Low bearing down

Thunder · Unread post by **Thunder** » Thu 28/10/2004 11:48

Hi

With this low bearing down on us I say possible storms for Canterbury tomorrow afternoon. A trough looks to be forming on the edge of mid/south Canterbury to move up the plains in the afternoon although it's not that well defined. The thing I'm worried about is high and mid level cloud once again which won't help things.

Auckland / Waikato looks good on Friday afternoon to, and high and mid level cloud doesn't look to be of much of a problem as it does in Canterbury. No good for storms in Canterbury on Saturday but I'm not sure about up north for Saturday. What are your thoughts Steven W (for this low in general aswell?).

Yes I've been looking at the tot tot charts

)) and I see 50 over the plains and quite a bit of the North Island on Friday, LAPS and GASP pretty much agree there (although the plots are 1pm for LAPS and 1am for GASP) so thats good.

An upper pool of cold air looks to be coming over Canterbury in the afternoon associated with the low of around -20 which isn't the best but it's colder than the upper air has been recently.

CAPE isn't showing much but there's some there (20/30?). I'm noticing that the GFS models seems to under predict temps here in Canterbury so maybe that might have something to do with it?

I can't see any NE winds on the models before the trough (more NNW is what they say) so I'm not sure there. Tony, I know you mentioned that the models aren't too good with our NE so what are your thoughts?

Now be gentle

but please give my inexperianced mind different thoughts on tomorrow which would be much appreciated!

tich · Unread post by **tich** » Thu 28/10/2004 13:35

An upper pool of cold air looks to be coming over Canterbury in the afternoon associated with the low of around -20 which isn't the best but it's colder than the upper air has been recently.

MetService are now predicting thunder and hail for Canterbury tomorrow afternoon.

Thunder · Unread post by **Thunder** » Thu 28/10/2004 14:05

Yes Ben, always a good sign!

The trough has become more defined now on the latest model run so thats good. Most things are pretty much the same still except there's not as much moisture at 300mb now, still it's the same for the rest. It'll be easier to look at sat pics tomorrow anyway. I notice pseudo NE coming in from the ESE to meet up with the SSW also so that's good.

And sorry, CAPE looks more like 5/7 for Cant, not the best but that's a model speaking.

Convective outlook John?

TonyT · Unread post by **TonyT** » Thu 28/10/2004 15:04

I think you are well onto it Aaron, you seem to have looked at most of the useful predictors.

None of the models will predict a lee-trough NE for Canterbury - they dont have the resolution. So, look for lightish northerly quarter winds (say <10 knots at the surface) and you can be pretty sure we will in fact be getting NE.

However, I agree that middle level cloud might be the dampener tomorrow - perhaps too much to allow any decent convection to get going before the rain cloud associated with the trough arrives.

spwill · Unread post by **spwill** » Thu 28/10/2004 15:05

Aaron, the scenario you want tomorrow for TS down there is for the Front to have passed through by the afternoon with the Low and sunny weather over you prior to the southerly arriving.

NZ Thunderstorm Soc · Thu 28/10/2004 15:35

Aaron J Wilkinson wrote:
Convective outlook John?

Hi Aaron,
Judging by the consequences I have given tomorrow (and Saturday interestingly enough at the moment) a 2 but that could change judging how things will eventuate.
Cloud cover will probably be the main hindrance.
At the moment I think that any thundery outbreak that may occur, will be nothing much to get really exited about but it could be a good tester for Steven Graham's lightning detector.
Anyway, here's to the first possible thunderstorm for Canterbury this season $\:D/$

JohnGaul
NZTS

dogmelon · Unread post by **dogmelon** » Thu 28/10/2004 16:51

There is a season?

NZ Thunderstorm Soc · Thu 28/10/2004 18:30

dogmelon wrote:There is a season?

Has the daygone by without the

JohnGaul
NZTS

NZstorm · Unread post by **NZstorm** » Thu 28/10/2004 19:26

There is a season?

Dogmelon, you must be new to weather observation. Now that you are a member of this forum you have the opportunity to learn.

Thunder risk over the North Island tomorrow will be in that front and perhaps Isolated cb/storms in behind it ahead of Saturdays SW change.
Dewpoints should lift overnight, maybe as high as 18C tomorrow.

