26/27th TS Possible, Canterbury - Much of NI!!!

[NZ Thunderstorm Soc]

No thunder for Canterbury tomorrow sadly as I don't think the season is volitile for thunderstorm development, sadly
...but I liked to be prooved wrong.
Barometer pressures not low enough...

JohnGaul
NZTS

[David]

Wow. Heavy shower totaling 3.5mm just gone through with brief 50km/h wind gusts and 1 minute of torrential rain (1mm in 1min so 60mm/hr rate). Looks like a lot of Auckland stations not picking up much, so just getting lucky. Up to 6.5mm for the day here, and can see another anvil to the west which may be approaching.

Also of interest, I see not only was there hail in New Plymouth today (mentioned on TV weather) but there was a hailstorm in Upper Hutt as well: http://www.newstalkzb.co.nz/newsdetail1 ... yID=129894

[Michael]

Unfortunately were getting it too,its supposed to be the summer holidays etc

[melja]

wow very cold over night here in canterbury (rangiora) 2.1 deg at my house and 1 deg at the airfield at 5.46am.

http://crac.recwings.com/flight-plannin ... ather.html

Must have been a wee ground frost. dec record ? .

[jamie]

Cold fog here this morning before the sun came up. I had to put on extra clothing and gloves.

[Manukau heads obs]

wow, you had a fog in the waikato?
SW wind all night long here
but it was only 10oC here last night after the last winter like shower line went through,,...which is cold for the time of year!

[Wildland]

Cold here too. Overnight low of 6.7 degrees in Tawa.
Good excuse to rug up until the sun breaks through the murk.

[RWood]

Harden up! It got a lot colder in the "old" days - and we saw less of the sun!

[Willoughby]

wow, you had a fog in the waikato?
SW wind all night long here
but it was only 10oC here last night after the last winter like shower line went through,,...which is cold for the time of year!

Yes Brian, pops up even in Summer!
Overnight low down to 5C here, with 3C in Taupo and 2C in Waiouru.

Clear skies today, but becoming cloudy tomorrow... looks like a few consecutive 26C days on the way from Sunday.

[Storm Struck]

Interesting to see a low risk still up by MS for today, perhaps its because it may turn NW beforehand, However if it stays NE all day like it is now then I think the chances of a good storm could well be on the cards.
Nice day though warming up nicly after yesterdays cooler temperatures, also a few CU clouds going up inland to the N-NW.
Cheers
Jason.

[RWood]

Interesting contrasts here today. Instability in the Hutt Valley and some other parts northern has given big CU both yesterday and today. This morning the city has been mainly sunny with passing clouds but the northern part of the harbour and the Hutt have been dark with what looked like quite heavy showers.

Ch'ch is well ahead of us on sun this month at present and may pass us for the yearly total. Auckland is well behind (not so in 2005 & 2006).

[David]

Ch'ch is well ahead of us on sun this month at present and may pass us for the yearly total. Auckland is well behind (not so in 2005 & 2006).

Yes a poor effort from the sun up here this month, 116hrs so far. Lowest for December in my data set for Auckland (various sites) is 139hrs, but the next few days sunshine should ensure it will not be a record lowest for December. Interesting to see Rotorua only on 87hrs this month, with the average month to data figure being 179hrs (i.e 92hrs behind at this point in the month). Don't have sunshine data for Rotorua but I would think that this could be close to the record low for December there, unless the sun really shines hard for the next several days!

[NZstorm]

I wouldn't have liked to have been in a camp ground this morning in inland parts, 3C is too cold to be in a tent.

The cloudy month in Auckland thus far means our nighttime temps have been quite high. I'm guressing our average min for the month will come in around 16C.

[RWood]

For the current Aero site, Rotorua averages 217 hrs for Dec. (period 1976-2005), lowest value 163 in 2001. The older Whaka. site had rather poor exposure for much of its records (ended 1977), and the record low there would be in the low 140s or possibly lower.

Excluding some sites with poor exposure, here are some of the lowest totals recorded in NZ in December:

Greymouth 1987 109
Greymouth 2001 109
Oamaru Aero 1981 109
Taieri, Invermay 1959 109
Haast 1953 107
Timaru 1993 107
Waimate 1946 107
Waimate 1966 105
Palmerston North 1992 104
Timaru 1937 104
Waimate 1941 103
Dunedin 1959 100
Timaru 1959 90
Waimate 1937 82
Waimate 1959 60

The Waimate value in Dec. 1959 is easily the poorest for any NZ site in a summer month - only about 13% of the possible

[David]

Wow RWood, I wouldn't have expected an eastern area to have so many record low sunshine hours. That 60hrs in 1959 is very low indeed. Is it NE and E winds that bring cloudy skies to Canterbury? Would be interesting to know the prevailing wind direction during that month.

