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Wind Vectors

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Doug

05 Mar, 2021 05:14 AM

Do you have a detailed descriptor of the wind vectors? Are they generated from isobars, AGL, or ...? I use Caltopo's models extensively for visualizing airflow and interaction with terrain and would like details.

1. Support Staff 1 Posted by Julie on 05 Mar, 2021 05:39 PM

   

   Hi Doug,

   They're the wind direction values from the national digital forecast database, which should be the same as the wind direction graph from the NWS website's "hourly weather forecast" tool. We take the direction value as being at the center of each 2.5km grid square, and interpolate between those to draw the lines.
   The source data is via https://www.ncdc.noaa.gov/data-access/model-data/model-datasets/nat...

   Thanks,
   Julie

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2. Julie closed this discussion on 05 Mar, 2021 05:39 PM.

3. Douglas lewis re-opened this discussion on 05 Mar, 2021 06:28 PM

4. 2 Posted by Douglas lewis on 05 Mar, 2021 06:28 PM

   

   Hi Julie,

   Thanks for the quick reply. Still not sure what the answer is to my question. I understand where the data is derived but not sure if the vectors are free winds ( wind unaffected by terrain or winds based on an altitude/elevation which depending on the height would be affected by terrain.

   Cheers, Doug

   ________________________________

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5. