Updated Warnings

A slow moving and deepening sub-tropical low is drifting towards the upper North Island with WeatherWatch.co.nz predicting two or three very wet days on the way.

The incoming rain is being described as “significant” by the government owned forecaster, MetService and this morning they issued several Heavy Rain Warnings from Auckland and Northland down to Hawkes Bay and Taihape.

Northern, central and eastern regions, than ex-tropical cyclones Zelia and Vania mostly missed when they tracked to the west of the upper North Island earlier this week, will this weekend and Monday be in the direct line of this heavy rain event, says WeatherWach.co.nz head weather analyst Philip Duncan.

“This new sub-tropical low is growing in strength and fresh with energy – unlike Zelia and Vania which were both older and disintegrating.  This sub-tropical low is also tracking in a different direction that will push the heaviest rain into northern, central and north eastern parts of the North Island”.

Mr Duncan says the sub-tropical low is tapping into humid, moisture laden air and will travel very slowly across the upper North Island in the coming few days.  “Heavy sub-tropical rains combined with slow movement equals a recipe for flooding”.

Mr Duncan says some of the rainfall figures are extremely high for places such as Auckland.  “It’s very rare that MetService warns of rain up to 200mm for Auckland City”.

The good news is that Waikato is also included in the rain warnings.  “It’s not something that dairy farmers would often pray for but the Waikato people I’ve spoken to are happy that rain warnings have been issued despite the risk for flooding”.

Mr Duncan says people in the North Island need to be aware that this significant rain event brings with it a high risk for flooding.

Below are the official MetService warnings in their entirety, updated this afternoon.

Northland

Heavy Rain Warning, Areas Affected: Northland, Coromandel Peninsula and Auckland Rain is now expected to become heavy sooner than first forecast in these areas, and periods of heavy rain are expected during much of Saturday as well as Sunday. Consequently rainfall accumulations are now forecast to be higher. From midday Saturday to midnight Sunday, generally 150 to 250mm of rain is expected. However, for northern and eastern areas of Northland, Great Barrier Island and the Coromandel Peninsula, accumulations may reach 350mm. In all areas, rainfall intensities of 25 to 30mm/hr are possible.
Issued: 12:08 pm 22 Jan 2011 NZDT

Auckland

Heavy Rain Warning, Areas Affected: Northland, Coromandel Peninsula and Auckland Rain is now expected to become heavy sooner than first forecast in these areas, and periods of heavy rain are expected during much of Saturday as well as Sunday. Consequently rainfall accumulations are now forecast to be higher. From midday Saturday to midnight Sunday, generally 150 to 250mm of rain is expected. However, for northern and eastern areas of Northland, Great Barrier Island and the Coromandel Peninsula, accumulations may reach 350mm. In all areas, rainfall intensities of 25 to 30mm/hr are possible.
Issued: 12:08 pm 22 Jan 2011 NZDT

Waikato

Heavy Rain Warning, Areas Affected: Waikato, Waitomo, Taumarunui and Taihape Rain is expected to become persistent and heavier overnight Saturday. From midnight Saturday to midnight Sunday, 100 to 200mm is likely to accumulate in areas, with maximum rainfall intensities of 25mm/hr. Also note, rivers flowing into the Firth of Thames may be restricted at times due to high tides around midday and midnight combined with big seas associated with strong onshore winds.
Issued: 12:08 pm 22 Jan 2011 NZDT

Waitomo

Heavy Rain Warning, Areas Affected: Waikato, Waitomo, Taumarunui and Taihape Rain is expected to become persistent and heavier overnight Saturday. From midnight Saturday to midnight Sunday, 100 to 200mm is likely to accumulate in areas, with maximum rainfall intensities of 25mm/hr. Also note, rivers flowing into the Firth of Thames may be restricted at times due to high tides around midday and midnight combined with big seas associated with strong onshore winds.
Issued: 12:08 pm 22 Jan 2011 NZDT

Coromandel

Heavy Rain Warning, Areas Affected: Northland, Coromandel Peninsula and Auckland Rain is now expected to become heavy sooner than first forecast in these areas, and periods of heavy rain are expected during much of Saturday as well as Sunday. Consequently rainfall accumulations are now forecast to be higher. From midday Saturday to midnight Sunday, generally 150 to 250mm of rain is expected. However, for northern and eastern areas of Northland, Great Barrier Island and the Coromandel Peninsula, accumulations may reach 350mm. In all areas, rainfall intensities of 25 to 30mm/hr are possible.
Issued: 12:08 pm 22 Jan 2011 NZDT

