NZ Weather Forum

bit of a sea breeze convergence line here, but its not a continous line
might be late afternoon/early evening before things get cranking more?
looks to be a bit too stable looking personaly,just looks like a typical 'summers' day type situation?
update:
the convergence line over the auckland isthmus has had some nice billowing CU at times
might get some heavy drops of rain under them in another hour or so
but I dont think too much is going to develop?

Sitting right under the convergence line in Conifer Grove just north of Papakura, extensive cloud cover pushing both east and west. Light northeasterly here of around 5kts while across at the airport its southwest at a similar speed. Doesn't look like the conditions are going to go as pear shaped as Tuesday around this time when the heavens opened, and opened........... and the temp took a king hit! Temp here now has dropped a couple, hovering on 16C.

Have had little showers all afternoon here in Kaukapakapa

I see a line of showers now on the radar from Waikato up to Northland, NE v SW, most of Auckland staying dry, max today 18C, low was a cool 8C.

No need watering any gardens with a hose here,3rd day of late pm rain under the anticyclone.

had TV3 weather visit me today and I took them up to the heads/light house
and I pointed out the sea breeze convergence line start
which they aired on the weather 2 nite!
some glaciated CB tops visible from here currently for north waikato through to south auckland

Rapid development on the Waikato line, looks like some lightning strikes down there.

yes saw that on tv3.though the weather narration wasnt that great....but when listened on radiolive

spwill wrote:Rapid development on the Waikato line, looks like some lightning strikes down there.

Yup a good thundershower to SE around 10 to 7, that went for about 10 min or so

Taken heaps of shots of the developing convergence line. will post them soon.
Huge drops coming from the line, I have got completely soaked!

good cell developing over the city now...

Nice photo Brian, here's a photo taken under that cloud.

Nice photos.

I saw a funnel cloud today, early afternoon out over NW Auckland. Huge pity I didn't have a camera!

http://i.imgur.com/UBiJF.jpg
http://i.imgur.com/PpChV.jpg
Tuesday.

spwill wrote:Nice photo Brian, here's a photo taken under that cloud.

Great shot Brian and Simon Is that on the South Western Mtwy? It looks familiar.

Anyway here are my shots, the convergence line started forming around 5 PM athis evening and started dropping large sporadic drops at around 5.40 PM or so.
The convergence line developed ontop of me then shifted slightly east as it developed further, then back over me in the mature stage.
LCL's dropped quite a bit when precip started falling, as you will be able to see in the photographs.
6.40 onwards was when things became really interesting with small circulations occurring on the base and the hearing thunder just to my SE for about 10 min (cloud to cloud).

Quite a surprising setup really, the SFC temp only got to just shy of 20°C today, Upper temps were relatively cold but I thought the cap was a little to strong.

Yes a fanastic convergence here tonight. No photos but was amazing. Saw lightning and heard distant thunder. Caught the very edge with a few big drops of rain but nothing substantial like the other night.

Great photos Tim. Fantastic. Yes I saw some small bits of rotation at times but never anything to get a good funnel going.

good photos from tuesday's heavy showers there too aucklandstorm

Quite a surprising setup really, the SFC temp only got to just shy of 20°C today, Upper temps were relatively cold but I thought the cap was a little to strong

yes, I had my doubts anything would get going enough to provide a shower
but things suddenly ramped a few clicks around 7pm
I wonder what changed?
(the sea breeze died about then here)

I think some good convergence as the NE breeze pushed out the SW breeze

Great photos and nice formations there!

This was Whenapais 00Z sounding (1 PM NZ Time if I am correct), looks like a sea breeze didnt kick in then as the SFC DP was a little low.
Looking at my weather stations log's, I am surprised we even got any showers at all with the low SFC DP's (around 10-12°C) compared to 18-19°C Temp.

The sounding indicates there was some slight saturation occurring around 950mb, If a 6 PM/7PM sounding was done id like to check it.
I have a suspicion it wasntly souly driven by SFC moisture, some of the cumulus clouds (outside the convergence line) were very fibrousy which means they lacked moisture. According to various Tauranga weather stations there was a seabreeze (meso-scale cold front) albeit fairly weak on the SFC that occurred just after 3 PM.
It could be that the SFC air mixed out before getting inland, but the layer just above the surface (950mb) contained the required moisture from the sea breeze creating the stronger convergence. Then the precip falling from the cloud making the LCL lower (making it appear that the line was surface based).
However there is that cap to consider, I wonder if that storm just to my SE broke through the cap? Jamie did you see the top of that storm?
There is the possibility that it was just a low topped storm (they do happen on occasion), but these are all hypotheses...

Anyway a relatively unusual convergence line in my book, may have to do a bit more research

No sorry Tim. I could only see the Bottom at all times

Jamie did you see the top of that storm?

I could see fibros tops. Cloud tops would have been to about 7000m for the thunder to occur.

yes, there was glaciation occuring not long after 7pm, at a relatively low height....but then again the base of the clouds was relatively high too
coastal cloud slowly moving in from the SW here this morning
looks as predicted for you tomorrow jamie...SW winds and mainly fine...for your big day

Looks like more thunder on the cards early week!

If the gfs is correct there will be thunder over inland Otago/Canterbury Sunday afternoon.

Looks like thunder a possibility for the inland/eastern North Island Monday.

GFS output for Sunday.

Yes ive been watching that for Sun and Monday too hopefully