Tropical Low Moves Toward Western Australia

A Tropical Low over the South Indian Ocean was moving toward the coast of Western Australia on Thursday night.  The U.S. Joint Typhoon Warning Center is now designating the Tropical Low as Tropical Cyclone 17S.

At 10:00 p.m. EST on Thursday the center of Tropical Cyclone 17S was located at latitude 13.6°S and longitude 120.2°E which put the center about 355 miles (575 km) north-northwest of Broome, Australia.  Tropical Cyclone 17S was moving toward the southeast at 16 m.p.h. (26 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 955 mb.

The Australian Bureau of Meteorology issued a Warning for the portion of the coast from Broome to Kuri Bay.  The Warning included Derby.

A Watch was in effect for the portion of the coast from Bidyadanga to Broome.  A Watch was also in effect for the portion of the coast from Kuri Bay to Mitchell Plateau.

Tropical Cyclone 17S was exhibiting more organization on Thursday evening.  More thunderstorms were occurring in bands in the eastern and western side of the tropical cyclone.  There still were not a lot of thunderstorms near the center of Tropical Cyclone 17S.  The thunderstorms were starting to generate more upper level divergence that was pumping mass away from the tropical cyclone.  The removal of mass was causing the surface pressure to decrease.

The strongest winds were occurring in the northern side of Tropical Cyclone 17S.  Winds to tropical storm force extended out 175 miles (280 km) in the northern side of the tropical cyclone.  The winds in the southern half of Tropical Cyclone 17S were blowing at less than tropical storm force.

Tropical Cyclone 17S will move through an environment favorable for intensification during the next 24 hours.  Tropical Cyclone 17S will move over water where the Sea Surface Temperatures are near 30°C.  It will move under the middle part of an upper level ridge that is northwest of Australia.  The upper level winds are weak in the middle of the ridge and there will be little vertical wind shear.  Tropical Cyclone 17S will Intensify during the next 24 hours.  It could intensify rapidly.

Tropical Cyclone 17S Will move around the northwestern part of a high pressure system over Australia.  The high pressure system will steer the tropical cyclone toward the southeast during the next 24 hours.  On its anticipated track, Tropical Cyclone 17S will approach the coast of Western Australia near Cape Leveque in 24 hours.

Tropical Cyclone 17S will bring strong winds and heavy rain to the portion of Western Australia between Broome and Kuri Bay.  Heavy rain could cause flash floods in some locations.

Flood Watches are in effect for the Northwest Kimberley and Western Sandy Desert regions.

Tropical Cyclone 17S could also cause a storm surge of up to 7 feet (2 meters) along the coast of Western Australia.

Tropical Low Prompts Watch for Western Australia

The potential risk posed by a Tropical Low over the South Indian Ocean prompted the Australian Bureau of Meteorology to issue a Watch for a portion of the coast of Western Australia on Wednesday evening.  The Tropical Low is currently designated as Invest 91S by the U.S. Joint Typhoon Warning Center.

At 10:00 p.m. EST on Wednesday the center of the Tropical Low was located at latitude 11.4°S and longitude 118.9°E which put the center about 510 miles (825 km) northwest of Broome, Australia.  The Tropical Low was moving toward the southeast 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 1001 mb.

The Australian Bureau of Meteorology issued a Watch for the portion of the coast of Western Australia from Bidyadanga to Mitchell Plateau.  The Watch included Broome and Derby.

The circulation of the Tropical Low was in the early stages of organization on Wednesday evening.  There were not many thunderstorms near the center of the Tropical Low.  Thunderstorms were occurring in a band in the southern periphery of the circulation around the Tropical Low.  There also were not many thunderstorms in the northern side of the Tropical Low.

The Tropical Low will move through an environment favorable for the formation of a tropical cyclone during the next 24 hours.  The Tropical Low will move over water where the Sea Surface Temperatures are near 30°C.  It will move under the middle part of an upper level ridge that is northwest of Australia.  The upper level winds are weak in the middle of the ridge and there will be little vertical wind shear.  The Tropical Low is likely to continue to get better organized during the next 24 hours.

