Cold Outbreak behind a Low, 6th-9th

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sw_windbow
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Unread post by sw_windbow »

Beautiful rolling cumulus wall gliding in from the WSW, has a base height of about 400 metres and has blotted out that quite substantial snow fall on Mt Flagstaff.
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Unread post by 03Stormchaser »

spwill wrote:
Looks like weather forecasters may have been stumped again, re snow to lower levels! Although I never saw anything in models I guess its alot harder to forecast flurries more than anything
The ECMWF has been indicating a wintry out break for over a week now so no suprise to see the low level snow today.
Yes the models have indicated a wintry out break for over a week, and the metservice forcasts of snow lowering to 400-500m indicate what that the models were showing. So snow at Darfield wasn't what the models were spitting out. If you saw something to indicate snow would fall that low, I would be intersted in using those models! ;) :)

Unsure as to what Blueskies had forecasted.
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TonyT
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Unread post by TonyT »

I think we had snow to similar levels to Metservice. We did send a warning out two days ago to clients. Snow to near sea level is an exceptional (although as Ben noted, not unheard of) occurrance in November, and you would be looking for an exceptional set of data to predict it from. I dont think any of the models had that.
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Unread post by Fujita Phil »

Not much action here for a while but here's a picture for ya... Certainly not sea level
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There is no such thing as bad weather, just the wrong clothes.
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NZstorm
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Unread post by NZstorm »

Todays 0000Z NZNV sounding indicated snow to about 300m. But sometimes as a trough moves up the east of the SI in a cold unstable flow, it can become convectively more active and locally knock down the freezing level. Hard to forecast.

I like using the Maquarie Island sounding (YMMQ) in forecasting as its down steam from NZ, so much of our weather originates from that direction, and its actual information. :)
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Unread post by spwill »

It's always looked a very unstable weather situation for today and tomorrow, lots of Cb development, freezing levels fall under active Cb cloud.
tich
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Unread post by tich »

But sometimes as a trough moves up the east of the SI in a cold unstable flow, it can become convectively more active and locally knock down the freezing level. Hard to forecast.
That seems to be happening in Canterbury now, with snow falling even lower than MetService's updated 200m forecast. Now only 2.4C at Hillmorton, and looks like sleet with the rain in central Chch.

With an unstable trough in the cold air, freezing levels could easily drop lower than forecast in the central North Island tomorrow as well.
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Unread post by Andrew Massie »

No sleet here at sea level in CHCH, but a sad little 1 degree and 4mm rain... yawn again! :roll:
Manukau heads obs
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Unread post by Manukau heads obs »

also note that as the whole area now is dropping air pressure (deepening low pressure area), across the SI ,that also drops the temperature...
that is often overlooked....
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tidd66
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Unread post by tidd66 »

We have very heavy snow in Gore at the moment starting to settle too.
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Willoughby
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Unread post by Willoughby »

First active line due shortly.. picking up a few strikes now with it.. baro taking a plunge :)
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Unread post by spwill »

Looks like a line of heavy showers and thunderstorms to cross our area in about an hour, can see the Cb tops through our west.
However the shower line looks to be weakening as it moves east
Last edited by spwill on Thu 09/11/2006 06:48, edited 1 time in total.
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Willoughby
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Unread post by Willoughby »

Yep, heavy rain here falling (my windspeed has quit again :x ).. getting squally too from the WNW.

Poor timing with those thunderstorms.. if they came through at midnight it would've been game on!

Rain rate to 1.9mm/min just then..
Manukau heads obs
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Unread post by Manukau heads obs »

interestingly Foggy, i changed over to use a WMII windspeed, and no more problems with heavy rain for me now....
with your VP windspeed, you could try and replace the reed switch with a better quality (heavy duty one) one maybe...the one that comes with it is very small...but its not easy to change....hard to get the new one in there...
(sorry, off topic)
raininly steadily here now, have had a drop in temperature, wind direction shift and barometer increase so the front is through here now

update, now getting very heavy rain....with a 2nd squall line most likely

my my , just looked at the sat picture....this low has really deepened alot!
993hpa here now...
we are in for some gales today!
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Willoughby
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Unread post by Willoughby »

urrk.. :?
Slip forces evacuations
9/11/2006 6:24:03

Six people in Hamilton have been evacuated from their homes after a large slip near the central city.

A 10 metre high bank has come down in Awatere Ave, threatening two homes - one at the top and one below it.

The fire service and city council workers have been putting poles in place to try to shore it up since the event on Tuesday night.

One of the properties was having major earthworks done for a retaining wall, which appears to have subsided.

Drilling experts have been frantically shoring it up to try to stop the situation worsening.

-Newstalk ZB
Manukau heads obs
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Unread post by Manukau heads obs »

just checked by nexstorm replay...yes, lots of activity on that front mine picked up too! (especialy just to the south of us here)
then it died just as the front came on shore :(
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Manukau heads obs
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Unread post by Manukau heads obs »

lightning strikes in the BOP now (confirmed also via phone!)
update: new warning out from metservice (thunderstorm warnings)
risk of weak tornadoes!
a good day to meet up, aucklanders?
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KiwiWeather
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Unread post by KiwiWeather »

Absolutely!
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Unread post by tich »

Rain and sleet ceased in Chch before midnight, and the temperature dropped to near 0C by dawn. I've heard there's quite alot of snow on Mt Herbert, but I couldn't see any on the Port Hills. (though the highest hills can't easily be seen from my place)
Manukau heads obs
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Unread post by Manukau heads obs »

can see the first installment of CBs now...overshooting tops :)

Peopled diagram,and anyone else, if you want to come out for a drive, we could go up the new lighthouse, and experience 60 kt + squalls there this afternoon!
(i will head up that regardless, should be good!)
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Paul Mallinson
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Unread post by Paul Mallinson »

Go Brian Go!!

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Manukau heads obs
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Unread post by Manukau heads obs »

I will take my camera and video camera (New one, the one I took to the US broke), and so will be able to get some footage if it gets exciting :)
(the nowcasting is reporting gusting to 55 kts up at the signal station already :)
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spwill
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Unread post by spwill »

a good day to meet up, aucklanders
We should organise a chase day before Xmas but choose a day when every thing is not travelling at 100mph.

I hear on ZB news there was a Tornado in Tauranga this morn.
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Unread post by Weather Watcher »

Has anybody heard of any hail reports from around the Ashburton/Hinds area yesterday afternoon (about 2:00-2:30pm)? The radar indicated a strong hail signature on a storm there at that time, and it would be nice to have some confirmation. Thanks.
Manukau heads obs
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Unread post by Manukau heads obs »

I hear on ZB news there was a Tornado in Tauranga this morn
i was talking to kaimaikid on the phone and he was in the tepuke area and he said it was an impressive cell that went through there!
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