T-Storm Risk for Upper Nth Is. - Mar 18

[NZstorm]

That front out in the Tasman should turn a bit thundery tomorrow. Its not due to reach the North Island until Friday but I wondering whether there could still be some storms firing on it when it reaches the west of the NI Friday.

[NZstorm]

Still looks the potential for a thunderstorm or two over the upper North Island Friday. An upper trough will be approaching the area from the west with a weak surface trough with the possibility of cb development. Main problem is getting some surface convergence but will check on it again tomorrow.

[spwill]

Could be some local thundery falls on friday.

[NZstorm]

Looks like a weak front/upper short wave crosses the North Island tomorrow and this should trigger a few thunderstorms. Weak instability along the front will be reinforced by daytime heating, so should see a few storms develop over the inland North Island. GFS also has a bit of development over Northland. Here's hoping for a March thunderstorm.

[Manukau heads obs]

good call NZStorm:
http://metservice.com/national/warnings ... rm-outlook
looking like action stations tomorrow!

[Tornado Tim]

Upper air looks too warm for my liking tomorrow around where I am.

[NZstorm]

Almost fog here this morning, a sure sign of autumn.

That front will be more advanced across the North Island by this afternoon than I previously thought. Northland will be the spot for thunder this afternoon as will the Coromandal and BOP perhaps.

WZ shows front just to our west and an interesting blow up above Northland this morn.

[Manukau heads obs]

can see CB tops to to my south
and are picking up some lightning strikes from that line too

[NZstorm]

03Z gfs numbers for Rotorua, Lifted Index -3.0, dp 18C, 500mb -15C, 500mb wind NW30kts.

[Nev]

Latest update looks promising...

MetService - Severe Thunderstorm Outlook

Valid to: 12:00am Saturday 19 March 2011
Issued at: 9:15am Friday 18 March 2011

A front lying offshore to the west of the North Island this morning will slowly cross the upper North Island this afternoon and evening. As it does so, it is expected to become more active with heavy showers and some thunderstorms in many places north of the central high country.

There is a moderate to high risk of thunderstorms this afternoon and evening from Taupo and Bay of Plenty northwestward (including mainly eastern Waikato).These have the potential to produce local rainfall rates of 10 to 25mm/hr or higher. Over Coromandel Peninsula, mainly eastern parts of Auckland and much of Northland, there is a high risk that some of these thunderstorms will be SEVERE with rainfall rates in the 25 to 40mm/hr range. The potential for these storms is generally expected to be from later this afternoon and through this evening,but there is a risk they may persist over northern Northland until midnight.
There is a surrounding low risk of thunderstorms between the areas mentioned above, and northeast of a line from Waitomo to southern Hawkes Bay.

Elsewhere, no thunderstorms or significant convection expected.

[David]

yay, east Auckland is in the high risk zone But, will it come to much? Regardless of thunder or not - any rain is welcome...

[jamie]

Put your camera on the charge now guys, i am happy to leave work early if something gets going. Will definitly chase if there is something


Notice MS said these severe storms in northland could last into the night till midnight. that would be a fantastic chance for the people up there to take some night time lightning shots.

[spwill]

I see the MS outlook mentions thunderstorms in many places north of the central high country which is a big change from yesterdays mod risk of isolated storms.

[Manukau heads obs]

frontal line is weakening as it comes ashore
but
wait
theres more

way to the NW...

[spwill]

See what daytime heating can do this afternoon, will be east of here.

[Manukau heads obs]

the area of heavy rain to the NW of here, west of Kaitaia, moving towards me, now has become lightning active
goody

[jamie]

heavens have just opened up in hamilton!

[NZstorm]

I don't like all that anvil cloud over Northland, it blocks the sun and reduces afternoon CAPE. Looks like the best heating atm is SE of Auckland to BOP. T/cu out to SE.

[spwill]

This photo looking SE from here, clouds starting to build.

[Tornado Tim]

Yup Nice heavy downpour here with the line of showers going through.
Update: temp took a big dive when the showers hit from 25°C to 21.5°C, hopefully it recovers.

[David]

At the last minute this morning I decided to take an umbrella, wish I never had now Maybe the rain area to the NW will produce something later

[Manukau heads obs]

there is a line of heavy showers from Papakura to SE of there though

[spwill]

Looks like a heavy shower line forming across Auckland currently but the line is east of here, David should get it.

[David]

It's gone very dark looking just to my W and NW, not sure which way it's going though...

Ah, snap spwill...LOL
Hope you're right

[jamie]

very dark and low cloud to my east. took a picture. very very interesting cloud lowerings!!!!