Bomb Low: Jul 25-29th 2008

[Michael]

BOM has it directly over Auckland tomorrow at 968,it must be fast because its way up now in low latitudes.

[David]

It really is the calm before the storm! Peak gust for the day so far just 17km/h at 9:15am. Barometer steady currently, still on 1014hPa. It must be going to drop at an astounding rate - 40hPa over the next 24hours, wow

[Manukau heads obs]

re the speed of movement, 30kts I think, which is very fast for a depression
i.e 55 kmh
so in 24 hours that 550 km covered!

as Foggy says, its going to be a cold start to the morning....temperature dropping here alot atm, with the SE wind...i.e there will be cold air trapped ahead of the warm front

check out the barometer drop at Norkolk Island here:
http://weather.gladstonefamily.net/site/YSNF
and
http://www.wunderground.com/history/air ... atename=NA

edit, latest marine forecast for the Hauraki Gulf:

Rising to 50 knots gusting 65 knots in the afternoon

[Willoughby]

Gusts to 65 knots! Incredible for the gulf!

The GFS 18Z solution suggests 1 minute sustained ESE winds peaking to 86 knots (160 km/h) in the eastern quadrant of the low at height of 925 millibars, 210nm north of Cape Reinga... which would equate to sustained winds of 120km/h at the surface which is phenonmonal on the Beaufort scale.

Winds analysed this morning by quikscat attached... quite a large area of winds of over 50 knots!

check out the barometer drop at Norkolk Island here:

Yes, would be interesting to keep tabs on the pressure at Norfolk.

[spwill]

Philip Duncan wrote,

I think MetService say they have a 95% accuracy rate for Auckland.

Have to say I've found MetService forecasting for Auckland to be generally excellent.

[Storm Struck]

Surprised to see on MS in the warnings saying it may reach 130kmh in exposed places, i would have thought much stronger than that atleast 150kmh in some areas.
But then i guess there is the sheltering in some areas with hills and penninsula's in the NI too.
I just hope sky is working for you guys tomorrow night for the rugby if not a running comentary of the game from us perhaps .
Cheers
Jason.

[Manukau heads obs]

Yes, places like TeAroha and Paeroa and Matamata could get winds strong enough to lift roofs off (has happened before in those towns), being in the lee of the Kaimai ranges

first light rain bands showing up on the auckland rain radar now...or is that being echoed....as its moving fast...
I have seen gusts to 70 kts forecast for the Gulf before
Tiritiri Island through to Channel island will get the brunt of it, as the wind is squeezed between the top of the coromandel and great barrier island
also the Whangeroa peninsular and Orewa will be very exposed too

[Philip Duncan]

The Weather Watch Centre has a "Storm Alert" out for the Eastern Waikato - Te Aroha, Paeroa, Matamata with wind gusts at 180 to 200km/h. In ex-tropical cyclone Fergus wind gusts reached 220km/h on the mountain before the wind gauge broke! In town it was at 180km/h. This storm is nastier.

We're also predicting gusts to 150km/h in exposed parts of the Coromandel, Auckland and Northland - but most 'exposed" places aren't populated.

Phil
www.weatherwatch.co.nz

[spwill]

Tutukaka is an area that really catches the Easterly wind and big sea swells, would be an interesting spot to be tomorrow. There's a great Motel on an exposed Head Land there, they lost roofs in last years big blow.

[Philip Duncan]

Tutukaka is an area that really catches the Easterly wind and big sea swells, would be an interesting spot to be tomorrow. There's a great Motel on an exposed Head Land there, they lost roofs in last years big blow.

Yeah I remember that from the big storm last year...was incredible.

[Manukau heads obs]

Fergus though I think had alot of its winds at higher altitude....i.e the upper level must have had a much strong pressure gradient that at the surface
I remember that the clouds were really racing at higher altitude but the surface winds were not as strong
hence maybe why such strong winds recorded at the top of Mt Aroha?

The skip effect behind the kaimas gets all the way across to here
the big easterly winds last july caused trees to be blown over through out Franklin, but only in pockets

[David]

I see now the models are suggesting the lowest pressure Auckland will get is about 975hPa, rather than record low 968hPa level.

Also the models have taken a complete turn regarding the expected storm mid-week, almost suggesting it won't amount to anything at all now!
Ah but I remember now the models showed this storm to pass well to the east of NZ until several days ago

What amounts of rain are looking likely for Auckland tomorrow? Up to 50mm perhaps?

[Paul Mallinson]

re the speed of movement, 30kts I think, which is very fast for a depression
i.e 55 kmh so in 24 hours that 550 km covered!

This speed is an important factor Brian. It means that with the low moving to the southeast at 30kts then the winds in the southwestern quadrant will be a lot weaker (despite the pressure gradient) than the winds in the northeastern quadrant which will likely remain offshore - a good thing too!

Paul

[Manukau heads obs]

Yes, good point
I live in the wrong quadrant!!!

[gllitz]

I see that a "Civil Defense Alert" has been issued, as reported here:

http://www.stuff.co.nz/4629994a11.html

...stay safe up there, everyone!

[Willoughby]

MetService prognosis is interesting, down to 962mb? - Sunday 0000am NZST

[ricky]

The Peninsula estate weather station high and exposed on Waiheke Island has just been put back online, should have reasonably frequent updates as long as the power stays on... another one to watch http://waihekeweather.net/Oneroa/peninsula.htm

[kaimaikid]

Looks like that Coromandel and BOP ranges will cop most of the rain 150-200mm

my station is online too in Tauranga link in my sig (I think)

looking forward to watching this one - fingers crossed that no one is hurt and bugger all damage is done...

[NZstorm]

Pressure now 992hpa at Norfolk Island, dewpoint there a very high 19C.

[dija]

Finally, Ive been waiting for a decent storm surge to wipe out NZ most exspensive sand bar 'Omaha'

[Manukau heads obs]

updated severe weather warnings out from the Met service now
they are not beating about the bush on this one !!

This is a
potentially destructive and dangerous storm and people in the North
Island, especially from Waikato northwards, would be well advised to
avoid unnecessary travel.

[Michael]

Finally, Ive been waiting for a decent storm surge to wipe out NZ most exspensive sand bar 'Omaha'

The SE should blow a bit of sand across your beach too.

[TokWW]

This is going to be a big distraction from the normal Sou-Westers for the Akld folks! After E-SE there will be strong cold southerlies tending SW? to follow as well. A rough battle ahead...

[charlesg]

The Peninsula estate weather station high and exposed on Waiheke Island has just been put back online [/url]

Thanks for the help setting it up Ricky, I am charging a UPS to take up in the morning, I gather you got loggng going? Should be interesting to see if it survives.

[Philip Duncan]

It's so still it's creepy right now! (West Auckland).

It's quite an unsettling feeling...and one feels nervous after a day of 'talking it up' when it's this quiet!

SO interesting reading all your pieces.