Complex low pressure system & cold outbreak 3rd-8th August

[Bradley]

Really liking the look of EC's latest run for heavy snow above 300m for next Thursday for Canterbury, interestingly enough even the Metservice forecast is backing it up at this very early stage

[NZstorm]

Really liking the look of EC's latest run for heavy snow above 300m for next Thursday for Canterbury, interestingly enough even the Metservice forecast is backing it up at this very early stage

Looking like a warm advective snow set up. Early days to focus on numbers but typically these set ups drop a lot of snow.

[Bradley]

Really liking the look of EC's latest run for heavy snow above 300m for next Thursday for Canterbury, interestingly enough even the Metservice forecast is backing it up at this very early stage

Looking like a warm advective snow set up. Early days to focus on numbers but typically these set ups drop a lot of snow.

Every promising low level snow event has completely fizzled out this winter so far so I'm not even getting slightly excited by it yet, that cold air on Thursday is so marginal sliding too far East all it will take would be it to move 100km east and it's all over!

[spwill]

A slow moving low system so prolonged precipitation possible somewhere, something to watch.

[Bradley]

A slow moving low system so prolonged precipitation possible somewhere, something to watch.

Latest run of EC has gone berserk with 300mm for places like Kaikoura, 200mm for the foothills in mid Canterbury and nearly 100mm for Christchurch though it has lifted the snow level by 100-200m so 400-500m would be the snowline at the moment...

[spwill]

GFS is much slower to bring the low onto NZ but we are looking quite far out so just something to watch at the moment.

[treetop]

latest runs has the low moving backwards towards Australia ??? May bring very cold air to the sth of the S Is now but looks moisture starved.

[Bradley]

Tony going all out for the ski fields this week:

http://www.stuff.co.nz/the-press/news/8 ... canterbury

[Dean.]

Bring it on...some onshore weather would be nice after all the Northwest/west/southwest weather this year.Canterbury has been the most sheltered area of NZ

[mikestormchaser]

Something is interesting in the models I see today. I see a potential snow maker system end of week. "Warm advective" hinting some very heavy precipitation, 850mb Temps also hinting very cold temperatures a recipe for something interesting!

[Bradley]

What model is that Mike? EC has the system clearing out by Saturday morning

[matttbs]

What model is that Mike? EC has the system clearing out by Saturday morning

This mornings gfs run had it going from Thursday right through the weekend with some pretty cold 850mb temps hinting at quite the decent advective event, haven't checked this evenings run though so not sure if it's still looking good

[mikestormchaser]

What model is that Mike? EC has the system clearing out by Saturday morning

BSCH gfs Bradley. Definitely hinting something could be brewing. More Thursday into fri as Matt says. Some very cold low layer Temps at 925mb and 850. One problem could be a SE wind flow..Witch can warm up the air for costal Canterbury "ie" Christchurch and cause air to freeze inland, so at this stage id say more an inland event but ya never know! There is some heavy precipitation around this time. One to watch!

[Bradley]

What model is that Mike? EC has the system clearing out by Saturday morning

BSCH gfs Bradley. Definitely hinting something could be brewing. More Thursday into fri as Matt says. Some very cold low layer Temps at 925mb and 850. One problem could be a SE wind flow..Witch can warm up the air for costal Canterbury "ie" Christchurch and cause air to freeze inland, so at this stage id say more an inland event but ya never know! There is some heavy precipitation around this time. One to watch!

Latest 06 run of GFS is looking mighty impressive too Mike, let's hope it holds!!

[Bradley]

I see Metservice are as uncertain as the rest of us at this point about the potential snow level and are hedging their bets with a generic 'heavy snow to low levels' forecast for Thursday/Friday!

http://metservice.com/warnings/severe-weather-outlook

[matttbs]

Looking quite promising still, gfs has been pretty consistent now for a couple days

[melja]

Metservice have 300m in there Rural forecasts Bradley

[Bradley]

Metservice have 300m in there Rural forecasts Bradley

Yep just saw that, I wonder why they couldn't be more specific on their outlook then?

[mikestormchaser]

Not going to be warm Friday. I see a max temp for Christchurch of about 6-7C

[SnwAddct]

Looks like Central NI is now included in this weeks weather, not quite as moisture rich as Canterbury but plenty of moisture around and a freezing level of around 500m at times.. Great to see all these winter systems unfolding

[Bradley]

Latest run of EC has halved the moisture levels for Canterbury but has dropped the snowline down to about 100m, certainly going to be very cold. Looks like it has another cold blast on Monday as well, this time with snow to sea level but very little moisture, only 2-5mm

[NZstorm]

The winter event kicks off as warm advective snow inland South Island Wednesday with heavy falls typical of this type of scenario.

Gfs shows a decent polar outbreak by Friday with snow showers lowering to sea level in the South Island.

[Bradley]

Hanmer Springs looks to be in the firing line with 60cm + over the 4 days

[Razor]

Metservice now on board with a severe weather watch issued for Wednesday til the weekend. There will be some itchy farmers about

[Bradley]

This mornings run of EC has halved the moisture levels again for coastal Canterbury and most inland areas too, this looks to be one of those systems which is winding back the closer we get to the event which I guess is pretty consistent with every promising weather system this winter to date