NZ Weather Forum

Here we go again folks. Buckle up.

From a Chch perspective I am nervous. Flood retention basins are chocker from last week. I'm not sure where 50-10mm possible falls might go.

Pic this evening of Cashmere retention ponds by chch Adventure Park

Why does chch flood on such little rain? Was it like this before the quakes or have they changed the ground heights so much that it’s changed water flows?


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jamie wrote: ↑Mon 25/07/2022 05:37 Why does chch flood on such little rain? Was it like this before the quakes or have they changed the ground heights so much that it’s changed water flows?


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Because of topography mate. Flat coastal former swamp, flanked by Port Hills

Pretty wild here this morning. Gusting over 120 km/h in the Gulf.
Another 12mm so far since late yesterday...

I'm a litte concerned as well, the ground can't take much at the moment and I'm sure we'll see some flooding issues around by the rivers again.

A very windy morning at my place so the likes of Tamaki Drive must be getting hammered. 12mm here since yesterday afternoon.
Milder air moving in today after a cold Sunday.

Latest trend in the models has this system lingering a bit further south than CHCH now, so CHCH may not get quite as much as initially was looking. Still be sodden though!

Cantab03 wrote: ↑Mon 25/07/2022 09:52 Latest trend in the models has this system lingering a bit further south than CHCH now, so CHCH may not get quite as much as initially was looking. Still be sodden though!

GFS kinda alone in suggesting that, looks like most of the other models are still going for 50mm plus

Central Otago may get off lightly if the Metservice is to be believed.

Razor wrote: ↑Mon 25/07/2022 10:40

GFS kinda alone in suggesting that, looks like most of the other models are still going for 50mm plus

Even that last fall of 30mm the other day saw surface water flowing around here, the highest water table Ive ever seen.

22.5mm in my manual gauge for this event so far, certainly not as much as I thought we would be getting

No drizzle prior to it coming onto rain from 6pm.
Interesting to see how much will fall here from this event and to see how the local council got around to cleaning out the soak pits in our area.?

Richard wrote: ↑Mon 25/07/2022 11:29

Razor wrote: ↑Mon 25/07/2022 10:40

GFS kinda alone in suggesting that, looks like most of the other models are still going for 50mm plus

Even that last fall of 30mm the other day saw surface water flowing around here, the highest water table Ive ever seen.

It’s the same down here in Mid Canterbury. The council have only today opened roads around Methven due to flooding. The Ashburton River would have to be of concern again.

Another saturated few days ahead for the region, as others have said waterways are already at full capacity so flooding will be an issue even by first light tomorrow.
Te Waihora Lake Ellesmere was opened up last week for one of its annual drainings, but has since reached capacity too so waterways backing around the area Coes Ford the Selwyn river etc will flood very easily.
Very showery off and on from Thursday to Saturday, and of note the last few days a very cold but short surge of air due through Sunday into Monday next week.

The heavier stuff seems to be setting in earlier than expected here. I see Porters Pass has snow falling. Going to be some big avo risks going forward on the fields

26mm for the event here. A strong wind at times.

I see Keikeri has nearly 200mm for the event, 540mm so far for July.

Very Cold air underneath. Snow is falling much heavier and lower than expected.

talbotmj15 wrote: ↑Mon 25/07/2022 21:45 Very Cold air underneath. Snow is falling much heavier and lower than expected.

A colleague of mine is reporting snow is falling at Mt Somers.

I see Met Service saying CHCH has reached a record for July rain total
crazy

Hasn't been too much rain here from this low, just 28mm

Some pretty serious surface flooding again on the way to work this morning. SH75 at the corner of lincoln/halswell rd is almost down to one lane. We look to be only 30-40% of the way through the rain so things will be a lot worse on the way home I'd imagine.

Metservice says 32mm so far today for chch city.

Pretty interesting short drive from Halswell to Lincoln this morning, water going right out from paddocks accross the roads in a few places

Awhituobs wrote: ↑Tue 26/07/2022 06:47 I see Met Service saying CHCH has reached a record for July rain total
crazy

Its approaching an all time record for any month for Christchurch

Razor wrote: ↑Tue 26/07/2022 08:35 Pretty interesting short drive from Halswell to Lincoln this morning, water going right out from paddocks accross the roads in a few places

Much the same coming in from Rolly, all the catchments on the side of SH1/76 are well up and it's only just beginning.
This weather seems to bring out the worst in tailgaters and drivers as well.

Already had 40.6 mm of rain here since about 1pm yesterday.
Looking like it will continue with a similar amount today.