NZ Weather Forum

Milford Road closed due to significant damage

mattyj46 wrote: ↑Mon 03/02/2020 09:54 Milford Road closed due to significant damage

https://www.nzta.govt.nz/projects/sh94- ... ad-status/

Started a new topic given the magnitude of the rainfall that's now occurring over the main divide

Milford Sound has reported 347mm yesterday plus 230mm today as at 10am since midnight, and a further 200-450mm expected in the event. 250 people are stuck in Milford Sound at present I doubt they will get out before late tomorrow or Wednesday. Total falls will likely push up towards a 1000mm in some areas

Power outages and SH6 Road closure last night through Fox to Haast. Roads are very fragile over there following the December event.

Milford Sound showing a dew point of 19C, very moist air flow.

Ok for the first time Metservice since the new system was implemented has issued a Red Warning. This will be interesting to see what unfolds....

Issued at 11:55am Monday 3 Feb 2020

Significant heavy rain for the west and south of the South Island, and west to northwest gales for parts of southern and central New Zealand
A series of fronts are forecast to move slowly east across the South Island during Monday and Tuesday, bringing periods of heavy rain to the west and south of the South Island, including the Southern Alps, and strong west to northwest winds to parts of the South Island and the lower North Island.

A Heavy Rain Warning is in force for Fiordland, Westland, the headwaters of the Otago and Canterbury Lakes and Rivers, Southland, Clutha, Central Otago, the Southern Lakes.

Note: The warning in Westland and Fiordland south of Hokitka and north of George Sound had been upgraded to a RED WARNING. Significant impacts are already occuring and this event has high potential for further significant impacts, such as major slips, road closures and flooding, in the next 24 to 36 hours. This decision was made in consultation between Metservice Meteorologists and West Coast Regional Council Hydrologists and Civil Defence Officers.

Watches for heavy rain have now been issued for Dunedin and Buller.

A Strong Wind Watch remains in force for eastern parts of Otago and Canterbury, while Watches for possible severe gales have been issued for Marlborough, Wellington and Wairarapa

Note, for parts of the South Island, especially in the west of the island, this is likely to be a significant event with the potential for slips to disrupt transport, while near the east coast of the island rivers are likely to rise in response to the heavy rain falling in the headwaters.

People are advised to keep up to date with the latest forecasts in case any changes are made.

Heavy Rain Warning

This rain is expected to cause dangerous river conditions and significant flooding. Slips and floodwaters are likely to disrupt travel, making some roads impassable and possibly isolating communities.

Area: Westland south of Hokitika and Fiordland north of George Sound
Valid: 31 hours from 9:00am Monday to 4:00pm Tuesday
Forecast: Periods of heavy rain. Expect a further 300 to 450mm of rain to accumulate about the ranges on top of what has already fallen, and 90 to 150mm near the coast. Peak rates of 15 to 25mm/h in general, but 25 to 40mm/h possible - mostly with thunderstorms. Note, the heaviest rain in Fiordland is expected to ease overnight Monday and Tuesday morning.
Changes: Upgraded to RED WARNING

Heavy Rain Warning

Heavy rain may cause streams and rivers to rise rapidly. Surface flooding and slips are also possible and driving conditions may be hazardous.

Area: Westland from Hokitika northwards
Valid: 31 hours from 9:00am Monday to 4:00pm Tuesday
Forecast: Periods of heavy rain. Expect a further 250 to 350mm of rain to accumulate about the ranges on top of what has already fallen, and 80 to 100mm near the coast. Peak rates of 15 to 25mm/h in general, but 25 to 35mm/h possible - mostly with thunderstorms.

Area: The headwaters of Canterbury Lakes and Rivers
Valid: 31 hours from 9:00am Monday to 4:00pm Tuesday
Forecast: Periods of heavy rain. Expect 300 to 450mm of rain to accumulate near the Main Divide, with 130 to 250mm within 15km east of the Divide. Peak rates of 15 to 25mm/h, but 25 to 35mm/h possible - especially with thunderstorms.
Changes: Upgraded to an Orange Warning

Area: The headwaters of Otago Lakes and Rivers, Southern Lakes and Central Otago
Valid: 31 hours from 9:00am Monday to 4:00pm Tuesday
Forecast: Periods of heavy rain. Expect a further 300 to 400mm of rain to accumulate near the main divide on top of what has already fallen, with 130 to 250mm within 15km east of the Divide and 100 to 150mm elsewhere over the remainder of the Southern Lakes and Central Otago. Peak rates of 15 to 25mm/h, but 25 to 35mm/h possible - especially near the Divide and with thunderstorms.
Changes: Central Otago and Southern Lakes now included in the Orange Warning.

Area: Clutha and Southland
Valid: 31 hours from 9:00am Monday to 4:00pm Tuesday
Forecast: Periods of heavy rain. Expect 100 to 150mm to accumulate on top of what has already fallen. Peak rates of 15 to 25mm/h. Thunderstorms possible.

Area: Fiordland south of George Sound
Valid: 26 hours from 9:00am Monday to 11:00am Tuesday
Forecast: Periods of heavy rain. Expect a further 100 to 250mm of rain to accumulate on top of what has already fallen. Peak rates of 15 to 25mm/h in general, but 25 to 35mm/h in thunderstorms.

Heavy Rain Watch

Area: Buller
Valid: 11 hours from 10:00am to 9:00pm Tuesday
Forecast: A period of rain. Rainfall amounts may reach approach warning criteria.

Area: Dunedin
Valid: 19 hours from 11:00pm Monday to 6:00pm Tuesday
Forecast: Periods of rain, could be heavy at times. Rainfall amounts may approach warning criteria.

