Severe Cold Outbreak over NZ 18th-21st

[Gary Roberts]

lets wait and see, also small chance of something tomoro as southerly comes thru.

Yep, all the last couple of years of hyped fizzer events has made a lot of people down this way pretty cynical, but some of them (even me!) are beginning to cautiously pay attention to this one. Maybe just another load of the usual BS yet again, but maybe it's not. Definitely time to wait and see.

[Weathermad]

The latest from the Met Service is for strong to gale force winds over Banks Peninsula on Monday night whilst Blue Skies I understand is forecasting winds possibly up to storm force from the South...

Snow according to the Metservice should settle down to 200 metres with a few flurries of sleet and snow over Christchurch during Monday night, whereas Blue Skies is forecasting snow to blanket the city and at its worst, a repeat of the 1992 blizzard!

The headline in the Christchurch Press read this morning ' Superstorm on its way'....Just how severe could this weather system be?...I suppose only time will tell but it has caused quite a reaction already with some of the citys callers to the airwaves...

Is it one computer model that is showing such a significant system or more?...In 1992, many people complained that there wasnt enough of a warning given, so is it better to give a more notice to farmers and the public in general and run of the risk of it being not so severe or vice versa?

An air of excitement is around and it's not just about the election or the Ranfurly shield game tonight!!!

Weathermad

[Gary Roberts]

...is it better to give a more notice to farmers and the public in general and run of the risk of it being not so severe...?

I say yes.

As much as it irritates me to see hyped non-event after non-event, it makes more sense for the MetService to cover their a*ses by giving these warnings, even if privately they suspect it'll all come to nothing.

But then there's always the risk of 'Crying Wolf' syndrome I suppose. Damned if you do, damned if you don't...

[TonyT]

The latest from the Met Service is for strong to gale force winds over Banks Peninsula on Monday night whilst Blue Skies I understand is forecasting winds possibly up to storm force from the South...

Hi Richard

Doesnt look like storm force from this morning's model run, but gale to severe gale certainly possible on the Peninsula. Things could all change tomorrow!

Snow according to the Metservice should settle down to 200 metres with a few flurries of sleet and snow over Christchurch during Monday night, whereas Blue Skies is forecasting snow to blanket the city and at its worst, a repeat of the 1992 blizzard!

It looks to me as though the flow will go far enough to the southeast (for a time) to allow for some orographic enhancement of the precip over Canty, hence my concerns about heavy rain and/or snow. I dont think the models are taking account of this (a resolution issue). The temps are certainly cold enough for snow to sea level, but it wouldnt take much of a warming to bring the snow level up. As others have said, we will just have to wait and see, but there is certainly significant potential for sea level snow.

The headline in the Christchurch Press read this morning ' Superstorm on its way'....Just how severe could this weather system be?...I suppose only time will tell but it has caused quite a reaction already with some of the citys callers to the airwaves...

I'm pleased to hear it. If we can can avoid loss of life or loss of stock or unneccesary trauma then all the better.

Is it one computer model that is showing such a significant system or more?...In 1992, many people complained that there wasnt enough of a warning given, so is it better to give a more notice to farmers and the public in general and run of the risk of it being not so severe or vice versa?

An air of excitement is around and it's not just about the election or the Ranfurly shield game tonight!!!

Weathermad

Its multiple models, and they have been showing it (in one form or another) since about 10-12 days out. There's no doubt somethings going to happen on Monday/Tuesday. I dont think you can question the value of an advance warning, even if the event doesnt meet the full potential. If I'd left the warning till Sunday then how many more stock would get killed that could have been moved on Friday and Saturday? I hope I'm wrong, I hope there is no low level snow, that winds are only strong, and that snow at higher levels is manageable. And if I am, I'd far rather be criticised for that, than for failing to predict a more serious event.

As for 1992, well, I've said it many times before, all of our clients were well warned and had only minimal losses. Thats what lead to The Press setting up the old Press Weatherline service which we used to run, so farmers could get free access to accurate local forecasts.

