Rapidly Deepening Low and Possible Snow Event July 20-22nd

Nev · Unread post by **Nev** » Thu 20/07/2017 17:49

harleyb wrote:Auckland has dropped from 1012 hPa to 988 hPa in under 24 hours -- guess that makes it "bomb" territory but don't tell the media...

Has to be the centre of the low itself that drops 24 hPa in 24 hrs to qualify as a 'bomb low'…

David · Unread post by **David** » Thu 20/07/2017 18:30

The pressure here currently is 984.7hPa , lower than expected as GFS was showing 988 for this time.

Bradley · Unread post by **Bradley** » Thu 20/07/2017 18:42

David wrote:The pressure here currently is 984.7hPa , lower than expected as GFS was showing 988 for this time.

GFS has it at 976hpa at the lowest tmrw, I don't reckon it's accurate on this occasion...

snowchaser01 · Unread post by **snowchaser01** » Thu 20/07/2017 18:47

So far the Metservice forecasts are more accurate than their 3day maps. They have rain dveloping thing evening in chch where as the 3day maps indicate well after midnight. Radar is suggesting this evening as well!

David · Unread post by **David** » Thu 20/07/2017 18:56

Now 983.4 hPa here, getting quite gusty outside last 20 minutes

Bradley · Unread post by **Bradley** » Thu 20/07/2017 19:51

Huge downgrade for moisture levels around the Christchurch/Darfield region in EC's latest run - almost half down to around 40mm

melja · Unread post by **melja** » Thu 20/07/2017 20:10

Good

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cbm · Unread post by **cbm** » Thu 20/07/2017 20:30

Intense wind and rain here in Leamington, Cambridge. Normally if this bad here 70km inland and on low ground
fear what its like elsewhere but seems it's a line from Rotorua to here where it's concentrated at the moment.

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snowchaser01 · Unread post by **snowchaser01** » Thu 20/07/2017 20:37

It baffles me how we can be this close to the event (it has literally begun) and the models still flip flopping this much!

Razor · Unread post by **Razor** » Fri 21/07/2017 00:32

This event looks quite focused in Dunedin and North Otago/ South Canty from here

moylanr · Unread post by **moylanr** » Fri 21/07/2017 05:22

It's raining Its pouring

moylanr · Unread post by **moylanr** » Fri 21/07/2017 05:46

6.3mm/h 977mb

Razor · Unread post by **Razor** » Fri 21/07/2017 05:59

Looks like the worst of it will have moved on from here soonish.

midgrove · Unread post by **midgrove** » Fri 21/07/2017 06:25

Metservice computer rainfall predictions for Blenheim was for 5mm, so far 30mm has fallen in last 6 hours. Their computer rainfall predictions flip flop so much every run and hardly ever agree wit the manual forecasts. Pressure here has fallen 30Hpa in 24 hours. Not bad for a place that seems to have the most boring weather in New Zealand

Richard · Unread post by **Richard** » Fri 21/07/2017 07:24

17mm here so far and ive just found a leak in one of my roof tiles

Nev · Unread post by **Nev** » Fri 21/07/2017 07:58

Just 9mm here overnight and fairly blustery here yesterday arvo.
Gusts to 91 km/h at Whangaparaoa yesterday evening.

Highest gust recorded by MS yesterday was 191 km/h at Mahia Radar (420m) just before midnight

Interesting synoptic map from MS this morn…

On Facebook MetService wrote:Here is a hi resolution analysis of the situation at 6am this morning. A low has formed off the Kaikoura coast driving the rain southward and the lines of isobars indicate strong east to southeast flow heading towards the east coast of the South Island. Up top its a westerly flow and bands of showers are piling onto the North Island. Were in the spin cycle of a washing machine…

MetService Synoptic Map - Jul 21, 6am.jpg

Richard · Unread post by **Richard** » Fri 21/07/2017 08:03

Was quite windy about 5.00 am , dropped right away now.

snowstormwatcher · Unread post by **snowstormwatcher** » Fri 21/07/2017 08:08

Strong south/southeast wind here, Not a lot of rain yet only 6mm in the gauge so far.

