June

[David]

A very foggy start to June! I noticed fog developing when I looked out the window at 10.50 last night, later found out that patchy low cloud had developed already by 9.30pm. Visibility this morning probably up to 200m (at its best!). Got down to 7C overnight.

I was looking at Auckland weather stations yesterday evening and noticed the wind was dead calm for all of them..I thought great conditions for fog to develop...just didn't expect it so early!

Looks like much of Auckland is in fog this morning.

[NZstorm]

We get a flick of unstable air moving through here tomorrow. Can see the upper cold pool with cb's west of the South Island today, this cold pool moves across the North Island tomorrow.

[NZ Thunderstorm Soc]

Well my initial posting for this topic didn't eventuate to much, not very nice at all. Was there any thunder today as according to the forecasts?
Even though the upper level may of been more active to what I thought, maybe the surface may of been more interesting, even though pressures were a bit too high for things to eventuate.
Mind you today is the first day of winter.
Next week/WE might/may be more interesting with an intense anticyclone coming this way, in behind southerly fronts?
Like May, it might be a cold June.

JohnGaul
NZTS

[Manukau heads obs]

talking about a cold May, for me here, it was 1.9oC colder than the last 10 years
(due to cold nights)
thats a big drop
http://www.weather-display.com/windy/gb ... 52008.html

[NZstorm]

thats a big drop

and thats in a season that was expected to be milder than normal!

[Manukau heads obs]

also its a colder than normal month that followed on from a series of warmer than normal months
I guess it all resulted from the clearer sky, lighter winds and more SE winds at night, conditions (and lower DP in that SE/E wind)
just the way the weather pattern was for alot of May
now that we are back to more traditional WSW winds, the temperatures are alot higher (both day and night)

[David]

Note for Southlanders/Cantabrians:

If GFS proves to be accurate for next Sunday, you will have snow! Too bad its a week out though, the models will probably change their minds

(I think the models below are self-explanatory)

[gllitz]

Note for Southlanders/Cantabrians:

If GFS proves to be accurate for next Sunday, you will have snow! Too bad its a week out though, the models will probably change their minds

(I think the models below are self-explanatory)

Yeah, was tempted to post about this on FRI after seeing the GFSlr models, but they are not all that realiable...this perhaps needs to be in another thread, moderators? For the last few runs this has shown up "nicely" so we'll see...one can only hope, but these things always change, especially this far out

The numbers DO look good, though...

[NZstorm]

Well atleast the GFS has been consistent for the last few days on this. With the 12Z run snow would fall to quite low levels over the lower half of the NI early next week as well. We can only hope it verifies. Something to watch anyway.

[Inny Binny]

Something to look out for, yes...be pretty nice if the models stay stable.

[Gary Roberts]

June? Feels like early April right now!

A cloudless blue sky and quite mild temperatures (11.4 °C at 15:15).

The recent light rains have scrubbed everything clean.

Hard to believe it's less than 20 days until the Winter Solstice and 2008's shortest day!

[Inny Binny]

Gary, May was the coldest May since 1992 according to the press you realise? (haven't seen any Niwa statement yet)

http://weather.northcott.co.nz/index.ph ... 105&id=792 (redirects)

[Gary Roberts]

Yes, May was dry and cool. How much drier and cooler I don't know. It doesn't have to have been a lot cooler than previous Mays to be the coolest May in a while. But it's certainly a very warm start to June, which is tradionally a cold and (sometimes) snowy month.

[southernthrash]

Double figure temperatures are not unusual in the MacKenzie in the winter, or across the south island for that matter. Even the skifields record their share of double figure days in June, July and August (and double figures are not at all uncommon by september). NZ is not a cold place overall, we get the odd extreme.

Models are hinting at some interesting weather this weekend at this stage.

[southernthrash]

Hopefully that weather does come off, there's been a few missed opportunities already, due to the strength of that blasted high to the south of Aus, and its location a little to far to the east and refusal to budge.

