Extreme Temperatures early February

[NZ Thunderstorm Soc]

Well that's the end of the hot weather. hope you have enjoyed the show
Now down to 19C which should be the maximum for the next couple of days.
Wind more SW here than southerly with low stratus cloud cover over us.

JohnGaul
NZThS

[Janos]

Yep it was good while it lasted Dunedin yesterday and Christchurch today.
Until next time...

[spwill]

Well that's the end of the hot weather.

Stays hot up here due to high dewpoints, dewpoints currently 18C and on the rise. An uncomfortable muggy night on the way .
Reached 26C here today with increasing cloud.

[Nev]

Hmm... interesting comment about "not your usual weather station surroundings". I think most vineyards here are sited on north facing slopes (as opposed to typical official weather-stations being sited on flat-areas). Assuming the instruments are in a Stevenson-screen and met WMO standards, would these slopes tend to bias the temp readings somewhat, e.g. temps perhaps being higher on the ridges than say in the valleys?

Just curious, as it would be nice if they could be used as acceptable comparisons to other official sites.

I knew people would be interested Like most modern weather stations (including the majority of NIWA stations) the temp sensors are in a radiation shield, not a screen. What I meant about the environment is that the vineyard weather stations tend to be surrounded by vines and posts and wires etc, and often on a gentle slope as you point out, rather than on flat open ground which is typical of most long term weather stations. I doubt that many vineyard stations would meet WMO standards for exposure for these reasons, but they are also much better exposed than most home weather stations, and I think we can trust readings from them, at least for the purposes of discussing how hot it got today!

Thanks Tony. Yes, more important to know the crop temp I guess, so that makes sense and not too far off the official readings of 37.8°C for Cheviot and 36.2°C for Waipara West. Not sure about the 'Peninsular Estate' vineyard-site here on Waiheke though; sorry Charles, but temps often seem to well over-read on sunny days.

Your comment about the majority of NIWA stations using radiation shields other than Stevenson-screens is a little surprising though. From what I've heard, if they like the private-sites, they're usually happy to supply the Stevenson-screens (worth about $1,500 each)?

P.S. Sorry about the 40 odd post delay btw - seems like only yesterday.

[CHCH Weather Chaser]

Weird the winds have swung back around to the Northwest and the temperature in town climbed back up to 22 degrees.

[Dean.]

Would have thought a 34 degree temp in Christchurch with a dewpoint around 14 the feel like temperature would be lower not higher?.
34 degree temps with dewpoints 24-25 which is common up here in the tropics have feel like temps 40-41.

Just spent 3 weeks back home in Canty and the 30 degree days we had in Ashburton felt very comfortable compared to the high humidity 30 degree days in Cairns.

Cheers

[spwill]

Just spent 3 weeks back home in Canty and the 30 degree days we had in Ashburton felt very comfortable compared to the high humidity 30 degree days in Cairns.

I found living in Brisbane quite tough during the summer with the heat, winter weather was spectacular.

[mikestormchaser]

Yes was very warm today and particularly this morning!!
What was the temp at around 9am guys does anyone know? ill take a guess it was 27C?

[NZ Thunderstorm Soc]

What was the temp at around 9am guys does anyone know? ill take a guess it was 27C?

It was 26C here at 7am at West Melton with a NW blowing but when I got into town (Halswell) there was a slight easterly blowing and a temperature of 28C.

JohnGaul
NZThS

[TokWW]

If Radiation shields are at the correct height and have an active air movement by use of a fan exhausting air through the enclosure, they are often superior in performance to just a Stevenson screen. Davis has performed exacting scientific trials on their units, both passive and active and on industrial quality units as a comparison and the belief was the active shielded device responded quicker to ambient changes and was more accurate than one in a passive Stevenson screen.

I can dig out the reference trial if you wish Nev.

[Ryan Thomas]

Fun 40 min skate from Barrington to Hornby today on my longboard (1:50-2:30pm) def felt the temp dropping as I was getting closer to work the cool winds being a nice relief

[tgsnoopy]

I can dig out the reference trial if you wish Nev.

Perhaps posting a link?

I'd like to see that, as would others I'd expect.

[spwill]

I see Manapouri was just 4C at 7am, must have had a clear night in cooler dry air.
Could see some low temperatures in the deep South later in the week.

[tgsnoopy]

Looking like the south islands going to see a little snow on the alps later in the week?

Metservice seem to give that impression.

[TokWW]

I can dig out the reference trial if you wish Nev.

Perhaps posting a link?

I'd like to see that, as would others I'd expect.

I had to remember who the poster was and what some of the rearch words were,

Comparison between passive ventilated shields and active ventilated units -

Davis 7714 (PV)
Davis 7755 (fan aspirated, solar powered)
RM Young 4002 (PV)
Qualimetrics 8150A (fan aspirated, mains powered)

http://www.davisnet.com/product_documen ... ote_24.pdf

Note: this is a large pdf file.

Hope this generates some discussion...

Graeme

[NZstorm]

Tomorrows temperatures will be interesting over the South Island tomorrow. I don't know what the all time lowest max temps are for Dunedin and Invercargill but tomorrow's readings could be contenders. Forecast 850m temps down to -4.5C at Invercargill! The cool down will be felt across the whole country.

[Janos]

Its a frigid 7.3deg down the bay this moning with a good strong Southerly.

[GSVNoFixedAbode]

Just received an email from Stewart Island: there's snow on Table Hill there. It's about 700m at the highest point but not sure how low the snow is. And a chinese whisper of snowing in Invercargill, although that's about 3rd or 4th hand.

[Razor]

I've heard from work colleagues of snow in Alexandra this morning

[Achten]

last Monday was the hottest day I have ever experienced in the HB. I have nothing fancy when it comes to recording temp so I am a little reluctant to post, but when so many of your neighbours are around the same figure it can't be to far off. 41.2c I recorded. Driving home I had all the windows down and the closer I got to home the hotter it felt. My wife had the air con on full and we were still above 30c inside.

[spwill]

Appropriate the Rugby season should start down in the SouthIsland tonight with the bitterly cold weather down there, perhaps some frost for some inland areas tonight.

At 1pm Wanaka was on 12C while Haast was on 21C.

[tich]

Only 13C max in Chch today; probably a white dusting on Alps if moisture reached there.

[NZstorm]

7am temps for inland SI

Omarama(Tara Hills) 1C
Queenstown 2C
Wanaka 3C

[Michael]

The tap water is warmer than outside today!

[Andy]

7am temps for inland SI

Omarama(Tara Hills) 1C
Queenstown 2C
Wanaka 3C

Light frosts throughout inland Otago.