Mid August West Coast/ Nelson/ North Island flooding & record warmth

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David
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Re: Mid August West Coast/ Nelson/ North Island flooding risk

Unread post by David »

19.2C for me today, station record for August is 19.4 in 2016. Didn’t get the NW change here until almost 5pm.
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Re: Mid August West Coast/ Nelson/ North Island flooding risk

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19.2deg the high here as well
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Re: Mid August West Coast/ Nelson/ North Island flooding risk

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Re: Mid August West Coast/ Nelson/ North Island flooding risk

Unread post by BeaconHill »

Mods: Do we need to split out the “unseasonable warmth” posts from the “biblical deluge” posts for future defence purposes?
I know they came from the same weather event, but different outcomes!
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Re: Mid August West Coast/ Nelson/ North Island flooding risk

Unread post by asuth »

What a crazy and stressful few days! We live on the Tahunanui Hills in Nelson, there has been a lot of movement and slips on the hills and they are still very unstable. Luckily our street has escaped unscathed so far. So much destruction across Nelson and surrounding area. It’s going to take a very very long time to clean up. Even through the radar cleared last night we still had very heavy drizzle. More rain to come today, tomorrow and later in the week - not good for slips that are still moving.
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Re: Mid August West Coast/ Nelson/ North Island flooding risk

Unread post by Nev »

BeaconHill wrote: Sat 20/08/2022 21:58 Mods: Do we need to split out the “unseasonable warmth” posts from the “biblical deluge” posts for future defence purposes?
I know they came from the same weather event, but different outcomes!
Hmm... probably not. I think this particular prolonged atmospheric river event has certainly been one for the history books, both in terms of its high rainfall/flooding in some parts and its incredible warmth, especially the unprecedented overnight minima in other (or the same) parts, which were more akin to mid-summer temps than winter temps. Besides, trying to separate all those temp related posts from the rainfall related posts over the past 5 days or so into 2 separate coherent threads would be an almost impossible task, particularly as a lot of those posts mention both temps and rainfall. Perhaps for 'future defence purposes', it might be easier just to tweak the thread title? :smile:
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Re: Mid August West Coast/ Nelson/ North Island flooding risk

Unread post by BeaconHill »

2 graphs via Twitter user @marcdaalder showing just how wet 2022 has been for Nelson and Westport.
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FA3146E2-8EA4-4085-9EB8-D172FF66F6D0.jpeg
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Re: Mid August West Coast/ Nelson/ North Island flooding risk

Unread post by Nev »

Not surprised by that Nelson graph. NIWA's Nelson Aero site has recorded 343mm so far this month (incl. 319mm in just 4 days). Only the month of Dec 2011 with 464mm was wetter from records since 1941. This on top of its 2nd wettest July and 2nd wettest Feb so far this year.
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Re: Mid August West Coast/ Nelson/ North Island flooding risk

Unread post by snowstormwatcher »

Nev wrote: Mon 22/08/2022 16:16 Not surprised by that Nelson Graph. NIWA's Nelson Aero site has recorded 343mm so far this month (incl. 319mm in just 4 days). Only the month of Dec 2011 with 464mm was wetter from records since 1941. This on top of its 2nd wettest July and 2nd wettest Feb so far this year.
Would be interesting to see a long term trend of annual rainfall in Nelson as it seems in the last 10-15 years they are getting far more northerly rain compared to when I lived there in the 90s and early 2000s
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Re: Mid August West Coast/ Nelson/ North Island flooding risk

Unread post by Nev »

snowstormwatcher wrote: Mon 22/08/2022 17:05 Would be interesting to see a long term trend of annual rainfall in Nelson as it seems in the last 10-15 years they are getting far more northerly rain compared to when I lived there in the 90s and early 2000s
Below are some decadal averages based on NIWA's Nelson Aero rainfalls, which does show its average rainfall for the 1990's to be about the same as its 1981-2010 average of 959mm, while the 2000's were below average and the 2010's well above average (the latter on par with the 1950's and 1960's).

Nelson Aero 10 year rainfall averages (mm)
1941-1950 ... 928
1951-1960 .. 1028
1961-1970 .. 1046
1971-1980 ... 940
1981-1990 ... 997
1991-2000 ... 959
2001-2010 ... 921
2011-2020 .. 1047
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Re: Mid August West Coast/ Nelson/ North Island flooding & record warmth

Unread post by James »

Interesting article in today's Herald. Not one mention of the elephant in the room......
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Re: Mid August West Coast/ Nelson/ North Island flooding risk

Unread post by tich »

Nev wrote: Thu 25/08/2022 07:20
Below are some decadal averages based on NIWA's Nelson Aero rainfalls, which does show its average rainfall for the 1990's to be about the same as its 1981-2010 average of 959mm, while the 2000's were below average and the 2010's well above average (the latter on par with the 1950's and 1960's).

Nelson Aero 10 year rainfall averages (mm)
1941-1950 ... 928
1951-1960 .. 1028
1961-1970 .. 1046
1971-1980 ... 940
1981-1990 ... 997
1991-2000 ... 959
2001-2010 ... 921
2011-2020 .. 1047
https://paperspast.natlib.govt.nz/newsp ... 70/08/31/1

1961-70 would've included this devastating flood event in Nelson.
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Re: Mid August West Coast/ Nelson/ North Island flooding & record warmth

Unread post by Nev »

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