General August Weather

[jamie]

Looks like its still foggy at home and its nearly 1am. Glorious day here in the Taihape area.

[RWood]

August 2013 to date seems to be rivalling 2009 for the title of warmest August on record. August 2009 was 1.5C above the 1971-2000 national average temp of 8.7C, and most of the country so far looks to have been well above that.

Although figures are likely to be a little lower by month's end, Chch Aero's current T-mean is a remarkable 2.3C above its 1981-2010 August normal. Tauranga Aero, Wgtn (Kelburn), and Dunedin (Musselburgh) are 1.9C above their normals, while Hamilton is 1.8C and Akld (Mangere) 1.6C above.

Yes, could be a record-breaker yet. Offset by below average sunshine over virtually the whole country. At Kelburn - if the Dompost tales are correct - no Tmin has been below 5.2C so far. The record high monthly low for August there is 4.5C in 1987, so that might be surpassed.

[Tornado Tim]

2009 was a rather unusual year in terms of Temperature fluctuation. August 09 had an avg Temperature of 11.7°C then in September it dropped back to 11.5°C*.
I wonder if a similar pattern will occur this year. At the current date, August 2013 has an avg Temperature 11.5°C *.
Will be interesting to see when the month has ended.

According to the mean SOI figures collected by Weatherzone August 09 was also in a fluctuating pattern (which it seems we are still currently in), with a ever so slight positive mean SOI value.

September will certainly be a interesting month to see which way the SOI values will swing when we head into Summer.
Hopefully the Blocking nature of Highs will not return......

*=Matangi Weather Data
**= Chart courtesy of Weatherzone AU

[Nev]

2009 was a rather unusual year in terms of Temperature fluctuation. August 09 had an avg Temperature of 11.7°C then in September it dropped back to 11.5°C*.
I wonder if a similar pattern will occur this year. At the current date, August 2013 has an avg Temperature 11.5°C *.
Will be interesting to see when the month has ended.

Hamilton Aero and Ruakura didn't quite follow the same trend. For August 2009 Hamilton Aero's T-mean was 11.1C and Ruakura's was 10.9C, followed by 11.6C and 11.2 respectively for Sept. So far this month Hamilton Aero's T-mean is 11.4C and Ruakura's is 12.1C.

Note: I suspect that being on the eastern fringe of suburban Hamilton, Ruakura may be subject to Urban Heat Island effects during prevailing WSW'ers, which is probably why NIWA favour the airport for temps.

And yes, nationally 2009 overall (incl. a record cold May) was slightly on the cool side, unlike this year so far where only Feb has been (marginally) below normal. Early days yet though...

[Bradley]

This next system in the Tasman looks to largely pass north of Auckland tonight with most of precip in the far north.

Looks like a polar trough crossing the country mid next week. Haven't seen air that cold in the gfs for a while.

Yep easily the coldest front to hit NZ since mid July, a truly remarkable run of weeks without an even half decent cold front...can anyone else remember a winter in the South Island where we didn't get a cold front of any strength for 6 weeks?

[einzack]

I thought last August was warm, but this year is even milder. warmer nights and cooler days, so while the mean temp (1 minute) is 0.5°C warmer this year (8.5 °C vs 8.0°C), the mean (min+max) is the same for 2012 and 2013 at 9.5°C
For the last 2 years June has been the coldest month of the year, but this year has been approx 1.5°C warmer on average over winter.

"what winter?" people round here have been saying this year.

[Tornado Tim]

Hamilton Aero and Ruakura didn't quite follow the same trend. For August 2009 Hamilton Aero's T-mean was 11.1C and Ruakura's was 10.9C, followed by 11.6C and 11.2 respectively for Sept. So far this month Hamilton Aero's T-mean is 11.4C and Ruakura's is 12.1C.

Note: I suspect that being on the eastern fringe of suburban Hamilton, Ruakura may be subject to Urban Heat Island effects during prevailing WSW'ers, which is probably why NIWA favour the airport for temps.

I have had a look and seen where I suspect where the station is located. Its ontop of a container surrounded by a concrete carpark on Peachgrove Road. I am rather surprised that they would even stick a weather station there. There is lush green grass 200 meters further east!

I noticed that there is a Davis weather Station in Innovation Parks in the front paddock, would be cool to get a Hamilton Weather network going to ID the area's Microclimates

[jamie]

Hamilton Aero and Ruakura didn't quite follow the same trend. For August 2009 Hamilton Aero's T-mean was 11.1C and Ruakura's was 10.9C, followed by 11.6C and 11.2 respectively for Sept. So far this month Hamilton Aero's T-mean is 11.4C and Ruakura's is 12.1C.

