Monthly Archives: February 2020

Former Tropical Cyclone Esther Drops Heavy Rain Over Northwestern Australia

Former Tropical Cyclone Esther dropped heavy rain over parts of northwestern Australia on Wednesday.  At 10:00 p.m. EST on Wednesday the center of Tropical Cyclone Esther was located at latitude 15.3°S and longitude 130.8°E which put it about 240 miles (390 km) south of Darwin, Australia.  Esther 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 50 m.p.h. (80 km/h).  The minimum surface pressure was 996 mb.

The circulation around former Tropical Cyclone Esther remained very well organized on Wednesday even though it had been moving across northern Australia for several days.  There was a distinct low level center of circulation.  The circulation was surrounded by bands of showers and thunderstorms.  Strong thunderstorms developed south of Darwin in a band in the northern part of the circulation.  The Darwin harbor reported a wind gust of 44 m.p.h. (72 km/h).  The Wyndham airport reported a wind gust of 39 m.p.h. (63 km/h).

Former Tropical Cyclone Esther could strengthen back into a tropical cyclone if the center of circulation moves over the South Indian Ocean west of Australia.  Esther will move through an environment favorable for intensification during the next day or two.  The Sea Surface Temperature near the west coast of Australia is near 30°C.  Esther will move under an upper level ridge where the winds are weak and there is little vertical wind shear.  Former Tropical Cyclone Esther could intensify rapidly if the center of circulation moves completely over water.

Former Tropical Cyclone Esther will move around the western end of a high pressure system over Australia during the next several days.  The high will steer Esther toward the west during the next 24 to 48 hours.  It will turn more toward the south when it reaches the western end of the high pressure system.  On its anticipated track the center of former Tropical Cyclone Esther will pass near the southern end of the Joseph Bonaparte Gulf.

Elsewhere over the South Indian Ocean, Tropical Cyclone Ferdinand churned northwest of Australia.  At 10:00 p.m. EST the center of Tropical Cyclone Ferdinand was located at latitude 16.6°S and longitude 114.3°E which put it about 400 miles (645 km) north of Learmonth, Australia.  Ferdinand was moving toward the west at 3 m.p.h. (5 km/h).  The maximum sustained wind speed was 90 m.p.h. (145 km/h) and there were wind gusts to 115 m.p.h. (185 km/h).  The minimum surface pressure was 966 mb.

Tropical Cyclone Ferdinand Strengthens to Equivalent of Hurricane/Typhoon

Tropical Cyclone Ferdinand strengthened to the equivalent of a hurricane/typhoon over the South Indian Ocean northwest of Australia on Monday night.  At 10:00 p.m. EST on Monday the center of Tropical Cyclone Ferdinand was located at latitude 15.4°S and longitude 117.0°E which put it about 520 miles (840 km) north-northeast of Learmonth, Australia.  Ferdinand was moving toward the southwest at 5 m.p.h. (8 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.

The circulation around Tropical Cyclone Ferdinand exhibited much greater organization on Monday.  A very small circular eye formed at the center of circulation.  The eye was surrounded by a ring of strong thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms.  Storms around the eye generated upper level divergence which was pumping mass away form the tropical cyclone.  Bands of showers and thunderstorms were revolving around the core of Ferdinand.  Winds to hurricane/typhoon force extended out 25 miles (40 km) from the center of circulation.  Winds to tropical storm force extended out 70 miles (100 km) from the center.

Tropical Cyclone Ferdinand will move through an environment favorable for intensification during the next 24 to 36 hours.  Ferdinand will move over water where the Sea Surface Temperature is near 29°C.  It will move under an upper level ridge over the South Indian Ocean northwest of Australia.  The upper level winds will be weak and there will be little vertical wind shear.  Tropical Cyclone Ferdinand will continue intensify and it could strengthen to the equivalent of a major hurricane during the next 24 to 36 hours.

Tropical Cyclone Ferdinand will move north of a high pressure system over the South Indian Ocean.  The high will steer Ferdinand slowly toward the west-southwest during the next several days.  On its anticipated track Tropical Cyclone Ferdinand will remain well to the northwest of Western Australia.

