North Sails Weather Outlook for BOISW 2021

North Sails have enlisted Roger ‘Clouds’ Badham – one of the most respected meteorologists in yachting – to provide us with a daily weather forecast for BOISW.

‘Clouds’ has forecast for nine America’s Cups, seven Olympic Games, 30 around the world yacht races and over 35 Sydney to Hobart races, along with countless yacht races and regattas all around the world.

North Sails Weather Forecasts will be issued daily before racing begins – view them on the website, Facebook, email and BOISW app.

MON 25 8.30am

High pressure will be off the NW of the North Island today, tomorrow and Wednesday – then weaken and get pushed away as a cold front moves up NZ from the SW.
The front will move up across Northland later Thursday with a SW-S change, but then more importantly, the next high pressure will ridge in from the south and that will push a SE wind change up the east coast, across the BOP and then the Gulf with that SE wind change arriving at the BOI Friday afternoon – timing not yet certain.
A likely Tropical Cyclone up near Vanuatu next weekend looks likely to come south and may pass close to the BOI and Northland early next week – more detail to come on this as we progress during this week – something of note if/when getting the boat back south?

With high pressure not too far away to the west – the flow across Northland and the BOI is from the WSW – rather soft WSW and that will allow a weak afternoon N sea breeze to develop off the eastern coastline – but that may, or may not, get into the Bay this afternoon and if so, how far will it push in – or remain out off Brett?
The W-SW flow over the Bay is a rather fickle beast and with daytime warming over the land, the connection of the SW Bay breeze all the way to the west coast is rather fragile – and that’s when the east coast N weak sea breeze can push into the Bay.
However, during the day, the west coast SW breeze will strengthen and push across and re-connect to the Bay, but that won’t occur until early-mid afternoon at the earliest and if the N sea breeze has established, then it will hold up the west coast push.
Forecast models do not get the weak N sea breeze into the Bay today – but it should get in tomorrow, Wednesday and briefly on Thursday.

FORECAST (average range tws, no gust)
08 obs W/6-9 most areas
10 230-250/8-11
12 210-230/7-10
14 210-230/11-14
16 210-230/13-16
18 180-200/14-17
20 190-210/12-15

A N sea breeze is likely during the afternoons tomorrow, Wednesday and briefly on Thursday

TUE 26
S/10-13 easing to variable midday then N-NNW/12-16 easing after 5-6pm

WED 27
S-SE/3-5 shift to N by late morning/midday then N-NNW/13-16 afternoon with slow easing after 6pm

THU 28
SW/2-5 morning then NW/8-12 midday-early afternoon then back to SW/14-17 late afternoon

FRI 29
S-SSE/14-18 shifting bit more left to SSE-SE/ later afternoon