Note: I suspect that being on the eastern fringe of suburban Hamilton, Ruakura may be subject to Urban Heat Island effects during prevailing WSW'ers, which is probably why NIWA favour the airport for temps.

I have had a look and seen where I suspect where the station is located. Its ontop of a container surrounded by a concrete carpark on Peachgrove Road. I am rather surprised that they would even stick a weather station there. There is lush green grass 200 meters further east!

I noticed that there is a Davis weather Station in Innovation Parks in the front paddock, would be cool to get a Hamilton Weather network going to ID the area's Microclimates

No the station is in an open field in the Ruakura research station I believe. I'm pretty sure it's in the paddock near the east street entrance to ruakura.

I know the one youre meaning and I thought that was a air quality station.

[NZ Thunderstorm Soc]

Looks like a polar trough crossing the country mid next week. Haven't seen air that cold in the gfs for a while.

Yes. It might be a reminder that we are in a winter period, despite all the settled weather we have had lately so far this winter, apart from June.
At the moment it doesn't look like much, but enough to put us back into winter-mode

[NZstorm]

Cluody day with 16C in Auckland. A line of t/cu showers has developed to south.

[David]

Cluody day with 16C in Auckland. A line of t/cu showers has developed to south.

Had heavy rain here 2.50pm to 3pm, light/moderate now.

[spwill]

Some flooding for parts of Central Auckland last hr from very heavy showers that developed over the area . Just came through Mt Roskill, a lot of surface water in that suburb, took some photos.

[NZstorm]

Big cloud burst over Auckland Isthmus this afternoon with 33mm in 1 hr at Mt Roskill.

[NZ Thunderstorm Soc]

At least there is some interesting weather around the country.
Nothing much here for ages

[mikestormchaser]

To me wensday afternoon could be a thunder/hail chance for Canterbury, very cold upper air coming in and looks like strong wee SW change, but i dont like the cloud cover or NW flow before the change, anyways.. something to watch as the weather is getting warmer.

[NZ Thunderstorm Soc]

...then after that looks like another anticyclone settling in

[NZstorm]

That shower line yesterday was very slow moving hence lots of water.

We have fog this morning.

Yes, first week of September looks very anticyclonic.

[Richard]

A gentle NW wind this morning,10deg.

I hope you're right mike about the chances of thunder late Wednesday,can stick the hail though.

[Orion]

Misty in Ashburton currently.

[NZstorm]

Polar trough sweeps NZ Wednesday to Thursday time frame.

Looks like an active cold front will bring snow down to 500m in inland Otago/Canterbury tomorrow as the front moves north. Places like Tekapo township could get 10cm+.

Some weak shower activity behind the front will bring lighter snow to 300m in Southland/South Otago overnight Thursday.

Over the North Island Thursday, snow down to 800m.

[Andy]

Polar trough sweeps NZ Wednesday to Thursday time frame.

Looks like an active cold front will bring snow down to 500m in inland Otago/Canterbury tomorrow as the front moves north. Places like Tekapo township could get 10cm+.

Some weak shower activity behind the front will bring lighter snow to 300m in Southland/South Otago overnight Thursday.

Over the North Island Thursday, snow down to 800m.

I hope the frosts that follow aren't too serve, as crops and trees are about 3 weeks ahead due to a warm winter.

[spwill]

The first cold system to affect NZ since mid July, GFS shows the coldest air will cross the South Island Wednesday night /Thursday morning. I'm in Mosgiel near Dunedin this week visiting family .

[jamie]

The first cold system to affect NZ since mid July, GFS shows the coldest air will cross the South Island Wednesday night /Thursday morning. I'm in Mosgiel near Dunedin this week visiting family .

Thats good timing. You often time it well it seems

[NZstorm]

Looks a nice day in Auckland. A bit of a warm front sliding across the north Tasman toward northern NZ, may get some precip from this tonight in Auckland. Top of Northland may catch thunder, dps 14C up there.

The polar trough tomorrow should produce isolated thunderstorms/hail in the west of the North Island but the track of the upper trough will govern how much activity can occur. Fingers crossed we can get something of interest in Auckland.

[Nev]

MS a little late with this morn's Severe Thunderstorm Outlook update, but I see they've upgraded Akld's chances tonight from low to moderate.