NZ Weather Forum

To clear up the rubbish that we have been experienceing over the last weekends and into the new weeks, it looks likely a reversal, this coming WE with a very intense anticyclone moving over New Zealand.
A weather warning to this effect should be in place because we could get, lots of inversion, anticyclonic gloom, this depending on the slow movability of the anticyclone...
... but on the other hand, we, hopefully will get lovely fine, sunny days, to enhance the spring growth, with all the rain that we have been having lately.

JohnGaul
NZTS

We could do with weeks on end of just that, with the blocking placed to bring in enough warm air to start the Alpine snowmelt.

Perhaps a touch early for alpine snowmelt to get started. But would be a brilliant start to Spring. I don't believe that we've just had an early dose of wild Spring weather though, that wouldn't make sense really....there must be more to come, let's just hope it's not in December.

M/S has it up to 1046 at the moment!

I hope the anticyclonic NE flow that is due to persist over Auckland from Saturday onwards out to the end of next week is not too mucky. That wind direction can cloud Aucklands skies up and will certainly give exposed areas like east Northland drizzly showers.

Yeah, looks like it Steve.
I wonder how high this anticyclone will go?
Apparently, the world's highest ever barometric surface pressure occured on the last day in 1968 when the barometer at Agata, in north, central Siberia reached 1083.8hPa
Mind you the air temperature was minus 46ºC
A barometer in Aberdeen measured 1054.7hPa on the 31st January in 1902

JohnGaul
NZTS

Well if the MS rainfall map is right, we could see 1045hPa recorded somewhere in the Gisborne Region. I think that would be a North Island record? If not quite an NZ record.

If this happend during summer would that mean temperatures into the mid 30's about Central Otago? probly more around 25C temperatures along eastern coasts depending on how keen the onshore flow was.
Also the usual inland afternoon heat showers about the plains, ahh let summer be here soon ( 5 days until spring) .
It sure is going to be a bumper spring season for grass and plant growth, although i am sure your horses will enjoy some fresh green grass John .
Well atleast you wont have to mow them i wouldnt think .
Cheers
Jason.

I'd rather have an anticyclonic NE flow over a SW flow anyday,at least its not so windy and more predictable plus its warmer.

NZstorm wrote:I hope the anticyclonic NE flow that is due to persist over Auckland from Saturday onwards out to the end of next week is not too mucky. That wind direction can cloud Aucklands skies up and will certainly give exposed areas like east Northland drizzly showers.

NZstorm wrote:I hope the anticyclonic NE flow that is due to persist over Auckland from Saturday onwards out to the end of next week is not too mucky. That wind direction can cloud Aucklands skies up and will certainly give exposed areas like east Northland drizzly showers.

How could that be so? The pressures are expected to be 1040hPa+ for several days according to a lot of the models at the moment. I thought with pressures that high you'd have cloudless skies?

You can get cloud trapped underneath large highs in coastal areas....a damn pain in Auckland I can tell you! Also, the centre of the high wont be over Auckland - we'll be more on the fringes - so if that south east flow swtiches to the east or north east it can drag in a few light showers. But right now I'd take north east showers over south west showers any day!

yes, called anticyclonic gloom (caused by an inversion layer, with moisture (from the oceans (builds up more and more the older the high becomes) trapped under that (the inversion layer is caused by the sinking(more dense) air in the high warming up the atmoshere (above the inversion))
you also get convergence lines forming around the top of the high, with air spiriling out from high undercutting a different airmass (different origin (dew point), and moving at a different direction too)...something like that...

Was actually planning on writing a piece about Anticyclonic gloom, or "dirty" highs, later this week!

Practically anytime you get an onshore flow accompanied by high pressure you will get anticyclonic gloom. Auckland is very prone to it when the flow is anticyclonic SW or anticyclonic NE. You can bet your bottom dollar the weather will be mucky in those situations. And sometimes there can be sufficient depth under the inversion layer for low topped cumulus/showers to occur as well.

one good thing is it will be a newly developed high pressure....but the longer it hangs around, the more the cloud layer will increase....

also though if the wind is easterly enough, the cloud will burn off in the afternoon in the auckland area...

Sounds like a bit of a depressing anticyclone to me, even if it does bring extremely high pressures
Friday afternoon is when metservice is saying fine for Auckland, but I have an exam that afternoon.
A few consecutive fine sunny days just seems too much to ask!

it will be fine weather, for the first few days, but as the anticylone hangs around, the moisture off the pacific ocean will keep on increasing and it will become a cloudier and cloudier high....(e.g from monday on) but note that is around the top finges of the high...near the center will be better...
also inland or western coast (with a easterly or NEly wind) will be much clearer

the problem at this time of year is there is not enough heat in the sun to burn off the cloud layer until say mid afternoon (once it becomes a cloudy high)

one thing though to always watch out for with a new high moving on quickly after a cold front goes through, is the good ol easterly surge (i.e drizzle moves in from the east)

This high looks as though it will be a blocking feature to the east of NZ now with ridging extending back over NZ.
So any resistence to it will be of not much significance, even the trough over NZ next WE, because surface baro metric pressues will be high.

JohnGaul
NZTS

Shock and horror...I actually saw THE SUN today!!

This is the type of weather we need

NZ Thunderstorm Soc wrote:This high looks as though it will be a blocking feature to the east of NZ now with ridging extending back over NZ.
So any resistence to it will be of not much significance, even the trough over NZ next WE, because surface baro metric pressues will be high.

JohnGaul
NZTS

Beautiful weather today.
At this stage it's looking as if we won't be seeing any significant rain for the next week or two!

a far cry from february, when we were all crying out for some rain... now we have had just about enough!

12 in Westport now 4 in Haast.. Weird how the Warmest and Coldest are on the West Coast. Wow it got up to 17 today at Jeffs what a wonderful day

Pretty miserable here this morning - thick overcast, cool with a low of 6oC an hour ago, currently 10oC with a southeasterly gusting 31km/h. Rain radar even shows precipitation on the way

Its called "Auckland weather" Years of it I remember.Anyway back to today its no wind here,overcast and 9° tmin.Warmer than yesterday or Wednesday AM.

David wrote:Pretty miserable here this morning - thick overcast, cool with a low of 6oC an hour ago, currently 10oC with a southeasterly gusting 31km/h. Rain radar even shows precipitation on the way