Okay, if you regularly read this blog you will know I like the outdoors and occasionally blog about the weather. In the past most of it has been critical of the Metservice and the media for over hyping rain warnings. (In particular: http://www.brad.net.nz/blog/2008/07/once-in-10-year-storm/ )

However, the storm that is going to hit this weekend is not overhyped. In fact I believe that not enough warnings have been issued.

The storm itself is not very big, however, it is very very slow moving, this means that when it hits the accumulated amount of rain that will fall will be very high which could cause major flooding, and slips. In addition to this very strong winds are forecast which could take out trees and powerlines.

Be prepared for powercuts. Have a gas cooker, water, and dried/non-refrigerated food available. If you do not have these get them now.

Auckland Civil defense is advising people to stay at home all weekend, and not to cross the harbour bridge, it is simple looking too dangerous.

Here is the full weather warning:

Severe Weather Warning (full text)
Issued by MetService at 09:16am 27-Feb-2009

PERIOD OF HEAVY RAIN AND EASTERLY GALES EXPECTED IN NORTHERN NEW ZEALAND OVERNIGHT FRIDAY AND DURING SATURDAY.

MetService expects a low over the north Tasman Sea to deepen as it moves towards northern New Zealand today, Friday, and pass close to the west of the North Island on Saturday.

Forecasters advise that a broad band of rain with heavy falls and easterly gales is expected to move southwards over northern and central New Zealand ahead of the low, affecting Northland from this evening, Auckland and Coromandel Peninsula from Saturday morning and western Bay of Plenty and northern Waikato from Saturday afternoon.

There will probably be about 100 to 150mm of rain in parts of Northland and Auckland in a 24 hour period commencing from about 6pm Friday in Northland and 6am Saturday in Auckland. Coromandel Peninsula is likely to see greatest amounts of rain during this event with up to 250mm possible about the ranges. Rain is expected to become heavy in the western Bay of Plenty and northern Waikato from about Saturday afternoon with around 100mm likely in a 12 to 18 hour period.Rainfall rates could possibly peak at 20 to 30mm per hour at times, which could cause surface flooding, and streams and rivers are likely to rise quickly.

There is also expected a period of severe east to northeast gales with gusts of 120 km/h about parts of Auckland, inland Waikato near the Kaimai Range and also the Firth of Thames area from the early hours of Saturday to the afternoon. Winds of this strength could damage trees, powerlines and insecure roofs, and make driving hazardous for high sided vehicles and motorcyclists. Boat owners may wish to check their moorings.

MORE DETAILED INFORMATION FOR EMERGENCY MANAGERS AND TECHNICAL USERS FOLLOWS:

HEAVY RAIN WARNING

AREA/S AFFECTED: NORTHLAND, AUCKLAND, COROMANDEL PENINSULA, BAY OF PLENTY WEST OF KAWERAU, WAIKATO NORTH OF HAMILTON

FORECAST:

NORTHLAND Rain is expected to spread slowly south today, but will become heavy this evening. In the 18 to 21 hours starting about 6pm Friday from Bay of Islands northwards and about 9pm Friday further south, 80 to 100mm of rain is expected but there could be locally heavier falls around 150mm about the eastern hills as winds pick up to gale force for a time. Rainfall rates will probably peak at 20 to 30mm per hour overnight Friday.

AUCKLAND (INCLUDING GREAT BARRIER ISLAND)Rain is expected to spread slowly south from this afternoon, but is not expected to become heavy until early Saturday morning. In the 24 hour period starting about 3am Saturday from Whangapararoa northwards and about 6am further south,100mm is expected, but there could be up to 150mm north of Whangapararoa and also about the Hunua ranges.Rainfall rates of 20 to 30mm per hour are probable from about midday Saturday.

COROMANDEL PENINSULA Rain is expected to spread slowly south from this afternoon, but is not expected to become heavy until early Saturday morning. In the 24 hour period from about 6am Saturday, 150 to 200mm is expected but there could be around 250mm in the ranges. Rainfall rates of 20 to 30mm per hour are likely from about midday Saturday.

