I hear your grief - recently took a yacht from Port Phillip (Melb) to Gippy
Lakes and had quite vaiable winds (compared to the forecast!!) I guess you need to look at multiple sites to get a sense of what is likely to happen ??
So what were the 'other' sites you used? For off shore stuff I tend to rely on the BOM marine explorer (maybe I'm kidding myself also!!)
www.bom.gov.au/australia/meteye/So solid 30 knots - thats big !! - 40 to 45 knots thats just not fun but you were sailing into a low pressure system?? did you have a kite on board to make it fun?? LOL