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Cold spell September 5-7

Posted: Fri 04/09/2015 11:38
by matttbs
Thought it would be worth making a seperate thread for this one, as it looks like it could be shaping up a tad worse than first thought. Good ol metservice have issued a watch for majority of the South Island in regards to snow and being the time of year that it is I don't think it would take much of the white stuff to have some serious implications for those of us in the farming industry. Southland looks to be the hardest hit

Re: Cold spell September 5-7

Posted: Fri 04/09/2015 12:50
by SnwAddct
Does anyone recall what the 850hpa temps were over Auckland on the 10th of August? Wondering if the cold air will come north enough for more hail/graupel

Re: Cold spell September 5-7

Posted: Fri 04/09/2015 14:00
by petem8nz
From metservice facebook page,

Where is your air now? These trajectories from NOAAs HYSPLIT system show the route of air parcels due in at Wellington at midnight Sunday. In just three days they travel north from high above Antarctica to New Zealand. The three colours show air ending up at 1500m (red), 1000m (blue) and 500m (green). The current ice edge is also shown in cyan (also NOAA data). Google earth provides the visualisation. Wrap up warm. ^TA

Re: Cold spell September 5-7

Posted: Fri 04/09/2015 14:13
by Willoughby
SnwAddct wrote:Does anyone recall what the 850hpa temps were over Auckland on the 10th of August? Wondering if the cold air will come north enough for more hail/graupel
The Whenuapai soundings for that date recorded -2.5C in the morning and then -2.1 in the evening.

Re: Cold spell September 5-7

Posted: Fri 04/09/2015 14:48
by SnwAddct
Latest Severe Weather Outlook from MetService issued about 5 minutes ago..
MetService wrote: Issued: 2:44pm Friday 4 Sep 2015
Valid from Sunday 6 September 2015 to Wednesday 9 September 2015

On Sunday, strong bitterly cold southwesterlies are expected to affect the South Island and the entire country on Monday. Snow is expected to low levels over many South Island areas. Snow may also affect some higher roads over the lower and central North Island. The southwesterlies should ease on Tuesday and a ridge is expected to bring more settled weather to the country on Wednesday and Thursday.

On Sunday there is a moderate confidence that snow accumulations will reach warning amounts above 100 metres in Fiordland, Southland and Otago and above about 300 metres over the Banks Peninsula. A Watch for heavy snow that covers these areas has been issued. In addition to this there is a moderate confidence that southwesterly gales will become severe on Sunday over the Banks Peninsula and exposed coastal areas in Otago and a Watch for these areas has also been issued.

NOTE, that this unseasonably cold outbreak is likely to bring frosts to many South Island areas and parts of the lower and central North Island on Sunday and Monday.

For further details and any updates, please check the forecasts for your location.

Re: Cold spell September 5-7

Posted: Fri 04/09/2015 16:04
by hozza95
I don't get the "unseasonably" part mentioned by metservice. Snow is a normal part of September and October, happens every year

Re: Cold spell September 5-7

Posted: Fri 04/09/2015 16:19
by matttbs
hozza95 wrote:I don't get the "unseasonably" part mentioned by metservice. Snow is a normal part of September and October, happens every year
I think they are referring to the temps not the snow, it is looking very cold if not the coldest air this year

Re: Cold spell September 5-7

Posted: Sat 05/09/2015 07:41
by hozza95
Must be snowing in Queenstown, if not it's very close. 0.8 degrees and 3.4 mm of precipitation showing at the airport

Re: Cold spell September 5-7

Posted: Sat 05/09/2015 07:43
by spwill
SnwAddct wrote:Does anyone recall what the 850hpa temps were over Auckland on the 10th of August? Wondering if the cold air will come north enough for more hail/graupel
It wont be cold enough graupel over Auckland , those days are rare here but isolated hail is likely.