The Tropical Low Will move around the western side of a high pressure system over Australia.  The high pressure system will steer the Tropical Low toward the southeast during the next 24 hours.  On its anticipated track, the Tropical Low will approach the coast of Western Australia in 48 hours.

Tropical Cyclone Ewetse Brings Wind and Rain to Madagascar

Tropical Cyclone Ewetse brought wind and rain to Madagascar on Wednesday.  At 4:00 a.m. EST on Wednesday the center of the Tropical Cyclone Ewetse was located at latitude 24.0°S and longitude 43.7°E which put the center about 40 miles (65 km) south of Toliara, Madagascar.  Ewetse was moving toward the east at-northeast 8 m.p.h. (13 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 center of Tropical Cyclone Ewetse made landfall on the coast of southwest Madagascar south of Toliara on Wednesday morning.  Ewetse was the equivalent of a tropical storm at the time of landfall.  Winds to tropical storm force extended out 115 miles (185 km) from the center of Tropical Cyclone Ewetse.

Tropical Cyclone Ewetse will move around the eastern portion of a high pressure system that is east of South Africa.  The high pressure system will steer Ewetse toward the northeast during the next 24 hours.  On its anticipated track, Tropical Cyclone Ewetse will move inland over southern Madagascar.

Tropical Cyclone Eweyse will weaken as it moves inland over southern Madagascar.  Ewetse will continue to bring strong winds and locally heavy rain to parts of Madagascar during the rest of Wednesday.  Heavy rain could cause flash floods in some locations.

 

Tropical Cyclone Ewetse Forms Southwest of Madagascar

Tropical Cyclone Ewetse formed over the southern Mozambique Channel southwest of Madagascar on Tuesday.  At 4:00 p.m. EST on Tuesday the center of the Tropical Cyclone Ewetse was located at latitude 25.4°S and longitude 41.9°E which put the center about 200 miles (325 km) west of Beloha, Madagascar.  Ewetse was moving toward the east at 16 m.p.h. (26 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 low pressure system over the southern Mozambique Channel southwest of Madagascar strengthened on Tuesday and Meteo France La Reunion designated the system as Tropical Cyclone Ewetse.

Thunderstorms were developing near the center of Tropical Cyclone Ewetse on Tuesday afternoon.  More thunderstorms also formed in bands in the southern half of Ewetse’s circulation.  Bands in the northern side of Tropical Cyclone Ewetse consisted primarily of showers and lower clouds.  Storms near the center of Ewetse generated upper level divergence that pumped mass away to the south and east of the tropical cyclone.  The removal of mass caused the surface pressure to decrease.

The distribution of wind speeds in Tropical Cyclone Ewetse was relatively symmetrical.  Winds to tropical storm force extended out 125 miles (200 km) from the center of Ewetse’s circulation.

Tropical Cyclone Ewetse will move through an environment somewhat favorable for intensification during the next 12 hours.  Ewetse will move over water where the Sea Surface Temperatures are near 27°C.  It will move under the northeastern part of an upper level trough that is east of South Africa.  The upper level trough will produce northwesterly winds that will blow toward the top of Ewetse’s circulation.  Those winds will cause moderate vertical wind shear.  The moderate vertical wind shear will inhibit intensification, but the wind shear will not be enough to prevent intensification.  Tropical Cyclone Ewetse is likely to intensify during the next 12 hours.

The upper level trough east of South Africa will steer Tropical Cyclone Ewetse toward the east during the next 12 hours.  On its anticipated track, the center of Tropical Cyclone Ewetse will reach the coast of southwest Madagascar west of Beloha in 12 hours.  Ewetse will move over southern Madagascar on Wednesday.

Tropical Cyclone Ewetse will bring strong winds and locally heavy rain to southern Madagascar on Wednesday.  Heavy rain is likely to cause flash floods in some locations.

Elsewhere over the South Indian Ocean, Tropical Cyclone Dudzai was continuing to make a transition to an extratropical cyclone as it moved farther to the south of Mauritus.  At 1:00 p.m. EST on Tuesday the center of the Tropical Cyclone Dudzai was located at latitude 26.2°S and longitude 56.7°E which put the center about 365 miles (590 km) south of Port Louis, Mauritius.  Dudzai was moving toward the south-southwest at 14 m.p.h. (22 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 988 mb.

