Chatham Islands Strong Wind Advisory - Wednesday 18 March 2015 1.48pm

CHRIS NOBLE, MANAGER PUBLIC WEATHER SERVICES

Cyclone Pam is slowly moving away to the east of the Chatham Islands, but conditions there will be slow to ease throughout today and overnight. Here's the latest word from the Severe Weather team a short time ago:

Forecast issued by MetService at 01:15pm 18-Mar-2015

              STRONG WIND ADVISORY IS IN FORCE

Cylcone Pam is now 550km eastsoutheast of the Chatham Islands and slowly moving further away.  However southwest gales are continuing over the Island and gusts are reaching 90 to 100 km/h at times. Although these gusts are not quite warning strength they still have the potential to cause further damage to structures weakened by the cyclone and may make travelling around the islands difficult.

The winds are expected to slowly ease this evening and overnight into Thursday morning.

Note, winds over the Marine areas around the Chatham Islands are still expected to remain STORM FORCE (50 knots) until this evening. Combined waves are likely to peak at around 9 metres today about coasts exposed to the south and east, before slowly easing during Thursday and Friday.

Next update: 9pm Wednesday 18 March 2015

Please refer to Marine forecasts for Coastal and High Seas information.

You can view the latest coastal forecast for the Chatham Islands here:
http://metservice.com/marine-surf/coastal/chatham-islands

Chatham Islands Update - Wednesday 18th March 1:00am

RAVEEN DAS, METSERVICE METEOROLOGIST

At midnight on Tuesday Cyclone Pam was located about 420km southeast of the Chatham Islands. The system remains a very intense mid latitude cyclone with a central pressure of 949 hectoPascals and is moving southeast away from the Chatham Islands at about 20 km/h.

Enhanced infra-red satellite image from Wednesday at 1am New Zealand time showing Cyclone Pam to the southeast of the Chatham Islands. Enhanced infra-red satellite image from Wednesday at 1am New Zealand time showing Cyclone Pam to the southeast of the Chatham Islands.
The historical track of Cyclone Pam (red line) and its forecast track (blue line) with forecast positions marked as circled L’s in universal coordinated time (NZST = UTC +13 hours) The historical track of Cyclone Pam (red line) and its forecast track (blue line) with forecast positions marked as circled L’s in universal coordinated time (NZST = UTC +13 hours)

The pressure at the Chatham Islands has been gradually rising over the last six hours and rain continues to ease as Cyclone Pam moves away to the southeast

This image shows pressure the weather station at the Chtatham Islands siter rising as Cyclone Pam moves away to the south. This image shows pressure at the Chatham Islands weather station rising as Cyclone Pam moves away to the south.

Although Cyclone Pam is moving away to the southeast, gale southwesterlies and heavy swells continue to affect the Chatham Islands. Please refer to the following warning.

Chatham Islands Warnings:
Cyclone Pam, currently 420km southeast of the Chatham Islands, is expected to remain a very deep low while moving away to lie about 540km southeast of the Chatham Islands by midday today. The heavy rain has eased, but potentially damaging gales are expected to last through to this evening, and heavy swells until Friday morning.

Forecast for Land areas of the Chatham Islands:
Gale southwesterlies with gusts of 100 to 120 km/h should gradually ease this evening. Winds of this strength have the potential to topple trees, damage powerlines and structures, and make driving conditions hazardous.

The heavy rain has eased. However, another 20 to 30mm of light to moderate rain could accumulate through to midnight tonight.

Expect heavy easterly and southwest swells both 5 metres and combined seas of 8 metres. The easterly swell eases during today but the southwest swell rises to 8 metres this morning and the period lengthens. Combined sea will likely rise to 9 metres this morning, then begin to ease on Thursday. The heavy southwest swell(4 metres or greater) is expected to continue through to Friday morning. These swells have the potential to cause damage, easpecially to the eastern coastal areas.

Next update: 9am this morning 18 March 2015

Please refer to Marine forecasts for Coastal and High Seas information.