The Mountainwatch detailed forecast is provided by our kiwi mountain forecaster David Winterburn. This forecast is issued twice per week and is intended to provide an additional human element to the automated forecast data provided above. Sometimes we won't agree exactly with the model data - but if we ever call something significantly different we'll do our best to explain why.
South Island NZ Forecast Analysis
Thursday 2 September 2010
By David Winterburn
Summary:
Spring has arrived and with it comes some stormy weather. A strong south westerly flow will bring snow, rain and strong winds over the next few days. Saturday and Sunday look to be the best days for heading to the slopes, but don't expect bluebird days with another front set to arrive later on Sunday.
Synoptic Outlook:
A stormy end of week awaits the South Island as a strong SW flow develops over the next few days. Thursday sees a low (996hPa) develop around the lower part of the island. It's the first of a number of low pressure systems or fronts that will track either, just to the south of the island, or over the lower part of the island over the next few days.
Out to the west around Tasmania sits a large high (1031hPa). The high looks to arrive around Saturday but the centre is tracking a fair way north of the island. A large pressure gradient exists between the systems and this will fuel the SW flow over the next few days. The upper South Island should get some fine spells, but the Deep South should be experiencing a strong W/SW presence. Any fine weather will be short lived as another large low arrives sometime Sunday.
Thursday 2 September:
Rain/snow down to 1400m around the main divide. Showers out east. Strong SW winds about the tops.
Friday 3 September:
Rain/snow down to 1200m around the main divide spreading eastward at times. Strong SW winds about the tops.
Saturday 4 September:
Rain/snow showers on about the divide at first but slowly clearing. Mainly fine out east. Moderate/strong W/SW winds about the tops. Northerlies developing by the afternoon.
Sunday 5 September:
Rain/snow about or near the divide. Showers out east. Strong NW winds.
Canterbury:
The end of the week for Canterbury looks to be distinctly windy, especially out east. Make sure you check your snow reports before heading up the likes of Ohau, or Mt Hutt as I wouldn't be surprised if there is some wind affecting the lifts. The club fields should get some snow but it'll be accompanied by some strong wind so the conditions might be a bit 'challenging'. Target Saturday and early Sunday to be the days to be out and about if you're in Canterbury.
Southern Lakes:
There should be some new snow on the cards for the Southern Lakes with such a strong SW flow although it could be a case of snow falling down low, but not heaps of it. Expect some variable weather of the next few days-rain and snow showers with plenty of wind at times. Saturday could provide a sunny day but the centre of the high is forecasted to pass quite a bit northwards of the southern lakes so it might miss out. Northerly winds will on the increase by about late Saturday ahead of the next low pressure system.
Extended Synoptic Outlook:
More stormy weather ahead as a low rolls over the island.
Be sure to check the daily condition Reports and forecast info and maps daily to keep your finger on the pulse.
