Complex Low - Apr 20th-21st

[CHCH Weather Chaser]

24mm for the system so far. Looks all but over really, only decent rain was first thing yesterday morning with 14mm in 3 hours and then some trizzle this morning. Apart from that its been light spots of rain or fine mist.

The metservice tends to disagree with you suggesting a spell of heavy rain shortly. Its light to moderate here at the moment in town, with a few areas looking more significant on the radar

Yeah one more push perhaps but mostly over. Im having fun watching the radar up north today. The 3 day models show this as being the last band from the north to hit us and its not intensifying to allow significant hourly totals like the output data was saying. Maybe 2-5mm more i would say.

[Storm Struck]

That area of rain that hit the west coast before is coming across by the looks, so there might be another brief heavy spell of rain coming soon.
Thankfully no reports from what i know of any tornado's on the coast with that, as it was showing some rotation offshore before it got to Greymouth.

[snowstormwatcher]

heavy rain with thunder here in Nelson currently.

[snowstormwatcher]

Rain is bordering on torrential here now with lightning every minute or so. 62mm for the event so far.

[NZ Thunderstorm Soc]

Rain is bordering on torrential here now with lightning every minute or so. 62mm for the event so far.

bring it on down here Rain stopped here now. Haven't looked at the rain-gauge yet

[snowstormwatcher]

Absolutely torrential here now. Don't think Ive ever seen rain so heavy before. Cant get outside to check my gauge but there has to have been at least 30-40mm in the last hour.

[NZ Thunderstorm Soc]

Yeah, looks like it according to the RR.
Coming back onto rain here with 17.1mm so far since 10pm last night. Light WSW wind here, if any.

[snowstormwatcher]

Going to be major flooding if this keeps up much longer. Heaps of surface flooding road is flowing like a river. 27mm between 4 and 5pm in the Richmond CBD and the rain has gotten heavier since.

[Richard]

Going to be major flooding if this keeps up much longer. Heaps of surface flooding road is flowing like a river. 27mm between 4 and 5pm in the Richmond CBD and the rain has gotten heavier since.

Yer looks amazing on the radar

[snowstormwatcher]

78mm of rain in the Richmond CBD in the last hour. Heaps of lightning and Thunder currently.

[sw_windbow]

in one hour! extraordinary!!!

[David]

78mm of rain in the Richmond CBD in the last hour. Heaps of lightning and Thunder currently.

There is another station just to the west of Richmond reporting 95.5mm in one hour
http://www.tasman.govt.nz/environment/w ... 40/#hourly

[Orion]

Amazing!

[sw_windbow]

78mm of rain in the Richmond CBD in the last hour. Heaps of lightning and Thunder currently.

There is another station just to the west of Richmond reporting 95.5mm in one hour
http://www.tasman.govt.nz/environment/w ... 40/#hourly

95 000 cubic metres per km2!

The flooding will be catastrophic.

[sw_windbow]

Just read on Facebook that they have closed Pac n save in Richmond and are having to tow the cars out of the car park due to flooding.

Quote
puzzledpigeon (236 ) 5:49 pm, Sun 21 Apr #8

http://www.trademe.co.nz/Community/Mess ... 75&topic=5

[snowstormwatcher]

Just checked my own rain gauge. 140mm since 4.15pm Still raining but not as heavy.

[jamie]

so 140mm in 2 and a half hours. That's intense!

[melja]

Nelson metservice station looks to have been knocked out but still showing rain of 65mm in the last hour- has to be a record for a M/S station.

[snowstormwatcher]

Anyone know what the record for a 1hour total rainfall in a urban area is?
Another 30mm here overnight so a total of 230mm for the event.

[Nev]

Anyone know what the record for a 1hour total rainfall in a urban area is?

MS recorded 107mm in 1 hour at Whenuapai Aero on Feb 16, 1966, the second highest 1 hour rainfall for a non-alpine area. Leigh (also in the greater Akld region), recorded the highest, with 109 mm between 1:30am and 2:30am on May 30, 2001.

[Richard]

I just cant imagine what 95.5mm in one hour would like,ive had 47mm in one hour here and that was insane enough

[Orion]

A further 6mm rain since yesterday morning, making 51mm for the event here.

[RWood]

Anyone know what the record for a 1hour total rainfall in a urban area is?

MS recorded 107mm in 1 hour at Whenuapai Aero on Feb 16, 1966, the second highest 1 hour rainfall for a non-alpine area. Leigh (also in the greater Akld region), recorded the highest, with 109 mm between 1:30am and 2:30am on May 30, 2001.

The absolute NZ record was up at Cropp River's "Waterfall" (975m ASL in the Hokitika catchment), 8 Jan 2004 at 2300-2400 - 134mm. It doesn't hold the 12-hour record, but does for the 1 hour, 24 hour, calendar month, calendar year and 365 day periods.

[Skywatcher]

I recorded 35.8mm for the event.

I've seen some torrential rain here but it didn't last more than a minute or two. My highest daily total in 11 years of records is only 54.8mm !

[Storm Struck]

Poor buggers are looking at further severe storms in the area today/tomorrow with high rainfall rates, hows the clean up looking there? i know it drains reasonably quickly in most areas.
Ive said this before on here but in 1998 i was camping in Golden Bay and we had a thunderstorm one night with torrential rain so much so the camp flooded because the tide was high and the storm water was backing up onto the land.
We stayed and literally waded it out as always its a perfect sunny day the next day, that was 63mm in half an hour according to a local farmer that i bumped into in the Collingwood pub.

42mm for here from this event as we got those additional heavy showers on friday night over north canterbury.