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

[snowchaser01]

the front is moving quickly ahead of the low off Foirdland , onto westland
and will encourage a new replacement low center to form east of the alps once it cross over
and
as that happens,i.e as the barometer drops, you will get the warm advection setup

so, keep an eye on your barometer , people in Canterbury

why right it off before it has even started?

could not have said that better myself.

[TonyT]

the front is moving quickly ahead of the low off Foirdland , onto westland
and will encourage a new replacement low center to form east of the alps once it cross over
and
as that happens,i.e as the barometer drops, you will get the warm advection setup

so, keep an eye on your barometer , people in Canterbury

why right it off before it has even started?

could not have said that better myself.

That assumes the low centre will cross the Alps. If it did I would agree with you, but I dont think it will, the upper level dynamics won't support that, its going to get steered north-eastwards towards Auckland. The trough development off the SI east coast will be too far away to have much if any impact. Still a very cold SE flow, and still likely to bring snow to low levels, but not quite the killer punch it could have been IMHO.

Oh, and I'm not trying to write it off, just trying to inject a bit of realism into the hysteria the media have whipped on this one, eg the below front page of Stuff. "Many southern Kiwis waking up to a whiteout"? Many? Really? What will they write when it does actually snow where people live?!!?

[Manukau heads obs]

but I did not say anything about the low center crossing the alps
I am talking about a replacement low center to the east of the alps
and to watch for that development by keeping an eye on your barometer

[Razor]

Thank you Tony....well put, immensely frustrating to read newspaper articles that are clearly written in fantasyland at times

[jamie]

I have an opportunity to go down to central NI on Friday. I would only go if it is going to snow to at least 700m. It looks could enough but this moisture thing and the SE makes me think it will remain quite dry. I really cant decide. If I believed the GFS it will be dump down in the eastern CNI, but Im not sure I do believe it.

Any thoughts on it?

Tony you mentioned the words pasty and anemic for the North Island. Do you mean no moisture?

[TonyT]

I have an opportunity to go down to central NI on Friday. I would only go if it is going to snow to at least 700m. It looks could enough but this moisture thing and the SE makes me think it will remain quite dry. I really cant decide. If I believed the GFS it will be dump down in the eastern CNI, but Im not sure I do believe it.

Any thoughts on it?

Tony you mentioned the words pasty and anemic for the North Island. Do you mean no moisture?

Its not as moist as it could be (uh oh, starting to sound like a skin cream commercial) but clearly there will be some snow, probably in waves during the day. Depends how far east/west you are too.

I didn't mean specifically in terms of moisture, I was speaking generally (and obviously not very precisely!) about the general "look" and dynamic structure of the depression, especially in regards to its ability to influence the SI's weather once it gets that far north.

[snowchaser01]

To me, Thursday night into Friday, and then overnight Friday into Saturday both look cold enough for sea level... just depends in the amount of moisture caught up in the onshore flow I guess.

[Bradley]

I think what will end up being of more interest, for Christchurch anyway, will be the very low overnight temps that look to be on the cards on Monday and Tuesday with a huge high pressure system and bitterly cold air leftover from this system, I think the record low August Airport temp of -6.7C will be given a nudge on those 2 mornings!!

[TonyT]

To me, Thursday night into Friday, and then Overnight Friday into Saturday both look cold enough for sea level... just depends in the amount of moisture caught up in the on shore flow i guess.

Could not have said that better myself...

[TonyT]

I think what will end up being of more interest, for Christchurch anyway, will be the very low overnight temps that look to be on the cards on Monday and Tuesday with a huge high pressure system and bitterly cold air leftover from this system, I think the record low August Airport temp of -6.7C will be given a nudge on those 2 mornings!!

Agreed. And how icy things like roads are on Sunday and Monday mornings...

[Razor]

I think what will end up being of more interest, for Christchurch anyway, will be the very low overnight temps that look to be on the cards on Monday and Tuesday with a huge high pressure system and bitterly cold air leftover from this system, I think the record low August Airport temp of -6.7C will be given a nudge on those 2 mornings!!

Yes I was thinking the same thing last night- 3 nights in a row of -5 predicted

[Orion]

Very wet and cold morning in Ashburton, smoke from somewhere hanging low in the air at one point; I'm glad to be back indoors.
It's around 5deg.

[Richard]

Other extreme here,suns out and a light wind from the north, warming up nicely.

[03Stormchaser]

Today's rainfall well below forecasted, sitting on less than 2mms so far.

[Richard]

I think its looking more likely that this outbreak is going to effect the higher areas of the Southern NI more the eastern SI

[Razor]

Has morphed into a beautiful mild sunny afternoon here now

[einzack]

Well it's cold and wet down this part of the country, as predicted.
Currently 5.6°C with 16.6mm of rainfall so far.

[Dean.]

The clearance was forecasted for the north.Southerly to push in tonight.

[Orion]

5.6deg. here now with broken overcast moving up with the southerly, occasional glimpses of sunlight.

[Richard]

Certainly warmer than i thought it would have been today, 12deg

[Bradley]

It's looking like the coldest air is actually arriving around 4-6 hours earlier on Thursday night then previous data suggested so this may turn any rain/sleet that would have fell on late Thursday night/early Friday morning into snow so although the moisture levels hasn't increased the amount of snow that will fall in Christchurch may be more then first thought

[Growler]

Was a very definite change to the south at about 2:30 in the Sommerfield area, was great watching the 2 separate layers of cloud in diff directions.

[Dean.]

Radar showing signs of a more onshore flow,very dark to our east

[Razor]

Bright sunshine here its turned out a overall pretty decent day after scattered rain this morning

[Razor]

Mod note: deleted a few comments that were off topic to tidy up the thread.