March Outlook for NZ

Because El Nino’s bring more frequent southwesterlies, fewer moist northwesterlies may mean rainfall may be close to average over the Central Plateau, Manawatu, along the West Coast and in Southland.  Other regions may be drier than usual, especially Northland and South Canterbury including Timaru and Oamaru.  In the North Island very low rainfall is a possibility in Bay of Plenty, Rotorua and Gisborne. The southern hydrolakes may get good rain this month. Because the first two weeks of March are fairly dry, late holidaying and even hay-making are a possibility. The highest tidal variations will be 1st-4th and 30th-31st ,  and the smallest will be around the 10th . These also apply to the water table, which means that general irrigation may be less needed about the first and last weeks but more needed in the second week. Fishing chances may be best around 1st/2nd , 14th-17th,  and 29th-31st.  The 6th-9th, and 22nd-25th should also be better days than average.
Mean temperatures may be well below average on the West Coast, Waikato, Taranaki, the North Island Central Plateau, Rotorua, Manawatu and Central Otago.  Frequent El Nino SWs may mean a record cold month for some. For most, summer maximum temperatures end and drop to autumn temperatures in the third week, but not before some unseasonably hot days in Nelson, Timaru, Queenstown, coastal Otago and Southland. In the last week, gales may be a factor for the lower North Island.
The month starts with westerlies prevailing, leading into a southwesterly change that lasts about 10 days, which may be interrupted by a depression, (remains of tropical cyclone), passing over the North Island about the 3rd, followed by a ridge on 5th and northwesterlies on 6th.  This depression may bring strong winds to Auckland and much rain to Nelson, Manawatu and Wairarapa and possible hail storms in South Canterbury by the 7th.  Another hail storm may affect Nelson around March 10th which may damage ripening apple crops.  Also on 10th, early ground frosts from unseasonable cold southerlies may affect inland areas of the South Island and the Waikato may also get frosts. Apart from southwesterlies around 14th, anticyclonic conditions may prevail until about the 17th, followed by warm northerlies that precede a depression (formerly another tropical cyclone).  Southwesterlies after 20th may bring high temperatures at Alexandra and chance of very cold frosts in Waikato.  In the last week of March, strong northwesterly gales may buffet Wellington and Wairarapa enough to inflict property damage and affect air travel. 

Most likely rainfall times by region:

Northland to Hamilton incl BoP: 3rd, 10th, 17th-19th, 27th-30th (heaviest 17th)

Western, Central North Is: 2nd-3rd, 6th-10th, 17th-19th, 25th-31st (heaviest 3rd, 19th, 31st)

Taupo: 3rd, 10th, 17th-19th, 27th-28th, 30th (heaviest 19th)

Gisborne/HB: 3rd, 10th-11th, 14th, 18th-19th, 21st-25th (heaviest 19th)

Lower North Is: 2nd-3rd, 6th, 9th-11th, 18th-19th, 23rd-31st (heaviest 3rd, 19th, 29th)

Nelson and Marlborough: 2nd-5th, 10th, 18th-19th, 28th-31st, (heaviest 18th-19th)

Canterbury: 3rd, 7th-10th, 13th, 19th-20th, 23rd, 28th-30th (heaviest 10th, 27th-29th)

Inland Otago: 5th, 9th, 27th-31st (heaviest 5th, 10th, 27th-29th)

Coastal Otago: 2nd, 8th-10th, 20th, 24th-31st(except Oamaru) (heaviest 9th, 20th)

Southland: 3rd-7th(far south), 8th-10th, 18th-31st (heaviest 9th, 19th, 27th-30th)

Buller/West Coast/Fiordland: 1st-3rd, 5th-10th, 13th, 18th-31st (heaviest 1st, 5th, 26th-31st)

MOON IN MARCH

1st: Full moon

1st: Crossing equator

8th: 3rd Quarter

8th: Southern Declination

12th: Apogee

15th: Crossing Equator

16th: New Moon

23rd: 1st Quarter

23rd: Northern Declination

28th: Perigee #8

29th: Crossing Equator

30th: Full moon

© Ken Ring 2010