Richard · Unread post by **Richard** » Fri 21/07/2017 08:22

winds have swung around to the north now, still pouring down

Chris W · Unread post by **Chris W** » Fri 21/07/2017 09:29

Rain looks to be a little slow heading south, it looked like it would be largely done in Christchurch by 9am but arrived later than expected and still going strong. The Avon was working its way up its banks in town a couple of hours ago and it hasn't really stopped raining since.

snowchaser01 · Unread post by **snowchaser01** » Fri 21/07/2017 09:31

It looks like the "feed zone" is further north than what the models expected too. I can't really see this rain letting up all day in ChCh.

Storm Struck · Unread post by **Storm Struck** » Fri 21/07/2017 09:33

Heavy rain out this way this morning still is, noticed the wind has been southerly since last night instead of northerly been some strong gusts earlier on too.
But what a spectacle to look at on the radar

It will ease up around mid afternoon for christhurch, but return overnight into Saturday.

snowchaser01 · Unread post by **snowchaser01** » Fri 21/07/2017 09:34

Storm Struck wrote:Heavy rain out this way this morning still is, noticed the wind has been southerly since last night instead of northerly been some strong gusts earlier on too.
But what a spectacle to look at on the radar
It will ease up around mid afternoon for christhurch, but return overnight into Saturday.

Considering the models had it easing by 9am in chch for the last 2 days... haha

harleyb · Unread post by **harleyb** » Fri 21/07/2017 09:35

Nev wrote:
harleyb wrote:Auckland has dropped from 1012 hPa to 988 hPa in under 24 hours -- guess that makes it "bomb" territory but don't tell the media...
Has to be the centre of the low itself that drops 24 hPa in 24 hrs to qualify as a 'bomb low'…

I know... hence my comment about the media and "bombs"...

snowchaser01 · Unread post by **snowchaser01** » Fri 21/07/2017 09:42

Latest info for Canterbury in the weather warnings... for future reference...

HEAVY RAIN WARNING
AREA/S AFFECTED
Canterbury from Arthurs Pass to Banks Peninsula, northwards
FORECAST
Heavy rain is expected to continue until around midday Saturday, especially about the foothills and ranges.

In 27 hours from 9am today to midday Saturday, expect 100-120mm of rain to accumulate about the foothills and ranges, with lesser amounts of 50 to 70mm expected towards the coast. Rain, turns to snow above 800 metres on Saturday morning, then rain and snow eases.

FREEZING LEVEL: About 2000 metres, lowering to 1200 metres Saturday morning.

AREA/S AFFECTED
Canterbury from Arthurs Pass to Banks Peninsula, southwards
FORECAST
Rain is expected to become heavy this morning and ease by midday Saturday.

In the 27 hours from 9am today to midday Saturday, expect 150 to 200mm of rain to accumulate, especially about the foothills and ranges. Peak intensities of 10 to 15mm per hour. Rain turns to snow above 800 metres in South Canterbury but 600 metres inland North Otago early Saturday morning.

FREEZING LEVEL: About 2000 metres, lowering to 1200 metres early Saturday morning.

NZ Weather Forum

Rapidly Deepening Low and Possible Snow Event July 20-22nd

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Re: Rapidly Deepening Low and Possible Snow Event July 20-22nd

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Re: Rapidly Deepening Low and Possible Snow Event July 20-22nd

Re: Rapidly Deepening Low and Possible Snow Event July 20-22nd

Re: Rapidly Deepening Low and Possible Snow Event July 20-22nd

Re: Rapidly Deepening Low and Possible Snow Event July 20-22nd

Re: Rapidly Deepening Low and Possible Snow Event July 20-22nd