Nokaen Strengthens Back to a Tropical Storm

Former Tropical Depression Nokaen strengthened back to a tropical storm over the Western North Pacific Ocean on Monday night.  At 10:00 a.m. EST on Tuesday the center of the Tropical Storm Nokaen was located at latitude 17.4°N and longitude 132.3°E which put the center about 700 miles (1130 km) northwest of Yap.  Nokaen was moving toward the east at 17 m.p.h. (28 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.

After weakening to a tropical depression on Sunday, Nokaen strengthened back to a tropical storm on Monday night.  Thunderstorms developed in several bands in the eastern side of Tropical Storm Nokaen.  Bands in the western side of Nokaen’s circulation still consisted primarily of showers and lower clouds.  The thunderstorms in the eastern side of Nokaen started to generate some upper level divergence that pumped mass away to the east of the tropical storm.

The strongest winds were occurring in the western side of Tropical Storm Nokaen.  Winds to tropical storm force extended out 115 miles (185 km) in the western half of Nokaen’s circulation.  The winds in the the eastern side of Tropical Storm Nokaen were blowing at less than tropical storm force.

Tropical Storm Nokaen will move through an environment that will be unfavorable for intensification during the next 24 hours.  Nokaen will move over water where the Sea Surface Temperatures are near 28°C.  However, it will continue to be surrounded by drier air.  In addition, Tropical Storm Nokaen will move under the southern portion of the midlatitude upper level westerly winds.  Those winds will cause vertical wind shear.  The drier air and the vertical wind shear will prevent Tropical Storm Nokaen from intensifying.

Tropical Storm Nokaen will move around the northwestern part of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Nokaen toward the east during the next 24 hours.  On its anticipated track, Tropical Storm Nokaen will remain northwest of Yap.

Tropical Cyclone Dudzai Moves Southeast of Mauritius

Tropical Cyclone Dudzai moved southeast of Mauritius on Monday.  At 10:00 p.m. EST on Monday the center of the Tropical Cyclone Dudzai was located at latitude 23.5°S and longitude 56.0°E which put the center about 205 miles (330 km) south-southeast of Port Louis, Mauritius.  Dudzai was moving toward the southwest at 16 m.p.h. (26 km/h).  The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 80 m.p.h. (130 km/h).  The minimum surface pressure was 994 mb.

Tropical Cyclone Dudzai strengthened a little on Monday even though it was in the early stages of a transition to an extratropical cyclone.  The inner end of a rainband wrapped around the western side of the center of Dudzai’s circulation.  Bands of showers and thunderstorms revolved around the center of Tropical Cyclone Dudzai.  Storms near the center of Dudzai generated some upper level divergence that pumped mass away from the tropical cyclone.  The removal of mass in the upper levels was very nearly equal to the convergence of mass in the lower levels of the atmosphere.  So the surface pressure remained nearly constant on Monday.

The distribution of wind speeds in Tropical Cyclone Dudzai became a little more symmetrical even though Dudzai was in the early stages of a transition to an extratropical cyclone.  Winds to tropical storm force extended out 125 miles (200 km) in the southern half of Dudzai’s circulation.  Winds to tropical storm force extended out 90 miles (145 km) in the northern half of Tropical Cyclone Dudzai.

Tropical Cyclone Duzai will move through an environment that will be unfavorable for intensification a tropical cyclone during the next 24 hours.  Dudzai will move over water where the Sea Surface Temperatures are near 25°C.  It will move under the middle of an upper level low that is south of Mauritius.  The upper level winds will blow from the same direction as the winds at lower levels in the atmosphere.  So there will be little vertical wind shear.  Tropical Cyclone Dudzai is likely to maintain its intensity while it continues to make a transition to an extratropical cyclone during the next couple of days.

Tropical Cyclone Dudzai will move around the western part of a high pressure system over the South Indian Ocean.  The high pressure system will steer Dudzai toward the south during the next 24 hours.  On its anticipated track, tropical Cyclone Dudzai will move farther to the south of Mauritius on Tuesday.