[Fujita Phil]

I hope I'm wrong, I hope there is no low level snow, that winds are only strong, and that snow at higher levels is manageable. And if I am, I'd far rather be criticised for that, than for failing to predict a more serious event.

I hope you are wrong... well the bit about the low level snow. I see you are quoted in the Otago Daily Times today also Tony. Yes there is always that danger of falling into the "Peter and the Wolf" scenario, but true, I would rather be criticised about a severe warning than having livelyhoods, even lives, on my conscience.

Beautiful morning here with gorgeous coloured clouds at varying levels... Now turned to muck. Cloud base, low, thick and wet. Might put a few student voters off now. They should really have those polling booths in one of the student pubs down here

[Gary Roberts]

Cloud base, low, thick and wet. Might put a few student voters off now. They should really have those polling booths in one of the student pubs down here

Sane Americans were pinning their hopes on the youth vote saving them from another round of Bush retardedness, but the young ones didn't come through. I hope the same doesn't happen to us.

[gllitznz]

Well, the MetService has "caved-in" a bit and has posted the following (but this has already been noted in previous posts HERE):
...
After this depression departs ...
it will draw a southerly flow over the South Island. The southerly should become colder and colder, and reach its coldest over the south of the South Island Sunday night/early Monday, and Monday night/early Tuesday over Canterbury and Marlborough. The wind may pick up to strong for a time, especially in coastal areas, accompanied by single digit temperatures and wintry showers resulting in wind chill temperatures between zero and -5C. There is potential for snow to fall to quite low levels but it is too early to call whether a Severe Weather Warning will be required over any part of the South Island.During the coldest phase, snow showers may fall to sea level, with 5 to 10cm accumulating at 200 metres and 10 to 20cm at 500 metres provided the southerly is able to pick up sufficient moisture as it approaches over the sea.
...

Hmmm...indeed...This is my first post here and I am actually quite excited about what's in store (many thanks to Jeff for introducing me to this forum!)...I have been looking at the NOGAPS and GFS models since early last week and they haven't changed much at all...normally they "fizzle out" as has been said before...should be neat to see what happens, either way! (To be honest, I just want to be able to make a snowman with my daughter this year! )
Cheers!

[Weathermad]

Thanks for the clarification there Tony and I agree...

I believe it's better to inform everyone early ( so well done to you for doing that ) but where the conflict lies is when you get two different providers giving different information...who is the public to believe?...Is there a way to do this does anyone think?...I believe the Metservice are again being a little conservative in their approach...In saying that now, I see the MetService have issued a special weather advisory at 1.45pm and I quote...

After this depression departs ...

it will draw a southerly flow over the South Island. The southerly should become
colder and colder, and reach its coldest over the south of the South Island
Sunday night/early Monday, and Monday night/early Tuesday over Canterbury and
Marlborough. The wind may pick up to strong for a time, especially in coastal
areas, accompanied by single digit temperatures and wintry showers resulting in
wind chill temperatures between zero and -5C. There is potential for snow to
fall to quite low levels but it is too early to call whether a Severe Weather
Warning will be required over any part of the South Island.During the coldest
phase, snow showers may fall to sea level, with 5 to 10cm accumulating at 200
metres and 10 to 20cm at 500 metres provided the southerly is able to pick up
sufficient moisture as it approaches over the sea.

Farmers who are currently caught up with lambing should be wary of the wind
chill factor and the prospects of some snow settling on the ground. Residents
and travellers can expect interruptions to travel across inland passes and
roads.

They are not yet prepared to put an official warning out as yet...why is that?

Anyway it's quite a colourful time and the public interest is what I would label ' high '...

19 degrees currently...hard to believe that 9 degrees is tomorrows high!

Weathermad

[Willoughby]

I have been looking at the NOGAPS and GFS models since early last week and they haven't changed much at all...normally they "fizzle out" as has been said before

Quite True! ECMWF has also been on the button.
Welcome to the forum!

