Active Front / Gale NW'ers - Sept 10-13

[Avalanche]

Models are continuing to show a good southwesterly storm on the horizon for next week. Hoping it brings some much needed snow for the north island ski fields. Looks like it could be quite windy with a blocking high in the north. Freezing blizzards in the south for some places to going on the latest model. Watching with interest.

[matttbs]

weatherwatch just posted an article on these westerlies and said that temperatures can hit the early 20's for eastern NZ so wouldnt snow be out of the question??

[snowstormwatcher]

Looks cold from about the 12th with 850 temps down to -7c over the southern south island

[spwill]

temperatures can hit the early 20's for eastern NZ so wouldnt snow be out of the question??

The big low system in the South Tasman that helps bring up the cold air also helps generate the strong pre frontal fohn NW winds/ warmer air.

[NZstorm]

There was a story on NewstalkZB today about a big storm next week. It didn't state the source of the prediction.

Models showing both warm and cold air in the mix! Real spring weather.

[Avalanche]

I noticed this morning the barometric pressure has dropped to 952hp for the developing low. Isobars are going well over the Antarctic land mass now too. The other feature i noticed which is much like the August 2011 storm the skinny HIGH going from Australia deep into the Southern Ocean. Then in the north it appears we have a blocking/Stationary high. It will be interesting to see how this one pans out.

[03Stormchaser]

Looking at big rain totals right up the west coast on Sept 10th-11th, 200mm+ easy in places. Potential definitely there for flooding. Looking warm on both these days on the Canterbury east coast, very spring like as NZstorm said.

[Avalanche]

Looking at big rain totals right up the west coast on Sept 10th-11th, 200mm+ easy in places. Potential definitely there for flooding. Looking warm on both these days on the Canterbury east coast, very spring like as NZstorm said.

Would be heavy snow for the mountain ranges though wouldnt it with the isobar direction SW coming from Antarctica?

[NZstorm]

Would be heavy snow for the mountain ranges though wouldnt it with the isobar direction SW coming from Antarctica?

The heavy precip occurs with in the warm airmass coming in from the North Tasman. So the snow levels will be quite high during the main rainfall event. Looks likely to be a good lightning set up for the alps as well.

[Avalanche]

Would be heavy snow for the mountain ranges though wouldnt it with the isobar direction SW coming from Antarctica?

The heavy precip occurs with in the warm airmass coming in from the North Tasman. So the snow levels will be quite high during the main rainfall event. Looks likely to be a good lightning set up for the alps as well.

I see, sounds like its gonna be a stormy week with lots of factors coming into play. Warm Cold, Wind, Rain, and snow up high. Its been abit quiet on this forum post so far what do some of you experts think from the latest obs?

[shovelopikis]

Bloody hell...out of everyday the cook strait gales whip up is when im taking a van over to the north island.

and from current obs it would be safe to say one or two flight and ferry cancelations woudn't be out of the question
just look at the swell outlook!

[CWUweather]

Looking like severe gales possible for the upper half of the south island on Tuesday, then the lower half of the north island on Wednesday. Also looking like very heavy rain for the south Islands west coast!! What are your thoughts?

[Tornado Tim]

Looking like severe gales possible for the upper half of the south island on Tuesday, then the lower half of the north island on Wednesday. Also looking like very heavy rain for the south Islands west coast!! What are your thoughts?

Mod Note: Merged the new thread you made to this one as it is exactly the same weather system.
Please check the threads before making a new one.

[Dale]

Whitebait has just started here in the Grey so we are guaranteed a polar blast.. bring it!

[NZstorm]

The title of this thread needs to change. The significant weather is ahead of the front. The cold change doesn't look significant for snow.

Ahead of the front there will be strong to severe gale NW'ers depending on how exposed to a NW flow you are. Wellington looks like getting a hammering. The front will bring frequent lightning to the Alps and given the 80knot at 500mbs there could be some spillover lightning. Looks like big rainfall totals for Westland and Buller, fairly normal weather for West Coasters. Obviously the system will give the North Island a good soaking as well.

[NZ Thunderstorm Soc]

The title of this thread needs to change. The significant weather is ahead of the front. The cold change doesn't look significant for snow.

The front will bring frequent lightning to the Alps and given the 80knot at 500mbs there could be some spillover lightning.

Yes I'm looking forward to it

[Tornado Tim]

Thursday looks very favorable for Thunderstorms over New Plymouth, Waikato and Auckland. Based on forecasted soundings the atmosphere to the tropospause looks to be saturated,unstable with favorable lift!

Might not be a chase day as I expect the activity to be embedded on the front.

Hopefully the forecast doesn't change, havnt had a very good forecast for storms in ages.

[Storm Struck]

It sure is going to be an eventful but typical spring like pattern this coming week, the west coast will get some good thunderstorms even possibly spilling into the Canterbury high country at times so lightning to the west at night could be quite sporadic Tuesday night.
Thursday at this stage looks to be a good set up for thunderstorms and hail eastern Otago/Canterbury

[Tornado Tim]

Some of the SWEAT values coming back on Thursday forecast are returning very high numbers for NZ (300+).
Will be regularly checking models for this incoming system, as quite few parameters are favouring severe weather….

If the current forecast continues down the road we are in for some exciting weather

[jamie]

yea this week looks interesting for sure. And that goes for many places around the country.

[Talbotm]

The thread is correct i wouldn't change it. Latest models show a decent pool of cold air which i have been watching for the last week. Looks to be very strong winds pre the cold but also a lot of moisture around too. As for the cold air if it keeps up snow will get down to vary low if not sea level in the south below about timaru above that will be a bit higher but thats my obs going off the latest forecast model runs. Also looks to be some reasonable moisture left for the polar blast too. Also the direction of the wind is changing its gone from a WSW to a SW now if it keeps straightening and that low moves north we will be in a lot of trouble.

[NZ Thunderstorm Soc]

A NE developing prior the SW flow could be interesting over the next week or so

[mikestormchaser]

Some cold upper air thursday.. with SW change looks to bring a chance of thunderstorms for Canterbury. maybe the best chance of spring so far..??

[NZstorm]

Some of the SWEAT values coming back on Thursday forecast are returning very high numbers for NZ (300+).
Will be regularly checking models for this incoming system, as quite few parameters are favouring severe weather….

If the current forecast continues down the road we are in for some exciting weather

Very strong wind flows create the risk of damaging gusts with thunderstorms.

[jamie]

Westland looks like its in for a bit of a thumping. Could be some great storms.