 

Nokaen Weakens to a Tropical Depression

Former Tropical Storm Nokaen weakened to a tropical depression over the Western North Pacific Ocean east of Luzon on Monday morning.  At 10:00 a.m. EST on Monday the center of the Tropical Depression Nokaen was located at latitude 17.1°N and longitude 127.4°E which put the center about 365 miles (530 km) east-southeast of Aparri, Philippines.  Nokaen was moving toward the northeast at 6 m.p.h. (10 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 1000 mb.

Former Tropical Storm Nokaen continued to move through an environment containing drier air on Monday.  The drier air caused most of the thunderstorms in Tropical Depression Nokaen to dissipate.  A few thunderstorms were still occurring in a band in the far northern periphery of Nokaen’s circulation.  The bands in the other parts of Tropical Depression Nokaen consisted primarily of showers and lower clouds.

Tropical Depression Nokaen will move through an environment that will be unfavorable for intensification during the next 24 hours.  Nokaen will move over water where the Sea Surface Temperatures are near 28°C.  However, it will continue to be surrounded by drier air.  In addition, Tropical Depression Nokaen will move under the southern portion of the midlatitude upper level westerly winds.  Those winds will cause vertical wind shear.  The drier air and the vertical wind shear will cause the circulation around Tropical Depression Nokaen to continue to weaken.

Tropical Depression Nokaen will move around the western end of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Nokaen toward the east-northeast during the next 24 hours.  On its anticipated track, Tropical Depression Nokaen will continue to move farther away from Luzon as it gradually spins down.

Tropical Cyclone Dudzai Passes Southeast of Rodrigues

Tropical Cyclone Dudzai was passing southeast of Rodrigues on Sunday evening.  At 10:00 p.m. EST on Sunday the center of the Tropical Cyclone Dudzai was located at latitude 21.3°S and longitude 62.2°E which put the center about 130 miles (210 km) east-southeast of Port Mathurin, Rodrigues.  Dudzai was moving toward the west-southwest at 13 m.p.h. (21 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 993 mb.

The intensity of Tropical Cyclone Dudzai did not change much on Sunday.  Even though Dudzai’s intensity did not change a lot, its structure began to show signs of the start of a transition to an extratropical cyclone.  Tropical Cyclone Dudzai moved over slightly cooler water on Sunday.  Since the slightly cooler water contained less energy, thunderstorms in Dudzai did not rise as high into the atmosphere.  There were also fewer thunderstorms near the center of Tropical Cyclone Dudzai.  Some bands of showers and thunderstorms were still revolving around the center of Dudzai’s circulation.

The distribution of wind winds speeds in Tropical Cyclone Dudzai continued to be very asymmetrical.  Winds to tropical storm force extended out 165 miles (265 km) in the southern half of Dudzai’s circulation.  Winds to tropical storm force only extended out 60 miles (95 km) in the northern half of Tropical Cyclone Dudzai.

Tropical Cyclone Duzai will move through an environment that will be unfavorable for intensification a tropical cyclone during the next 24 hours.  Dudzai will move over water where the Sea Surface Temperatures are near 26°C.  It will move under the eastern part of an upper level low that is southeast of Mauritius and La Reunion.  The upper level low will produce northeasterly winds that will blow toward the top of Dudzai’s circulation.  Those winds will cause moderate vertical wind shear.  The vertical wind shear and cooler Sea Surface Temperatures will cause Tropical Cyclone Dudzai to make a transition to an extratropical cyclone during the next couple of days.

Tropical Cyclone Dudzai will move around the northern part of a high pressure system over the South Indian Ocean.  The high pressure system will steer Dudzai toward the west-southwest during the next 24 hours.  On its anticipated track, ropical Cyclone Dudzai will move away from Rodrigues on Monday.  Dudzai will pass southeast of Mauritius and La Reunion early this week.

Tropical Storm Nokaen Weakens East of the Philippines

Tropical Storm Nokaen weakened east of the Philippines on Sunday morning.  At 10:00 a.m. EST on Sunday the center of the Tropical Storm Nokaen was located at latitude 15.5°N and longitude 125.9°E which put the center about 310 miles (500 km) east-southeast of Casiguran, Philippines.  Nokaen was moving toward the north-northeast 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 998 mb.

