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

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

Unread post by Tornado Tim »

Further Discussion about the Developing Tasman Low can go here..............
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Re: Tasman Low- Storms and Rain - 4th to 9th Nov

Unread post by jamie »

Looking forward to this week. Our first real summer set up of the season.
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Re: Tasman Low- Storms and Rain - 4th to 9th Nov

Unread post by David »

GFS showing Lifted Index -2 to -3 and CAPE above 500 Wednesday afternoon, but it's looking to be cloudy and wet so not much daytime heating...
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Re: Tasman Low- Storms and Rain - 4th to 9th Nov

Unread post by treetop »

king country across to East cape more likely a focus for storms, given the increased heating /assisted lift and convergence.
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Re: Tasman Low- Storms and Rain - 4th to 9th Nov

Unread post by NZstorm »

Thunder looks likely over Northland/Auckland/Coromandal with the front late Tuesday into early Wednesday.
The upper air is cold 500mb-23C/lase rates 7C and strong forcing so that should produce lightning. Small hail possible.

Western Waikato looking good Wednesday afternoon. Just need to get the heating which should happen.
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Re: Tasman Low- Storms and Rain - 4th to 9th Nov

Unread post by jamie »

This sort of setup is reminding me of one in about October or November 2004-ish. We had a brilliant storm over western Waikato build over the hills and then sweep eastward over the basin. That setup had a similar low (probably slightly tighter low and possibly deeper) mover across the north island.
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Re: Tasman Low- Storms and Rain - 4th to 9th Nov

Unread post by Tornado Tim »

Manuwatu is another place that looks favourable for storms later on this week. High Cape and low shear meaning there is the potential for severe muticell storms (strong outflow gusts and assoc microbursts which contain very heavy rain)
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Re: Tasman Low- Storms and Rain - 4th to 9th Nov

Unread post by Nev »

NZstorm wrote:Thunder looks likely over Northland/Auckland/Coromandal with the front late Tuesday into early Wednesday.
The upper air is cold 500mb-23C/lase rates 7C and strong forcing so that should produce lightning. Small hail possible.
Not surprisingly, MS in fill agreement :D
MetService - Severe Thunderstorm Outlook

Valid to: Midnight Tuesday 5 Nov 2013
Issued at: 10:42am Monday 4 Nov 2013

An active front is expected to move over the top of the North Island late on Tuesday. There is a high risk of thunderstorms ahead of the front over Northland late afternoon and evening, spreading down to Auckland in the evening and overnight. These thunderstorms are expected to be accompanied by heavy rain and strong wind gusts around 110km/h. There is also a low risk that severe thunderstorms may develop with tornadoes and wind gusts in excess of 110km/h.

Elsewhere, no risk of thunderstorms or significant convection.
MetService Severe T-storm Outlook Map - Is. Nov 4, 10.42am.png
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Re: Tasman Low- Storms and Rain - 4th to 9th Nov

Unread post by Tornado Tim »

Wednesday is still looking positive for storms for Waikato with high numbers of CAPE and good moisture and lift.
The forecasts soundings are suggesting there is the potential for good shear however the steer or mid level flow is weak making any potential sufficient shear non existent (hence why the SHEAR values on sounding look weak).

Still looking like a potential severe multi cell storm day at this stage.
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Re: Tasman Low- Storms and Rain - 4th to 9th Nov

Unread post by NZstorm »

Yes, does appear that shear could be lacking Wednesday afternoon. That'll keep the hail size down although I wouldn't rule out marble.

A good shear number to use is the 0-5km shear. It is the difference between the surface wind vector and 5km wind vector and expressed in knots. The Americans use 0-6km shear also referred to 6km bulk shear.
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Tasman Low- Storms and Rain - 4th to 9th Nov

Unread post by ben g »

Lots of moisture pouring in on the nor easterly from over the Hauraki gulf this morning
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Re: Tasman Low- Storms and Rain - 4th to 9th Nov

Unread post by Manukau heads obs »

thunderstorm and race day! :)
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Re: Tasman Low- Storms and Rain - 4th to 9th Nov

Unread post by spwill »

Guy Fawkes night tonight :-)
The dewpoint temperatures are not particularly high with this system, dewpoints 12 -13C but the upper air is quite cold. I see next week we could see higher dewpoints , 17C around a High, would be our first taste of Summer here.
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Re: Tasman Low- Storms and Rain - 4th to 9th Nov

Unread post by Orion »

ben g wrote:Lots of moisture pouring in on the nor easterly from over the Hauraki gulf this morning
Great picture - very soggy-looking _b
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Re: Tasman Low- Storms and Rain - 4th to 9th Nov

Unread post by Tornado Tim »

Latest Outlook:
Metservice wrote: An active front is expected to sweep southeast over Northland and Auckland this afternoon and evening. There is a high risk of thunderstorms slightly ahead of the front and with the front in the far north this afternoon and then extending south over the north of Auckland this evening. These storms could be accompanied by heavy rain 15-25mm/hr, strong wind gusts 90 to 110 km/h and possibly small tornadoes.

There is a moderate risk of SEVERE thunderstorms slightly ahead of and with the front over the east of Northland this afternoon and evening and the northeast of Auckland this evening as indicated on the map. These storms could be accompanied by damaging wind gusts in excess of 110 km/h, tornadoes and downpours, 25 to 35mm/hr.

Daytime heating is likely to generate some showers over the Tarararua Ranges this afternoon and there is a low risk that some of these could be thundery with hail.

Elsewhere, no thunderstorms expected.
The front is still active according to NZAPStrike/Blitzortung, will see how the situation pans out for you Auckland folk :)
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Re: Tasman Low- Storms and Rain - 4th to 9th Nov

Unread post by David »

Latest outlook has the risk slightly more north, i.e north of central Auckland now...
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Re: Tasman Low- Storms and Rain - 4th to 9th Nov

Unread post by tilly123 »

This looks interesting, if only I lived in Auckland ;)
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Re: Tasman Low- Storms and Rain - 4th to 9th Nov

Unread post by jamie »

tomorrows outlook looks fairly decent too.
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Re: Tasman Low- Storms and Rain - 4th to 9th Nov

Unread post by spwill »

Tornado Tim wrote: will see how the situation pans out for you Auckland folk :)
A case of just watching now. Some low level instability around Auckland this morning with some showers developing. 18C, dp 14C.
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Re: Tasman Low- Storms and Rain - 4th to 9th Nov

Unread post by KiwiWeather »

Some activity in Dargaville right now.
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Re: Tasman Low- Storms and Rain - 4th to 9th Nov

Unread post by Manukau heads obs »

have had a couple of good heavy shower lines come through here :)
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Re: Tasman Low- Storms and Rain - 4th to 9th Nov

Unread post by spwill »

A couple of gusty showers here.
Some isolated storm activity over the top Northland last hr
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Tasman Low- Storms and Rain - 4th to 9th Nov

Unread post by littleheaven »

Crikey, the Metservice thunderstorm outlook for tonight contains the text "damaging tornadoes possible" which I don't think I've ever seen before.
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Re: Tasman Low- Storms and Rain - 4th to 9th Nov

Unread post by Manukau heads obs »

I have seen that wording before

the front on the sat image has been looking much better compared to the rain radar...
i.e cold cloud tops....but not much under those blown off anvils
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Re: Tasman Low- Storms and Rain - 4th to 9th Nov

Unread post by David »

Just cleaned my rain gauge before the rain arrives tonight, the spiders sure go crazy with their webs at this time of year! Some fireworks already being set off... I prefer nature's fireworks (thunder and lightning just in case I have to make that clear ;P )
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