Tag Archives: Coral Sea

Tropical Cyclone Maila Strengthens to Equivalent of a Major Hurricane

Tropical Cyclone Maila strengthened to the equivalent of a major hurricane as it moved slowly over the Solomon Sea on Monday night.  At 5:00 a.m. EDT on Tuesday the center of Tropical Cyclone Maila was located at latitude 9.9°S and longitude 156.5°E which put the center about 605 miles (970 km) east of Port Moresby, Papua New Guinea.  Maila was moving toward the east at 2 m.p.h. (3 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. (235 km/h).  The minimum surface pressure was 953 mb.

Tropical Cyclone Maila intensified to the equivalent of a major hurricane on Monday night.  A circular eye was present at the center of Maila’s circulation.  The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the center of Tropical Cyclone Maila. Storms near the center of Maila generated upper level divergence that pumped mass away from the tropical cyclone.  The removal of mass caused the surface pressure to decrease.

The distribution of wind speeds around Tropical Cyclone Maila was fairly symmetrical.  Winds to hurricane/typhoon force extended out 45 miles (75 km) from the center of Maila’s circulation.  Winds to tropical storm force extended out 140 miles (220 km) from the center of Tropical Cyclone Maila.

The Hurricane Intensity Index (HII) for Tropical Cyclone Maila is 20.6.  The Hurricane Size Index (HSI) is 16.5 and the Hurricane Wind Intensity Size Index (HWISI) is 37.1.  Tropical Cyclone Maila is similar in intensity to Hurricane Rita when Rita hit Southwest Louisiana in 2005.  Maila is smaller than Rita was.

Tropical Cyclone Maila will continue to be in an environment that will be mostly favorable for intensification during the next 24 hours.  Maila will be over water where the Sea Surface Temperatures are near 30°C.  It will be under the middle of an upper level ridge that is over the Solomon Sea.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  Since Tropical Cyclone Maila has been moving slowly over the Solomon Sea, the strong winds near the surface of the ocean are mixing cooler water to the surface.  If enough cooler water mixes to the surface of the ocean, then the cooler water could stop the intensification of Maila.  Tropical Cyclone Maila could intensify slowly during the next 24 hours, unless too much cooler water mixes to the surface of the ocean.

Tropical Cyclone Maila will continue to be in a region where the steering winds are weak during the next 24 hours. Tropical Cyclone Maila is forecast to meander over the Solomon Sea because the steering winds are weak.  A high pressure system is forecast to develop over the Coral Sea later this week.  The high pressure system will steer Maila toward the west after it develops.

Elsewhere over the South Pacific Ocean, Tropical Cyclone Vaianu passed southwest of Fiji.  At 5:00 a.m. EDT on Tuesday the center of Tropical Cyclone Vaianu was located at latitude 19.7°S and longitude 175.6°E which put the center about 175 miles (285 km) southwest of Nadi, Fiji.  Vaianu was moving toward the south-southeast at 14 m.p.h. (22 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. (235 km/h).  The minimum surface pressure was 954 mb.

Tropical Cyclone Narelle Strengthens to Equivalent of Hurricane/Typhoon

Tropical Cyclone Narelle strengthened to the equivalent of a hurricane/typhoon as it moved over the Coral Sea on Tuesday evening.  At 8:00 p.m. EDT on Tuesday the center of Tropical Cyclone Narelle was located at latitude 12.4°S and longitude 153.3°E which put the center about 600 miles (970 km) east-northeast of Cairns, Australia.  Narelle was moving toward the west at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 90 m.p.h. (145 km/h).  The minimum surface pressure was 986 mb.

The Australian Bureau of Meteorology issued a Watch that was in effect for the portion of the coast of Queensland from Lockhart River to Port Douglas.  The Watch extended across the central Cape York Peninsula to the Gulf of Carpentaria.  The Watch was in effect for the west coast of the Cape York Peninsula from Weipa to Kowanyama.

Tropical Cyclone Narelle intensified to the equivalent of a hurricane/typhoon on Tuesday evening.  The inner end of a rainband wrapped around the center of Narelle’s circulation.  A small eye formed at the center of Tropical Cyclone Narelle.  The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the center of Narelle’s circulation.  Storms near the center of Narelle generated upper level divergence that pumped mass away from the tropical cyclone.  The removal of mass caused the surface pressure to decrease.

The circulation around Tropical Cyclone Narelle was small.  Winds to tropical storm force extended out 115 miles (185 km) from the center of Narelle’s circulation.

