General December Weather

[Meangreen]

Thunderstorm coming down the Wairau Valley towards Blenheim. Have heard a number of rumbles from it over the last half an hour.

[NZ Thunderstorm Soc]

Muggy day here in Lower Hutt with some interesting cloud forms towards the Remutakas this afternoon,

[Storm Struck]

Meri kirihimete to everyone today, eat plenty and observe the bubbling clouds .

There is one difference today compared to the last few days in that not only is there convergence but also a small upper trough is crossing from the west.
Back in November this is what brought more scattered thunderstorms across the plains and coast, just that extra omph to move them abit.
So I wouldn't be surprised if there were a few rumbles this afternoon.

[David]

Merry Christmas all! A fairly nice day here, partly cloudy with 26C

[midgrove]

Multiple lightning strikes in Marlborough with heavy showers on the radar, anvil outflow clearly visible from Blenheim

[Richard]

Sun has not set and the grass has dew already, its 20deg atm with 60%, yet https://bmcnoldy.rsmas.miami.edu/Humidity.html say the dew point is 8.3, how does work

[NZ Thunderstorm Soc]

Similar weather to yesterday but much weaker Cu forms.

[NZ Thunderstorm Soc]

Fine and warm day in the Lower Hutt region and into he mid 20's

[Nev]

Sun has not set and the grass has dew already, its 20deg atm with 60%, yet https://bmcnoldy.rsmas.miami.edu/Humidity.html say the dew point is 8.3, how does work

Those figures look to be based on Fahrenheit, in which case you'd be talking extreme frost rather than dew...
So 20.0°C at 60% RH should give you a DP of 12.0°C (or closer to 12.6°C going by NIWA's data at that time).
Still seems a little odd to have dew on the grass with those temps though?
Maybe there was some residual ground moisture coming to the surface with some evaporative cooling taking place?

P.S. Below is my favourite calculator site, which also gives you absolute humidity in terms of grams of water moisture per cubic metre of air. It also has a nice little explanation about humidity and dew points.
https://www.calculator.net/dew-point-calculator.html

[Razor]

Some very welcome rain here in Christchurch. Garden is bone dry, needs a good drink

[David]

A little residual instability here this afternoon, had 2 minutes of fat raindrops around 5.45 from a buildup

[dogmelon]

We're back into a stable period with no boil-ups. When is the next period?

[NZ Thunderstorm Soc]

Looks like a stable end of the year with main;y settled weather for the rest of the week.
Fine and sunny up in the Kapiti/Horowhenua region today.

[Richard]

Lovely stable day with some broken cloud which totally cleared off late afternoon, 23.5 deg the high, higher tomorrow.

[spwill]

It is turning into a sunny December here after a cloudy first two weeks to the month.

[cbm]

Check out the water temp description at Bowentown.

Sent from my SM-S908E using Tapatalk

[Orion]

Warm today, 32°C and around 33% humidity at my place. Tar melting on the streets.

[NZ Thunderstorm Soc]

Warm day up in the Wairarapa where we were today. Noticed tar melting on the street in Ekatahuna today.

[NZ Thunderstorm Soc]

Not as warm as yesterday up here in the Belmont Hills. The clagg moved in later this afternoon and evening with colder southerlies.
From about 30C yesterday it was about 16C for much of the day after the clagg rolled through.
I countered about 16 spit of drizzle at various times.

[David]

Quite a sudden arrival of the ENE/NE breeze here early this morning, temperature rose from 16C at 3am to 20.5C by dawn.

[NZ Thunderstorm Soc]

Fine day here in Lower Hutt but with a cool wind from off the Port Nickelodeon harbour.

[David]

December 2022 summary for Howick:

Mean temp: 19.2C (+0.5C)
Mean daily high: 23.8C (+0.6C)
Mean daily low: 15.3C (+0.5C)
Lowest temp: 10.4C (on day 6)
Highest temp: 26.6C (on day 28)
Total rainfall: 85mm (pretty much bang on average)

[Richard]

Dec for Medbury

Rainfall 61.4mm
Max temp 28.4deg, 29th
Min temp 5.7 deg, 8th and 5th
Lowest max temp 11.5 deg, 2nd
Highest min 14 deg 27th
Thunder heard on 4 days

[Nev]

Despite a relatively cool start, December 2022 ended up being exceptionally warm overall, rounding off what is more than likely to be NZ's warmest year on record for the second consecutive year. There was, however, a notable difference between near-record warm Dec temps for parts of the West Coast and slightly below normal Dec temps for parts of north Canterbury and Marlborough.

Dec 2022 Climate Anomaly Maps ℅ NIWA.png

Preliminary stats for the main centres:

Code: Select all

Dec 2022 Average Temps, Rainfall, Sunshine and departures from 1981-2010 normals ℅ NIWA

Site                     T-max °C      T-min °C      T-mean °C     Rain mm      Sun hrs

Auckland, Mangere       23.3  +1.7    16.1  +1.3    19.7  +1.5     97  113%    234  118%
Tauranga Aero           22.8  +0.6    15.7  +1.8    19.2  +1.2    137  145%    
Hamilton Aero *         23.7  +1.5    13.6  +2.0    18.6  +1.7    104   99%    233  112%
Wellington, Kelburn     19.9  +1.3    13.5  +1.2    16.7  +1.3    100  120%    218   98%
Christchurch Aero       20.5  -0.5    11.8  +1.3    16.2  +0.4     63  135%    223  101%
Dunedin, Musselburgh    17.9  +0.6    11.4  +1.0    14.7  +0.9     30   37%    188  112%
Greymouth Aero          21.1  +2.9    12.9  +1.7    17.0  +2.3     93   37%    263  158%

* Sunshine from Ruakura 

[NZ Thunderstorm Soc]

December's Weather from Raukapuka, Geraldine.

Rainfall 105.6mm over 21 days
Max temp 32.3C deg, Thursday the 29th
Min temp 7.5C deg, Thursday the First
Lowest max temp 14.4C deg, Sunday the 18th
Highest min temp 15.3C deg, Tuesday the 27th
Thunder heard on 4 days

Rainfall total for the year was 1011.9mm over 170 days.