The cloudy month in Auckland thus far means our nighttime temps have been quite high. I'm guessing our average min for the month will come in around 16C.

For the month to date at Owairaka (up to and including 26th):
Average minimum: 15.4C
Average maximum: 21.8C

For the month to date at Auckland Airport (up to and including 26th):
Average minimum: 15.5C
Average maximum: 22.3C

For the month to date at Whenuapai Aero (up to and including 26th):
Average minimum: 14.7C
Average maximum: 21.7C

For the month to date at Mangere (up to and including 26th):
Average minimum: 15.7C
Average maximum: 21.8C

With my readings (to the 26th as well) I get 14.8C and 22.5C.

Close guess NZstorm

[NZstorm]

yes, that was a good guess, and within the urban heat Island of the CBD it would be milder still.

RWood, is sunshine still recorded by a card being burnt by a glass ball? Forgot the technical name for the instrument.

[RWood]

[quote="David"]Wow RWood, I wouldn't have expected an eastern area to have so many record low sunshine hours. That 60hrs in 1959 is very low indeed. Is it NE and E winds that bring cloudy skies to Canterbury? Would be interesting to know the prevailing wind direction during that month.[quote]

Yes, it's E/NE flows that helped create those low totals. Dec. 1959 was particularly dominated by them in the S Island especially, with very low sun from South Otago to North Canterbury, and to a much lesser extent in parts of Wairarapa and Hawkes Bay. With the nearby hill configurations (or something else perhaps) Waimate seemed to be particularly vulnerable, especially before the 60s. Even Gary Roberts' much-derided Oamaru couldn't match it. I saw a case of a stream of cloud crossing the coastline and spreading to the Hunter? hills near Waimate one otherwise clear day in February once when driving through - no cloud was present north or south of that band. It appears that nowadays months as cloudy as some of those in that list are less common, at least as the data lead one to think.

There are some very low totals at an older Franz Josef site but it had a very restricted exposure. For very low totals in winter, most of the "prizes" go to the King Country and the like (Taumaranui).

[NZ Thunderstorm Soc]

Will you please stay on topic.
No thunderstorms for ChCh, when the southerly arrives, just low stratus and about 5 and a half spits of drizzle
The NW have hit, so thunderpossibilty is now totally shagged

JohnGaul
NZTS

[RWood]

yes, that was a good guess, and within the urban heat Island of the CBD it would be milder still.

RWood, is sunshine still recorded by a card being burnt by a glass ball? Forgot the technical name for the instrument.

There's still an extensive network of Campbell-Stokes recorders, some sites having used them for 70 years or so but according to info. I got from NIWA they are being phased out in favour of devices which measure direct solar radiation (as I understand it) which presumably has to exceed some appropriate level. NIWA have now installed about 20-odd Kipp & Zonen (?name) recorders around the country, and parallel observations are being kept at a few sites.

[mikestormchaser]

NZstorm wats your thoughts on a thunderstorm in chch tonight? conditions set or not? NW has hit but its not blowing a howling gale yet and it has been NE most of the day. opinion please.

[NZstorm]

I think thunder in Canterbury this evening is unlikely. The southerly is due mid evening, the upper air is only marginally cold.
So even with the NE breeze persisting it was going to be struggle street for thunderstorm development.

[melja]

yep not a summer for storms in canterbury and it could be a trend as you need moisture and there aint much of that around here been heaps of chances so far but just lacking the good dew points to get things going.

[mikestormchaser]

oh ok dammit then i need expert opinion as im not lol, dont understand models very well etc, just a big extreme weather lover! oh well its disappointing however its not surprising lol.
Yeah storms have changed here in Canterbury, not as often, seem to get them early spring now days and then late summer feb, april, march and when we do get them they are quite big!! witch is a good thing

[NZ Thunderstorm Soc]

Thunderstorms for ChCh/Canterbury are a 'Gone-burger' or 'NoBurger'as Mr Hickey would say, sadly
Better luck next year.

JohnGaul
NZTS

[Storm Struck]

I curse my camera's ever since I bought a video and and digital camera about 2 years ago we havnt had a decent storm come over typical I say.
Roll on 2008 .
Cheers
Jason.