Weathermad, i'm going for a high of 6c for Christchurch on Monday with morning snow

Arrgh two BIG storms brewing tonight!!

Cheers

[Storm Struck]

Precipitation falling over BP alright nice dark big towers out there stevens tracker has only picked up one strike could have been what i thought was a silent rumble of thunder before whilst taking photo's but then I jst shruggeed it off thinking it was impossble to hear such a thing with NW blowing behind my back.
I have a good feeling thunder may be heard tonight in CHCH when that change comes through of course considering the instsbility there is out there at the moment with a warm dry NW wind shows wat a SW change could do here's hoping.
Cheers
JASON.

[TonyT]

Thanks for the clarification there Tony and I agree...

I believe it's better to inform everyone early ( so well done to you for doing that ) but where the conflict lies is when you get two different providers giving different information...who is the public to believe?...Is there a way to do this does anyone think?...I believe the Metservice are again being a little conservative in their approach...In saying that now, I see the MetService have issued a special weather advisory at 1.45pm

Some good questions there. Sorry if this is off-topic.

Its not Blue Skies job to issue public warnings (we dont get paid for it) and 99% of the time we don't do it. I never make a press release to the media on a forecasting matter (unlike some climate stuff which we think is interesting, and worthy of a wider audience). But I will always respond when asked for comment by the media - if they think its worth contacting me about, then I will give my opinion. Its up to them whether they use it or not (and sometimes they dont, thats fine by me).

We do have a number of clients for snow warnings in Canterbury, who pay (what I think is a small fee) for the service we offer - ie to give them as much warning as possible of snow events which may affect them.

Our forecasts have had the chance of significant rain/snow and a cold SE event in them since Friday 9th, and since Wednesday the risk of heavy snow has looked pretty significant. We sent the first snow warning for this event out on Thursday morning, then another yesterday (Friday) morning. At that point I was sufficiently concerned about the potential for this to be a major event, that I also sent the snow warning to our other (ie non snow warning) clients, and to many contacts who are not current clients (eg people who get forecasts from us but not at this time of year, and also to family, friends and colleagues). My motivation for this was simply to try to avoid the 1992 scenario, when the heavy snow was forecast (by us) but not enough people knew about it.

One of the friends I sent it to works for The Press, and rang me. He respected that what I had sent was a personal message, not a press release, but wanted to write a story for the paper on it. I had no objection. You have seen the result. I am perfectly happy with it. There is/was no intention to create confusion in the minds of the public, it was up to the Press to decide if it was newsworthy. They could have chosen not to write the story in the first place, write it and not use it, tuck it away on page 34, or put it on the front page. I had no input into that.

Ultimately, you dont have to believe it, and you dont have to take it seriously if you dont want to. If you want to wait for the "official" warning thats fine by me. But I have a responsibility to our clients, and I also feel a moral responsibility towards the people of Canterbury, without whom there probably would be no Blue Skies Weather, to help them by doing my job as well as I can when there are significant risks present. The consistency of the models and the severity of their content lead to the decision to send the warning to a wider audience.

This probably belongs in another thread, Steven feel free to move it if you wish. I hope this goes some ways towards answering your excellent question Richard.

[gllitznz]

Yes, Jasestrm -
If the SW change tonight due here in CHCH is anything like the one we had back in May...eek!

I remember hearing lots of crackles and booms of thunder then the "plonk plonk plonk" of HAIL!...woke my daughter up, who would normally sleep through a cannon going off next to her room.....

Today is very similar to that day, so we'll see...what a weekend!
(BTW...my wife hates me now that I have found this forum.......)
Cheers!

[TonyT]

Interesting that there is no mention about the risk of severe gale or stronger southerlies through Cook Strait, and in southern Wairarapa, or the risk of heavy snowfalls to moderate (not low) levels on the ranges of Wairarapa. Kaikoura can also pick up severe gales in this type of southerly.

