at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 105 m.p.h. (170 km/h) and there were wind gusts to 125 m.p.h. (200 km/h).  The minimum surface pressure was 949 mb.

The center of Typhoon Yutu made landfall near Palanan Point on the northeast coast of Luzon late on Monday.  Yutu had a large circulation.  Winds to typhoon force extended out about 80 miles (130 km) from the center of circulation.  Winds to tropical storm force extended out about 270 miles (435 km) from the center.  The Hurricane Intensity Index (HII) for Typhoon Yutu was 17.8.  The Hurricane Size Index (HSI) was 25.5 and the Hurricane Wind Intensity Size Index (HWISI) was 43.3.  Typhoon Yutu is capable of causing widespread serious damage.

Typhoon Yutu could cause a storm surge of up to 10 feet (3 meters) on the northeast coast of Luzon.  It will also produce destructive winds as it moves across northern Luzon.  Yutu will move westward across Luzon.  It will move into the South China Sea south of Vigan, Philippines.  Typhoon Yutu will drop very heavy rain over parts of northern Luzon and flash flooding will be very likely.  Rapid runoff into the Cagayan River could cause it to flood.

Typhoon Yutu will move over the Sierra Madre mountains and the Cordillera Central when it moves across northern Luzon.  Those two mountain ranges will disrupt the lower levels of the circulation and Yutu will be weaker when it reaches the South China Sea.  Yutu could still be a typhoon when it moves back over water, but it may weaken to a tropical storm by then.

Typhoon Yutu will move around the western end of a ridge of high pressure over the Western North Pacific Ocean when it reaches the South China Sea.  Yutu will move toward the north when it reaches the western end of the ridge and it could approach China in four or five days.

Powerful Typhoon Yutu Threatens Northern Luzon

Powerful Typhoon Yutu continued to pose a threat to northern Luzon on Saturday.  At 11:00 p.m. EDT on Saturday the center of Typhoon Yutu was located at latitude 18.0°N and longitude 129.6°E which put it about 475 miles (765 km) east of Cape Engano, Philippines.  Yutu was moving toward the west at 12 m.p.h. (19 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 929 mb.

There were minor fluctuations in its intensity on Saturday, but Typhoon Yutu remains a very powerful tropical cyclone.  A circular eye is at the center of circulation.  The eye is surrounded by a ring of strong thunderstorms and the strongest winds are occurring in that ring of storms.  Several bands of showers and thunderstorms are revolving around the core of Typhoon Yutu.  Storms around the core are generating strong upper level divergence which is pumping mass away from the typhoon in all directions.

Typhoon Yutu has a large circulation.  Winds to typhoon force extend out about 75 miles (120 km) from the center of circulation.  Winds to tropical storm force extend out about 250 miles (400 km) from the center.  The Hurricane Intensity Index (HII) for Typhoon Yutu is 31.6.  The Hurricane Size Index (HSI) is 28.3 and the Hurricane Wind Intensity Size Index (HWISI) is 59.9.  Typhoon Yutu is capable of causing wide spread significant damage.

Typhoon Yutu will continue to move south of a ridge of high pressure over the Western North Pacific Ocean.  The ridge will steer Yutu in a generally westerly direction for another 36 to 48 hours.  On its anticipated track Typhoon Yutu will reach northern Luzon in about 36 to 42 hours.  Yutu will create a storm surge at the coast.  It will cause significant wind damage over northern Luzon.  Yutu will also drop locally heavy rain and cause flash floods over parts of northern Luzon.

Powerful Typhoon Yutu Churns Toward Northern Luzon

Powerful Typhoon Yutu churned toward northern Luzon on Friday.  At 5:00 p.m. EDT on Friday the center of Typhoon Yutu was located at latitude 17.7°N and longitude 135.9°E which put it about 900 miles (1450 km) east of Cape Engano, Philippines.  Yutu was moving toward the west-northwest at 17 m.p.h. (28 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 920 mb.

After completing an eyewall replacement cycle Typhoon Yutu strengthened again on Friday.  Yutu is once again the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale.  The eyewall replacement cycle also caused an increase in the size of Typhoon Yutu’s circulation.  Winds to typhoon force extend out about 80 miles (130 km) from the center of circulation.  Winds to tropical storm force extend out about 260 miles (420 km) from the center.  The Hurricane Intensity Index (HII) is 35.0.  The Hurricane Size Index (HSI) is 28.9 and the Hurricane Wind Intensity Size Index (HWISI) is 63.9.

Typhoon Yutu has a large, very well organized circulation and it will remain in an environment capable of supporting a powerful typhoon for several more days.  Yutu will move over water where the Sea Surface Temperature is near 31°C.  It will move through an area where the upper level winds are weak and there will be little vertical wind shear.  Typhoon Yutu could strengthen a little more during the next 12 to 24 hours.  At some point another rainband is likely to wrap around the existing eye and eyewall, and another eyewall replacement cycle could occur.  If there is another eyewall replacement cycle, then Yutu would weaken, at least temporarily.