Elsewhere, Tropical Cyclone Esther was moving westward over the Northern Territory of Australia.  At 10:00 p.m. EST on Monday the center of Tropical Cyclone Esther was located at latitude 17.3°S and longitude 135.4°E which put it about 125 miles (200 km) east of Newcastle Waters, Australia.  Esther was moving toward the west at 7 m.p.h. (11km/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 997 mb.  Tropical Cyclone Esther was dropping locally heavy rain over parts of the Northern Territory.  A Flood Watch was in effect for the Coastal Carpentaria Rivers, Barkly and the Western Top End.

Tropical Cyclone Esther Makes Landfall in Northern Australia

Tropical Cyclone Esther made landfall in northern Australia just to the east of the border between Queensland and the Northern Territory on Sunday night.  At 10:00 p.m. EST on Sunday the center of Tropical Cyclone Esther was located at latitude 16.7°S and longitude 137.9°E which put it about 65 miles (105 km) west of Mornington Island.  Esther was moving toward the west-southwest at 10 m.p.h. (16 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 988 mb.

A Warning remained in effect for the portion of the coast from Port McArthur to Karumba, Australia including Borroloola and Mornington Island.

Tropical Cyclone Esther was intensifying slowly when it made landfall just east of the border between Queensland and the Northern Territory of Australia.  Winds to tropical storm force extended out 75 miles (120 km) from the center of circulation.  A weather station at Mornington Island reported a sustained wind speed of 35 m.p.h. (57 km/h) and a wind gust of 54 m.p.h. (87 km/h).  The station measured 6.77 inches (172 mm) of rain.

Tropical Cyclone Esther will weaken as it moves inland.  Esther will move north of a high pressure system over Australia.  The high will steer Tropical Cyclone Esther toward the west during the next few days.  On its anticipated track Esther will move across the Northern Territory.  Tropical Cyclone Esther will drop locally heavy rain and it could cause flash floods in some locations.  There is a potential for Esther to strengthen again in a few days when it moves over the South Indian Ocean northwest of Australia.

Elsewhere, Tropical Cyclone Ferdinand developed over the South Indian Ocean northwest of Australia.  At 4:00 p.m. EST on Sunday the center of Tropical Storm Ferdinand was located at latitude 13.8°S and longitude 117.8°E which put it about 450 miles (750 km) north of Port Hedland, Australia.  Ferdinand was moving toward the southwest at 7 m.p.h. (11 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 993 mb.  Tropical Cyclone Ferdinand is forecast to move toward the west-southwest and to strengthen into the equivalent of a hurricane/typhoon.

Tropical Cyclone Esther Develops Over Southern Gulf of Carpentaria

Tropical Cyclone Esther developed over the southern Gulf of Carpentaria on Sunday.  At 1:00 p.m. EST on Monday the center of Tropical Cyclone Esther was located at latitude 16.0°S and longitude 139.1°E which put it about 50 miles (80 km) north of Mornington Island.  Esther was moving toward the southwest at 6 m.p.h. (10 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 991 mb.

The Australian Bureau of Meteorology issued a warning for the portion of the coast from Port Roper to Gilbert River Mouth including Borroloola and Mornington Island.

A Tropical Low over the southern Gulf of Carpentaria strengthened into Tropical Cyclone Esther on Sunday.  The circulation around Esther was large.  Winds to tropical storm force extended out about 125 miles (200 km) from the center of circulation.  There were a few thunderstorms near the center.  Most of the thunderstorms were in two large bands in the outer part of the circulation.  One of the bands was south of the center of Tropical Cyclone Esther and the other band was north of the center of circulation.

Tropical Storm Esther will move through an environment favorable for intensification during the next 12 hours.  Esther will move over water where the Sea Surface Temperature is near 30°C.  It will move under and upper level ridge.  The upper level winds will be weak and there will be little vertical wind shear.  Esther could make intensify before it makes landfall on the coast of Australia.

Tropical Cyclone Esther will move around the northwestern part of a high pressure system during the next 12 to 24 hours.  The high will steer Esther toward the southwest.  On its anticipated track Tropical Cyclone Esther could make landfall on the coast of Australia near the border between Queensland and the Northern Territory in about 12 hours.  Esther will bring gusty winds to coastal locations.  Tropical Cyclone Esther is already dropping locally heavy rain over far northwestern Queensland and the eastern part of the Northern Territory.  Flood watches have been issued for river basins near the Gulf of Carpentaria.  Esther could move westward across the Northern Territory after it makes landfall.

