Low Pressure Systems 5- 13 July

[David]

we got to 19.3 here just before a wind change to the NW
soil temperature now 13.9c!

I see you got to 19.7c David! (and same for Ricky!)

19.3 was my max. Both June and July have broken the record this year

[Awhituobs]

ops, my bad, 19.3 it is

[Awhituobs]

I wonder if we might get to 19c again tuesday? (it is forecasted to)

[spwill]

Another 17mm here with some heavy showers this afternoon, 47mm for this event.

[jamie]

46mm so far. 14 in that last hour but it’s clearing now. Amazing how 14mm in an hour causes so much surface runoff in winter after 400mm in 6 weeks vs 60mm in an hour in summer.


Sent from my iPhone using Tapatalk

[David]

Another 11mm in the manual gauge this afternoon vs 7.2 on the VP2

[Richard]

Very little to report from Westport, one wee shower overnight and a few heavy ones late afternoon yesterday..

[Awhituobs]

a couple of flashes of lightning here at 6:30am as a squall line moved through.

[Razor]

Interesting 3 days ahead. Jetstream injection incoming

[moylanr]

Friend caught in AKL due to Air NZ issues thinks she’s found a solution.

97124D07-72D1-423E-B929-C6A9CB0C1830.jpeg

So I looked at the swell forecast for Cook Strait on Tues. Should I warn her?…

[tgsnoopy]

Friend caught in AKL due to Air NZ issues thinks she’s found a solution.
97124D07-72D1-423E-B929-C6A9CB0C1830.jpeg
So I looked at the swell forecast for Cook Strait on Tues. Should I warn her?…

A true friend would warn her.

What Air NZ issues? Flights seem to be ok between AKL-CHC at the mo.

[moylanr]

A true friend would warn her.

What Air NZ issues? Flights seem to be ok between AKL-CHC at the mo.

Saturday afternoon she advised: "Bad news is, with Air NZ delays, I might not be back in Christchurch until Tuesday..." and posted screen shots of options to rebook not starting until Tuesday.

I've sent her (with the qualifier that I dont know how accurate swell forecasts are):

220711 Swell.JPG

[Awhituobs]

I see that Banks Peninsula and eastern Otago has been needing rain
more to come with this next low (with the onshore flow)

[TonyT]

Major system incoming.

[Razor]

I see that Banks Peninsula and eastern Otago has been needing rain
more to come with this next low (with the onshore flow)

Can't speak for Otago, but Banks Peninsula and ChCh have been punching out near to above average rainfall month on month this year

[jamie]

Jeez I’m not looking forward to this system. We just need a break from the rain. 460mm in exactly the last 8 weeks with 50-70 in the next 24 hours. Why do we seem to have a on switch and off switch for rain in recent years but nothing between the two modes. It’s crazy.


Sent from my iPhone using Tapatalk

[mikestormchaser]

Big system coming in. Heavy rain and flooding likely for coastal areas of north to mid Canterbury. Heavy snow to 4 or 500m inland areas.

[darcyplumb]

Let’s see how the Ashburton River copes with this. The damaged stop banks from the May 2021 event are still only temporary fixes in most places.

[JP.]

Can't speak for Otago, but Banks Peninsula and ChCh have been punching out near to above average rainfall month on month this year

Hmmm I thought this year has been very dry, I seem to find Jeff's station at Hoon Hay a lot more accurate than the Metservice airport site.

Jeff's rainfall
Jan: 29.6mm (expected 45mm)
Feb: 79.4mm (expected 36.6mm)
Mar: 25.4mm (expected 54.1mm)
Apr: 16.2mm (expected 72mm)
May: 21.8mm (expected 57mm)
Jun: 21.8mm (expected 83mm)

194.2mm of an expected 347.7mm

So by those numbers we are circa 55% of expected rainfall so far this year, only 20.6mm so far in July but I'm looking forward to that changing over the next week.

[Richard]

The first system the weather played out what is a common for Westport. Because it sits out from the nearby ranges if misses a lot of the rain that can be falling along those seaward ranges and beyond. That's what it was like in Westport Friday night, just one 5min shower overnight, yet driving from there Saturday morning the Buller was dirty and up a bit, not a big flood by any means It showed there had been some reasonable falls inland overnight. Halfway between Inangahua and Murchison at a spot called Lyell the westcoast put a dozie of downpour mixed with small hail, very lucky to have got through, we were the last car before they closed the road, at an older resent slip, rocks and slow moving soft rock were flowing down it as we went past. Would have been an extra two hour drive to have had gone back around through Springs Junction.

[TonyT]

Jeez I’m not looking forward to this system. We just need a break from the rain. 460mm in exactly the last 8 weeks with 50-70 in the next 24 hours. Why do we seem to have a on switch and off switch for rain in recent years but nothing between the two modes. It’s crazy.


Sent from my iPhone using Tapatalk

Because La Nina seasons enhance meridional (north/south) flow over zonal (westerly) flow, which for our latitude promotes a much wider humidity range than usual through the atmosphere. So when it rains it tends to rain harder, and when it doesn't rain, it tends to stay dry for longer.

The coming spring and early summer may turn out to be quite dry with more high pressure systems, leading to talk of drought by year's end.

Screen Shot 2022-07-11 at 1.53.30 PM.png

[Awhituobs]

@Razor, there was a recent news article where Banks Peninsula farmers were praying for rain and the NIWA data shows soil mosture levels there a well below averege
there wish is about to come true

https://www.rnz.co.nz/news/country/4705 ... o-rainfall

[TonyT]

Such wide variation over short distances - here in North Canterbury we have been above normal for 5 of the last 6 months, and not just by a few mm. We are really keen for soils to dry out! Plants are showing signs of root rot.

[jamie]

Yea you were right on the money with that comment back in early May Tony.


Sent from my iPhone using Tapatalk

[Richard]

A watch for snow to 400m north of Waimakariri River means likely to snow here, dam, had quite a good number of years without the horrible stuff, gotta happen one day I suppose.