Monthly Archives: December 2018

Tropical Cyclone Penny Forms Over Gulf of Carpentaria

Tropical Cyclone Penny formed over the eastern Gulf of Carpentaria on Monday.  At 4:00 p.m. EST on Monday the center of Tropical Cyclone Penny was located at latitude 12.7°S and longitude 140.9°E which put it about 70 miles (110 km) west of Weipa, Australia.  Penny was moving toward the east-southeast at 5 m.p.h. (8 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 996 mb.

A Tropical Cyclone warming was in effect for the portion of the coast from Cape York to Pormpuraaw including adjacent coast areas.

A tropical low over the eastern Gulf of Carpentaria strengthened on Monday and the Australian Bureau of Meteorology designated the system as Tropical Cyclone Penny.  The circulation around Tropical Cyclone Penny was still organizing.  A band of showers of showers and thunderstorms wrapped around the western and northern sides of the center of circulation.  Other bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Penny.  Storms near the core were generating upper level divergence which was pumping mass away from the tropical cyclone.

Tropical Cyclone Penny could strengthen during the next few hours.  Penny 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 weaker and there will be little vertical wind shear.  Tropical Cyclone Penny will make landfall on the Cape York Peninsula near Weipa in about 12 hours.  Penny will weaken while it crosses northern Queensland.  Tropical Cyclone Penny could strengthen again when it moves over the Coral Sea in 24 to 36 hours.

Tropical Cyclone Penny will move south of a ridge centered northeast of Australia.  The ridge will steer Penny in an east-southeasterly direction.  On its anticipated track Tropical Cyclone Penny will make landfall on the Cape York Peninsula near Weipa in about 12 hours.  Penny could emerge over the Coral Sea south of the Lockhart River in 24 to 36 hours.

Tropical Cyclone Penny will bring rain and wind to the west coast of the Cape York Peninsula.  Penny will drop locally heavy rain over parts of northern Queensland.  The heavy rain could cause flooding.  A Flood Watch is in effect for coastal catchments north of Caldwell, Australia and the Cape York Peninsula.

Tropical Depression 35W Drops Heavy Rain on the Philippines

Tropical Depression 35W dropped heavy rain on parts of the Philippines on Friday.  At 10:00 a.m. EST on Friday the center of Tropical Depression 35W was located at latitude 10.7°N and longitude 127.3°E which put it about 135 miles (215 km) east of Tacloban, Philippines.  It was moving toward the west at 7 m.p.h. (11 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 1001 mb.

The distribution of rain around Tropical Depression 35W was asymmetrical.  Most of the heavy rain was falling in thunderstorms northwest of the center of circulation.  A few thunderstorms were developing northeast of the center, but most of the bands in the rest of the tropical depression consisted of showers and lower clouds.  Tropical Depression 35W was located southwest of a strong subtropical ridge over the Western North Pacific Ocean.  The ridge was producing strong upper level winds which were blowing from the east-southeast.  Those winds were blowing across the top of the tropical depression and they were causing strong vertical wind shear.  The strong wind shear was the reason why most of the heavy rain was falling northwest of the center of circulation.

Tropical Depression 35W will move through an environment marginally favorable for intensification.  It will move over water where the Sea Surface Temperature is near 29°C.  The subtropical ridge will continue to cause vertical wind shear.  However, the tropical depression could move under slightly weaker upper level winds when it moves a little farther to the west.  If it moves under weaker upper level winds, then Tropical Depression 35W could strengthen into a tropical storm.

The subtropical ridge will steer Tropical Depression 35W westward for another 24 to 36 hours.  When the depression moves west of the Philippines, it will encounter strong northeasterly winds blowing around a high pressure system over Asia.  Those winds will steer Tropical Depression 35W toward the southwest when it moves over the South China Sea.

Tropical Depression 35W will drop heavy rain over parts of the Philippines.  The heaviest rain is likely to fall over Samar, Cebu, Bohoi, Panay, Mindoro and the southeastern part of Luzon.  The heavy rain will cause flash floods, and mudslides could occur in regions of steeper terrain.

