The request was for periods less than 10 knots. The notification is correct. The real forecast is under 10 knots but the forecast in the email shows above 20 knots.

I'd like to see longer time periods for alerts.

For example, I'd like to be alerted when there are calm conditions over three days.

I go out boating for 3-7 days at a time. A nine hour max gives you a clue as to the weather but is not much use for my purpose.

So I would like to say less than 9 knots over 3 days.

Longer periods bring outliers into account. A better solution would be to specify a percentage of the time that the condition ought to apply for.

So how about less than 9 knots over 3 days for 80% of the time?