South Island Snowstorm - June 18-19

[03Stormchaser]

Compared to the USA the models available is pretty pathetic here. Population and demand would play into that.
Looks like an interesting setup later today into tonight. Can't see snow at sea level in chch but these warm advection setups are notoriously hard to forecast!

[TonyT]

Its all on the FB page, but...

This is what went out to clients earlier today. Not very different to what I have been saying to them since Monday.

Snow Forecast for Canterbury High Country and Plains:
We still have quite significant disagreement from various sources of computer guidance as to the details of today’s forecast, but it seems increasingly likely a significant event is beginning which will bring heavy snow to at least some parts of Canterbury.

We see a high risk that heavy snow falls will affect inland areas of Mid and South Canterbury from mid afternoon through tonight, with 10-20cm likely above 200m, and 30-50cm above 400m. Significant snowfalls are also likely above 400m in North Canterbury, with at least 20-30cm expected there.

There is a moderate risk of 5-10cm of snow falling below 200m in Mid and South Canterbury, possibly as low as sea level. This includes Christchurch city. There is a moderate risk of 5-10cm falling to 200m in North Canterbury as well.

We see a low risk of 10-15cm affecting the eastern Plains of Mid and South Canterbury under 200m, and a small chance of these accumulations in Christchurch, at least on the hills. There is also a low risk of 5-10cm falling below 200m in North Canterbury, possibly as low as sea level.

Rain and snow will clear early tomorrow morning, probably before dawn.

A period of strong westerly winds later on Friday will mainly affect North Canterbury but temperatures should be a little milder with slow but steady snowmelt across the region.

A period of very cold airflow is expected to arrive late on Sunday and ease on Monday. Some snow showers seem likely to sea level during this time, but should be light and mainly coastal. Expect a few cm accumulation above about 100m.

We will update this forecast tomorrow morning.

(C) Blue Skies Weather & Climate Services Ltd 2015

[Orion]

Light rain falling; 8.3°C and it looks colder, because of thick overcast that makes the day very gloomy, trees tossing in wind etc. Brrr!

[Skywatcher]

SW wind and light rain has now reached here.

[Bradley]

Awesome, thanks very much Tony, I like your "moderate risk" for 5-10cms down to sea-level!

[melja]

I think the rain might beat the cold air and be all over before it really gets cold.

[matttbs]

I think the rain might beat the cold air and be all over before it really gets cold.

Already snowing Here, large flakes too

[bpo]

Around 20-40mm on the ground in Omarama. Lucky it didn't snow overnight or there'd likely be a fair bit more. Hopefully it'll run out of steam fairly soon and what's left will quickly melt away.

[Orion]

One of my Spies reports it's started snowing, "Coming down well", in Staveley.
Altitude there around 380m. asl.

[melja]

Yeah i see its getting cold quick in the likes of Timaru and Ashburton. Is it me or does this setup look very much like the 1945 snow storm now?
Heavy rain here in Rangiora now and temp dropped 2C in 15 min.

[talbotmj15]

According to the Metservice the snow that is falling in Geraldine and Mayfield wasn't meant to start until 7 pm ish. This makes the cold air appear to be ahead of schedule by about 6 hours. I wonder how this will effect accumulations. I suspect theirs another 6 hours of heavy snow which could give that area around another 20-30 cm on top of what was predicted.????

[Bradley]

Oh god, social media websites are now in full overdrive stating 'high risk of half a foot of snow down to sea-level for Christchurch'

[bpo]

Yay! It's definitely starting to ease down here and the sun is trying break through. Fingers crossed it's almost over.

[bpo]

Oh god, social media websites are now in full overdrive stating 'high risk of half a foot of snow down to sea-level for Christchurch'

"Z0mG utz zuh und uv thuh wuld!!!!!111 kluk huh tuh rudd muh uhbutt ut!!!!!!!!111"

[melja]

You want to see the supermarkets I delivered to late this morning, just crazy.

[Andy]

No snow here just light cold rain snowing higher up 250-300+m. Qtown and Wanaka have settled snow and also further up the valley Omakau north. Temp 3degrees

[talbotmj15]

Heavy sleet is now starting to fall around 300m in Sheffield

[Nev]

According to the Metservice the snow that is falling in Geraldine and Mayfield wasn't meant to start until 7 pm ish. This makes the cold air appear to be ahead of schedule by about 6 hours. I wonder how this will effect accumulations. I suspect theirs another 6 hours of heavy snow which could give that area around another 20-30 cm on top of what was predicted.????

All the warnings and watches I've read say from late morning?

[MoorfNZ]

Big flakes in the sleet now.. (nr Sheffield)

[Orion]

Second Spy reports it's snowing from halfway between Ashburton and Westerfield, so from around 150m asl.

[petem8nz]

Yeah i see its getting cold quick in the likes of Timaru and Ashburton. Is it me or does this setup look very much like the 1945 snow storm now?
Heavy rain here in Rangiora now and temp dropped 2C in 15 min.

Hmmm perhaps. Check out this article it has weather maps of all the major snow storms over the years.

https://www.niwa.co.nz/sites/niwa.co.nz ... e_2006.pdf

[Manukau heads obs]

looks rain getting into north canty on the rain radar?
(re they needing rain there)

[snowstormwatcher]

heavy snow in Fairlie currently around 2cm on the ground

[matttbs]

5cm on the ground already and absolutely dumping down!

[MoorfNZ]

Heavy snow now falling, big flakes (nr Sheffield)