As for the South island, I can't add any thing further as to whats already been predicted. Chance of cb's developing east of the alps in the afternoon/evening as the low passes through.

As for Saturday, I think Gisborne is the region mostly likely to catch some thunder.

TonyT · Unread post by **TonyT** » Thu 28/10/2004 22:01

dogmelon wrote:There is a season?

To everything - turn, turn, turn
There is a season - turn, turn, turn
And a time for every purpose under heaven

A time to watch clouds, a time to eat snow
A time to measure rain, and tell all of us
A time to see halos, a time to hear thunder
A time for cirrus, alto-cu, and cumulonimbus

To everything - turn, turn, turn
There is a season - turn, turn, turn
And a time for every purpose under heaven

Feel free to add more verses...

Fujita Phil · Unread post by **Fujita Phil** » Thu 28/10/2004 22:15

dogmelon wrote:There is a season?

Some would say there's

"4 Seasons in One Day"

Dean. · Unread post by **Dean.** » Thu 28/10/2004 22:33

Well I love a rainy night
I love to hear the thunder
Watch the lightning
When it lights up the sky
You know it makes me feel good
Well I love a rainy night
It's such a beautiful sight
I love to feel the rain
On my face
To taste the rain on my lips
In the moonlight shadow
Showers wash
All my cares away
I wake up to a sunny day
'Cause I love a rainy night
Yes I love a rainy night
Well I love a rainy night

03Stormchaser · Unread post by **03Stormchaser** » Fri 29/10/2004 09:05

its overcast here this morning which isnt a good start to the day.
11C And SW

Manukau heads obs · Fri 29/10/2004 09:17

typicaly the ftront fixzled as it approached the NI (i could see that was going to happen)
but a new front is developing now
and i see ricky has a lightning strike in one of the blobs out there
so it could get interesting as this new front develops and moves closer!

tich · Unread post by **tich** » Fri 29/10/2004 10:34

Started raining in central Chch within the last 1/2-1 hour. 10AM radar shows solid rain about the foothills and upper plains of mid Canterbury.

spwill · Unread post by **spwill** » Fri 29/10/2004 12:06

Mostly overcaste all morning but dry, Warm and humid,now 20c dewpoint 17c.
10 am Met service radar showed thundery Cb out to our west at sea but they are moving SE.

Manukau heads obs · Fri 29/10/2004 12:16

to our west at sea but they are moving SE.

so typical aint it
again the king country is in the firing line...
its certainly got that good thundery look about it here though

still, i think we will still get something, as there is still a generation area to our NW

Thunder · Unread post by **Thunder** » Fri 29/10/2004 12:34

Those are nice figures Spwill! Hope you guys get something.

Here I just don't know, winds are variable to calm at the moment, I think it might be tending ENE here at the moment as I see clouds outside moving very slowly. Temp is rising slightly but I think that's due to the calm. We might get a sunny spell or two in the afternoon before the southerly arrives which I think will be towards 5pm or a bit later now. But other than that I'm not sure.

Manukau heads obs · Fri 29/10/2004 12:49

skies cleared a bit here now
i can see the CB's out to our west now
impressive
very high tops, lots of cirrus/very white in the sun...

with the sun coming out, i think the ingredients will be the later for some good development in a few hours time here!
(its now 20oC and 17.5 dp

spwill · Unread post by **spwill** » Fri 29/10/2004 13:34

Hav'nt seen much of the sun here today but with the high dew points and that line of heavy showers just out to our west( 1pm radar) TS are possible here this afternoon.

Willoughby · Unread post by **Willoughby** » Fri 29/10/2004 15:10

Currently thunder heard, no precip, black skies to the west... no tops visible
21c, high humidity, gusty northerly

Manukau heads obs · Fri 29/10/2004 15:11

yes, that will be the shower we got
2.8mm fell here pretty quickly
and ricky's ligthning detector shows strikes in the waikato...
the CB peaked past us here....oh well

Willoughby · Unread post by **Willoughby** » Fri 29/10/2004 15:25

Bucketing down now with more thunder

Manukau heads obs · Fri 29/10/2004 15:48

the latest sat picy shows big cb's over the central NI, right where rickys lightning detector plots them
dont touch that dial ricky!

Willoughby · Unread post by **Willoughby** » Fri 29/10/2004 15:51

It's detecting nothing in Waikato, esp. Hamilton