Thunderstorm possibilities North Island 30th Sept

[NZstorm]

Polar trough crosses the North Island Monday with the chance of thunder in the west in the morning. Daytime heating also should allow of few thunderstorms/hail to pop up over the central North Island/Bay of Plenty/Gisborne/HB in the afternoon. The upper trough will be over Gisborne by evening.

Keeping an eye on tonights front as well. Front looks lightning active out to NW of Northland where higher dewpoints 14C-15C are.

500mb gfs chart for midday.

[Tornado Tim]

Yes still looking favourable for some storm activity tomorrow for the North Island morning, afternoon and early evening

Issued at: 9:05pm Sunday 29 Sep 2013

A front is expected to move east across the upper North Island in the morning.Ahead of the front, there is a moderate risk of thunderstorms with heavy rain (10-25mm per hour) and strong wind gusts 90 to 110km/h. Behind the front, a low is expected to move over the central North Island with a moderate risk of thunderstorms bringing heavy rain to parts of Waikato, Waitomo and Taumarunui as shown on the chart. There is also a low risk elsewhere over the North Island north of a line from Taranaki to Gisborne.

Elsewhere, no thunderstorms or significant convection expected.

756c-141684d5300-1416c2a1800-14168c09514.0.png

Issued at: 9:07pm Sunday 29 Sep 2013

A low should move away east of the North Island Monday afternoon and evening. An associated upper air cold pool over the North Island should also move slowly east. There is a moderate risk of thunderstorms developing because of afternoon heating over an area east of a line Hawkes Bay to Waikato to Bay of Plenty, as shown on the chart with a low risk over a surrounding area. Any thunderstorms that develop may produce heavy rain with rainfall rates 10-25 mm per hour. In addition, in this same area, their is a low risk that one or two of these thunderstorms may become severe for a time with rainfall rates in the 25-40mm/hr range due to slow storm motions.

Elsewhere, no thunderstorms or significant convection expected.

[spwill]

I see the top of Northland is catching some storm activity, a lightning active Front north of NZ currently

[NZstorm]

GFS Lifted index chart for this afternoon. I would say Taupo to Gisborne is the best area this afternoon for pop up thunder/hail.

Waikato may catch some early thunder.

[jamie]

we had some very heavy rain during the night. could swear we had hail mixed in it.

[jamie]

What do people think about the chances of a spout or two appearing today? Im asking the question because we often see a small tornado reported when we have a slow moving, tightly wrapped low moving over the North Island.

[Tornado Tim]

Looking at the radar, the Low looks to have a trajectory for the central south Waikato.

The risk may be a bit higher north than MS are saying as the cold pool is on the northern side of the low.

I see there are a few CB's around to the NE, not lightning active though….

[Tornado Tim]

The frequent showers are stopping any good DTSH here, completely overcast and a cool 13°C!

[spwill]

However it is looking very unstable over inland parts of the North Island with a few thunderstorms showing up now but the cloud cover will spoil.
I'm not chasing today as it is all too far away.

[Tornado Tim]

I'm not chasing today as it is all too far away.

Yea neither am I, its not a good chase day, everything is too mucky…..
Sunday next week may prove more active?……...

[spwill]

There will be less cloud muck east of high ground.
This map shows the thunderstorm activity last 40mins, you would expect activity to increase over the next couple of hrs

[jamie]

There will be less cloud muck east of high ground.
This map shows the thunderstorm activity last 40mins, you would expect activity to increase over the next couple of hrs

Yea espescially given we are in Day light saving time now.

Sunday next week may prove more active?……...

Yea last i looked it was Saturday that looked the goods. Either way the weekend has a bit of promis.

[spwill]

Todays central NI TS activity all moved quickly out to the east

[tgsnoopy]

Early lightning out to the NE this morning, but not enough to get me motivated. Otherwise it was just a day with occasional showers.

[NZstorm]

Story in the herald about a Gisborne car being struck by lightning yesterday.

http://www.nzherald.co.nz/nz/news/artic ... d=11133042

[Manukau heads obs]

there was alot of strikes showing up in the gisborne area on blitzortung yesterday afternoon at one stage alright