I work for the National Roofing Contractor’s Association in the technical department. I am researching wind uplift and was hoping you could answer a question for me about weather and specifically wind speeds seen on TV. When designing roofs, the standard often used to calculate design uplift pressure from wind is ASCE 7. The most recent versions of this standard uses maps like this one to determine the 3-second gust speed at 33 feet above the ground.
What I understand is that there are different ways of measuring and reporting wind speed other than 3-second gust, and that the same wind event can yield different speeds depending on how it is measured.
My question is, when I watch the weather on TV and see wind speeds listed, what kind are they? Is it fair to assume they are 3 second gust wind speeds, or is there a conversion to 3-second gust?
TV weather wind speeds
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ASDC - micook
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TV weather wind speeds
The wind forecasts that are provided by broadcast meteorologists and weathercasters are typically standard model output form their broadcast weather systems. This means that the wind height is 10 meters (10m) and is usually the sustained wind prediction. That means a 1-minute average wind prediction. If the forecast is for gusty winds, the banner at the top or bottom of the screen should indicate that the wind forecasts are "Gusts" and predicted to be instantaneous wind predictions, not three-second averages.
Numerical weather prediction models (NWP) do have output field options of 2m or 10m AGL (Above Ground Level) but I am pretty sure that broadcast mets use the default 10m AGL height for the prediction you see on TV weather maps. I took a little extra time to poll some current broadcast meteorologists on what they use and they responded with the 10m AGL value. This also includes the wind gust predictions (10m AGL).
Current TV weather systems likely have the option of plotting the 2m winds and gusts, but I am not sure how many actually do that since the 10m AGL is the 'official' wind measurements form observing systems across the nation. I hope this helps.
Dave Jones
Go to full postNumerical weather prediction models (NWP) do have output field options of 2m or 10m AGL (Above Ground Level) but I am pretty sure that broadcast mets use the default 10m AGL height for the prediction you see on TV weather maps. I took a little extra time to poll some current broadcast meteorologists on what they use and they responded with the 10m AGL value. This also includes the wind gust predictions (10m AGL).
Current TV weather systems likely have the option of plotting the 2m winds and gusts, but I am not sure how many actually do that since the 10m AGL is the 'official' wind measurements form observing systems across the nation. I hope this helps.
Dave Jones
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geocollaborate
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Re: TV weather wind speeds
The wind forecasts that are provided by broadcast meteorologists and weathercasters are typically standard model output form their broadcast weather systems. This means that the wind height is 10 meters (10m) and is usually the sustained wind prediction. That means a 1-minute average wind prediction. If the forecast is for gusty winds, the banner at the top or bottom of the screen should indicate that the wind forecasts are "Gusts" and predicted to be instantaneous wind predictions, not three-second averages.
Numerical weather prediction models (NWP) do have output field options of 2m or 10m AGL (Above Ground Level) but I am pretty sure that broadcast mets use the default 10m AGL height for the prediction you see on TV weather maps. I took a little extra time to poll some current broadcast meteorologists on what they use and they responded with the 10m AGL value. This also includes the wind gust predictions (10m AGL).
Current TV weather systems likely have the option of plotting the 2m winds and gusts, but I am not sure how many actually do that since the 10m AGL is the 'official' wind measurements form observing systems across the nation. I hope this helps.
Dave Jones
Numerical weather prediction models (NWP) do have output field options of 2m or 10m AGL (Above Ground Level) but I am pretty sure that broadcast mets use the default 10m AGL height for the prediction you see on TV weather maps. I took a little extra time to poll some current broadcast meteorologists on what they use and they responded with the 10m AGL value. This also includes the wind gust predictions (10m AGL).
Current TV weather systems likely have the option of plotting the 2m winds and gusts, but I am not sure how many actually do that since the 10m AGL is the 'official' wind measurements form observing systems across the nation. I hope this helps.
Dave Jones