Tropical Cyclone Pam continued to intensify on Thursday and it has attained an intensity equivalent to a Category 5 hurricane on the Saffir-Simpson Scale.  At 5:00 p.m. the center of Tropical Cyclone Pam was located at latitude 15.0°S and longitude 169.6°E which put it about 100 miles east of Maewo, Vanuatu and about 560 miles northwest of Fiji.  Pam was moving toward the west-southwest at 10 m.p.h.  The maximum sustained wind speed was 160 m.p.h. and it was estimated that there could be wind gusts to 200 m.p.h.  The minimum surface pressure was 918 mb.

Pam is in an almost ideal environment for a tropical cyclone.  The Sea Surface Temperatures are warm and the upper level winds are very light.  It has a well developed circulation with a tight inner core.  Upper level divergence is pumping out mass in all directions.  Some further intensification is possible during the shorter term.  Eventually, when Pam moves farther south in a couple of days, it will move over cooler Sea Surface Temperatures and into a region where the upper level winds are stronger.  At that time it should start a steady weakening trend.  In the interim eyewall replacement cycles could produce fluctuations in intensity, but Pam is likely to be a big strong tropical cyclone for several more days.

An upper level ridge to the east of Pam is steering it generally toward the south.  It has moved a little west of due south today and that has brought the western part of the circulation closer to Vanuatu.  Any further westward movement could bring strong winds very close to Maewo, Pentecote, Ambrym, Epi, Efate and numerous smaller islands in southeastern Vanuatu.  Pam is a large, strong tropical cyclone and it is capable of causing serious damage on any island it crosses.

Tropical Cyclone Pam continued to intensify on Wednesday and it is now the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale.  At 11:00 p.m. EDT on Wednesday the center of Tropical Cyclone Pam was located at latitude 12.6°S and longitude 170.2°E which put it about 200 miles northeast of Espiritu Santo and about 670 miles northwest of Fiji.  Pam was moving toward the south-southeast at 6 m.p.h.  The maximum sustained wind speed was 130 m.p.h. and there were gusts to 160 m.p.h.  The minimum surface pressure was 937 mb.

A large eye formed in the center of Pam and the strongest winds are occurring in the ring of thunderstorms surrounding the eye.  Pam is moving over warm Sea Surface Temperatures and the upper level winds are fairly light.  As a result, it has developed strong upper level outflow in most directions.  The environment is favorable for further intensification, but strong tropical cyclones often go through eyewall replacement cycles which produce fluctuations in the intensity

Pam is being steered southward by an subtropical ridge to the east of the tropical cyclone.  This general steering pattern is expected to continue during the next several days.  The projected path of Pam takes the center east of Vanuatu and New Caledonia and west of Fiji.  However, a slight deviation to the west could bring strong winds to some of the islands of Vanuatu.

Tropical Cyclone Pam continued to intensify quickly on Tuesday.  At 10:00 p.m. EDT on Tuesday the center of Tropical Cyclone Pam was located at latitude 11.0°S and longitude 169.8°E which put it about 710 miles northwest of Fiji and about 220 miles north-northeast of Espiritu Santo.  Pam was moving toward the southwest at 5 m.p.h.  The maximum sustained wind speed was 115 m.p.h. and there were wind gusts to 135 m.p.h.  The minimum surface pressure was 948 mb.

Pam remains in a very favorable environment.  It is over warm Sea Surface Temperatures and it is in a region of light upper level winds.  The strong core of the tropical cyclone has generated well developed upper level outflow that is pumping out mass in all directions.  Unless it is interrupted by an eyewall replacement cycle, the intensification is likely to continue.

Pam is being steering toward the south by a subtropical ridge located to its east.  The ridge strengthened slightly on Tuesday and pushed the tropical cyclone slightly to the west of the projected track.  The ridge is expected to continue to steer Pam toward the south during the next few days.  The projected track continues to predict that Pam will move east of Vanuatu and New Caledonia and west of Fiji.  However, a further deviation to the west could bring the circulation closer to Vanuatu.  Because of the intensify and large size of the circulation, impacts could be serious if Pam moves over any islands.