A combination of drier air and vertical wind shear caused Tropical Storm Nokaen to weaken east of the Philippines on Sunday morning.  A large high pressure system over eastern Asia was transporting drier air into the environment around Tropical Storm Nokaen.  The drier air caused many of the thunderstorms in Nokaen’s circulation to dissipate.  An upper level ridge over the Western North Pacific Ocean was producing southerly winds that blew the tops off of many of the thunderstorms remaining in Tropical Storm Nokaen.

Most of the bands in Tropical Storm Nokaen consisted primarily of showers and lower clouds on Sunday morning.  A few new thunderstorms formed northeast of the center of Nokaen’s circulation.  The dissipation of many of the thunderstorms in Nokaen reduced the upper level divergence.   Without thunderstorms to pump mass away from Nokaen, convergence in the lower levels of the atmosphere caused the surface pressure to increase.

The distribution of wind speeds in Tropical Storm Nokaen remained asymmetrical.  Winds to tropical storm force extended out 115 miles (185 km) in the northern half of Nokaen’s circulation.  Winds to tropical storm force extended out only 25 miles (40 km) in the southern half of Tropical Storm Nokaen.

Tropical Storm Nokaen will move through an environment that will be unfavorable for intensification during the next 24 hours.  Nokaen will move over water where the Sea Surface Temperatures are near 28°C.  However, the western end of the upper level ridge over the Western North Pacific Ocean will continue to produce southerly winds that will blow toward the top of Nokaen’s circulation.  Those winds will cause strong vertical wind shear.  In addition drier air will continue to surround Tropical Storm Nokaen.  Tropical Storm Nokaen is likely to continue to weaken slowly during the next 24 hours.

Tropical Storm Nokaen will move around the western end of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Nokaen toward the northeast during the next 24 hours.  On its anticipated track, the center of Tropical Storm Nokaen will move farther away from Luzon.

Tropical Cyclone Dudzai Approaches Rodrigues

Tropical Cyclone Dudzai was approaching Rodrigues on Saturday night.  At 10:00 p.m. EST on Saturday the center of the Tropical Cyclone Dudzai was located at latitude 19.2°S and longitude 66.1°E which put the center about 210 miles (335 km) east-northeast of Port Mathurin, Rodrigues.  Dudzai was moving toward the southwest at 6 m.p.h. (10 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 993 mb.

Tropical Cyclone Dudzai continued to weaken on Saturday, although Dudzai’s intensity appeared to have stabilized on Saturday evening.  Bands of showers and thunderstorms were still revolving around the center of Dudzai’s circulation.  Storms near the center of Dudzai generated upper level divergence that pumped mass away to the south and east of the tropical cyclone.  However, the removal of mass in the upper levels was less than the convergence of mass in the lower levels of the atmosphere for much of Saturday.  So, the surface pressure continued to increase on Saturday.  The removal of mass seemed to be moving back into equilibrium with the convergence of mass in the lower levels on Saturday evening.

The distribution of wind speeds in Tropical Cyclone Dudzai continued to be asymmetrical.  Winds to tropical storm force extended out 185 miles (300 km) in the southern half of Dudzai’s circulation.  Winds to tropical storm force extended out 65 miles (105 km) in the northern half of Tropical Cyclone Dudzai.

Tropical Cyclone Duzai will move through an environment that will be marginally favorable for intensification during the next 24 hours.  Dudzai will move over water where the Sea Surface Temperatures are near 27°C.  It will move under the western part of an upper level ridge that is over the South Indian Ocean.  The upper level ridge will produce northerly winds that will blow toward the top of Dudzai’s circulation.  Those winds will cause moderate vertical wind shear. The vertical wind shear will inhibit intensification, but the wind shear may not be enough to prevent intensification.  Tropical Cyclone Dudzai could intensify a little on Sunday.

Tropical Cyclone Dudzai will move around the northern part of a high pressure system over the South Indian Ocean.  The high pressure system will steer Dudzai toward the west-southwest on during the next 24 hours.  On its anticipated track, the center of Tropical Cyclone Dudzai will pass near Rodrigues in 18 hours.

Tropical Cyclone Dudzai will bring strong winds and locally heavy rain to Rodrigues.  Heavy rain could cause flash floods in some locations.