APCEDI Alert 13P, Cyclone Ivy #7, 2004

Dear Colleagues

Alert 7, Cyclone Ivy 13P / 24 February 2004, Sydney 17:00 EDT

Cyclone Ivy continues to have an elongated central core of deep convection without forming a defined eye feature. The deepest convection is in the northeast part of this core just to the east of Anuta and Tikopia. Ivy continues to defy models both in terms of directional movement and intensification. It is maintaining a slow northwestward drift and seems to not have intensified any further this afternoon. Central pressures of around 975 hPa and the general form of Ivy are in line with a Category 1 Cyclone.

This large central convection area has now moved over Tikopia and Anuta. In Vanuatu, the Banks and Torres Groups, Maewo, Northern Pentecost, and Ambae are under the southern part of this convection, and this area is beginning to move into Santo, Ambrym and Malakula. In the Solomons all the main islands of the Santa Cruz Group are under a main feeder band, with the central area of convection nearing Vanikolo.

All day most predictive models have been showing an imminent southern shift in the storm’s track, but it has not materialised. The official track out of the JTWC still has Ivy moving over Maewo, Ambae, Santo and Malakula and strengthening to Category 3 by the time it is west of Malakula. However, there is an increasing degree of uncertainty and nonalignment in the predictive models, and the slow northwest trend seems to continue.

The current situation is summarised as follows:

Damaging Sustained Category 1 Cyclonic Gales and Heavy Rain
Solomons
Anuta
Tikopia

Sustained Gales and Heavy Rain
Solomons
Vanikolo
Vanuatu
Banks Group (entire group)
Maewo
Northern Pentecost
Ambae

Intermittent Gales and Heavy Rain
Solomons
Utupea
Nendo
Nupani
Duffs
Swallows
Vanuatu
Torres Group (entire group)
Ambae
Southern Pentecost
Santo
Ambrym
Malakula

Given the continuing Category 1 nature of the storm, damage at this time should be light to moderate and localised. It will likely include lowland tidal flooding and flash-flooding in hill areas. Some crop damage is also likely. As Ivy continues to be slow moving, this will likely result in heavy localised rainfall which could result in flash-flooding of mountain and hill areas as well as known flood prone areas. This is especially critical for the large Vanuatu Islands. Due to their very high relief and the slow movement of the storm, flash flooding will be a major threat throughout tonight and tomorrow especially if the the storms passes over the islands slowly or even stalls. If a central eye wall manages to emerge later tonight, and the storm strengthens to Category 2-3, damage along its path will certainly be more severe.

Anuta and Tikopia
By this time Anuta and Tikopia will have been subjected to very heavy rains, high seas and and sustained Category 1 gales for about 10 hours with another possible 6-12 hours of the same. This will likely result in tidal flooding of low-lying areas, some crop damage and possibly some damage to unstable structures. However, the overall damage will not be anywhere as bad as with Cyclone Zoe. However, the cumulative effects of 3 major cyclones in 14 months (Zoe, Gina and now Ivy) may well be wearing down the ability of the people and their environment and its resources to sustainably cope. NDMO and Donors should endeavour to make contact with the islands as soon as the storm passes to assess both the immediate effects of Ivy and cumulative effects of the last 3 storms on the overall situation.

General Alert
Authorities in Vanuatu from the Torres Islands to Efate (including Torres and Banks Islands, Pentecost, Ambae, Santo, Malakula, Ambrym, Paama, Ulveah, Epi, Shepherd Islands and Efate including all small islands in these areas) as well as all of the Santa Cruz Group in the Eastern Solomons should be on alert, monitor the path of the storm closely throughout tonight and tomorrow and take immediate actions to protect people and property. People in mountain areas along the eastern and southern slopes of ranges should be on alert for heavy rain resulting in flash flooding. Low lying coastal areas especially along east and southern parts of large islands should also be on alert for tidal flooding.

Concerns in New Caledonia, the main islands of the Solomon Islands and the islands of Southern Vanuatu should continue to monitor this storm as it develops over the next few days. Outermost feeder bands are already bringing rains and gusty winds to many of these areas as far away as Guadalcanal and the Louisades, and this will likewise increase during the day.

APCEDI will continue monitoring the event. More detailed information about the storm can be found on

https://metoc.npmoc.navy.mil//jtwc.html
http://www.met.gov.fj/advisories.html
http://www.nrlmry.navy.mil/tc_pages/tc_home.html

Kevin Vang
APCEDI Coordinator