Tropical Cyclone Cilida Passes East of Mauritius

Strong Tropical Cyclone Cilida passed east of Mauritius on Saturday night.  At 10:00 p.m. EST on Saturday the center of Tropical Cyclone Cilida was located at latitude 20.2°S and longitude 60.3°E which put it about 170 miles (275 km) east of Port Louis, Mauritius.  Cilida was moving toward the south-southeast at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 145 m.p.h. (230 km/h).  The minimum surface pressure was 953 mb.

Tropical Cyclone Cilida was being steered to the south-southeast between an upper level trough near Madagascar and a subtropical ridge over the South Indian Ocean.  Those weather systems steered Cilida east of Mauritius.  Northwesterly winds blowing on the eastern side of the upper level trough were causing vertical wind shear.  Tropical Cyclone Cilida was weakening, but it was still the equivalent of a major hurricane.  There was a circular eye at the center of Cilida.  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.

Winds to hurricane/typhoon force extended out about 45 miles (75 km) from the center of Tropical Cyclone Cilida.  Winds to tropical storm force extended out about 115 miles (185 km) from the center.  Cilida passed far enough to the east of Mauritius that the strongest winds remained offshore.  A weather station at Belle Mare on the east coast of Mauritius reported a maximum wind speed of 38 m.p.h. (61 km/h).  An automated weather station on Signal Mountain reported a maximum wind speed of 49 m.p.h. (79 km/h).  Tropical Cyclone Cilida probably brought winds to tropical storm force to Mauritius, especially at higher elevations.

The stronger rainbands around Tropical Cyclone Cilida also passed east of Mauritius.  Cilida dropped light rain over most of Mauritius.  Heavier rain did fall over locations where the wind blew up the slopes of ridges and mountains.  1.44 inches (36.6 mm) of rain fell at Mon Bois and 1.31 inches (33.4 mm) fell at Mare Aux Vacoas.

The upper level trough over Madagascar will continue to steer Tropical Cyclone Cilida toward the south-southeast.  On its anticipated track Cilida will move farther away from Mauritius.  Tropical Cyclone Cilida will continue to weaken as it moves over cooler Sea Surface Temperatures and the vertical wind shear increases.

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.

Tropical Cyclone Cilida Quickly Intensifies Into Equivalent of a Major Hurricane

Tropical Cyclone Cilida quickly intensified into the equivalent of a major hurricane north of Mauritius on Thursday.  At 10:00 p.m. EST on Thursday the center of Tropical Cyclone Cilida was located at latitude 14.5°N and longitude 58.0°E which put it about 410 miles (660 km) north of Port Louis, Mauritius.  Cilida was moving toward the southwest at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 120 m.p.h. (195 km/h) and there were wind gusts to 150 m.p.h. (240 km/h).  The minimum surface pressure was 949 mb.

Tropical Cyclone Cilida intensified quickly on Thursday.  A symmetrical, circular eye appeared more distinctly on satellite images.  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 near the core of Cilida generated strong upper level divergence which pumped mass away from the tropical cyclone.  The removal of mass allowed the surface pressure to decrease rapidly and the wind speed increased in response to a larger pressure gradient force.  Winds to hurricane/typhoon force extended out about 35 miles (55 km) from the center of circulation.  Winds to tropical storm force extended out about 120 miles (195 km) from the center.

Tropical Cyclone Cilida will move through an environment favorable for strong tropical cyclones during the next 24 to 36 hours.  Cilida will move over water where the Sea Surface Temperature is near 28°C.  It will move through an area where the upper level winds are weak and there will be little vertical wind shear.  Tropical Cyclone Cilida will get stronger during the next day or so unless an eyewall replacement cycle begins.  If a rainband wraps around the existing eyewall, then an eyewall replacement cycle could cause Cilida to weaken.