Tropical Cyclone Narelle will move through an environment that will be favorable for intensification during the next 24 hours.  Narelle will move over water where the Sea Surface Temperatures are near 29°C.  It will move under the middle of an upper level ridge that is over the northern part of the Coral Sea.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  Tropical Cyclone Narelle will intensify during the next 24 hours.  Narelle could intensify rapidly at times.  Tropical Cyclone Narelle could strengthen to the equivalent of a major hurricane by Thursday.

Tropical Cyclone Narelle will move around the northern side of a high pressure system that is over the Coral Sea.   The high pressure system will steer Narelle toward the west during the next 24 hours.   On its anticipated track, Tropical Cyclone Narelle will approach the coast of Queensland near Cape Melville in 35 hours.

Tropical Cyclone Narelle will bring strong winds and heavy rain to the northern part of the Cape York Peninsula later this week.  Heavy rain is likely to cause flash floods in some locations.

Flood Watches are in effect for parts of the Cape York Peninsula and the North Tropical Coast of Queensland.

Tropical Cyclone Narelle Develops Over the Coral Sea

Tropical Cyclone Narelle developed over the Coral Sea on Monday night.  At 11:00 a.m. EDT on Tuesday the center of Tropical Cyclone Narelle was located at latitude 12.4°S and longitude 154.8°E which put the center about 705 miles (1140 km) east-northeast of Cairns, Australia.  Narelle was moving toward the west at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were wind gusts to 85 m.p.h. (135 km/h).  The minimum surface pressure was 987 mb.

A low pressure system over the Coral Sea strengthened on Monday night and the Australian Bureau of Meteorology designated the system as Tropical Cyclone Narelle.

The Australian Bureau of Meteorology issued a Watch for the coast of Queensland from Lockhart River to Port Douglas.

Tropical Cyclone Narelle was intensifying rapidly on Tuesday morning.  The inner end of a rainband wrapped around the center of Narelle’s circulation.  A small eye appeared to be forming at the center of Tropical Cyclone Narelle.  Bands of showers and thunderstorms were revolving around the center of Narelle’s circulation.  Storms near the center of Narelle generated upper level divergence that pumped mass away from the tropical cyclone.  The removal of mass caused the surface pressure to decrease.

The circulation around Tropical Cyclone Narelle was small.  Winds to tropical storm force extended out 115 miles (185 km) from the center of Narelle’s circulation.

Tropical Cyclone Narelle will move through an environment that will be favorable for intensification during the next 24 hours.  Narelle will move over water where the Sea Surface Temperatures are near 29°C.  It will move under the middle of an upper level ridge that is over the northern part of the Coral Sea.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  Tropical Cyclone Narelle will intensify during the next 24 hours.  Narelle could intensify rapidly.  Tropical Cyclone Narelle will strengthen to the equivalent of a hurricane/typhoon during the next few hours.  Narelle could intensify to the equivalent of a major hurricane by Thursday.

Tropical Cyclone Narelle will move around the northern side of a high pressure system that is over the Coral Sea.  The high pressure system will steer Narelle toward the west during the next 24 hours.  On its anticipated track, Tropical Cyclone Narelle will approach the coast of Queensland near Cape Melville in 48 hours.

Tropical Cyclone Narelle will bring strong winds and heavy rain to the northern part of the Cape York Peninsula later this week.  Heavy rain is likely to cause flash floods in some locations.

Flood Watches are in effect for parts of the Cape York Peninsula and the North Tropical Coast of Queensland.

Tropical Cyclone Koji Nears Queensland

Tropical Cyclone Koji was nearing the coast of Queensland on Saturday morning.  At 7:00 a.m. EST on Saturday the center of the Tropical Cyclone Koji was located at latitude 17.9°S and longitude 147.9°E which put the center about 115 miles (185 km) northeast of Townsville, Australia.  Kohi was moving toward the south at 7 m.p.h. (11 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 988 mb.

The Australian Bureau of Meteorology issued a Warning that was in effect for the portion of the coast of Queensland from Lucinda to Mackay.  The Warning included Townsville, Palm Island, Bowen, Proserpine, and the Whitsunday Islands.

Tropical Cyclone Koji was strengthening as it neared the coast of Queensland on Saturday morning.  More thunderstorms formed near the center of Koji’s circulation.  More thunderstorms also developed in bands revolving around the center of Tropical Cyclone Koji.  Storms near the center generated upper level divergence that pumped mass away from the tropical cyclone.  The removal of mass caused the surface pressure to decrease.

The circulation around Tropical Cyclone Koji was very large.  Winds to tropical storm force extended out 220 miles (350 km) from the center of Koji’s circulation.