[Myself]

Double figure temperatures are not unusual in the MacKenzie in the winter, or across the south island for that matter. Even the skifields record their share of double figure days in June, July and August (and double figures are not at all uncommon by september). NZ is not a cold place overall, we get the odd extreme.

Models are hinting at some interesting weather this weekend at this stage.

I don't buy the idea of the MacKenzie being incessantly cold, even in winters past. It's hard to make anything hang around for *that* long in New Zealand. With average high temperatures supposedly being in the region of 7C there in winter, that is quite mild, but cold by NZ standards.

[RWood]

30-year mean for Tekapo for July gives mean max = 5.9, mean min = -2.5, mean = 1.7
Omarama (Tara Hills) for Jul has mean max = 6.7, mean min = -2.9, mean = 1.9

[Myself]

30-year mean for Tekapo for July gives mean max = 5.9, mean min = -2.5, mean = 1.7
Omarama (Tara Hills) for Jul has mean max = 6.7, mean min = -2.9, mean = 1.9

Looks like I was wrong in terms of winters there not being incessantly cold...

Clearly it's the cold minima that have the greatest impact then. And I suppose in mid-winter, it may well get to 6C or 7C, but perhaps not for long.

Central high country would be interesting temperature wise if we veered away from the standard mean = (min+max)/2 method and instead used hourly 24-hour data and averaged that. I'd bet the means would come out a fair bit lower.

Certainly an example of the mistake I made of depending too much on the quoted maximum temperature. In winter, there will often be a sharp peak around that maxima, unlike during longer days. A 16C winter max is never the same as a 16C summertime max. It's easy for me to get blinded by numbers.

[southernthrash]

24 hour running averages could well reveal warmer means, if I had the time I'd do the calcs.

Bottom line is, NZ isn't really that cold of a place, not normally for extended periods, unless you live in central otago.

The one factor which may give rise to Gary's traditional winter, is the old snow + hard frost effect. A good frost after a snowfall can cause it to last for bloody ages, especially if some melt occurs prior to re-freezing. Best way to consolodate a snowpack, that, which is why ski race courses get pumped full of water.

[Manukau heads obs]

Myself, I agree, that is why my average temperature data for May came out so low...because its calculated on every 1 minute data samples...and then do the longer colder nights is weighted more than the warmer shorter days (compared to just using the (min+max/2)

[Gary Roberts]

My own experience down here, as well as anecdotal evidence, suggests that overall winter temperatures are slightly higher and snowfall quantities significantly lower.

When I first stayed in Otago and Canterbury, back in the mid-'90s, the Mackenzie was usually colder than I've experienced since living in the area - and it snowed more often and in greater quantity.

The rate of change has accelerated: each subsequent winter has been less severe than the previous one, since the '90s at least.

It may be a statistical anomaly, but it's also real; The oldtimers down here used to regard the GCC hypothesis with a lot of healthy scepticism, but not any more. They can see for themselves that winters are less brutal.

[spwill]

24 hour running averages could well reveal warmer means

My guess is the mean temps would be higher in the north of NZ due to the higher dewpoint temps( the higher moisture level slowing cooling)
reverse for many locations in the south/east of NZ


Brian wrote,

Myself, I agree, that is why my average temperature data for May came out so low...because its calculated on every 1 minute data samples...and then do the longer colder nights is weighted more than the warmer shorter days (compared to just using the (min+max/2)

Dewpoints have been low acoss the Ak area recently with the cool SE flows

[Manukau heads obs]

Yup, I noted that very fact in one my other posts about it being a cold may here

[RWood]

Tara Hills mean monthly temps. 1949-2006 - was already posted some months back I think.

OMARAMA.XLS

Some months/year values missing. Value on left are monthly means as multiples of 0.1C, and annual values as sum of monthly means on same scale. I don't think you need to be brilliant to see the general trend over this period.

[TokWW]

From the spreadsheet, May June and August showed the effect the most, some other months seem to show a cycle such as Mar Oct, and Nov. Very interesting data.