Storm highlights and facts

Filed in:

Trees were uprooted, roofs lifted, lightning hit some buildings and powerlines, and power cut to thousands of people - and that was all just the North Island. 

The South Island had gales along the West Coast and heavy snow and bitterly cold wind chills in Southland and Otago.

Christchurch was spared the gales, snow and thunderstorms - but Mother Nature kept herself busy with an increase in larger aftershocks on Friday night and again this morning.

So what are the highlights of the storm so far?  Check out our Q&A's below...

Size:
Question:  Was this storm really the size of Australia? 

Answer:  Yes - in fact, it may have even been larger.  WeatherWatch.co.nz estimates the whole system covered an area about 4000kms wide.

The two maps below, courtesy of the NZ Govt, clearly show the size of the low covering the entire map from left to right.


 

Air Pressure:
Question: Is it true the storm had a central air pressure similar to an intense hurricane? 

Answer:  Yes.  In fact as you can see from the map below the air pressure was 948hPa.  Category 4 Hurricane Igor in the Atlantic Ocean had a central air pressure of 942hPa at the same time.   But it's important to note that a polar storm is built very differently from a tropical storm. 

However it's fair to say that this storm was a significant one by world standards - but like many of the hurricanes that have made headline news in America this year, it remained well offshore luckily. 

Storm impact
Question: Was all of New Zealand affected?

Answer:  Yes and No.  Yes, most regions received rough weather for a time, whether it was hail, snow, gales, thunder or squalls. But some regions luckily didn't receive severe conditions, such as Christchurch.  Also, for example, snow that fell in parts of Dunedin has so far been very light. 

Hawkes Bay had gusty winds but we haven't received any reports of damage from there. 

There were also pockets of places amongst the regions hardest hit that missed out on severe weather - as was the nature of this squally system.

See the map from MetService on Friday indicating all the warnings in place.  Their forecasters were certainly kept very busy over the past few days.

Damage
Question: Did WeatherWatch.co.nz expect more damage from this storm?

Answer:  No, in fact we were surprised at just how much damage was reported.  Westerly gales are common in spring and wind speeds weren't anything out of the ordinary for a spring storm, it was the number of regions that were going to get severe weather at the same time that caught our attention.

 


Comments

Have to say was pretty much a

Have to say was pretty much a non-event here in Hastings, few good gusts of wind but didnt notice anything in the way of damage anywhere.
However my inlaws in Waipukurau lost power on Friday night and didnt get it back until Saturday.
Beginning to feel somewhat left out here in Hastings as all the interesting weather disappears before it gets to us.

Whangarei didn't even notice

Whangarei didn't even notice there was a storm either yesterday or today. It was a little bit blustery, but nothing out of the ordinary. Bit disappointing really.

Wellington city was pretty

Wellington city was pretty much unaffected today. Sun nearly all of the day, and the partial sheltering from the gradient W/WSW flow meant winds were sometimes light when nearer WSW/SW aloft, fresh when closer to W. NW have strengthened after dark now but should ease off later tomorrow.

More after the equinoctial full moon

Yes, Wellington had its extreme weather a few days ago, is now enjoying respite, but another dose is due to return next weekend for most districts north of Oamaru, including Wellington. Meanwhile the rest of the country is still riding this lot out. October, too, should be particularly nasty for Wellington with the likelihood of at least double the October precipitation average. Winter is still far from over for the country.

So let's just clarify this,

So let's just clarify this, "another dose" meaning extreme weather ie storms and gale force winds similar to what has occurred in the last few days, in Wellington, this weekend Saturday 25 and Sunday 26th. Not just the odd shower and/or a stiff breeze, serious weather that would prompt Metservice to issue warnings. Is that what you mean Ken?

Weather for latter part of next week

..that central pressure looks to be around 940 Mb ( hectopascals)..ref. Indian Ocean 1200 MSL Anal.....8 - D

More of the same for later in the week?

