Polar blast lines up for spring

[spwill]

yes the Met service has Saturday now with fine and not much wind .

Once again they had teased us ch ch folk with the prospect of snow.

The flow has been tending more into the west for Saturday but you will get wintry showers on friday with the trough.

This trough will bring the first low level snow of the year to south east coast locations, usually this arrives in May.

[Dean.]

yes the Met service has Saturday now with fine and not much wind .

Once again they had teased us ch ch folk with the prospect of snow.

The flow has been tending more into the west for Saturday but you will get wintry showers on friday with the trough.

This trough will bring the first low level snow of the year to south east coast locations, usually this arrives in May.

Early June we had a brief snowfall in Ashburton at 100m asl,settled for an hour or two.

[Razor]

yes the Met service has Saturday now with fine and not much wind .

Once again they had teased us ch ch folk with the prospect of snow.

The flow has been tending more into the west for Saturday but you will get wintry showers on friday with the trough.

This trough will bring the first low level snow of the year to south east coast locations, usually this arrives in May.

We had low level snow back sometime in June actually, settled to about 200m for several hours around the western end of the Port Hills before rapidly melting in rain that followed, and sleeted/ snowed breifly to sea level very early that morning. Sorry can't recall the date

So strictly speaking, low level snow has occured here this year.

And our Canterbury Plains posters have has a couple of other events too, down to about 300m I recall.

[spwill]

I was thinking Catlins to Dunedin . Yes, Canterbury has been more in the firing line for snow this winter but there wont have been much snow on BP below 400m and the snow on the plains has been inland.

[snowstormwatcher]

Had a couple of decent falls of snow here this winter one around 5cm and the other around 10cm . Fridays southerly change is looking like a mainly coastal event so wont get much here. Any snow that does fall out near the coast will probably be brief as it looks like it will be showers rather than rain.

[NZstorm]

The forecast thickness level of 5220 for Southland/Otago will be the lowest we've seen this winter, if it occurs.

[Chris Raine]

I am driving down to Southland on Friday so will let you know whether it snows and how low it goes . Will attempt the Clinton - Matuara back road

[Michael]

Really proves seasons dont begin and end until the equinoxes not the arbitrary 1st of a month.

The forecast thickness level of 5220 for Southland/Otago will be the lowest we've seen this winter, if it occurs.

[GSVNoFixedAbode]

I was thinking Catlins to Dunedin . Yes, Canterbury has been more in the firing line for snow this winter but there wont have been much snow on BP below 400m and the snow on the plains has been inland.

That'd be typical - I'm heading Dunedin to Chch on Friday for the weekend. So bets are on there will be snow in Dunners but nothing in the garden city.

[MoorfNZ]

[Vertigo]

so long as it avoids us during the weekend 4th-5th, ill be happy!

[NZstorm]

The gfs has the Invercargill thickness on Friday 5200 at midday! Don't often see air that chilly over Southland.

[NZ Thunderstorm Soc]

BEWARE. There's an "active from" approaching

This from MetService's 7:14pm Situation Statement.

Situation for all New Zealand issued at
7:14pm 1 September 2010
A slim ridge over the North Island moves away to the east as an active from approaches the country from the west. The front should move onto the North Island Thursday afternoon, followed by an unsettled and cold southwest flow.

I usually keep well aware of the weather when froms, especially active ones approach from the west. Froms usually produce heavy rainfall situations in areas that don't normally receive rain from their associated fronts.

JohnGaul
NZThS

[Richard]

BEWARE. There's an "active from" approaching

This from MetService's 7:14pm Situation Statement.

Situation for all New Zealand issued at
7:14pm 1 September 2010
A slim ridge over the North Island moves away to the east as an active from approaches the country from the west. The front should move onto the North Island Thursday afternoon, followed by an unsettled and cold southwest flow.

I usually keep well aware of the weather when froms, especially active ones approach from the west. Froms usually produce heavy rainfall situations in areas that don't normally receive rain from their associated fronts.

JohnGaul
NZThS

That from is not going give us any rain on our side today John

[NZstorm]

Looking like the coldest airmass to reach NZ this year arrives tomorrow all be it brief. The airmass is a bit on the dry side but wintry precip still expected. Dunedin hill surburbs should catch a light snowfall as may the Christchurch hill suburbs. Snow also to low levels over the lower North island.

[Richard]

But looking at some of the charts,the fetch is not coming off Antarctica like any descent heavy duty polar blast should,
I'm a bit on this one

http://www.bom.gov.au/australia/charts/ ... cean.shtml

[Razor]

Monday looks more interesting to me at this stage.....

[gllitz]

GFS numbers are promising for snow to very low levels for tomorrow arvo in CHCH, but no real precip around means probably only a few scattered flakes here and there..."oooh look, there's a snowflake!" Yippee, skip...can hardly contain my excitement..........

[spwill]

tomorrow arvo in CHCH, but no real precip around

Would expect some heavy showers to develop in that very cold trough but perhaps Banks Peninsula will be more in the firing line .

[Razor]

Yeah maybe a short burst in town then some minor activty round Coastal Canty but the bulk of the fun will head out over the Peninsula and to sea - thats my pick based on what usually happens with these

[NZ Thunderstorm Soc]

Some interesting Cu to the South at the moment, not quite coming from TC.
Not doing much though
NW here whereas it was still NE in town when I came home from work.


JohnGaul
NZThS

[Storm Struck]

CB sitting to the south at the moment, it is a thunderstorm John as i happened to look at the right time to see a CG come down faintly in the distance.
Again i didnt expect to see any convective development today, but tomorrow should see a better risk certainly.
Nice splash of rain around midday at work but winds have been N-NE most of the day, now gusty westerly.

[Tornado Tim]

Depends on what you constitute as a thunderstorm.

In the U.S weak thunderstorms are called thundershowers and then they move onto on to full fledged thunderstorms then strong t-storms, after that severe t-storms.

I havent heard M/S saying the word thundershower here so i suppose any cloud that produces lightning constitutes a thunderstorm even though it could be a one clap wonder.

[NZ Thunderstorm Soc]

Must of been a one off as things seems to be dwindling now and looking more settled. I tapped the barometer and it when up, sadly

JohnGaul
NZThS

[NZ Thunderstorm Soc]

Depends on what you constitute as a thunderstorm.

In the U.S weak thunderstorms are called thundershowers and then they move onto on to full fledged thunderstorms then strong t-storms, after that severe t-storms.

I havent heard M/S saying the word thundershower here so i suppose any cloud that produces lightning constitutes a thunderstorm even though it could be a one clap wonder.

Yes, well they have their own thunderstorm warning criteria.
A possibility of a 'thundershower' dosen't come under the thunderstorm risk strategy of MetService, only at a time where a thunderstorm has severe weather possibilities, from what I can gather.
As for their thunderstorm map a 'thundershower' may occur where they have stencilled the words NO THUNDERSTORMS in appropiate conditions.
Paul Mallinson, have you any comments on this?

JohnGaul
NZThS