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Thursday 13 March 2014

Cyclone Lusi mirrors Cyclone Bola

Blog as at 8/3/2018 update at blog end.


Between March 9 and 12th 1988 Cyclone Bola ravaged the upper and eastern areas of North Island of New Zealand.  I was serving on HMNZS Monowai surveying around East Cape and we rode out the storm at anchor off Hicks Bay.  Whilst the cyclone was doing it's worst we sent shore parties ashore to help locals with securing their dwellings and post cyclone clean up.

As part of that period, and as a surveyor, one of my jobs was to monitor weather faxes coming in from Met Service.  I clearly remember the reason why Bola was so devastating.  Bola, like Lusi now, came in directly from the North west Pacific after striking Fiji and Vanuatu.  It travelled really quickly into our region, and the impact was made more severe by two facts.

This prognosis weather map from Metservice website shows clearly Lusi and those two reasons Bola was severe.  The first is the ridge of high pressure blocking any clear run to the south.  That blocking High is also anchored by a deep Low Pressure system below the south of the country.  The same systems were in place when Bola hit.

The reason why Bola was as severe as it was was the time frame it hung around.  Winds became even more fierce due to that blocking High and Bola had nowhere to go so just hung around and caused mayhem.  Eventually the Low to the south moved on and the high pressure system weakened and moved off to the east allowing Cyclone Bola to downgrade to a low pressure system and slip to the south east of the country.

So you folks up north.  batten down the hatches.  Cyclone Lusi when it hits will be a Cyclone for sure.  Already it has very high winds associated with it, and plenty of rain contained.  And it won't be downgraded for quite a few days.  Make sure you have your supplies ready. And to be honest, the Metservice prognosis maps suggest that this may in fact be more devastating than Bola was.

Ok have to add this info 1855hours 13/3/14.

The similarities aren't quite the same, the blocking High Pressure at Bola's time moving off to the east forcing Bola to track west then southwest as can be seen in this study  You'll notice the Isobars in Bola were not as tight as those expected from Lusi, meaning higher winds but maybe less rain.  But the track of Lusi compared to Bola are very similar, the only imponderable being the final track of Lusi when it gets to our shores.

I have noticed too that WOMAD and the Pacific Island Festivals in Taranaki and South Auckland respectively are going ahead.  Judging by the isobars of Lusi, not a good move.  There will be strong winds, very strong winds, if it doesn't weaken and as Met Service show on their projections, it's not going to just yet.

Update.

8/3/2018




This Sunday on 11th March 2018 celebrates 30 years since one of the biggest most devastating Cyclone's hit the North and East of the North Island. Over 3 days she dumped heavy rain and strong winds. She is used to define future cyclones as the current science makes it easier to track prospective other Cyclones.
Currently there is a Cyclone brewing off New Caledonia. Although this one is in the vicinity of Bola's birthplace I think the similarity ceases there. The thing though with Tropical Cyclones no two are the same.
Current track. I think you'd be better off being wary of an earthquake.

1 comment:

  1. Thankfully folks the weather transpired to become a non event (thankfully for everyone except farmers). From a scientific viewpoint, the blocking low down south moved rapidly east and allowed the High to leak eastward as well allowing Lusi to pass down the country weakening as it went. Oh well, better to be prepared than stung.

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