[Manukau heads obs]

there is a storm warning out for cook straight on the met service site, coastal warnings

[TonyT]

The 0Z GFS still has THK of 523/4 over Chch on Monday night and Tuesday morning, and 850T of -7 on Tuesday morning, so snow still possible to sea level. Its backed off a little on the precipitation amounts, and the winds while still strong are now tending SSW rather than S. This may reduce any orographic enhancement of the precip (except over the Peninsula, where it makes little difference) so perhaps the risk of a heavy snowfall is a little reduced, at least inland.

Will be intersesting to see how it is shaping up tomorrow.

[Manukau heads obs]

might all depend on how long the original low stays off the NI west coast as the new low forms on the NI east coast?
(how SE the wind will be over the SI)

[Manukau heads obs]

http://www.metservice.co.nz/default/ind ... key=205505

that looks like a snow producing SEr over the SI

[Gary Roberts]

http://www.metservice.co.nz/default/ind ... key=205505

that looks like a snow producing SEr over the SI

The consensus around the Waitaki and lower Mackenzie now appears to be that this is going to be just another fizzer, although everybody is watching closely.

Most have recently completed shearing and there are a lot of lambs about, so it'd be the perfect time for the Cosmic Joker to pull a nasty one.

Me? I'd love to see some action weather down here at last, especially after enduring the World's Most Boring Winter, but suddenly I give up...

[Manukau heads obs]

The consensus around the Waitaki and lower Mackenzie now appears to be that this is going to be just another fizzer, although everybody is watching closely.

how do they come to that conslusion ?

the latest sat seq shows a good looking front moving north at the bottom of the sat picture, and as that combines with what is developing up here....well, we will have to wait and see

[Gary Roberts]

The consensus around the Waitaki and lower Mackenzie now appears to be that this is going to be just another fizzer, although everybody is watching closely.

how do they come to that conslusion ?

the latest sat seq shows a good looking front moving north at the bottom of the sat picture, and as that combines with what is developing up here....well, we will have to wait and see

Some are saying that it's most likely to lead to little more than some inclement weather in south Canterbury, and not effect us at all. Others are saying that we may see a little of something - maybe a light dusting on the Lindis and higher peaks overnight - but not much of anything.

I believe it's just a case of the Heard-It-All-Befores for most people. It seems like everytime they've been told the weather is shaping up for something it turns out to be just a big fat nothing, so nobody is really giving this a lot of credence.

Whatever happens, happens, but the needle of my excite-o-meter just dropped back to the Slightly Above Comatose level.

[Manukau heads obs]

maybe a light dusting on the Lindis and higher peaks overnight

but the worst of the weather for the SI east coast is not likely until monday by the looks, as it takes a while for all that off the ice cap air to actualy get dragged up here

"it wont happen overnight, but it will happen"

[TonyT]

http://www.metservice.co.nz/default/ind ... key=205505

that looks like a snow producing SEr over the SI

The consensus around the Waitaki and lower Mackenzie now appears to be that this is going to be just another fizzer, although everybody is watching closely.

While I dont think the event itself is a fizzer, I would say that of all the parts of Canterbury, the area least likely to be affected by a heavy SE snow storm is the McKenzie. So it may yet stay fine at your place Gary...

[Gary Roberts]

maybe a light dusting on the Lindis and higher peaks overnight

but the worst of the weather for the SI east coast is not likely until monday by the looks, as it takes a while for all that off the ice cap air to actualy get dragged up here

"it wont happen overnight, but it will happen"

Nah, sorry, didn't mean tonight!

Anyhow, I don't know squat about the weather really...I defer to you guys.

[Manukau heads obs]

i dont know all that much about the SI mountain weather either!
but i did spend 3 years at CHCH..

what does give mckenzie snow?
(weather patern wise)

[Fujita Phil]

http://www.metservice.co.nz/default/ind ... key=205505

that looks like a snow producing SEr over the SI

Looks like that Gunger angle i've been waiting for