Having just looked at the Australian Indian Ocean latest Analysis, one would have to side with Ken's prediction....but then, you can never really tell with the weather! 8 - ]

addendum/ erratum/ whatever!

...into that moon stuff now!

Well of course I believe the

Well of course I believe the weather is as predictable as the tides, being part of the same mechanism. For Christchurch from the middle of next week onwards I have only about 6 significant rain days over the next 4 weeks. Then November should be particularly dry.

Heaviest snowfalls since 1945 for Canty

Well, Ken. If you don't mind me asking . Since NV has just had one of it's heaviest snow falls for many years, are we still likely to get that promised? dumping for CH, in 2010, or are you extending that event a bit further down the track? 8 - [. Can we read anything into that polar outbreak at present which appears to be lining itself as we speak ,and projected out at up to 7 days, and possibly 5 days, by yours truly ?...

p.s. My dad used to say, 'if the moon is holding water, it's going to rain' 8 - ]
...and he was always right! 8 - D ...and he would remind me months later when it did rain....amazing, I thought....but then I was only a lad of 14 or 15 and I wasn't into moon stuff, back then.... 8 - ]

Completely unrelated, well, almost - I don't believe man has set foot on the moon..and a few other things besides, but that's a story for another day 8 - D..

I am not sure why I added that , but, well, it's the Moon.....and I'm kinda into that moon stuff!..

Heaviest snowfalls since 1945 for Canty

Well, Ken. If you don't mind me asking . Since NV has just had one of it's heaviest snow falls for many years, are we still likely to get that promised? dumping for CH, in 2010, or are you extending that event a bit further down the track? 8 - [. Can we read anything into that polar outbreak at present which appears to be lining itself as we speak ,and projected out at up to 7 days, and possibly 5 days, by yours truly ?...

p.s. My dad used to say, 'if the moon is holding water, it's going to rain' 8 - ]
...and he was always right! 8 - D ...and he would remind me months later when it did rain....amazing, I thought....but then I was only a lad of 14 or 15 and I wasn't into moon stuff, back then.... 8 - ]

Completely unrelated, well, almost - I don't believe man has set foot on the moon..and a few other things besides, but that's a story for another day 8 - D..

I am not sure why I added that , but, well, it's the Moon.....and I'm kinda into that moon stuff!..

David All forecasting carries

David
All forecasting carries about an 80km radius error so it is difficult to pinpoint. It's like someone having an allergy, say if everytime they eat chocolate they may be able to predict getting pimples on their face. You can then say if you eat chocolate as before the facial pimples will probably appear, but exactly down to which particular centimetre on the face, well, that's speculative. I have the potential for more rough weather north of Christchurch next week and both north and south of Christchurch in the first week of October. Christchurch should get something, but the brunt? As you have pointed out, I said there was the potential this month for the worst snow in 50 years for Christchurch in my almanac, written from two years ago. And further south down the road has just had the worst snow in 50 years. Sometimes that's as close as I can get.
We don't have good enough instrumentation. There's moving satellites taking photos of the tops of moving clouds from above the ever-changing atmosphere, a small bunch of thermometers dotted around airports, weather balloons that drift all over the place measuring pressure where they are, and odd Argos buoys floating around recording scattered samples of surface sea temperatures. It is all sparse and primitive. That's why we can only make general predictions in a general timeframe and we ask for some leeway when we get it out by a few miles or by a few mm.
cheers!

Hey Ken, What was the comment

Hey Ken,

What was the comment you made on the MetService YouTube video? - I note they deleted it!

- Phil

Phil I just commented in

Phil
I just commented in general terms that no weather organisation owns the weather. But then I thought better of the situation and I deleted it, so can't blame them. I didn't want to churn up any fuss as I thought people need to be focussed on precautionary measures, not who said what first. If they really wanted to know who warned of this September storm+snow then I said it first to the media on 17 August, and I will be commenting again at 11.30am today on the same radio network. I think MS should welcome the fact that there are other weather services out there now, as it is an opportunity for each to specialise with a different style and it is a chance for the public to pick and choose what suits them best.