Typhoon Yutu will move south of a ridge of high pressure over the Western North Pacific Ocean.  The ridge will steer Yutu in a generally westward direction.  On its anticipated track Typhoon Yutu could reach northern Luzon in about four days.  Yutu is very likely to be a strong typhoon when it approaches Luzon.

Dangerous Typhoon Yutu Slams Tinian and Saipan

Dangerous Typhoon Yutu slammed Tinian and Saipan on Wednesday.  At 5:00 p.m. EDT on Wednesday the center of Typhoon Yutu was located at latitude 15.5°N and longitude 144.8°E which put it about 35 miles (55 km) west-northwest of Saipan.  Yutu was moving toward the northwest at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 175 m.p.h. (280 km/h) and there were wind gusts to 205 m.p.h. (330 km/h).  The minimum surface pressure was 908 mb.

Typhoon Warnings were in effect for Rota, Tinian and Saipan.  Tropical Storm Warnings were in effect for Guam, Alamagan, Pagan and Agrihan.

The eye of Typhoon Yutu passed directly over Tinian on Wednesday and the northern side of the eyewall moved over Saipan.  So, they would have experienced the strongest parts of Typhoon Yutu.  The Hurricane Intensity Index (HII) for Typhoon Yutu is 40.4.  The Hurricane Size Index (HSI) is 26.7 and the Hurricane Wind Intensity Size Index (HWISI) is 67.1.  Typhoon Yutu was capable of causing widespread catastrophic damage when it passed over Tinian and Saipan.

Yutu is still a very powerful typhoon, but an eyewall replacement cycle appears to have started.  A rainband has wrapped around the original eye and eyewall.  The inner eye and eyewall are still intact and the strongest winds are occurring in the ring of thunderstorms that surround the original eye.  The imminent formation of a second, outer eyewall increased the size of the circulation around Typhoon Yutu.  Winds to typhoon force extend out about 70 miles (110 km) from the center of circulation.  Winds to tropical storm force extend out about 240 miles (390 km) from the center.

Typhoon Yutu will remain in an environment capable of supporting a very strong typhoon for several more days.  Yutu will move over water where the Sea Surface Temperature is near 31°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  The incipient eyewall replacement cycle will cause Typhoon Yutu to weaken when the inner eyewall dissipates.  However, Yutu could strengthen again, if it remains in a favorable environment and the outer eyewall contracts closer to the center of circulation.  Typhoon Yutu is likely to remain a powerful typhoon during the next 48 hours.

Typhoon Yutu will move southwest of a ridge of high pressure over the Western North Pacific Ocean.  The ridge will steer Yutu toward the west-northwest during the next several days.  On its anticipated track Typhoon Yutu will move away from the Northern Marianas, and conditions should gradually improve there.  Yutu could be south of Okinawa in four or five days.

Typhoon Yutu Intensifies Rapidly to Equivalent of Cat. 4 Hurricane, Imminent Threat to Marianas

Typhoon Yutu intensified rapidly on Tuesday into the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale and Yutu posed an imminent threat to the Marianas.  At 11:00 p.m. EDT on Tuesday the center of Typhoon Yutu was located at latitude 13.6°N and longitude 147.5°E which put it about 155 miles (255 km) east-southeast of Rota.  Yutu was moving toward the northwest at 14 m.p.h. (22 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 935 mb.

Typhoon Warnings are in effect for Rota, Saipan and Tinian.  Tropical Storm Warnings are in effect for Guam, Alamagan, Pagan and Agrihan.

Typhoon Yutu intensified rapidly during the past 24 hours.  A circular eye developed at the center of Yutu.  The eye is surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Numerous bands of showers and thunderstorms were revolving around the core of Typhoon Yutu.  Storms near the core were generating strong upper level divergence which was pumping mass away from the typhoon in all directions.  The removal of mass allowed the surface pressure to decrease rapidly.

Typhoon Yutu has a large circulation.  Winds to typhoon force extend out about 65 miles (105 km) from the center of circulation.  Winds to tropical storm force extend out about 210 miles (335 km) from the center.  The Hurricane Intensity Index (HII) for Typhoon Yutu is 31.6.  The Hurricane Size Index (HSI) is 20.8 and the Hurricane Wind Intensity Size index (HWISI) is 52.4.  Typhoon Yutu is capable of causing widespread extensive damage.

