Forecasted winds

A quick question to the EC folks. I've taken up flying RC aircraft - great hobby! It's made me more aware of the wind speed forecast by EC, however. And lately, the winds being forecast are out to lunch a bit, in my area at least.

Today's forecast, for example. No mention of winds at all. Yesterday's forecast predicted calm for today as well.

Mainly sunny. High 18. UV index 6 or high.

However, it's currently fairly breezy all over Pictou County, and mainland NS in general.

Pictou Causeway is currently SW22G30
Mt Thom is currently SW19G29
Truro S14G20

Thoughts? Is this breeze temporary, and therefore not worth mentioning? Or has something changed (Harper et al?) at EC, making forecasting tougher? I've noted in the past that anything under 20km/he has been described as light, however today's forecast doesn't even mention 'winds light'.

No mention of wind implies sustained winds are expected to be less than 20 km/h. This is not a new practice though. "Light winds" haven't mentioned in public forecasts for about 10 years. Only winds of 20 km/h or greater are mentioned.

You will sometimes see the forecast saying something like...

"Winds west 20 becoming light after midnight"

Jonathan nailed where I saw the term light being used, as we look for that in forecast. Usually for our use it's winds xx km/hr becoming light in the evening. That term light is important because some of the best flying is under 20km/hr, and we've come to discover that 20 seems the be the cutoff for mentioning winds in forecasts.

But lately the winds being forecast don't seem to match reality. Today is a prime example. It's still quite breezy out, still no wind in the forecast, and I was just curious if this wind is a temporary aberration, or is something in the climate making forecasting more difficult lately?

The winds indeed matched the forecast today, EC stations of Port Hawkesbury, Caribou Point and Debert all had winds below 20 km/h today, the forecast was correct. winds today were light unless all those stations are wrong which i highly doubt.

Not sure what the wind forecast was for here today, but they have been sustained 20-30 and gusting to 40 all day here. Its been really breezy.

The winds indeed matched the forecast today, EC stations of Port Hawkesbury, Caribou Point and Debert all had winds below 20 km/h today, the forecast was correct. winds today were light unless all those stations are wrong which i highly doubt.

Go check the Caribou Point station, and where it's sited. Then get back to us...

No way what it was measuring this afternoon represented the reality away from that sheltered spot. You just have to look at the random wind directions to know that. It was a gusty day for sure.

The Pictou causeway highway cam, at the time of this picture, was measuring 26G31 out of the SW. That's pretty representative of what the winds have been like here since about 11:00

EC's stations aren't the only game in town Jason. Sometimes you have to stick your head out the window, and use some common sense.



Attached Image (Click thumbnail to expand)

Yeah, the marine layer kept winds very light out at Caribou Point this afternoon. That site is sheltered towards the southwest anyway, so you might not get a representative windspeed reading even if winds were offshore. Once you work your way inland where all of the warmer, unstable air was today, it would indeed be more gusty. Depending on the exposure of the location your measuring from, speeds could certainly be over 20km/h on any given day.

I think the logic behind it is that when winds are generally "light", they can be highly variable from place to place... especially here in Nova Scotia because we've got so many hills and bays that make for a multitude of microclimates over just a short distance. It's just a part of EC's forecasting procedure. They offer vague details over a broad forecast region. If they did a site specific forecast, then things might be different. You best bet is to check TWN... they give a site specific forecast, and even offer an hourly forecast of temperature, wind, sky conditions and precip. Take the temp forecast with a grain of salt though, because it's certainly far from perfect.

I sometimes wonder if it is harder to forecast the wind speed than the temp. A general temperature can be forecast for a fairly large area with just a minimal difference depending on location or proximity to water. Wind has much more terrain to deal with, as Jonathan says, with all the hills and bays around to break it or enhance it.