Deepening low prediction/ cold outbreak Mid June

[Razor]

is it just me or has that line of showers just drifted inshore a tad?

[gllitz]

is it just me or has that line of showers just drifted inshore a tad?

Not you...they have...won't last, though...?

[Storm Struck]

Looks like it has edged a little closer, possibly clipping the Port Hills now with some snow.
Could be an outside chance of a few good showers coming through in the next few hours but very coastal, snow flakes still a possibility going by how steady those showers are on the radar.

[southernthrash]

southernthrash wrote

it certainly looks as though Invercargill missed most of the precip., which is often the case in these events.

Stewart Island has a major sheltering effect on Invercargill in SW flows and I'm sure thats part of the reason why the city gets less snowfall than eastern areas.

Never really bought that too much to tell you the truth, I've been inclined to think it's more to do with temp gradients, and for snow settling, the typically saturated state of the soil during winter. You normally only have to travel a short distance inland in any direction to see significant increases in accumulation. The Stewart Island hypothesis just doesn't seem very geographically sound, especially when talking about increases in snowfall to the E.

And I should have said accumulation, rather than precip sorry. I have no doubt that a fair whack of snow fell last night (having seen it), but it wasn't settling in a hurry.

[spwill]

Never really bought that too much to tell you the truth, I've been inclined to think it's more to do with temp gradients, and for snow settling, the typically saturated state of the soil during winter.

Saturated soil state wont be a factor but Invercargill temps probably are.

Mid afternoon sat pic, perhaps some sheltering showing up for Invercargill from Stewart Island in this snap shot.

http://satellite.landcareresearch.co.nz ... d16069.txt

[Razor]

Hmm sky radar update suggests it should be raining accross town now...or worse?

[NZstorm]

The Stewart Island hypothesis just doesn't seem very geographically sound,

It certainly does have an effect but obviously there is a critical direction. It doesn't stop all precip but cuts it down quite a bit.

Invercargill is also a fairly maritime location so the sea warms the low level air in wintry conditions.

[Janos]

A photo taken at lunch time in Macandrew bay.

[Razor]

yup...sleety rain confirmed here. seems to be settling in too...7.45 radar shows it might last a wee while. A temp drop would be handy now

[Storm Struck]

Looks like the showers are swinging into that chain line thing they often do .
Heavy snow on the Port Hills now too.

[frosty]

hail shower here with some flaaaaaaakes in the mix

[mikestormchaser]

Went up for a drive on port hills, yeah its snowing up there ineedy!
summit road it is settling so i thought i would turn back because i don't particularly want to get stuck or slide off the cliff
The latest radar does look good with those showers joining up and and quite good depth to them to.
The main key for me again would have to be the lack of moisture..
But hey there will come a time when we will get a warm advection snow event, we are due for a big dump again in Christchurch.

[frosty]

ur keen going up there

[CHCH Weather Chaser]

Yes, just been up the port hills around Victoria Park area for the last hour - hour and a half and have had several nice snow showers. Good thick flakes as well. Also managed to catch a pure snow shower in Barrington ( so reaching to sea level at times, probably from an isolated heavier pocket). If this chain shower hangs about and takes a while to clear like it normally does then the port hills could get 2-3cm settling on the ground by morning.

[tich]

Just cold sleety rain now in central Chch, no snow. (yet)
Reports of snow to unusually low levels again in parts of lower North Island this afternoon, eg Marton and Pahiatua. East Coast probably getting the full impact of the southerly now. (Gisborne down to 5C at 9pm, with recent precip)

[CHCH Weather Chaser]

SNOW SHOWER!! Nice one too atm, dont know if it will last, prob an isolated heavy pocket but never the less its snowing!

[Razor]

Sleet and snow in St Albans. Wind has picked up a lot too.

[mikestormchaser]

yup grapel turnd to snow here to.. then back to grapel again.. my car is white and the road has a coating to.

[tich]

Probably been some flakes in central city too, but I couldn't be bothered going outside in the cold to look all the time.

[NZ Thunderstorm Soc]

Probably been some flakes in central city too, but I couldn't be bothered going outside in the cold to look all the time.

I don't blame you, Ben Stay in the warmth.
Nothing out here, just a cold wind and 2.8C now.

JohnGaul
NZThS

[Storm Struck]

Just had some rain here with sleet , southerly breeze picked up abit too.

[Razor]

Snow has settled on the cars outside now, just very light falls though

[CHCH Weather Chaser]

Hasnt done anything here for around 20-30mins now unfortunately. The chain line seems to have been broken. I guess 11pm radar will tell the story.

[southernthrash]

Never really bought that too much to tell you the truth, I've been inclined to think it's more to do with temp gradients, and for snow settling, the typically saturated state of the soil during winter.

Saturated soil state wont be a factor but Invercargill temps probably are.

Mid afternoon sat pic, perhaps some sheltering showing up for Invercargill from Stewart Island in this snap shot.

http://satellite.landcareresearch.co.nz ... d16069.txt

Saturated soil has a greater thermal capacity (due to increased water content), this changes the thermal inertia of the soil, and slows down radiative heat loss. Subsequently, the lag between cooling of soil and air increases, meaning that the surface onto which snow falls is relatively warm, causing melting of snowflakes on impact, therefore snow can't settle. This effect has been observed with the presence of asphalt and concrete overburdens as well.

Dunedin has just as much, if not more, of a maritime climate as Invercargill.

Also, if you consider the direction of flow today, which here had a considerable W component, the Stewart Is thing still doesn't really hold much sway. A correlation between a trough in the wave pattern induced by mountains in Fiordland / W Southland hills and Invercargills location seems more likely...

Interesting to note that such effects are not seen for Dunedin under the same conditions, when topographic barriers are larger and more numerous.

[southernthrash]

Should also add, I have just been out in Makarewa (just north of Invercargill) where I was surprised to see there was still plenty of snow on the ground, and some pretty decent ice as well.

Had a hail / sleet shower on the drive back into town, so still pretty cold out there.