Tropical Atmospheric River 13-17 Dec

[Bradley]

Good lord, the Metservice precipitation model for Christchurch now gives 170mm + for the event. Thats gotta be a rogue output, surely

That was what 3 day map was showing earlier this afternoon and this evening, but its just updated again and pulled back somewhat. Still very decent rain but Thursdays rainfall is clearing a lot earlier on metservice model run now, instead of the very heavy falls lasting to midday.

EC has just doubled Christchurch predicted rain with 130mm for the event now!!

[David]

Not much showing on radar here, supposed to be heaviest this evening/tonight

[Chris W]

MS revised their warning text which now has 100-140mm for the plains and 100-180mm for the Kaikõura coast. Maximum intensities a bit lower for Chch as already noted, which may help.

[David]

75mm here for this event. There was a sharp temperature rise from 19 to 21 in the early morning which was interesting

[Razor]

Metservice now back to 80mm with a midnight clearance . GFS suggesting the rain will continue into Thursday. Fascinating day ahead. 4mm so far

[Cantab03]

Seems to be a little bit of a shadow affect happening at the moment, as you can see on radar about the City. Still raining but not as much as other areas. Radar not at the intensity I would have expected further north yet. See how it develops over the next 3 or 4 hours, think we will have a good picture then.

[Chris W]

Early signs driving to Amberley aren't great, heavy rain from just out of Chch and already plenty of standing water. Not as bad in the city.

[darcyplumb]

Heavy rain falling all night in Hanmer Springs with lots of ponding developing. It rained here all day yesterday too which probably won’t help things. Heading back to Ashburton this afternoon. Could be interesting.

[Richard]

Heavy rain falling all night in Hanmer Springs with lots of ponding developing. It rained here all day yesterday too which probably won’t help things. Heading back to Ashburton this afternoon. Could be interesting.

You were in that slow moving rain band from about and north of Culverden, didn't start to rain till last evening here.

The 18mm of rainfall rate so far here has been remarkably steady since its started, nothing heavy, just a moderate steady rain

Screenshot 2021-12-15 at 08-34-16 Neon System.png

[Tornado Tim]

Storms more probable over the lower north island today as the cooler pool of air sinks down into Taupiri, Manawatu, Palmerston north ways. Plenty of moisture and some surface heating forecast today. Just depends if its going to be enough heating to get it going ensure enough release of potential instability.
Upper level jet will help as it kicks down into the lower north island island by early afternoon.

[Richard]

Anyone noticing the wave effect caused by Banks Peninsula, looks neat when rocked back and forth.

Screenshot 2021-12-15 at 08-45-08 National Rain Radar and Rainfall Maps - Metservice New Zealand.png

[Chris W]

Storms more probable over the lower north island today as the cooler pool of air sinks down into Taupiri, Manawatu, Palmerston north ways. Plenty of moisture and some surface heating forecast today. Just depends if its going to be enough heating to get it going ensure enough release of potential instability.
Upper level jet will help as it kicks down into the lower north island island by early afternoon.

Yes, there's a severe thunderstorm watch out for Wellington-Wairarapa-Whanganui today. Got all IMBY and forgot to mention that

[Razor]

Anyone noticing the wave effect caused by Banks Peninsula, looks neat when rocked back and forth. Screenshot 2021-12-15 at 08-45-08 National Rain Radar and Rainfall Maps - Metservice New Zealand.png

I'm not sure that shadow is a real thing. My drive from Christchurch to Lincoln between 8:30 and 9am had steady consistent rain the whole way

[Rogue]

One of the hottest and muggiest mornings I can recall here on the Kapiti coast, 25 degrees at 9am. No concerns about heating, full sun across most of the Manawatu. On standby for a chase, but it will probably kick off before I can finish at work. Forecast sounding for Palmy, 4pm.

[Chris W]

Amberley South weather underground station over 50mm with intensity up to 16mm/h, heavy rain continues:
https://www.wunderground.com/dashboard/ ... wx_pwsdash

[Razor]

Amberley South weather underground station over 50mm with intensity up to 16mm/h, heavy rain continues:
https://www.wunderground.com/dashboard/ ... wx_pwsdash

That's a lot so early into the event!

[harleyb]

One of the hottest and muggiest mornings I can recall here on the Kapiti coast, 25 degrees at 9am. No concerns about heating, full sun across most of the Manawatu. On standby for a chase, but it will probably kick off before I can finish at work. Forecast sounding for Palmy, 4pm.

The first chance of something interesting happening in Palmy in over 200 years, bring it on!

[Richard]

Anyone noticing the wave effect caused by Banks Peninsula, looks neat when rocked back and forth. Screenshot 2021-12-15 at 08-45-08 National Rain Radar and Rainfall Maps - Metservice New Zealand.png

I'm not sure that shadow is a real thing. My drive from Christchurch to Lincoln between 8:30 and 9am had steady consistent rain the whole way

Ok, interesting makes you wonder whats happening aloft to make it show like that on the radar.

[Richard]

The first chance of something interesting happening in Palmy in over 200 years, bring it on!

well good luck anyway.

[Dean.]

Report of over 100mm already north of Cheviot

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[darcyplumb]

Report of over 100mm already north of Cheviot

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Wow! What’s it like in Ashburton? We are just leaving Hanmer Springs now to drive back.

[Dean.]

Report of over 100mm already north of Cheviot

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Wow! What’s it like in Ashburton? We are just leaving Hanmer Springs now to drive back.

Just over 12mm steady rain gradually getting heavier

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[Chris W]

Amberley South weather underground station over 50mm with intensity up to 16mm/h, heavy rain continues:
https://www.wunderground.com/dashboard/ ... wx_pwsdash

That's a lot so early into the event!

Yes, it's heavier earlier than I'd anticipated. Perhaps it's moving through more quickly than modelled or otherwise the higher moisture estimates are ringing true.

[Razor]

Latest metservice rain model for ChCh back up again, 120mm today and another 40mm through to dawn tomorrow.

Very serious situation looming if that holds true

[darcyplumb]

Totals have increased for Ashburton again too. Also don’t like what I’m seeing on radar with the rain banking up against the foothills. I hope those along the Ashburton River have taken precautions. Feel for CHCH too if those numbers verify.