BAY OF PLENTY WEST OF KAWERAU Rain is expectecd to develop this evening but will probably not become heavy until Saturday afternoon. In the 18 hours from about 3pm Saturday, 100 to 140mm is expected in the ranges with 60 to 90mm possible at lower levels. Rainfall rates of 20 to 30mm per hour are possible in th ranges from Saturday evening.

WAIKATO NORTH OF HAMILTON Rain is expectecd to develop this evening but will probably not become heavy until Saturday afternoon. In the 12 hours from about 3pm Saturday, 70 to 100mm is expected. Rainfall rates of 15 to 25mm per hour are possible from Saturday evening.

STRONG WIND WARNING

AREA/S AFFECTED: PARTS OF AUCKLAND, INLAND WAIKATO WEST NEAR THE KAIMAI RANGES AND ALSO THE FIRTH OF THAMES AREA afternoon.

FORECAST:

PARTS OF AUCKLAND, INLAND WAIKATO WEST NEAR THE KAIMAI RANGES AND ALSO THE FIRTH OF THAMES AREA East to northeast winds are expected to rise to gale after midnight Friday and to severe gale early Saturday. In the 12 hours from 3am Saturday gusts of 120 km/h are possible.

NEXT SEVERE WEATHER WARNING WILL BE ISSUED AT OR BEFORE 9:00pm Friday 27-Feb-2009

Forecast prepared by: Gerard Barrow

A service provided through a contract with the Crown

And the following places are on a watch… i.e. they could end up with a weather warning.

SEVERE WEATHER WATCH FOR BAY OF PLENTY EAST OF KAWERAU, THE RANGES OF
GISBORNE AND THE CENTRAL NORTH ISLAND, WAIKATO, TARANAKI, WANGANUI,
MANAWATU AND THE KAPITI COAST
ISSUED BY METSERVICE AT 1001hrs 27-Feb-2009

PERIOD OF HEAVY RAIN AND EASTERLY GALES EXPECTED TO SPREAD OVER MUCH
OF THE NORTH ISLAND ON SATURDAY

MetService expects a low over the north Tasman Sea to deepen as it
moves towards northern New Zealand today, Friday, and pass close to
the west of the North Island on Saturday to lie west of the upper
South Island by Sunday morning.

Forecasters advise that a broad band of rain with heavy falls and
easterly gales is expected to move southwards over northern and
central Zealand ahead of the low. A heavy rain warning is already in
force from Northland to northern Waikato and also the Coromandel
Peninsula and western Bay of Plenty. A severe wind warning is also
now in force for severe east to northeast gales in parts of Auckland,
inland Waikato near the Kaimai Range and the Firth of Thames.

Metservice is maintaining a watch for heavy rain on Saturday and
Sunday morning for the remainder of the Bay of Plenty and the ranges
from Gisborne to the central North Island.
Streams and rivers are likely to rise quickly and there is the
potential for surface flooding and slips.

There also could be a period of severe gale easterly winds Saturday
afternoon and evening in places about and west of the main ranges
from Waikato to the Kapiti Coast and also near Mount Taranaki.
Winds may become hazardous for high sided vehicles and motorcyclists
and could damage trees, powerlines and insecure roofs.

People are urged to keep up to date with weather forecasts.
This Watch will be reviewed by 9pm Friday 27 February 2009
Forecast prepared by: Gerard Barrow

I will be working on Saturday so will not have any time during the day to update this blog. However, these sites could be very useful:

www.metvuw.com – an alternative weather forecasting system.

www.nzherald.co.nz – the evil media

www.metservice.com – New Zealand Met Service, currently the site is being overloaded.

http://weatherwatchcentre.co.nz/content/stormy-weekend-north-island – This site contains more local weather news.

Forecasted accumulated rainfall between 1am and 7am Saturday morning, red is very heavy rain

Tags: Auckland, North Island, Rain, Weather

This entry was posted on Friday, February 27th, 2009 at 3:34 pm and is filed under News & Current Events. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.