Tropical Cyclone Koji will move through an environment favorable for intensification during the next 12 hours.  Koji will move over water where the Sea Surface Temperatures are near 28°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Tropical Cyclone Koji is likely to intensify during the next 12 hours.  Koji could strengthen to the equivalent of a hurricane/typhoon.

Tropical Cyclone Koji will move around the western side of a high pressure system that is east of Australia.  The high pressure system will steer the Koji toward the south-southwest during the next 24 hours.  On its anticipated track, the  center of Tropical Cyclone Koji will reach the coast of Queensland near Ayr in 12 hours.

Tropical Cyclone Koji will bring strong winds and locally heavy rain to the portion of the coast between Lucinda and Mackay.  Heavy rain could cause floods in some locations.

Major Flood Warnings are in effect for the Herbert River, the Pioneer River, the Flinders River, the Concurry Rivers, and the Haughton River Catchment.  Moderate Flood Warnings are in effect for the Bohle River, the Don River, the Norman River, the Thompson River, and the Tully River.  Flood Warnings are in effect for the Gilbert River, the Black River and Bluewater Creek.  Flood Watches are in effect for the Coastal Rivers between Cooktown and Rockhampton, and for the Cape York Peninsula.

Tropical Cyclone Koji could also cause a storm surge of up to 7 feet (2 meters) along the coast of Queensland.

Tropical Low Prompts Warning for Queensland

A Tropical Low over the Coral Sea prompted the Australian Bureau of Meteorology to issue a Warning for the coast of Queensland on Thursday night.  At 7:00 a.m. EST on Friday the center of the Tropical Low was located at latitude 14.9°S and longitude 148.1°E which put the center about 210 miles (335 km) northeast of the Cairns, Australia.  The Tropical Low was moving toward the south-southwest at 4 m.p.h. (6 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 995 mb.

The Australian Bureau of Meteorology issued a Warning for the portion of the coast of Queensland from Port Douglas to Airlie Beach.  The Warning includes Cairns, Innisfail, Townsville and Bowen.

A low pressure system over the Coral Sea was strengthening on Friday morning.  The Australian Bureau of Meteorology was classifying the system as a Tropical Low.  The U.S. Joint Typhoon Warning Center was designating the system as Invest 92P.

A Tropical Low over the Coral Sea was strengthening on Friday morning.  Thunderstorms were occurring in bands in the northwestern part of the Tropical Low.  Another cluster of thunderstorms was located southeast of the center of circulation.  Storms near the center began to generated upper level divergence that pumped mass away from the Tropical Low.  The removal of mass caused the surface pressure to decrease.

The strongest winds were occurring in the thunderstorms northwest and southeast of the center of the Tropical Low.  Winds to tropical storm force extended out 140 miles (225 km) from the center of circulation.

The Tropical Low will move through an environment favorable for intensification during the next 24 hours.  The Tropical Low will move over water where the Sea Surface Temperatures are near 28°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  The Tropical Low is very likely to intensify to a named tropical cyclone during the next 24 hours.

The Tropical Low will move around the western side of a high pressure system that is east of Australia.  The high pressure system will steer the Tropical Low toward the south-southwest during the next 24 hours.  On its anticipated track, the Tropical Low will approach the coast of Queensland near Townsville in 24 hours.

The Tropical Low is likely to be the equivalent of a tropical storm when it approaches the coast.  It will bring strong winds and locally heavy rain to the portion of the coast between Port Douglas and Airlie Beach.  Heavy rain could cause flash floods in some locations.

Tropical Cyclone Alfred Weakens

Tropical Cyclone Alfred weakened over the Coral Sea east of Australia on Saturday.  At 10:00 p.m. EST on Saturday the center of Tropical Cyclone Alfred was located at latitude 23.6°S and longitude 155.0°E which put the center about 330 miles (530 km) north-northeast of Brisbane, Australia.  Alfred was moving toward the south at 8 m.p.h. (13 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 984 mb.

An upper level trough over eastern Australia produced northwesterly winds that blew across the top of Tropical Cyclone Alfred on Saturday.  Those winds blew the tops off of the thunderstorms in the northern half of Alfred’s circulation.  Thunderstorms were still occurring in bands in the southern half of Tropical Cyclone Alfred.  Bands in the northern part of Alfred’s circulation consisted primarily of showers and lower clouds.

Even though Tropical Cyclone Alfred weakened substantially on Saturday, the circulation around Alfred was still large.  Winds to tropical storm force extended out 195 miles (315 km) from the center of Alfred’s circulation.