Typhoon Yutu will move through an environment favorable for further intensification during the next several days.  Yutu will move over water where the Sea Surface Temperature is near 31°C.  It will move through a region where the upper level winds are weak and there is little vertical wind shear.  Typhoon Yutu could intensify into the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale.  At some point a rainband will wrap around the existing eye and eyewall, and an eyewall replacement cycle will occur.  Yutu will weaken during the eyewall replacement cycle, but the typhoon could strengthen afterwards if it remains in an environment favorable for intensification.

Typhoon Yutu will move around the southwestern portion of a ridge of high pressure over the Western North Pacific Ocean.  The ridge will steer Yutu in a general west-northwesterly direction.  On its anticipated track Typhoon Yutu will reach the Northern Marianas in about 12 hours.  The core of Yutu will pass between Rota and Tinian.  Rota, Tinian and Saipan are likly to have winds to typhoon force.  Typhoon Yutu will be capable of causing extensive damage in those locations.  Guam, Alamagan, Pagan and Agrihan are likely to receive winds to tropical storm force.  Wind speeds will be stronger on the northern part of Guam and the damage potential is greater there than it is for the southern part of Guam.

Major Hurricane Willa Makes Landfall in Mexico

Major Hurricane Willa made landfall on the coast of Mexico between Teacapan and Mazatlan on Tuesday evening.  At 8:00 p.m. EDT on Tuesday the center of Hurricane Willa was located at latitude 22.6°N and longitude 106.0°W which put it about 50 miles (80 km) south-southeast of Mazatlan, Mexico.  Willa was moving toward the north-northeast at 10 m.p.h. (16 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 965 mb.

A Hurricane Warning is in effect for the portion of the coast from San Blas to Mazatlan, Mexico.  Tropical Storm Warnings were in effect for the portions of the coast from Playa Perula to San Blas and from Mazatlan to Bahia Tempehuaya, Mexico.

An eyewall replacement cycle occurred in the core of Hurricane Willa on Tuesday.  When the original inner eyewall dissipated, the core of Willa was larger even though the maximum sustained wind speed was slower.  Winds to hurricane force extend out about 35 miles from the the center of Hurricane Willa.  Winds to tropical storm force extend out about 100 miles from the center of circulation.  The Hurricane Intensity Index (HII) for Hurricane Willa is 22.1.  The Hurricane Size Index (HSI) is 12.7 and the Hurricane Wind Intensity Size Index (HWISI) s 34.8.  Hurricane Willa is capable of causing regional major damage.

Hurricane Willa will produce hurricane force winds along the coast between Tecuala and Mazatlan.  Those winds will be capable of causing major damage.  The winds will also push water toward the coast and a storm surge of 10 to 12 feet (3 to 4 meters) is possible.  Hurricane Willa will dissipate fairly quickly when it moves over the Sierra Madre Occidental Mountains.  However, Willa will drop locally heavy rain over the southern part of Sinaloa and over Durango.  The locally heavy rain is likely to cause flash floods in some locations.

Hurricane Willa Strengthens to Cat. 5, Poses Imminent Threat to Mexico

Hurricane Willa strengthened Monday morning to Category 5 on the Saffir-Simpson Scale and Willa poses an imminent threat to Mexico.  At 11:00 a.m. EDT on Monday the center of Hurricane Willa was located at latitude 19.1°N and longitude 107.2°W which put it about 135 miles (215 km) southwest of Cabo Corrientes.  Willa 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 190 m.p.h. (305 km/h).  The minimum surface pressure was 925 mb.

A Hurricane Warning was in effect for the portion of the coast from San Blas to Mazatlan, Mexico.  Tropical Storm Warnings were in effect for the portion of the coast from Playa Perula to San Blas and from Mazatlan to Bahia Tempehuaya, Mexico.

Hurricane Willa strengthened from a tropical storm to a Category 5 hurricane in 36 hours.  Willa is a small, very well organized hurricane.  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 are occurring in that ring of storms.  Several bands of showers and thunderstorms are revolving around the core of Hurricane Willa.  Storms near the core are generating strong upper level divergence which is pumping mass away from the hurricane.

Hurricane Willa is a small hurricane.  Winds to hurricane force extend out about 30 miles ( 50 km) from the center of Willa.  Winds to tropical storm force extend out about 100 miles (160 km) from the center of circulation.  The Hurricane Intensity Index (HII) for Hurricane Willa is 35.0.  The Hurricane Size Index (HSI) is 9.7 and the Hurricane Wind Intensity Size Index (HWISI) is 44.7.  The core of Hurricane Willa is capable of causing catastrophic damage.

Hurricane Willa will remain in an environment capable of supporting strong hurricanes for about another 24 hours.  Willa will move over water where the Sea Surface Temperature is near 29°C.  It will move through an environment where the upper level winds are weak and there will be little vertical wind shear.  If an outer rainband wraps around the existing eye and eyewall, then an eyewall replacement cycle could cause Hurricane Willa to weaken.  An upper level trough near the West Coast of the U.S. will produce southwesterly winds which will blow toward the top of Hurricane Willa on Tuesday.  Those winds will cause vertical wind shear and the shear will start to weaken Willa.  Since Willa is a small hurricane, it will weaken faster than a larger hurricane would weaken.

