Tasman Low- Storms and Rain - 4th to 9th Nov

[Manukau heads obs]

I might be able to get a chase in...

[Thunder]

Great photo's Spwill. Man I'd love to come up there and come along for a chase! One day I'll fly up there and do that, one day.

Aaron

[tgsnoopy]

I'm starting in Hamilton at 9am, then head down Te Awamutu and Tokoroa in the afternoon. Fingers crossed for something. It's the other side of the Kaimai Force Field so ya never know

[NZstorm]

The convergence zone will run down the west of the North Island. The upper steering flow is E 20knots, meaning convection will tend to migrate westward. I think the road to Raglan could be a good spot.

[Manukau heads obs]

good patches of blue around here and over the north waikato this morning

[jamie]

good patches of blue around here and over the north waikato this morning

yes blue-ish to my north but very overcast to my south. Hopefully it all clears thismorning

[spwill]

Man I'd love to come up there and come along for a chase! One day I'll fly up there and do that, one day.
Aaron

I hope to chase in the South Island this Summer, just need a big slow moving cold upper system to lure me down.

Hopefully the on going showers/cloud cover over the NI wont spoil thunder chances today.

[NZstorm]

Man I'd love to come up there and come along for a chase! One day I'll fly up there and do that, one day.
Aaron

I hope to chase in the South Island this Summer, just need a big slow moving cold upper system to lure me down.

Hopefully the on going showers/cloud cover over the NI wont spoil thunder chances today.

I'll be in Timaru for Xmas so hopefully a good Canterbury storm set up while I'm down there.

[Manukau heads obs]

the wind has increased here from the SE now

ideal would be more easterly wind

the sea breeze will tilt that SE flow to a southerly

[jamie]

Darn! That rain to the east is going to push in. It might take a while to pass over

Tomorrow looks another good day though with a convergence line running down the north island.

[David]

Raining nicely in Howick at the moment, good for the garden

[Manukau heads obs]

thinking out loud here....the current cloud layer that has moved in...might be a good thing...like a cap...keeping a lid on things...so when it does burn off...whamo...

I notice cloud build ups over the waitakere ranges just from orographic lift in the SE wind...so does not need much of a trigger

[jamie]

wow dont think i have ever seen so much of the country under a severe thunderstorm watch before

[NZstorm]

thinking out loud here....the current cloud layer that has moved in...might be a good thing...like a cap...keeping a lid on things...so when it does burn off...whamo...

I notice cloud build ups over the waitakere ranges just from orographic lift in the SE wind...so does not need much of a trigger

The amount of instability is directly related to the amount of surface heating/temperature. So the ideal scenario is like we had yesterday with lots of heating. See what happens this afternoon.

[Manukau heads obs]

yeah , I was just thinking though that if you get too much heating too early..it clouds up too quicky..which then kills it again

yesterday lunch time had that classic pop corn cu sky look

[NZstorm]

yeah , I was just thinking though that if you get too much heating too early..it clouds up too quicky..which then kills it again

yesterday lunch time had that classic pop corn cu sky look

Yes, the afternoon clouded up a bit with high anvil.

[Tornado Tim]

Darn! That rain to the east is going to push in. It might take a while to pass over

I wouldnt worry about that, the Kaimais are weakening that rain into nothing going by radar.The Sun should get rid of the muck cloud left over.

[jamie]

yea your right Tim - and its nice and sunny now with the temp shooting up.

SE winds are usually our warmest quarter winds in the summer but also our driest. Anyone concerned about the potential for a drying atmosphere under these conditions? Or is there ample moisture with high CAPE vales (by NZ standards).

[Tornado Tim]

yea your right Tim - and its nice and sunny now with the temp shooting up.

SE winds are usually our warmest quarter winds in the summer but also our driest. Anyone concerned about the potential for a drying atmosphere under these conditions? Or is there ample moisture with high CAPE vales (by NZ standards).

Some of the best Thunder day's occured on a SE (Feb 2010 setup etc), a SE is what I call the thunderwind.
A SSE can be dry but that is a fohn wind for the Waikato which is dry but a SE derived from a Seabreeze isnt. The setup should come out well due upper level moisture, even if the air being drawn in is a little drier (DP around 15-13C), it will condense quite easily.

[Tornado Tim]

Damb that line coming in from the east isnt weakening! It better move out pronto!

[Manukau heads obs]

light rain here and overcast and only 14.7c

[Hordur]

Satellite image from 9am this morning. Some large clear patches over the upper North Island.

Sat image.JPG

[jamie]

This rain is building on what heating we managed this morning. So it will suck away all that and will be back to square one once it passes, but with a potentially moisture rich lower atmosphere?

[spwill]

Thanks Hordur, Waikato is down stream from the showers/cloud generating in the BOP.
I think the weather is improving over Northland

[Tornado Tim]

If this rain passes before midday I think we will have a good chance....