Tropical Cyclone Wasi Brings Wind and Rain to Samoa

Tropical Cyclone Wasi brought wind and rain to Samoa  on Saturday.  At 10:00 p.m. EST on Saturday the center of Tropical Cyclone Wasi was located at latitude 16.7°S and longitude 171.3°W which put it about 140 miles (225 km) south-southwest of Pago Pago, American Samoa.  Wasi was moving toward the south-southeast at 14 m.p.h. (22 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.

The eastern side of Tropical Cyclone Wasi brought wind and rain to parts of Samoa on Saturday.  A weather station in Pago Pago, American Samoa reported a sustained wind speed of 25 m.p.h. (40 km/h) and a wind gust of 43 m.p.h. (69 km/h).  Several inches of rain also fell on parts of Samoa.

Tropical Cyclone Wasi moved under the western side of an upper level ridge over the South Pacific Ocean.  The ridge produce strong northerly winds which blew across the top of Wasi.  Those winds caused strong vertical wind shear and Tropical Cyclone Wasi began to weaken.  Many of the taller thunderstorms dissipated.  Some storms were still occurring in a band south and east of the center of circulation.  Bands in other parts of the circulation consisted primarily of showers and lower clouds.  Winds to tropical storm force extended out 75 miles (120 km) from the center of Wasi.

Tropical Cyclone Wasi will move through an environment unfavorable for intensification.  Wasi will move over water where the Sea Surface Temperature is near 28°C.  However, the upper level ridge will continue to cause strong vertical wind shear.  The shear will be strong enough to prevent significant intensification and Tropical Cyclone Wasi could continue to weaken since it has a small circulation.

Tropical Cyclone Wasi will move around the western end of a high pressure system over the South Pacific Ocean.  The high will steer Wasi toward the south.  On its anticipated track Tropical Cyclone Wasi could pass near Niue in about 18 hours.  Wasi will bring gustier winds and rain showers to Niue on Sunday.

Elsewhere over the South Pacific Ocean, Tropical Cyclone Vicky was dissipating south of Niue.  At 10:00 p.m. EST on Saturday the center of Tropical Cyclone Vicky was located at latitude 22.6°S and longitude 168.6°W which put it about 250 miles (400 km) south-southeast of Niue.  Vicky was moving toward the south at 10 m.p.h. (16 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 1004 mb.

Tropical Low Strengthens Over Gulf of Carpentaria

A Tropical Low designated as Invest 99P by some agencies strengthened over the Gulf of Carpentaria on Saturday.  At 4:00 p.m. EST on Saturday the center of the Tropical Low was located at latitude 14.3°S and longitude 138.2°E which put it about 110 miles (180 km) east of Groote Eylandt, Australia.  The Tropical Low was moving toward the south at 4 m.p.h. (6 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 1000 mb.

The Australian Bureau of Meteorology issued a Warning for the portion of the coast from Numbulwar to Kowanyama including Mornington Island.

More bands of thunderstorms began to develop around a Tropical Low on Saturday.  The bands were revolving around the center of circulation.  The Tropical Low will move through an environment favorable for intensification during the next 24 hours.  It will move over water where the Sea Surface Temperature is near 30°C.  The Tropical Low is under an upper level ridge and the upper level winds are weak.  There will be little vertical wind shear and the Tropical Low is forecast to strengthen into a tropical cyclone.

The Tropical Low will move around the western end of a high pressure system.  The high will steer the Low toward the south.  On its anticipated track the Tropical Low will approach the coast of Australia near the border between Queensland and the Northern Territory.  It will bring gusty winds and locally heavy rain.  Heavy rain could cause flash floods in some locations.

Tropical Cyclone Wasi Develops Near Samoa

Tropical Cyclone Wasi developed near Samoa on Friday night.  At 10:00 p.m. EST on Friday the center of Tropical Cyclone Wasi was located at latitude 13.6°S and longitude 172.9°W which put it about 20 miles (35 km) west of Falealupo, Samoa and about 185 miles (300 km) west-northwest of Pago Pago, American Samoa.  Wasi was moving toward the southeast at 11 m.p.h. (17 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 993 mb.

