What is the best forecaster for Vic Wind. I am heading down to Inverloch on Sunday and getting widely different forecast.
eg
BOM say B/w Bass Starit and approaches and their Cape Otway to Wilson prom forecast 15 - 20 kts in the am and 10 - 15 in afternoon.
Whereas Windguru and Seabreeze are saying 8 - 9 kts all day.

If anyone can help out and specifically on wind forecasts for Inverloch that would be great

Ok, I am slightly biased as i work at the BoM (though not in weather forecasting - i'm a climate guy). The seabreeze/windguru stuff relies upon computer models. They should be ok in general. However the BoM stuff is a human forecaster who uses several models as tools to generate that forecast. So you have more models plus human experience.

That said... BoM forecasts will tend to over forecast to some degree, as it is better - for safety - to err slightly too high. That said they dont deliberately forecast, say, 10% too high, but rather, if there is any uncertainty they will err on the side of caution (ie high). The BoM forecasts will also look at what may be the higher winds in a certain domain - for instance Port Phillip is a big place, so 20knots may be in the northern end while 10 knots are in the south; so a 20 knot forecast would be considered correct even though a person in the south would be wondering what gives....

Computer models - if raw data is used - will be too low, as they tend to strike drag problems close to the ground/sea. Often there will be some sort of bias correction applied in model post processing, which may bring it back up. Or sometimes people just use a model level that is actually 50-100m above the ground to get away form the models ground effects.

So in short and generalising horribly (so not always the case); BoM slightly high (but not much), models slightly low.

Hey Windjunky, thanks for information. Helps to understand situation a little better.
Anyway to get Inverloch wind forecasts? or somewhere close by that would be indicative.

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windjunky said...

as i work at the BoM (though not in weather forecasting - i'm a climate guy).

Dont listen to him! When the forecast says 35knots SW and you get a 5knot NE... Blame him! I always do after the wind drops out, makes me feel better!!
Jeeez we need SOMEONE to blame!

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Old Salty said...

Hey Windjunky, thanks for information. Helps to understand situation a little better.
Anyway to get Inverloch wind forecasts? or somewhere close by that would be indicative.

Was curious about that also... would Wilsons Prom. be a reasonably accurate graph to look at for Inverloch I wonder?

Too late now for this to be of use to you that WE but Wilsons Prom forecast is probably too high by quite a bit for Inverloch. It is not far off for Easterlies for Sandy Point but often the sea breeze effect over 90 mile beach kicks it up a well over in summer and I have had 25-30 knots East -NE at Sandy and driven to Inverloch and there it is 10 knots!!! Came back again immediately to 25-30 knots.

For Westerlies the BOM forcasts for coastal waters PPbay to Prom are usually pretty good for Sandy and probably only a bit over for Inverloch.

Generally places East of Sandy get stronger Northerlies (especially the Bays) and I think Inverloch may be far enough East for that. NW is pretty much the same as the Bays

Try making a custom spot on Windguru for Inverloch and then observe what corrections factors it needs in typical conditions over time.

Hey Oldie

That is awesome information, just what I was chasing. Do you sail in the inlet often? What winds work the best from what area of the inlet. I am trying to build up a data base that maybe we can all use.