Tropical Cyclone Alfred will move through an environment that will be unfavorable for intensification during the next 24 hours.  Alfred will move over water where where the Sea Surface Temperatures are near 28°C.  However, the upper level trough over eastern Australia will continue to produce northwesterly winds that will blow toward the top of Alfred’s circulation.  Those winds will cause moderate vertical wind shear.  The wind shear will inhibit intensification.  Tropical Cyclone Alfred could be close to being in equilibrium with its surrounding environment.  Tropical Cyclone Alfred could maintain its intensity during the next 24 hours.

Tropical Cyclone Alfred will move around the western side of a high pressure system that is east of the Coral Sea.  The high pressure system will steer Alfred toward the south during the next 24 hours.  Alfred could start to move toward the west on Monday.  On its anticipated track, Tropical Cyclone Alfred could move toward the coast of southern Queensland early next week.

Tropical Cyclone Alfred Continues to Strengthen

Tropical Cyclone Alfred continued to strengthen over the Coral Sea on Wednesday.  At 10:00 p.m. EST on Wednesday the center of Tropical Cyclone Alfred was located at latitude 17.0°S and longitude 155.5°E which put the center about 660 miles (1050 km) north-northeast of Brisbane, Australia.  Alfred was moving toward the south at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 110 m.p.h. (175 km/h) and there were wind gusts to 130 m.p.h. (210 km/h).  The minimum surface pressure was 962 mb.

Tropical Cyclone Alfred continued to strengthen over the Coral Sea on Wednesday.  A very small circular eye was visible at the center of Alfred’s circulation on satellite images.  The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Alfred.  Storms near the core generated upper level divergence that pumped mass away from the tropical cyclone.  The removal of mass caused the surface pressure to decrease.

The size of the circulation around Tropical Cyclone Alfred increased when Alfred strengthened on Wednesday.  Winds to hurricane/typhoon force extended out 60 miles (95 km) from the center of Alfred’s circulation.  Winds to tropical storm force extended out 200 miles (325 km) from the center of Tropical Cyclone Alfred.

The Hurricane Intensity Index (HII) for Tropical Cyclone Alfred is 19.2.  The Hurricane Size Index (HSI) is 22.7 and the Hurricane Wind Intensity Size Index (HWISI) is 41.9.  Tropical Cyclone Alfred is similar in size and intensity to Hurricane Gustav when Gustav hit Louisiana in 2008.

Tropical Cyclone Alfred will move through an environment favorable for intensification during the next 24 hours.  Alfred will move over water where where the Sea Surface Temperatures are near 29°C.  It will move under the middle of an upper level ridge over the Coral Sea.  The winds are weak near the middle of the upper level ridge and there will be little vertical wind shear.  Tropical Cyclone Alfred is likely to intensify during the next 24 hours unless an eyewall replacement cycle occurs.  If the inner end of a rainband wraps around the existing eye and eyewall, then concentric eyewalls will form.  If concentric eyewalls form, then an eyewall replacement cycle will cause Alfred to weaken.

Tropical Cyclone Alfred will move around the western side of a high pressure system that is over Vanuatu.  The high pressure system will steer Alfred toward the south during the next 24 hours.  On its anticipated track, Tropical Cyclone Alfred will move parallel to the east coast of Australia.  Alfred could move closer to the coast of Queensland by the weekend.

Tropical Cyclone Alfred Meanders over the Coral Sea

Tropical Cyclone Alfred meandered over the Coral Sea on Tuesday.  At 10:00 p.m. EST on Tuesday the center of Tropical Cyclone Alfred was located at latitude 15.0°S and longitude 155.0°E which put the center about 850 miles (1370 km) north of Brisbane, Australia.  Alfred was moving toward the south at 3 m.p.h. (5 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. (165 km/h).  The minimum surface pressure was 975 mb.

Tropical Cyclone Alfred continued to intensify gradually on Tuesday.  The inner end of a rainband wrapped around the center of Alfred’s circulation.  An eye appeared to be forming at the center of Tropical Cyclone Alfred.  A ring of thunderstorms surrounded the developing eye and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Alfred’s circulation.  Storms near the core of Alfred generated upper level divergence that pumped mass away from the tropical cyclone.  The removal of mass caused the surface pressure to decrease.

The circulation around Tropical Cyclone Alfred was small. Winds to hurricane/typhoon force extended out 15 miles (25 km) in the southern side of Alfred’s circulation.  Winds to tropical storm force extended out 80 miles (130 km) from the center of Tropical Cyclone Alfred.

