NZ Weather Forum

NZ Thunderstorm Soc wrote: ↑Fri 30/06/2023 22:49 Fine overnight and this morning.
Cloud building up this afternoon and developing more so late afternoon with a thunderstorm developing to the NW to west of here late this afternoon and evening.
Some vivid horizontal lightning flashes resulting in long thunder booms and one 'dump'.
11.3C with only 0.5mm of rain. There would be isolated heavier falls in areas where the thunderstorm was.
Not much wind all day today.
Here's a photo I took returning from Temuka of instability towards the 4 Peaks area an hour or so before the thunderstorm.

MetService June 2023 Brief Summary – A mix of quick-moving westerly weather makers

The start of winter brought a mix of northerly lows and brief wintry spells. This delivered further heavy rain events and anomalously warm temperatures across many northern regions, quite reminiscent of a hangover from waning La Niña-like conditions as we head into the snowy season.

A Red Rain Warning was issued on June 22nd for Gisborne during a week-long rain event which culminated in more than 400mm accumulation about the ranges. Auckland remained wet through the month, with a half-yearly rainfall total of 1135mm [updated to 1154mm]. This officially eclipsed their average annual rainfall total of 1118.9mm [for Akld Aero].

Looking towards the South Island, the West Coast saw its fair share of heavy rain events, but the most notable aspect of June was the lack of large snow dumps. A few minor snow events managed to sneak their way across the island, but abnormally warm temperatures helped keep snow accumulation to a minimum. Saying that, parts of Otago experienced persistent freezing fog for days on-end under a low-level inversion.

The weather regime shifted towards a strong and active westerly flow during the final days of June, with snow to low levels waiting in the wings for parts of the South Island. Expect an increased frequency in these quick-moving events as El Niño builds over the remaining winter months.

Jun 2023 Average Temps, Rainfall, Sunshine and departures from 1991-2020 normals ℅ NIWA

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

Auckland, Mangere       16.3  +0.8     8.6   0.0    12.4  +0.4    119   94%    155  123%
Tauranga Aero           16.3  +0.9     8.9  +1.8    12.6  +1.4    227  188%
Hamilton Aero *         15.5  +1.1     5.0  +0.2    10.3  +0.7    166  128%    148  123%
Wellington, Kelburn *   13.8  +1.4     8.1  +0.8    11.0  +1.1     48   39%    129  128%
Christchurch Aero       12.5  +0.8     3.7  +2.5     8.1  +1.7     51   75%     92   80%
Dunedin, Musselburgh    12.2  +1.4     5.9  +2.0     9.1  +1.7     51   86%     86   90%
Greymouth Aero          14.2  +1.9     6.3  +0.8    10.3  +1.4    185   79%    134  144%

* Hamilton sunshine from Ruakura. * Wgtn missing first 1-2 days of all data. 

Nev wrote: ↑Sun 02/07/2023 08:05 A relatively warm June overall, except for central Otago and some parts of Northland. Also very wet for the east and north of the North Island, but generally much drier elsewhere.

JP. wrote: ↑Sun 02/07/2023 10:58 That T min is very warm for June in Christchurch. I knew it was going to be high as I still haven’t had a frost on my car this year yet.

NZ Thunderstorm Soc wrote: ↑Tue 04/07/2023 22:36 I noticed that Wellington has had it's most windless June for 11 years?
For June apparently it had a mean speed of 11k/hr.

The monthly mean wind speed at Wellington Airport was 4.3 m/s [15.5 km/h]. This was its lowest mean wind speed for June, and second-lowest of any month, since the anemometer mast was moved to its existing location in 1993.

Nev wrote: ↑Wed 05/07/2023 07:18

NZ Thunderstorm Soc wrote: ↑Tue 04/07/2023 22:36 I noticed that Wellington has had it's most windless June for 11 years?
For June apparently it had a mean speed of 11k/hr.

I think you mean Wellington Aero's June mean wind speed of around 17 km/h was its lowest for any month in 11 years...

Razor wrote: ↑Wed 05/07/2023 14:26 Meanwhile ChCh ave. minimum was 3.9 degrees above normal...nearly all the freezes were inland with the ENE flows

https://www.stuff.co.nz/national/weathe ... go-shivers