Tropical Cyclone Wasi spun up out of the same elongated trough of low pressure near Samoa that produced Tropical Cyclone Vicky on Thursday.  A small center of low pressure developed west-northwest of Samoa on Friday.  More thunderstorms formed near the center of circulation and the system was classified as Tropical Cyclone Wasi.  Microwave satellite imagery indicated that there was a tight inner core in the tropical cyclone.  Storms near the core were generating upper level divergence which was pumping mass away from Tropical Cyclone Wasi.  The circulation around Wasi was even smaller than the circulation around Tropical Cyclone Vicky.  Winds to tropical storm force only extended out about 50 miles (80 km) from the center of Tropical Cyclone Wasi.

Tropical Cyclone Wasi will move into an environment somewhat favorable for intensification during the next 24 to 36 hours.  Wasi will move over water where the Sea Surface Temperature is near 28°C.  It will move under the western end of an upper level ridge over the South Pacific Ocean.  The ridge will produce northwesterly winds which will blow toward the top of the tropical cyclone.  Those winds will cause moderate vertical wind shear, but the winds may not be strong enough to prevent intensification.  Tropical Cyclone Wasi could strengthen during the next 24 to 36 hours.  Since the circulation around Wasi is so small, if the tropical cyclone moves into an area where the upper level winds are stronger, it could weaken quickly.

Tropical Cyclone Wasi will move around the western end of a high pressure system over the South Pacific Ocean.  The high will steer Wasi toward the southeast during the next 12 hours.  Wasi will move more toward the south later in the weekend.  On its anticipated track Tropical Cyclone Wasi will bring gust winds and locally heavy rain to portions of Samoa during the next 24 hours.

Elsewhere over the South Pacific Ocean, Tropical Cyclone Vicky weakened as it passed near Niue on Friday.  At 10:00 p.m. EST on Friday the center of Tropical Cyclone Vicky was located at latitude 19.7°S and longitude 168.7°W which put oit about 95 miles (150 km) southeast of Niue.  Vicky was moving toward the south-southeast at 13 m.p.h. (20 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.

Tropical Cyclone Vicky Forms Near Samoa

Tropical Cyclone Vicky formed near Samoa on Thursday.  At 10:00 p.m. EST on Thursday the center of Tropical Cyclone Vicky was located at latitude 15.2°S and longitude 170.6°W which put it about 35 miles (55 km) south of Pago Pago, American Samoa.  Vicky was moving toward the southeast at 9 m.p.h. (15 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 small low pressure system developed quickly within a large elongated trough extending east-southeast across Samoa on Thursday.  A small well defined circulation was evident on satellite imagery.  Thunderstorms developed near the center of the low pressure system and it was designated as Tropical Cyclone Vicky.  Storms near the center began to generate upper level divergence which pumped mass away from the tropical cyclone.  Winds to tropical storm force extended out 80 miles (130 km) from the center of circulation.  A weather station at Pago Pago reported a sustained wind speed of 43 m.p.h. (69 km/h) and a wind gust of 75 m.p.h. (120 km/h) when the developing tropical cyclone passed nearby.

Tropical Cyclone Vicky will move through an environment only marginally favorable for intensification during the next several days.  Vicky will move over water where the Sea Surface Temperature is near 28°C.  It will move under the western side of an upper level ridge over the South Pacific Ocean that extends southeast of Samoa.  The ridge will produce strong northwest winds which will cause moderate to strong vertical wind shear.  The wind shear will inhibit intensification and could cause Tropical Cyclone Vicky to weaken.  Since the circulation around Vicky is small, it could weaken rapidly if the wind shear increases.

Tropical Cyclone Vicky will move around the western side of a high pressure system over the South Pacific Ocean southeast of Samoa.  The ridge will steer Vicky toward the south during the next 24 to 48 hours.  On its anticipated track Tropical Cyclone Vicky could approach Niue in about 48 hours.  Vicky could be the equivalent of a tropical storm when it approaches Niue.

Tropical Cyclone Gabekile Develops South of Diego Garcia

Tropical Cyclone Gabekile developed south of Diego Garcia on Saturday.  At 10:00 a.m. EST on Saturday the center of Tropical Cyclone Gabekile was located at latitude 17.4°S and longitude 74.1°E which put it about 700 miles (1125 km) south of Diego Garcia.  Gabekile was moving toward the south-southwest at 5 m.p.h. (8 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h).  The minimum surface pressure was 995 mb.