Tropical Cyclone Cilida will move around the western end of a subtropical ridge over the South Indian Ocean.  The ridge is likely to steer Cilida toward the southwest for another 12 hours or so.  Tropical Cyclone Cilida will move more toward the south when it reaches the western end of the ridge.  In 36 to 48 hours Cilida will begin to be affected by the westerly winds in the middle latitudes and those winds will start to steer the tropical cyclone toward the southeast,  On its anticipated track Tropical Cyclone Cilida could approach Mauritius in about 36 hours.

Elsewhere over the South Indian Ocean Tropical Cyclone Kenanga weakened slowly well to the southeast of Diego Garcia.  At 10:00 p.m. EST on Thursday the center of Tropical Cyclone Kenanga was located at latitude 16.2°S and longitude 80.2°E which put it about 825 miles (1330 km) southeast of Diego Garcia.  Kenanga was moving toward the west-northwest at 6 m.p.h. (10 km/h).  The maximum sustained wind speed was 95 m.p.h. (155 km/h) and there were wind gusts to 115 m.p.h. (185 km/h).  The minimum surface pressure was 965 mb.

Tropical Cyclone Cilida Forms North of Mauritius

Tropical Cyclone Cilida formed north of Mauritius on Wednesday.  At 10:00 p.m. EST on Wednesday the center of Tropical Cyclone Cilida was located at latitude 12.2°S and longitude 59.8°E which put it about 585 miles (945 km) north-northeast of Port Louis, Mauritius.  Cilida was moving toward the southwest at 5 m.p.h. (8 km/h).  The maximum sustained wind speed was 55 m.p.h. (90 km/h) and there were wind gusts to 70 m.p.h. (110 km/h).  The minimum surface pressure was 989 mb.

The circulation around Tropical Cyclone Cilida organized quickly on Wednesday. A small circular eye formed at the center of circulation.  A ring of strong thunderstorms formed around the eye and the strongest winds were occurring in that ring of storms.  A strong band of storms wrapped around the western and northern sides of Cilida.  Other bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Cilida.  Winds to tropical storm force extended out about 100 miles (160 km) from the center of circulation.

Tropical Storm Cilida will move through an environment favorable for intensification during the next 48 to 72 hours.  Cilida 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.  Cilida is likely to strengthen into the equivalent of a hurricane/typhoon on Thursday and it could intensify rapidly.  Tropical Cyclone Cilida could intensify into the equivalent of a major hurricane in two or three days.

Tropical Cyclone Cilida will move around the western end of a subtropical ridge.  The ridge will steer Cilida toward the south during the next several days.  On its anticipated track Tropical Cyclone Cilida could approach Mauritius from the north in about 48 hours.

Elsewhere over the South Indian Ocean Tropical Cyclone Kenanga drifted southeast of Diego Garcia.  At 10:00 p.m. EST on Wednesday the center Tropical Cyclone Kenanga was located at latitude 16.5°S and longitude 81.9°E which put it about 910 miles (1470 km) southeast of Diego Garcia.  Kenanga was stationary.  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 947 mb.

Tropical Cyclone Kenanga Intensifies Into Equivalent of a Major Hurricane

Tropical Cyclone Kenanga intensified into the equivalent of a major hurricane on Tuesday.  At 10:00 p.m. EST on Tuesday the center of Tropical Cyclone Kenanga was located at latitude 15.9°S and longitude 82.6°E which put it about 920 miles (1485 km) southeast of Diego Garcia.  Kenanga was moving toward the southwest at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 130 m.p.h. (215 km/h) and there were wind gusts to 160 m.p.h. (260 km/h).  The minimum surface pressure was 944 mb.

Tropical Cyclone Kenanga intensified quickly into the equivalent of a major hurricane on Tuesday.  A large circular eye with a diameter of 50 miles (80 km) formed at the center of circulation.  A ring of strong thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Kenanga.  Storms around the core of Kenanga were generating upper level divergence which was pumping mass away to the west and north of the tropical cyclone.  Winds to hurricane/typhoon force extended out about 60 miles (95 km) from the center of circulation.  Winds to tropical storm force extended out about 200 miles (320 km) from the center.