Hurricane Willa will move around the western end of a ridge of high pressure over Mexico.  The ridge will steer Willa toward the north for another 12 hours or so.  Then the upper level trough will turn Hurricane Willa toward the northeast.  On its anticipated track Hurricane Willa will move over the Islas Marias on Tuesday morning.  Willa will reach the coast of Mexico between San Blas and Mazatlan on Tuesday afternoon or evening.

Hurricane Willa could still be a major hurricane when it reaches the coast of Mexico.   Willa will be capable of causing major damage.  The core of Hurricane Willa will bring damaging winds.  It will also produce a storm surge of 10 to 13 feet (3 to 4 meters) near where core of Willa makes landfall.  Hurricane Willa will drop heavy rain over Nayarit, Sinaloa and Durango.  The heavy rain could cause flash floods in some locations.

Elsewhere over the Eastern North Pacific Ocean, upper level divergence from Hurricane Willa appeared to be causing wind shear which was weakening Tropical Storm Vicente.  At 11:00 a.m. EDT on Monday the center of Tropical Storm Vicente was located at latitude 14.9°N and longitude 100.8°W which put it about 365 miles (590 km) southeast of Manzanillo, Mexico.  Vicente was moving toward the west-northwest at 12 m.p.h. (19 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 1004 mb.

Willa Rapidly Intensifies Into a Major Hurricane, Warnings Issued for Mexico

Hurricane Willa intensified rapidly into a major hurricane on Sunday and Warnings were issued for Mexico.  At 11: 00 p.m. EDT on Sunday the center of Hurricane Willa was located at latitude 17.7°N and longitude 107.2°W which put it about 210 miles (340 km) south-southwest of Cabo Corrientes, Mexico.  Willa was moving toward the north-northwest at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 145 m.p.h. (230 km/h) and there were wind gusts to 170 m.p.h. (275 km/h).  The minimum surface pressure was 941 mb.  Hurricane Willa was a Category 4 hurricane on the Saffir-Simpson Scale.

A Hurricane Warning was in effect for the portion of the coast from San Blas to Mazatlan, Mexico.  A Tropical Storm Warning was in effect for the portion of the coast from Playa Perula to San Blas.  A Tropical Storm Warning was also in effect for the portion of the coast from Mazatlan to Bahia Tempehuaya.

Hurricane Willa intensified from a tropical storm to a Category 4 hurricane in 24 hours.  A small circular eye formed at the center of Hurricane Willa.  The eye was surround by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Several bands of showers and thunderstorms were revolving around the core of Hurricane Willa.  Storms near the core were generating strong upper level divergence which was pumping large quantities of mass away from the hurricane.  The strong divergence allowed the surface pressure to decrease quickly and that caused the wind speeds to increase rapidly.

Willa is a small hurricane.  Winds to hurricane force only extend out about 25 miles (40 km) from the center of Hurricane Willa.  Winds to tropical storm force only extend out about 90 miles (145 km) from the center of circulation.  The Hurricane Intensity Index (HII) for Hurricane Willa is 29.9.  The Hurricane Size Index (HSI) is 8.2 and the Hurricane Wind Intensity Size Index (HWISI) is 38.1.

Hurricane Willa will move through an environment favorable for intensification during the next 12 to 24 hours.  Willa 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 not be much vertical wind shear.  Hurricane Willa could strengthen to a Category 5 hurricane on the Saffir-Simpson Scale during the next 12 hours.  An upper level trough near the west coast of the U.S. will produce southwesterly winds which will start to affect Hurricane Willa in about 24 hours.  Those winds will cause vertical wind shear, which will cause Willa to start to weaken.

Hurricane Willa will move around the western end of a ridge of high pressure over Mexico.  The ridge will steer Willa toward the north on Monday.  The upper level trough near the west coast of the U.S. will turn Hurricane Willa toward the northeast on Tuesday.  On its anticipated track Hurricane Willa could make landfall on the coast of Mexico on Tuesday night.  Willa could be a major hurricane when it approaches the coast.  It will be capable of causing major wind damage and a significant storm surge along the coast.  Willa will also drop locally heavy rain and it could flash floods when it moves inland over Mexico.

Elsewhere over the Eastern North Pacific Ocean Tropical Storm Vicente was moving near the southeastern periphery of Hurricane Willa.  At 11:00 p.m. EDT on Sunday the center of Tropical Storm Vicente was located at latitude 13.9°N and longitude 98.7°W which put it about 220 miles (355 km) south-southeast of Acapulco, Mexico.  Vicente was moving toward the west at 10 m.p.h. (16 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.