Tropical Cyclone Alfred will move through an environment favorable for intensification during the next 24 hours.  Alfred will move over water where where the Sea Surface Temperatures are near 29°C.  It will move under the middle of an upper level ridge over the Coral Sea.  The winds are weak near the middle of the upper level ridge and there will be little vertical wind shear.   Tropical Cyclone Alfred is likely to intensify during the next 24 hours.

Tropical Cyclone Alfred will move around the western side of a high pressure system that is over Vanuatu.  The high pressure system will steer Alfred slowly toward the south during the next 24 hours.  On its anticipated track, Tropical Cyclone Alfred will move parallel to the east coast of Australia.  Alfred could move closer to the coast of Queensland by the weekend.

Tropical Cyclone Alfred Spins over the Coral Sea

Tropical Cyclone Alfred continued to spin over the Coral Sea on Monday.  At 10:00 p.m. EST on Monday the center of Tropical Cyclone Alfred was located at latitude 14.6°S and longitude 154.5°E which put the center about 670 miles (1085 km) north of Brisbane, Australia.  Alfred was moving toward the south at 4 m.p.h. (6 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 984 mb.

Tropical Cyclone Alfred strengthened to the equivalent of a hurricane/typhoon as it spun over the Coral Sea on Monday.  The inner end of a rainband wrapped around the center of Alfred’s circulation.  A small circular eye was evident at the center of Tropical Cyclone Alfred on visible satellite images.  The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Alfred.  Storms near the center of Alfred generated upper level divergence that pumped mass away from the tropical cyclone.

The circulation around Tropical Cyclone Alfred was small.  Winds to hurricane/typhoon force extended out 15 miles (25 km) in the southern side of Alfred’s circulation.  Winds to tropical storm force extended out 60 miles (95 km) from the center of Tropical Cyclone Alfred.

Tropical Cyclone Alfred will move through an environment favorable for intensification during the next 24 hours.  Alfred will move over water where where the Sea Surface Temperatures are near 29°C.  It will move under the western part of an upper level ridge over the Coral Sea.  The upper level ridge will produce northeasterly winds that will blow toward the top of Alfred’s circulation.  Those winds will cause some vertical wind shear, but the wind shear will not be enough to prevent intensification.  Tropical Cyclone Alfred is likely to intensify during the next 24 hours.

Tropical Cyclone Alfred will move around the western side of a high pressure system that is over Vanuatu.  The high pressure system will steer Alfred slowly toward the south during the next 24 hours.  On its anticipated track, Tropical Cyclone Alfred will move parallel to the east coast of Australia.  Alfred could move closer to the coast of Queensland by the end of the week.

Tropical Cyclone Alfred Forms over the Coral Sea

Tropical Cyclone Alfred formed over the Coral Sea on Sunday.  At 4:00 a.m. EST on Sunday the center of Tropical Cyclone Alfred was located at latitude 14.3°S and longitude 153.7°E which put the center about 560 miles (900 km) east-northeast of Cairns, Australia.  Alfred was moving toward the east at 8 m.p.h. (13 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 990 mb.

A low pressure system over the Coral Sea strengthened on Sunday and the Australian Bureau of Meteorology designated the system as Tropical Cyclone Alfred.  The circulation around Tropical Cyclone Alfred exhibited more organization on Sunday.  More thunderstorms formed near the center of Alfred’s circulation.  More thunderstorms also developed in bands revolving around the center of Tropical Cyclone Alfred.  Storms near the center of Alfred generated upper level divergence that pumped mass away from the tropical cyclone.  The removal of mass caused the surface pressure to decrease.

The circulation around Tropical Cyclone Alfred was fairly large.  Winds to tropical storm force extended out 180 miles (290 km) from the center of Alfred’s circulation.

Tropical Cyclone Alfred will move through an environment favorable for intensification during the next 24 hours.  Alfred will move over water where where the Sea Surface Temperatures are near 29°C.  It will move under the middle of an upper level ridge over the Coral Sea.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  Tropical Cyclone Alfred will intensify during the next 24 hours.

Tropical Cyclone Alfred will move around the southern side of a high pressure system that is near the Equator.  The high pressure system will steer Alfred toward the east during the next 24 hours.  On its anticipated track, Tropical Cyclone Alfred will move farther away from Australia.  Alfred is like to start to move toward the south early next week.

Elsewhere, Tropical Cyclone Bianca formed over the South Indian Ocean northwest of Australia.  At 4:00 a.m. EST on Sunday the center of Tropical Cyclone Bianca was located at latitude 17.0°S and longitude 106.9°E which put the center about 590 miles (950 km) northwest of Exmouth, Australia.  Bianca was moving toward the west-southwest at 15 m.p.h. (24 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 998 mb.