Tropical Cyclone Kenanga may be near its peak intensity.  Kenanga is over water where the Sea Surface Temperature is near 28°C, but it will start to move over slightly cooler water during the next day or two.  Tropical Cyclone Kenanga is in an area where the upper level winds are weak and there is little vertical wind shear.  However, Kenanga will move closer to upper level westerly winds in the middle latitudes later this week and the vertical wind shear will increase.  Tropical Cyclone Kenanga could maintain its intensity or weaken slowly during the next day or so.  Kenanga could weaken more quickly later this week.

Tropical Cyclone Kenanga will move south of a subtropical ridge over the South Indian Ocean.  The ridge will continue to steer Kenanga toward the southwest.  On its anticipated track Tropical Cyclone Kenanga will pass well to the south of Diego Garcia.

Elsewhere over the South Indian Ocean Tropical Cyclone 07S developed north-northeast of Mauritius.  At 10:00 p.m. EST on Tuesday the center of Tropical Cyclone 07S was located at latitude 10.9°S and longitude 60.8°E which put it about 690 miles (1115 km) north-northeast of Port Louis, Mauritius.  It was moving toward the south-southwest at 3 m.p.h. (5 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 998 mb

Tropical Cyclone Phethai Brings Wind and Rain to India

Tropical Cyclone Phethai brought wind and rain to parts of eastern India on Sunday night.  The center of Phethai made landfall southwest of Visakhapatnam, India near the Mouths of the Godavari.  At 10:00 p.m. EST on Sunday the center of Tropical Cyclone Phethai was located at latitude 15.7°N and longitude 82.4°E which put it about 150 miles (240 km) southwest of Visakhapatnam.  Phethai was moving toward the north at 11 m.p.h. (17 km/h).  The maximum sustained wind speed was 55 m.p.h. (90 km/h) and there were wind gusts to 75 m.p.h. (120 km/h).  The minimum surface pressure was 989 mb.

Tropical Cyclone Phethai strengthened earlier on Sunday, but it started to weaken slightly when it approached the east coast of India.  Phethai moved over slightly cooler water as it moved farther north over the western Bay of Bengal.  Tropical Cyclone Phethai moved closer to upper level westerly winds in the middle latitudes and the vertical wind shear increased.  Cooler water and more wind shear caused Phethai to start to weaken when it approached the coast.

Even though Tropical Cyclone Phethai started to weaken when it approached the coast of India, the circulation remained well organized.  There was a distinct center of circulation.  Stronger thunderstorms were occurring just to the west of the center.  Additional bands of showers and thunderstorms were located north and east of the center of Tropical Cyclone Phethai.  Winds to tropical storm force extended out about 140 miles (225 km) from the center of circulation.

Tropical Cyclone Phethai is moving around the western end of a ridge of high pressure over southeast Asia.  The ridge will steer Phethai in a north-northeasterly direction.  On its anticipated track Tropical Cyclone Phethai will move over eastern Andhra Pradesh and southern Orissa.  Phethai will drop locally heavy rain as it moves inland and flash flooding could occur in some locations.

Elsewhere, Tropical Cyclone Kenanga strengthened over the South Indian Ocean.  At 10:00 p.m. EST on Sunday the center of Tropical Cyclone Kenanga was located at latitude 12.7°S and longitude 83.7°E which put it about 1095 miles (1770 km) east-southeast of Diego Garcia.  Kenanga was moving toward the southwest at 20 m.p.h. (32 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 987 mb.

