Thunder/Hail Storms for Sth Is. - Sunday, Mar 25

[Paul Mallinson]

Hey you Christchurch guys, looks like you've got some action coming tomorrow afternoon. Cold trough moves over with temps aloft at 500 hPa falling to -28C or so over south Canterbury and eastern Otago. It been a while since we had a trough this cold moving over during the afternoon early evening.

Cheers,

Paul

[Storm Struck]

I must say a thunderstorm set up day for my birthday tomorrow would go down a treat , will definatly take chase and bring up a new report for the new website.
When theres even a moderate risk from mid morning over south canterbury thats generally good signs, and the westerly looks to cut off tomorrow bringing lighter surface and upper level winds.

[Thunder]

Yes Paul, Jase and me were discussing this potential last night but at that stage it seemed more restricted to morning but now....... looks primed for afternoon / evening indeed.

But why on a Sunday........... the last few good troughs have come through on Sundays. Noooo. I'll have to see what I can do.

[Nev]

Thought this event might warrant its own thread.

Map looks nice...

[mikestormchaser]

Yes very nice indeed to hear this! i will be watching out from early morning and may head down ashburton way around 10am to get in position atleast.. might stop at a nice cafe or sumthing in rakia town along the way, All depending on what it happening. i am free to chase so charging up the cameras as i type
Big happy birthday to jase aswel!!

cheers

[NZ Thunderstorm Soc]

Not looking as hopeful as we get closer to the scenario,sadly.
The elements for thunderstorm growth ( I hate the term thundery showers) are diminishing especially as I can see cloud cover being a hindrance and the fact it will be SW from early in the morning or overnight.
but then........

...by the way Happy Birthday Jase I never got a thunderstorm, which I ordered for my birthday, but you may be in luck tomorrow if you go south

[Storm Struck]

Today should i say will be an interesting one, i see MS going for moderate risk more widespread now with high risk down Ashburton way.
I dont think cloud cover will be a problem because the first initial front comes through around 4-7am and brings a brief SW change which in a way is good because for one thing it clears the air of the westerly and two once that goes through it will die off by mid morning to let coastal sea breezes in.
Then the trough and colder air comes up from afternoon, and the cloud would have cleared through by middy i reackon.

[mikestormchaser]

How are those conditions from models looking like today guys? anyone re-checked? better or for worse? lol
Nice sun shining morn ing in Christchurch has a good feel about it.

[Storm Struck]

Looks good still from what ive seen, infact a stronger pool of air comes up this evening .
I see MS say chance small tornadoes over south canty too, light converging winds there i would say will lead to slow storm motions good for decent cells.
The heating is already there so will take chase at some stage, best spot would be ashburton or slightly further south.

[NZstorm]

I see MS say chance small tornadoes over south canty too

There could be waterspouts off the coast. The air looks too dry with a lack of low level shear for a tornado over land. But you can always gets the funnel clouds, the lapse rates are very steep today 7-8C which is good for funnels.

[Nev]

This morns latest update (for the record )...

MetService - Severe Thunderstorm Outlook

Valid to: Midnight Sunday 25 Mar 2012
Issued at: 9:31am Sunday 25 Mar 2012

An upper level cold trough is forecast to cross the South Island today, with conditions expected to be very unstable, especially this afternoon. Heavy showers accompanied by small hail can be expected over western and southern parts of the South Island today spreading up eastern areas this afternoon and evening. There is a moderate to high risk of thunderstorms for the South Island West Coast this morning and afternoon before upper level temperatures warm there this evening. There is also a low to moderate risk of thunderstorms for southern parts of the South Island this afternoon. Any thunderstorms in these areas are likely to produce localised heavy rain up to 15mm per hour and small hail up to 10mm in diameter.

A southerly change moving through eastern Otago and south Canterbury this afternoon is expected to trigger thunderstorms and is likely to spread through mid and north Canterbury this evening. There is a high risk of thunderstorms from Dunedin up to about Ashburton this afternoon and early evening. Any thunderstorms that develop here are likely to produce localised heavy rain of 10 to 20mm per hour, hail of 10 to 20mm in diameter, and possibly a small tornado. This is also a moderate risk of thunderstorms spreading up to coastal parts of north Canterbury this evening, which could produce localised heavy rain and hail up to 15mm in diameter. A broad low risk of thunderstorms is also indicated up to western Nelson and southern Marlborough, as shown on the chart.

No thunderstorms or significant convection expected over the North Island today.

[spwill]

This cold pool put light snow on the Mnts around Hobart Friday morning and Qtwn today.
Good timing for thunder in the east when the coldest air and wind change can arrive in the afternoon hrs.

For Auckland we usually have to wait until May to get the very cold upper level air.

[NZ Thunderstorm Soc]

I'm glad my predictions for today were wrong.
Bright sunny morning with light N or westerly. Even has a dash of a NE
Some low based Cu forms to the south plus smoke from various burn-offs.
Should be interesting as the day wears on.

[Paul Mallinson]

Just had the first lightning strikes just north of Dunedin City. Convection is also going up in the area between Oamaru and Timaru.

Paul

[NZstorm]

plus smoke from various burn-offs.

I noticed that in South Canterbury last weekend when I was down there, puffs of smoke going up about the place. Adds to the Greenhouse effect!!

[snowstormwatcher]

Few spits of rain here now. Looking really dark to the northwest and south of here.
18c currently.

[Orion]

17.3 degrees here now, 50% humidity; have seen the first southerly clouds low down on the horizon - just checked, they are progressing this way slowly.
Wind west to south-westerly.

[snowstormwatcher]

Moderate shower here now with small hail around 5-6mm

[CHCH Weather Chaser]

Nice looking cell going by radar around the Dunedin area.

[Gary McConnochie]

Nice stormy sky here in Ashburton

[borris89]

Can see the tail end of that storm to the north of Dunedin, some nice mammatus. Looks to be some dark clouds coming in from the south

[CHCH Weather Chaser]

Not very unstable looking here at the moment at all. Perhaps due to the NW breeze we have? Although, the wind is only a light breeze so time will tell, perhaps some development over the next couple of hours.

[Dean.]

Radar looking juicy around South Canterbury

[bmo]

Some dark clouds appearing here

[snowstormwatcher]

Thunder and lightning here now.