quote:Cyclone Donna: Immediate storm threat to Vanuatu, possible rain threat to NZ next week
Tropical Cyclone Donna formed east of Vanuatu Wednesday night and was Thursday morning (NZT) upgraded to a Category 2 cyclone, likely to reach Severe Category 3 status by Friday morning.
Donna poses a serious threat to Vanuatu with the tracking likely to impact much of the nation as the storm intensifies, bringing flooding rains, damaging winds and damaging storm surges.
Donna may well be a Severe Cat 3 storm as it tracks over Vanuatu over the next few days.
At this stage Donna isn't likely to impact Fiji to the east or Australia to the west. New Caledonia may get some rain and large seas.
The Tropical Cyclone may also be short lived - possibly only lasting until just after the weekend when it falls apart as it drifts south towards the north of New Zealand and it's later next week that Donna may help shift tropical moisture down to New Zealand.
Donna has formed outside the cyclone season which ended on Sunday, April 30th. WeatherWatch.co.nz said back in March the set up this year meant the season was likely to extend into May, possibly even into winter.
WeatherWatch.co.nz head forecaster Philip Duncan says the modelling is still suggesting New Zealand may have flooding rains next week. "What we're seeing is a low in the Tasman working in conjunction with the remnants of Donna. A storm is not expected in New Zealand at this stage, but a period of heavy rain is looking increasingly possible and could be slow moving and intense enough to cause problems".
However it's too early to lock in if it will be enough of a threat to prompt rain warnings. "The global modelling from various sources suggests New Zealand is a target for heavy rain, but the modeling has also shown uncertainty about the timing and duration of the rain. This is the critical part to work out if this is just a one off fairly-nothing burst of rain, or a more prolonged serious event. We'll have a better idea by the end of the weekend" says Mr Duncan.
Donna is one to monitor due to the forecast set up next week which may see blocking high pressure on either side of New Zealand, possibly helping to funnel and focus this tropical moisture-rich air over the Upper North Island in particular. Following on from three significant flood events in the past two months authorities will already be closely monitoring this possible event
quote:Tropical Cyclone Donna becomes Category 5 storm, worst May storm on record in South Pacific
Cyclone Donna is now the worst-ever tropical storm to hit the South Pacific in May after reaching Category 5 this morning.
Weatherwatch.co.nz said according to CNN's Severe Weather Team Donna now had sustained winds of 215km/h gusting up to a ferocious 260km/h, making it the strongest May cyclone ever recorded in the Southern Hemisphere.
It eclipses Tropical Cyclone Nadu which struck in 1986.
New Caledonia is next in Donna's firing line as the vicious storm heads south but it's still not clear if it will bring havoc to our shores.
The Fiji MetService is yet to officially confirm any change in storm category. New Zealand's MetService says the Fijian weather agency is responsible for the cyclone and there is no expectation the storm will be upgraded in the its next update due around 1pm.
As Donna ramps up, forecasters are closely watching its projected path across the Pacific.
While it's expected to weaken as it moves down towards New Zealand both MetService and Weatherwatch.co.nz say it's unlikely there will be a direct hit.
But there was an outside chance of it colliding with a spell of bad weather from Australia due to hit the country late on Thursday.
Even if it passed by it was also likely to cause big swells and bring rain to parts of the country.
Forecasters say it won't be until midweek that they'll have the best idea of when, or if, Donna will pose any major problems.
Donna is currently buffeting Vanuatu where entire villages in the northern Torres group have sought shelter in caves. Elsewhere parts of Vanuatu's capital Port Vila have been submerged after heavy rain flooded low-lying areas.
Roofs have been lifted and buildings destroyed as Donna carves a trail of destruction across islands in the Torba province. Authorities are warning residents across central Vanuatu islands to get ready to go to shelter.
Weatherwatch.co.nz said after a "bouncy" tracking at the end of last week the tropical cyclone had finally turned south after waiting for the fine weather parked over New Zealand to leave.
Donna is expected to track past Noumea early Wednesday morning.
The cyclone would likely weaken once it left New Caledonia but could link up with a low crossing the country and bring incredibly heavy downpours.
There was also a chance the remnants of Donna could develop into a new low pressure system east of the North Island and deepen further.
MetService says Donna poses no immediate risk to New Zealand.
quote:Donna becomes strongest May cyclone ever to hit southern hemisphere
During the afternoon UTC hours of May 7, 2017, Tropical Cyclone "Donna" became the strongest May cyclone ever to hit the southern hemisphere. Donna peaked at 118.7 knots (220 km/h / 136 mph) at 19:32 UTC on May 7, before it started weakening. Vanuatu Meteorology and Geohazards Department reported estimated gusts close to the center reached as high as 300 km/h (186 mph).
At 12:00 UTC on May 8, Severe Tropical Cyclone "Donna" had maximum sustained winds of 203 km/h (126 mph) close to the center, according to the RSMC Nadi, Fiji, the authority for this part of the world. This placed Donna on the upper edge of Category 3 hurricane equivalent on the Saffir-Simpson hurricane wind scale.
At the time, the cyclone was located just 15 km (9.3 miles) north of the northern tip of Lifou Island (population ~10 000), New Caledonia, moving south-southeast at 13 km/h (8 mph) with an estimated central pressure of 935 hPa. Its center has just passed (~12:00 UTC) near or over Ouvea Island (population ~3 400), New Caledonia. Both Lifou Island and Ouvea belong the New Caledonia's Loyalty Islands Province. Damage reports from these islands are not available at the time.
Before it hit the Loyalty Islands, Donna wreaked havoc on Vanuatu, forcing people to hide in evacuation centers, strong houses, and caves. Currently available damage reports mention Torba Province as the most affected area. A significant number of houses were totally destroyed and the majority of houses damaged
quote:Tropical Cyclone Ella aims for Fiji
The Fiji Meteorological Service said the cyclone was 480km northeast of Vanua Belavu, the third-largest island in Fiji's Lau archipelago, at 6pm on Wednesday and was moving west southwest towards Fiji at 12km/h.
In a warning issued at 8pm, the Metservice said a tropical cyclone alert remained in force for Lau and the Lamaiviti group, Vanua Levu, Tavenui and nearby smaller islands.
It said people in those areas could expect strong southeasterly winds with average speeds of 45 km/h gusting to 80km/h, which were predicted to increase further to damaging gale force winds of 85km/h to 110km/h from Thursday evening.
For the rest of Fiji, moderate to fresh southeasterly winds were predicted to strengthen with gusts increasing to 80km/h on Friday.
Isolated showers and thunderstorms were also forecast with showers becoming frequent and heavy.
Fiji's Chief of Operations Rusiate Tudravu told FBC News people needed to take the necessary precautions for heavy rain and flash flooding in low lying areas.
People in Tonga's northernmost island group, the Niuas, were also preparing for Cyclone Ella.
The country's National Emergency Management Office director Leveni 'Aho said emergency services were on standby there, where up to 700 people live.
He said locals were preparing for tonight, when the storm would be at its closest.
"Get their fuel and batteries and radio and things like that. The normal things we do in preparation for cyclones."
There were no reports of damage yet, he said.
In Samoa, a heavy rain warning was in effect on Wednesday after the country's weather authorities warned flooding was possible in vulnerable areas.
A Samoan Disaster Management Office spokesperson said landslides were possible and people living on land that could be affected should consider moving to safer areas.
Meanwhile, as Cyclone Donna passed New Caledonia's Loyalty Islands further east than forecast, alerts were lifted and many schools had reopened.