Tropical Cyclone Phethai Forms Over Southwest Bay of Bengal

Tropical Cyclone Phethai formed over the southwest Bay of Bengal on Saturday.  At 4:00 p.m. EST on Saturday the center of Tropical Cyclone Phethai was located at latitude 11.1°N and longitude 84.5°E which put it about 480 miles (775 km) south-southeast of Visakhapatnam, India.  Phethai was moving toward the northwest at 5 m.p.h. (8 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 994 mb.

More thunderstorms developed closer to the center of a low pressure system over the southwestern Bay of Bengal and the Indian Meteorological Department designated the system as Tropical Cyclone Phethai.  The distribution of thunderstorms was asymmetrical.  Most of the stronger thunderstorms were occurring northwest of the center of circulation.  There were fewer thunderstorms southeast of the center, although several bands of thunderstorms were developing on the eastern periphery of the circulation.  Storms northwest of the center were generating upper level divergence which was pumping mass away to the north of the tropical cyclone.

Tropical Cyclone Phethai will move through an environment somewhat favorable for intensification.  Phethai will move over water where the Sea Surface Temperature is near 27°C.  It will move around the eastern end of an upper level ridge over southeast Asia.  The ridge is already producing southeasterly winds which are blowing toward the top of the circulation.  Those winds are causing moderate vertical wind shear and the shear is the reason for the asymmetrical distribution of thunderstorms.  The wind shear will continue and it will inhibit the intensification of Tropical Cyclone Phethai.  Phethai could strengthen during the next 24 to 36 hours, but the rate of intensification is likely to be slow.

The ridge over southeast Asia will steer Tropical Cyclone Phethai north-northwest during the next several days.  On its anticipated track Phethai will move toward the east coast of India.  Tropical Cyclone Phethai could approach the coast near Visakhaptnam in about 48 hours.  Phethai will bring gusty winds but heavy rain and flooding will be greater risks.

Elsewhere, Tropical Cyclone 06S formed over the South Indian Ocean on Saturday.  At 4:00 p.m. EST on Saturday the center of Tropical Cyclone 06S was located at latitude 9.1°S and longitude 91.2°E which put it about 1285 miles (2070 km) east of Diego Garcia.  It was moving toward the south-southeast at 3 m.p.h. (5 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 998 mb.

Tropical Cyclone Owen Makes Landfall in Queensland

After making landfall on the southwest coast of the Gulf of Carpentaria, Tropical Cyclone Owen reversed course and it is now making landfall on the coast of Queensland between Kowanyama and the Gilbert River Mouth.  At 1:00 p.m. EST on Friday the center of Tropical Cyclone Owen was located at latitude 16.2°S and longitude 141.4°E which put it about 55 miles (85 km) south-southwest of Kowanyama, Australia.  Owen was moving toward the southeast 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 975 mb.

A Tropical Storm Warning was in effect for the portion of the coast from Karumba to Cape Keerweer, Queensland and adjacent coastal areas including Kowanyama, Pormpuraaw, Croydon and Palmerville.

Tropical Cyclone Owen moved quickly across the southern Gulf of Carpentaria during the past 24 hours.  The circulation around Owen reorganized after the center of circulation moved away from the southwest coast of the Gulf of Carpentaria.  An eye reformed at the center of circulation and more thunderstorms developed.  Tropical Cyclone Owen strengthened back into the equivalent of a hurricane/typhoon.  The circulation around Owen is small.  Winds to hurricane/typhoon force only extend out about 20 miles (35 km) from the center of circulation.  Winds to tropical storm force extend out about 100 miles (160 km) from the center.

Tropical Cyclone Owen will be capable of causing minor wind damage over a localized area near the center of circulation.  Locally heavy rain will fall along the track of Owen as it moves inland across Queensland.  On its anticipated track the center of Tropical Cyclone Owen is forecast to pass south of Cairns and it could be near Townsville in about 36 hours.  The rain will likely cause flooding in some locations.  A Flood Warning has been issued for the Jordan River.  Flood Watches have been issued for the Gulf of Carpentaria, south Cape York Peninsula and coastal catchments from Cape Tribulation to Rainbow Beach in Queensland.