Bay Of Plenty

Heavy Rain Warning, Areas Affected: Bay of Plenty, Taupo and Tongariro National Park Rain is expected to become persistent and heavier overnight Saturday. From midnight Saturday to midnight Sunday, 300 to 400mm is likely to accumulate in the ranges, and 100 to 200mm is likely in lower lying areas of the Bay of Plenty during the same period. Maximum rainfall intensities could reach 30-40mm/hr. Also note, in the Bay of Plenty, high tides around midday and midnight may combine with high seas generated from onshore winds to restrict river flows at their mouths.
Issued: 12:08 pm 22 Jan 2011 NZDT

Taumarunui

Heavy Rain Warning, Areas Affected: Waikato, Waitomo, Taumarunui and Taihape Rain is expected to become persistent and heavier overnight Saturday. From midnight Saturday to midnight Sunday, 100 to 200mm is likely to accumulate in areas, with maximum rainfall intensities of 25mm/hr. Also note, rivers flowing into the Firth of Thames may be restricted at times due to high tides around midday and midnight combined with big seas associated with strong onshore winds.
Issued: 12:08 pm 22 Jan 2011 NZDT

Rotorua

Heavy Rain Warning, Areas Affected: Bay of Plenty, Taupo and Tongariro National Park Rain is expected to become persistent and heavier overnight Saturday. From midnight Saturday to midnight Sunday, 300 to 400mm is likely to accumulate in the ranges, and 100 to 200mm is likely in lower lying areas of the Bay of Plenty during the same period. Maximum rainfall intensities could reach 30-40mm/hr. Also note, in the Bay of Plenty, high tides around midday and midnight may combine with high seas generated from onshore winds to restrict river flows at their mouths.
Issued: 12:08 pm 22 Jan 2011 NZDT

Taupo

Heavy Rain Warning, Areas Affected: Bay of Plenty, Taupo and Tongariro National Park Rain is expected to become persistent and heavier overnight Saturday. From midnight Saturday to midnight Sunday, 300 to 400mm is likely to accumulate in the ranges, and 100 to 200mm is likely in lower lying areas of the Bay of Plenty during the same period. Maximum rainfall intensities could reach 30-40mm/hr. Also note, in the Bay of Plenty, high tides around midday and midnight may combine with high seas generated from onshore winds to restrict river flows at their mouths.
Issued: 12:08 pm 22 Jan 2011 NZDT

Taihape

Heavy Rain Warning, Areas Affected: Waikato, Waitomo, Taumarunui and Taihape Rain is expected to become persistent and heavier overnight Saturday. From midnight Saturday to midnight Sunday, 100 to 200mm is likely to accumulate in areas, with maximum rainfall intensities of 25mm/hr. Also note, rivers flowing into the Firth of Thames may be restricted at times due to high tides around midday and midnight combined with big seas associated with strong onshore winds.
Issued: 12:08 pm 22 Jan 2011 NZDT

Gisborne

Heavy Rain Warning, Areas Affected: Gisborne and Hawkes Bay Steady rain which has been falling in the ranges overnight Friday is expected to ease this afternoon, but should become persistent and heavier this evening. From 9pm Saturday to midnight Sunday, a further 150 to 250mm is expected to accumulate on top of that which has fallen during overnight Friday. Heaviest rain will be in the ranges, but 50 to 80mm is possible about coastal areas.
Issued: 12:08 pm 22 Jan 2011 NZDT

Hawkes Bay

Heavy Rain Warning, Areas Affected: Gisborne and Hawkes Bay Steady rain which has been falling in the ranges overnight Friday is expected to ease this afternoon, but should become persistent and heavier this evening. From 9pm Saturday to midnight Sunday, a further 150 to 250mm is expected to accumulate on top of that which has fallen during overnight Friday. Heaviest rain will be in the ranges, but 50 to 80mm is possible about coastal areas.
Issued: 12:08 pm 22 Jan 2011 NZDT