Seagull Soaring Index

I have a 2-meter "foamie" radio-controlled glider that I occasionally get to fly, mostly ridge soaring along ocean cliffs. It's relatively heavy, so it takes a pretty strong wind to keep it aloft, unlike the little Zagis and molded foam warbirds that have been developed in recent years.

On some long trips to the dunes at Pismo Beach, CA I invented my "Seagull Soaring Index". I watch the seagulls that are ridge soaring, and mentally count the longest intervals between episodes of flapping. If they can soar for 6 seconds at a time or longer, the wind is strong enough to launch my Highlander. Any less, and I will be trekking down the hill to retrieve it.

Smaller ships would probably fly on a SSI of two or three. I've thought of getting a wing or smaller glider, but since I really don't get to fly R/C all that often (I'd rather fly "full-scale") it's not worth the cost.

What weather-related "rules of thumb" do you use to help decide whether today (or tomorrow) will be a good soaring day?