The circulation around Tropical Cyclone Gabekile was small but well organized.  Some microwave images suggested that a small eye could be forming at the center of circulation.  The eyelike feature was surrounded by a tight ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the small core of Gabekile.  Storms near the core generated upper level divergence which pumped mass away from the tropical cyclone.  Winds to tropical storm force extended out 65 miles (105 km) from the center of circulation.

Tropical Cyclone Gabekile will move through an environment favorable for intensification during the next several days.  Gabekile will move over water where the Sea Surface Temperature is near 28°C.  It will move under the western end of an upper level ridge over the South Indian Ocean.  The ridge will produce northerly winds which will blow toward the top of the circulation.  Those winds will cause some vertical wind shear, but the shear will not be strong enough to prevent intensification.  Tropical Cyclone Gabekile could strengthen into the equivalent of a hurricane/typhoon.

Tropical Cyclone Gabekile will move around the western end of a high pressure system over the South Indian Ocean.  The high will steer Gabekile  toward the south.  On its anticipated track Tropical Cyclone Gabekile will move farther away from Diego Garcia.

Elsewhere over the South Indian Ocean, Tropical Cyclone Francisco was weakening as it moved slowly inland over east-central Madagascar.  At 7:00 a.m. EST on Saturday the center of Tropical Cyclone Francisco was located at latitude 20.0°S and longitude 48.3°E which put it about 10 miles (15 km) north of Marolambo, Madagascar.  Francisco was moving toward the southwest at 4 m.p.h. (6 km/h).  The maximum sustained wind speed was 30 m.p.h. (50 km/h) and there were wind gusts to 40 m.p.h. (65 km/h).  The minimum surface pressure was 1007 mb.  Tropical Cyclone Francisco was dropping locally heavy rain over parts of Madagascar.

Tropical Cyclone Francisco Redevelops Near East Coast of Madagascar

After moving slowly westward across the Southwest Indian Ocean for the past few days, Tropical Cyclone Francisco redeveloped near the east coast of Madagascar on Thursday.  At 7:00 a.m. EST on Thursday the center of Tropical Cyclone Francisco was located at latitude 17.9°S and longitude 50.7°E which put it about 90 miles (145 km) east of Toamasina, Madagascar.  Francisco was moving toward the west at 6 m.p.h. (9 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.

Strong vertical wind shear weakened Tropical Cyclone Francisco east of Rodrigues last Thursday, but the lower portion of the circulation remained intact.  The lower level circulation drifted slowly westward during the last seven days and it moved across Mauritius and La Reunion earlier the week.  More thunderstorms began to develop around the lower level circulation on Wednesday, when it moved closer to the east coast of Madagascar.  Bands of showers and thunderstorms began to reform.  Storms near the center of circulation started generating upper level divergence which pumped mass away from the tropical cyclone.  The removal of mass allowed the surface pressure to decrease and the wind speeds began to increase.

Tropical Cyclone Francisco has exhibited greater organization in recent hours.  However, the distribution of thunderstorms was asymmetrical.  Many of the stronger thunderstorms were occurring in bands in the western half of the circulation.  Bands in the eastern half of the circulation consisted primarily of showers and lower clouds.  Francisco was moving under the northern part of an upper level ridge.  The ridge was producing easterly winds which were blowing toward the top of the circulation.  Those winds were causing some vertical wind shear and the shear could be responsible for the asymmetrical distribution of thunderstorms.

Tropical Cyclone Francisco will move through an environment favorable for intensification during the next 6 to 12 hours.  Francisco will move over water where the Sea Surface Temperature is near 28°C.  The upper level ridge will still cause vertical wind shear, but the shear will not be strong enough to prevent intensification.  Tropical Cyclone Francisco will weaken when it moves over Madagascar.

Tropical Cyclone Francisco will move north of a high pressure system over the Southwest Indian Ocean.  The high will steer Francisco toward the west.  On its anticipated track Tropical Cyclone Francisco could make landfall on the east coast of Madagascar in about 12 hours.  Francisco will drop locally heavy rain over parts of central Madagascar.  The heavy rain could cause flash floods in some locations,