Tropical Cyclone Grace

21 - 23 March 2004


Mid-March saw an active MJO phase move over northern Australia, resulting in the development of an active monsoon and of several tropical cyclones. A low-level circulation formed in the active monsoon trough on 17 March and began to drift slowly to the south-east. The monsoon flow provided good low-level convergence which, combined with a fairly favourable upper-level flow, resulted in a slow intensification of a complex lowpressure area. Grace was estimated at tropical cyclone strength on 20 March. Grace reached its peak intensity on 22 March, with winds up to 50 knots. On 23 March, Grace moved into Nadi's area of responsibility, and continued tomove southeast into a less favourable extratropical environment.

As Grace underwent extratropical transition, increased shear led to the dissipation of the vertical structure of the system. A vertical circulation remained at lower levels of the atmosphere, but the upper-level structure did not persist and Grace was downgraded to a tropical depression at 1800 UTC on 23 March, 240 nautical miles southwest of New Caledonia. The low continued to the east, producing a broad area of gales to its south and Nadi continued to issue warnings for another 24 hours following the decay of Grace .

Track and intensity

All times in UTC. Add 10 hours to convert to EST.

Best Track of Tropical Cyclone Grace