Tropical Cyclone Idai Strengthens to Equivalent of a Major Hurricane

Tropical Cyclone Idai strengthened into the equivalent of a major hurricane over the Mozambique Channel on Monday.  At 11:00 p.m. EDT on Monday the center of Tropical Cyclone Idai was located at latitude 18.2°S and longitude 42.0°E which put it about 490 miles (785 km) east-northeast of Beira, Mozambique.  Idai was moving toward the southwest at 5 m.p.h. (8 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 952 mb.

Tropical Cyclone Idai intensified into the equivalent of a major hurricane on Monday and then it appeared to begin an eyewall replacement cycle.  A rainband wrapped around the original eye and eyewall.  Convergence became concentrated on the outer eyewall and the inner eyewall began to dissipate.  The overall size of the circulation increased.  Winds to hurricane/typhoon force extended out about 40 miles (65 km) from the center of circulation.  Winds to tropical storm force extended out about 130 miles (210 km) from the center.

The Hurricane Intensity Index (HII) for Tropical Cyclone Idai was 20.6.  The Hurricane Size Index (HSI) was 15.2 and the Hurricane Wind Intensity Size Index (HWISI) was 35.8.

Tropical Cyclone Idai will remain in an environment favorable for intensification for several more days.  Idai will move over water where the Sea Surface Temperature is near 30°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Tropical Cyclone Idai could strengthen further once the inner eyewall dissipates completely and the eyewall replacement cycle ends.

Tropical Cyclone Idai will move around the southeastern part of a subtropical ridge over southern Africa.  The ridge will steer Idai on a course that is a little south of due west.  On its anticipated track Tropical Cyclone Idai could reach the coast of Mozambique near Beira in less than 72 hours.  Idai could still be the equivalent of a major hurricane when it reaches the coast.