Possible Storms Upper North Island - 28th Sep

Tornado Tim · Unread post by **Tornado Tim** » Sun 27/09/2015 21:49

Metservice wrote:During the afternoon, surface temperatures will continue to rise and sea breezes are likely to develop about several coastal areas of the North Island. This should elevate the risk of thunderstorms for much of the north of the North Island.

There is a broad low risk of thunderstorms during the afternoon and evening for the North Island from inland Taranaki, Wanganui, northern Manawatu and Hawkes Bay northwards, with activity in southwestern areas more likely during the afternoon. The risk increases to moderate for eastern Northland, Auckland, the Coromandel Peninsula, Waikato, Taupo, Bay of Plenty, Gisborne and northern Hawkes Bay. If these thunderstorms occur they are likely to be accompanied by localised heavy rain with intensities of 10 to 25mm per hour and hail of 5 to 15mm diameter. Although the thunderstorm activity should ease in most places during the evening around East Cape the moderate risk extends until midnight.

No other areas of severe convection or thunderstorms are expected.

Instability may be a little weak depending on the SFC Moisture..... Hopefully we might get something on a Sea-breeze front.

Tornado Tim · Unread post by **Tornado Tim** » Mon 28/09/2015 00:37

Blimey, Storms initiating now, this late! Just heard a good rumble of Thunder just now

jamie · Unread post by **jamie** » Mon 28/09/2015 05:06

Didn't get woken by the thunder. Got woken by heavy rain now tho.

Radar shows Brian right on the edge of a massive red blob. on the radar.

NZstorm · Unread post by **NZstorm** » Mon 28/09/2015 07:14

The set up is crossing Waikato/Auckland a bit early and will be east of the area in the afternoon.

Could be good for hail in Coromandel/Bay of Plenty/Gisborne if they get enough heating over there.

500mb temperature chart for the record.

Manukau heads obs · Mon 28/09/2015 07:20

15mm here overnight that i did not expect

NZstorm · Unread post by **NZstorm** » Mon 28/09/2015 07:34

0.4mm only in Grey Lynn.

500mb vorticity chart shows the vortex well. 00Z today.

Manukau heads obs · Mon 28/09/2015 07:39

I notice a sporadic glitch on rain radar too
line down west coast
heavy shower line that we got to move onto the city this morning?

David · Unread post by **David** » Mon 28/09/2015 08:56

Manukau heads obs wrote:I notice a sporadic glitch on rain radar too
line down west coast
heavy shower line that we got to move onto the city this morning?

That glitch has been there on and off for at least several days now

Tornado Tim · Unread post by **Tornado Tim** » Mon 28/09/2015 09:29

Thunderstorm Outlook very much the same from last night:

This afternoon, as surface temperatures rise, sea breezes are likely to develop about coastal areas of the North Island. This should elevate the risk of thunderstorms for much of the north of the North Island.

There is a broad low risk of thunderstorms during the afternoon and evening for the North Island from inland Taranaki, Wanganui, northern Manawatu and Hawkes Bay northwards, with activity in southwestern areas more likely during the afternoon. The risk increases to moderate for Northland, Auckland, the Coromandel Peninsula, Waikato, Taupo, Bay of Plenty, Gisborne and northern Hawkes Bay. Any thunderstorms that occur are likely to be accompanied by localised heavy rain with intensities of 10 to 25mm per hour and hail of 5 to 15mm diameter. Although the thunderstorm activity should ease in most places this evening, around East Cape the moderate risk continues until midnight.

No other areas of severe convection or thunderstorms are expected.

spwill · Unread post by **spwill** » Mon 28/09/2015 09:35

There was some thunderstorm activity overnight west and east of Auckland over the warmer sea.
Coromandel/BOP might be the area for a storm this afternoon

Tornado Tim · Unread post by **Tornado Tim** » Mon 28/09/2015 12:37

Nice crisp cumulus congestus going up around Raglan, looking good

shovelopikis · Unread post by **shovelopikis** » Mon 28/09/2015 13:01

Massive clouds here over pureroas , getting odd showers from them,awesome bases, going for drive later this arvo over waikato, will be interesting.

spwill · Unread post by **spwill** » Mon 28/09/2015 13:32

Pea size hail here at Pokeno, lightning/thunder also.

cbm · Unread post by **cbm** » Mon 28/09/2015 13:56

Over 6C difference between Ruakura and Ham Airport stations ATM. 17.1 verses 10.9

Tornado Tim · Unread post by **Tornado Tim** » Mon 28/09/2015 14:00

cbm wrote:Over 6C difference between Ruakura and Ham Airport stations ATM. 17.1 verses 10.9

Yea the remaints of a shower passing by, my station is half way between Ruakura and Hamilton AP in terms of location and temp. 14.9.

cbm · Unread post by **cbm** » Mon 28/09/2015 14:23

Does cooler air come down in the shower as a downdraft or does the rain cool the surface air? It certainly seems to be a strong effect this time of year.

jamie · Unread post by **jamie** » Mon 28/09/2015 14:33

Some decent towers going up to my North, East and south east

Manukau heads obs · Mon 28/09/2015 14:42

report of lots of hail just north of taupo .could see that cb from here 1 pmish

Razor · Unread post by **Razor** » Mon 28/09/2015 14:51

From the NZ Herald website...sleety showers? Oh my word http://www.nzherald.co.nz/nz/news/artic ... d=11520218

While the ground temperature at the city's airport is a relatively mild 14C, the clouds hanging over the region are packing some hail, MetService meteorologist Lisa Murray said.

"It's a case of 'do they get to the ground before they melt?'"
Early this afternoon hail stones have been reported in the city.

Ms Murray said the day would bring "sleety showers" and there was a moderate risk of thunder storms from a trough moving over Auckland.

shovelopikis · Unread post by **shovelopikis** » Mon 28/09/2015 15:17

Pea size hail 5km west taupo, been covering the roads for a good 10mins so far.

Manukau heads obs · Mon 28/09/2015 15:48

also a report of hail snells beach

shovelopikis · Unread post by **shovelopikis** » Mon 28/09/2015 17:21

South waikato ones have been very slow moving...constant loud bangs here with odd flashes, more hail around tokoroa

spwill · Unread post by **spwill** » Mon 28/09/2015 17:28

Some hail in Mt Eden mid afternoon. Some nice cloud build ups around.
The thunderstorm activity today has been isolated.

NZstorm · Unread post by **NZstorm** » Mon 28/09/2015 17:43

A brief shower in Freemans Bay. A lack of instability over Auckland today.

spwill · Unread post by **spwill** » Mon 28/09/2015 18:37

Photo of a cumulus line near the Bombay hills ( produced a brief thunderstorm with pea size hail) and cumulus over east Auckland

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