Re: Cold spell September 5-7

Posted: Sat 05/09/2015 07:49
by hozza95
Snow being reported In frankton, despite ms Not predicting snow there til this afternoon, meanwhile wanaka is still on 6

Re: Cold spell September 5-7

Posted: Sat 05/09/2015 07:55
by hozza95
Heavy snow at Qtown airport

Re: Cold spell September 5-7

Posted: Sat 05/09/2015 09:35
by hozza95
Temp has dropped 2.1 degrees in minutes to 5.3 here, but still a while before we get to the temp we need for snow

Re: Cold spell September 5-7

Posted: Sat 05/09/2015 10:09
by hozza95
Hmmm should be a very interesting 24 hours for us here in eastern Southland if this happens, we are at 200 metres so could be in for a decent dumping ourselves
SEVERE WEATHER WARNING.

ISSUED BY MetService AT 10:00 am 05-Sep-2015

Heavy snow for eastern Southland and Clutha, especially the Catlins


A very cold southwesterly flow is expected to bring snow showers to sea level over the lower South Island from this evening through to Monday. The heaviest falls are expected about eastern Southland and Clutha, where 25 to 30cm could accumulate in a 24 hour period above 300 metres.

The combination of strong southwesterlies and snow showers are likely to bring blizzard conditions, putting vulnerable livestock at risk.

The snow will also likely affect a number of roads over the lower South Island.

HEAVY SNOW WARNING

AREA/S AFFECTED
Clutha and Southland east of Lumsden

FORECAST


Snow showers are expected to lower to sea level this evening, then gradually ease on Monday along with the snow level rising. In the 24 hours from midnight Saturday to midnight Sunday, expect 25 to 30cm to accumulate above 300 metres, especially about the Catlins.

NEXT SEVERE WEATHER WARNING WILL BE ISSUED AT OR BEFORE 9:00 pm Saturday 05-Sep-2015

Re: Cold spell September 5-7

Posted: Sat 05/09/2015 11:45
by 03Stormchaser
Could be a local chase this afternoon around Christchurch. First for the season :)

Re: Cold spell September 5-7

Posted: Sat 05/09/2015 12:42
by TonyT
03Stormchaser wrote:Could be a local chase this afternoon around Christchurch. First for the season :)
First of many!

Posted: Sat 05/09/2015 13:16
by melja
Heavy snow just starting here in Arthur's pass, weekend in the family Bach.

Re: Cold spell September 5-7

Posted: Sat 05/09/2015 13:27
by Richard
TonyT wrote:
03Stormchaser wrote:Could be a local chase this afternoon around Christchurch. First for the season :)
First of many!
I like the sound of that _b

Re: Cold spell September 5-7

Posted: Sat 05/09/2015 14:51
by dogmelon
Will El Niño mean more chances of thunderstorms on southerly changes like today?

Re: Cold spell September 5-7

Posted: Sat 05/09/2015 15:18
by TonyT
dogmelon wrote:Will El Niño mean more chances of thunderstorms on southerly changes like today?
Yes!

Re: Cold spell September 5-7

Posted: Sat 05/09/2015 15:26
by Storm Struck
Yeah generally there is more chances during spring even right through December, you only have to go back to 1999 -2004 when el nino was present and we had some good storms typical busters even 2-3 days in a row.

Today isnt exactly the best set up and the cool westerly is abit of a killer, some heating should return soon so the next few hours will be the time to watch.
Nothing major though maybe a few peels of thunder in heavier showers with hail until 7pm.
Showers just starting to edge into South Canterbury now

Re: Cold spell September 5-7

Posted: Sat 05/09/2015 16:45
by hozza95
First flakes of snow starting to fall here

Re: Cold spell September 5-7

Posted: Sat 05/09/2015 18:39
by hozza95
Blizzard conditions now!! Extremely strong wind and snow , so think the power may not last long

Re: Cold spell September 5-7

Posted: Sat 05/09/2015 21:19
by NZ Thunderstorm Soc
dogmelon wrote:Will El Niño mean more chances of thunderstorms on southerly changes like today?
YES YES YES\:D/ :D :smile:
sorry haven't had proper internet connection, so I would of answered that question before Tony T did <3
This speaking as the founder of the NZThS =D> :smile:

Re: Cold spell September 5-7

Posted: Sun 06/09/2015 06:44
by Richard
Don't even know if the southerly wind change brought any cloud little own rain,clear here this morning with a frost.

Re: Cold spell September 5-7

Posted: Sun 06/09/2015 07:26
by matttbs
Got 5.2mm of rain intermixed with snowflakes last night. Woke up to -2.2C and snowflakes frozen to everything