Re: General August Weather
Posted: Sat 28/08/2021 23:21
Another day of cloud and clagg. 11.1C for today with 0.7mm of occasional drizzle. Light NE.
There was a recent flare but it wasn't major. An M4 I think from memory. There would be some geomagnetic storming going on currently from that, but not a huge energy input. I'd be looking more at the SSTs in the Tasman as supporting moist uplift.
Done.NZ Thunderstorm Soc wrote: ↑Tue 31/08/2021 22:17 ... not like what occurred in Auckland that was not RED warned by MS.
Maybe Mods could make this a separate topic on this as it looked like it was a significant event.
MetService August 2021 Summary - A sting in winter’s tail
The final month of meteorological winter was dominated by negative Southern Annular Mode (a measure of how stormy the Southern Ocean is) and negative SAM means enhanced westerlies for New Zealand, especially South Island. Whilst these westerlies did indeed throw front after front at the West Coast delivering well above average August rain from Fiordland to Farewell Spit, it was the slower moving features which made the most impact. A slow-moving feature brought heavy rain and damaging winds to central New Zealand on the 8th followed by a sharp southerly change and snow.
The westerlies soon returned though, continuing to run drier than average for eastern South Island south of Kaikoura as well as eastern North Island. The rest of North Island, apart from Auckland, had near normal rainfall in August, picking up the scraps of the westerly fronts from South Island between dry spells thanks to recurring high pressure. Auckland was tracking the same way until late in the month when high pressure sat to the east, then edged south, slowing down an approaching Tasman low, which brought persistent, heavy, flooding rain to Auckland.
Code: Select all
Aug 2021 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 15.8 +0.8 8.9 +0.7 12.3 +0.7 104 92% 160 109%
Auckland Aero 15.8 +0.9 8.8 +0.6 12.3 +0.7 91 82%
Tauranga Aero 15.5 +0.5 7.1 +0.4 11.3 +0.5 42 38% n/a n/a
Hamilton Aero 14.8 +0.1 4.7 +0.2 9.8 +0.2 143 120%
Hamilton, Ruakura 15.1 +0.5 5.1 +0.1 10.1 +0.3 112 102% 122 85%
Wellington, Kelburn 12.3 +0.1 7.4 +0.7 9.9 +0.5 148 127% 129 88%
Christchurch Aero 13.1 +0.7 3.0 +1.0 8.1 +0.9 80 128% 157 102%
Dunedin, Musselburgh 13.0 +1.8 5.3 +1.1 9.1 +1.4 44 80% 144 118%
Greymouth Aero 13.3 +0.5 6.2 +1.1 9.7 +0.8 234 122% 115 90%
I wouldn't use all those main centre sites (+ Greymouth) as an overveiw, as it's a little bias towards the north, i.e. I normally include 2 sites for Akld (Mangere for main centre figures and Akld Aero for the national Seven Station Series (7SS), and 2 sites for Hamilton (Hamilton Aero for main centre temps and rainfall, and Ruakura for sunshine). Greymouth is just to add some west coast balance.Cyclone Tracy wrote: ↑Thu 02/09/2021 09:35 Locally, 2020's winter was warmer by 0.2 than this 2021 winter for me. Looking at Nev's 9 station preliminary stats he loads each month for 9 stations, 2020 was marginally warmer at 10.39c compared to this year 10.36c.
Fair enough. I was just posting my local observations and having a glance at the sites you post each month, my post was not related to NIWA's 7SS.Nev wrote: ↑Thu 02/09/2021 13:31I wouldn't use all those main centre sites (+ Greymouth) as an overveiw, as it's a little bias towards the north, i.e. I normally include 2 sites for Akld (Mangere for main centre figures and Akld Aero for the national Seven Station Series (7SS), and 2 sites for Hamilton (Hamilton Aero for main centre temps and rainfall, and Ruakura for sunshine). Greymouth is just to add some west coast balance.Cyclone Tracy wrote: ↑Thu 02/09/2021 09:35 Locally, 2020's winter was warmer by 0.2 than this 2021 winter for me. Looking at Nev's 9 station preliminary stats he loads each month for 9 stations, 2020 was marginally warmer at 10.39c compared to this year 10.36c.
NIWA's preliminary national 7SS figures suggest that this winter may be about 0.2C warmer than last year's record winter.
https://twitter.com/NiwaWeather/status/ ... 0422780947Winter 2021 was the warmest winter on record in Aotearoa New Zealand, surpassing winter 2020 that set the record just last year.
The nationwide average temperature for winter 2021 was 9.7°C (1.3°C above the 1981-2010 average from NIWA’s seven-station temperature series which begins in 1909), making winter 2021 the warmest winter on record.
The key statement I took was 76 locations had a record or near record warm winterNev wrote: ↑Fri 03/09/2021 14:47 From today's NIWA Winter 2021 Climate Summary:
https://twitter.com/NiwaWeather/status/ ... 0422780947Winter 2021 was the warmest winter on record in Aotearoa New Zealand, surpassing winter 2020 that set the record just last year.
The nationwide average temperature for winter 2021 was 9.7°C (1.3°C above the 1981-2010 average from NIWA’s seven-station temperature series which begins in 1909), making winter 2021 the warmest winter on record.
Warmest on record - until next winter. Or will there be a change in weather patterns by then?Nev wrote: ↑Fri 03/09/2021 14:47 From today's NIWA Winter 2021 Climate Summary:
https://twitter.com/NiwaWeather/status/ ... 0422780947Winter 2021 was the warmest winter on record in Aotearoa New Zealand, surpassing winter 2020 that set the record just last year.
The nationwide average temperature for winter 2021 was 9.7°C (1.3°C above the 1981-2010 average from NIWA’s seven-station temperature series which begins in 1909), making winter 2021 the warmest winter on record.