Strong Wind Watch

Area: Wellington and Wairarapa south of Mount Bruce
Valid: 18 hours from 9:00am Tuesday to 3:00am Wednesday
Forecast: Northwest winds may approach severe gale in exposed places at times.

Area: Marlborough
Valid: 17 hours from 6:00am to 11:00pm Tuesday
Forecast: Northwest winds may approach severe gale in exposed places at times.

Area: Canterbury High Country
Valid: 29 hours from 9:00am Monday to 2:00pm Tuesday
Forecast: Northwest winds may approach severe gale in exposed places at times.

Area: Central Otago and Southern Lakes
Valid: 11 hours from 9:00am to 8:00pm Monday
Forecast: Northwest winds may approach severe gale in exposed places at times.

An update for severe weather will be issued by 9:00pm Monday 3 Feb 2020.

A service provided through a contract with the Crown.

(C) Copyright Meteorological Service of New Zealand Ltd 2020.

State of Emergency now declared in Fiordland....road out for at least the week and I gather now 500 peeple trapped in Milford Sound

spwill wrote: ↑Mon 03/02/2020 11:23 Milford Sound showing a dew point of 19C, very moist air flow.

The airport there today has been reporting dewpoint 20C with heavy rain and some thunder earlier.

Milford raingauge has gone offline since midmorning, I presume thats because it is underwater or the comms have gone done. I recall that happened last year too.... we never really got a handle on what actually fell that previous time

Razor wrote: ↑Mon 03/02/2020 14:19 Ok for the first time Metservice since the new system was implemented has issued a Red Warning. This will be interesting to see what unfolds....

Issued at 11:55am Monday 3 Feb 2020

Significant heavy rain for the west and south of the South Island, and west to northwest gales for parts of southern and central New Zealand
...

Rather odd to make this call mid-event. Not criticising their forecasting for this event, they have had warnings out for days and the event has been well anticipated by a variety of modelling and relatively well forecasted by many, including by MS themselves (or so it appears). So if its worthy of being called a red warning now, after there has been destruction and consequences, why wasn't that designation applied to the warnings 2 days ago to help the vulnerable anticipate? Its almost as if they forgot they had the "red warning" designation available to be used.

Razor wrote: ↑Mon 03/02/2020 15:17 Milford raingauge has gone offline since midmorning, I presume thats because it is underwater or the comms have gone done. I recall that happened last year too.... we never really got a handle on what actually fell that previous time

Try this one.. looks to be at the Milford airport
https://fenz.harvest.com/?cmd=gph&sid=7 ... h_id=53560

Certainly a major event. Serious flooding now closing many main routes into Dunedin, Queenstown and Invercargill

MS reports over 1000mm in 2 days recorded

Sent from my Redmi Note 4 using Tapatalk

TonyT wrote: ↑Mon 03/02/2020 16:42
Rather odd to make this call mid-event. Not criticising their forecasting for this event, they have had warnings out for days and the event has been well anticipated by a variety of modelling and relatively well forecasted by many, including by MS themselves (or so it appears). So if its worthy of being called a red warning now, after there has been destruction and consequences, why wasn't that designation applied to the warnings 2 days ago to help the vulnerable anticipate? Its almost as if they forgot they had the "red warning" designation available to be used.

You raise a very interesting point. I've done some analysis on how MS missed the red alert until mid event. It seems to be a similar mistake to the December event.

On model run 00Z 01/02/2020 here were the 5 day precip outputs per global model for Milford Sound area which has had 1000mm+ so far. I didn't keep a record of the MS local output.

Icon - 900mm to 1000mm
Access G - 850mm to 950mm
UK - 750mm to 850mm
EC 550mm to 650mm
GFS 450mm to 550mm
CMC - 400mm to 500mm

It seems like they have again fallen for the EC, GFS output for their forecast and disregarded Icon, UK and Access. Both EC and GFS are continually underestimating SI West Coast rain events. Icon especially is blitzing the field again, the German's maths are stacking up

December event model output for reference https://www.weatherforum.nz/phpBB3/view ... 96#p187796

Ste of Emergency now declared in Southland. Gore under siege from the Mataura

Been here 12 years and never came close to a flood this bad. 200mm and counting. Luckily we're up high so no flooding on the main farm, but the other block is on the banks of the Waikaka stream which has been around 4 metres above normal all day.

I'd definitely add Southland and Otago, maybe even South Canterbury, to this thread title. It's a fairly widespread event with some incredible images coming out from out west and down south.

Chris W wrote: ↑Tue 04/02/2020 17:55 I'd definitely add Southland and Otago, maybe even South Canterbury, to this thread title. It's a fairly widespread event with some incredible images coming out from out west and down south.

Yes the damage to the Milford rd is truly shocking

Civil defence now advising Southland to prepare for a 1 in 100 year event tonight. I'm on mobile, can a mod online update the title please?

Razor wrote: ↑Tue 04/02/2020 19:48 Civil defence now advising Southland to prepare for a 1 in 100 year event tonight. I'm on mobile, can a mod online update the title please?

Where are they saying that?

Just got sent an emergency alert from civil defence on my phone, so they must be expecting it to get quite bad

So Chris Lynch said that. I'm surprised the printed media didn't post it if that's what Civil Defence Southland actually said. Nothing on their website or Facebook. Anyway, calling it a 1 in 100 year flood is a moot point considering the last big one was just over 40 yrs ago!

Hope you stay safe hozza95

1 in 100 year is just a statistical term
i.e the odds are it will be 100 years before it will happen again, as its a rare thing
but if you get the right setup occuring then it can happen again..and sooner (and some of the extreme setups are happening more regularly now)

Preparations for Evacuation time in Gore , this looks bad.

It will peak tomorrow morning fingers crossed it holds. A farm owning friend in Garston tells me that his family haven't seen water coming off the hills like today since his grandfather's days.