Ground Hog Week or (Cold End To June)

[Lawrence]

The models are all over the place with this cold snap. Unlike our more stable prognosis at the end of May.First the cold hits on Sunday 22nd then its out till Tuesday 24th,then its back to Sunday. And now its a double whammy on Sunday Night and Tuesday. Well any way, its still a bit too far out to call yet,but seeing it's being awkward and my calculations are now somewhat a bit more making sense of this cold outlook,I'll say with fairly reasonable confidance that we are in for a fairly cold one. If it calms down and stays on track.

[Ryan Thomas]

Can someone post pictures of the models and such?

[Inny Binny]

It's a bloody age away yet. But I can see predictions of 850mb temps of -10 floating around at the moment.

Though, I would have waited one more day for this thread, but oh well.

[NZstorm]

At this stage it looks like the real cold change will pass through Tuesday but as the southern oceans are so mobile it will be a brief cold flick. North island affected Wednesday. Of interest also could be the deep thundery low crossing the North Island Monday. A bit far out there yet.

Picture here of latest 850mb temps from the GFS for next Tuesday 6pm.

[Lawrence]

Can someone post pictures of the models and such?

Just the Sunday for now.For Comparison.

Other things I have taken into account are that the current period of solar inactivity has now become unusually long in duration.The sun usually runs on an 11-year cycle, with maximum sunspot activity during the middle of the cycle and a minimum of activity as the cycles change. The current period has gone on longer than usual, and scientists are not sure why and they do not know how long it will continue to be inactive. The last cycle (#23) peaked in 2001 and is ending now, while the new cycle (#24) should peak around 2012.Also much of the southern hemisphere was close to or below normal for temperatures in May. This has also been going on for quite a while now.Very recent cooling of the equatorial region and a large part of the southern hemisphere has also become apparent.But I just look at these as background points.

[NZstorm]

Yes, the Sunday set up should bring snow to the ski fields atleast.

[NZ Thunderstorm Soc]

Today, ECMWF have a quite a westerlyish regime for next week ????
If this does eventuate, should look good for the lakes

JohnGaul
NZTS

[gllitz]

Wow...GFS throwing up some really low numbers for next week with latest run...but that will change, I'm sure...still impressive, tho...too early to call, too.

[Inny Binny]

Yeesh, they are low numbers at the moment.

[Lawrence]

Nice Be great if this was predicted one day out.

[Ryan Thomas]

Thats very cold! Wheres our snow?

[jamie]

Crazy temps in that run of the models. It is even putting down snow for a rather large portion of the top of Mt Pirongia which normally gets a dusting every 2 or 3 years. Last true (visible) dusting would have been 2006 i think.

[David]

I like the look of this system, it looks like some colder and squally weather for us in the North Island. Maybe thunder and hail look possible at this stage? GFS has shown incredibly cold 500mb temps to cross the whole country about Tue, -36C across Auck. and much cooler in the south and east of the south island! If the huge anticyclone in the South Australian Bight could extend a ridge down into the southern ocean we could see a real polar blast move up the country.

Also metservice's severe weather outlook has a low risk of heavy rainfalls including the eastern parts of Auckland.

Winter left here for a few days, from the 15th to 17th, when the temperatures did not even drop to 12 at all. The high pressured anticyclones of recent have been miserable and brought cloudy weather. Today was nice but the cloud has all rolled in now. This system should bring true winter weather.

By the way, it should be a good sign metservice are mentioning thunderstorms in their forecasts 4 to 5 days away

[gllitz]

Wow, even better numbers now on the latest GFS run....but still a wee bit early to call....next MON night and TUES will be very interesting to watch, indeed....

[NZstorm]

I like the look of this system, it looks like some colder and squally weather for us in the North Island. Maybe thunder and hail look possible at this stage?

First chance of thunderstorms for the North island will come on Sunday as an incoming front runs into the moisture coming in over the top of the high.
Monday and Tuesday also look like possible thunderstorm/hail days for the North Island. Just have to see how this winter system verifies.

Certainly looks good for snow over the SI, the coldest most unstable air passing through on Tuesday. I can't believe the 850mb temps of -10C over the lower South Island. Also don't believe the 850mb -5C over Auckland Tuesday.

[Lawrence]

Certainly looks good for snow over the SI, the coldest most unstable air passing through on Tuesday. I can't believe the 850mb temps of -10C over the lower South Island. Also don't believe the 850mb -5C over Auckland Tuesday.

Absolutely agree. That’s sort of too cold if you know what I mean. Lots of moisture too. Definably possible with the temps we are looking at for some thunderstorms in the North. It’s really hard to believe. Looking like an overnight snow event for us as well. Just after sunset. Met service has a lovely low 984mb forming right over the Banks.

[Ryan Thomas]

That looks damn cold overnight.. For Precipitation to fall that is.. Under 0 for a while... To cold for perfect snow?

[tich]

At the most extreme, GFS has the 520 thickness level as far north as the Bay of Plenty!

[southernthrash]

This is why I like winter. Next tuesday looking amazing for Southland/Otago on GFS, getting closer...

[Inny Binny]

Well, it's jumping all over the place, a not so good precip. run just turned up for Canterbury, but for the Southland/Otago area, yes...50mm+.

Looks more to be a down south event again really, it has for a while...

Though, according to snow-forecast:

http://www.snow-forecast.com/maps/static/nz/144/snow

nzsnow144_eeef.jpg

[Ryan Thomas]

5-10CM in Canterbury?, looks like it says. And speaking of cold its -2.4 locally!

And

Snow likely next week
The Press | Thursday, 19 June 2008


"Weather forecasters are giving an early warning of a cold blast and possible snow to sea level around Canterbury early next week.

Blue Skies forecaster Tony Trewinnard said computer models were consistently predicting a very cold outbreak on Tuesday, with a low-pressure system expected to deepen off the South Island's east coast on Monday night bringing southerly gales and air cold enough for snow to sea level.

The air over the region from ground level up to about 1500m was forecast to be the coldest it had been for many years.

Blue Skies would be issuing a snow warning today, he said."

[Razor]

Yep I agree this event looks to be a good one. Will possibly be the 3rd time I've seen snow in ChCh in Winter 2008, hopefully a decent amount will settle this time accross my part of town (Central City) as theres nothing like a good snowfall in an urban environment to get the camera busy!

[Ryan Thomas]

3rd time in '08? Did you see snow in early May?

[Razor]

yup that cold snap at the beginning of May saw sleet, hail and a few light flurries in the CBD in the wee small hours as I was driving around. Nothing settled though.

[jamie]

Oh you have to be joking. I dont belive this for one second. Snow on the Bombays? Snow at the tip of the Coromandle Pinisula? Even snow on Taupiri mountain (which officially isnt even a mountain as it is a couple of meters short of the mountain threshold..or so ive been told)? If this is the case then at sunrise in around the Waikato and even further north will be stunning with all the snow in the area.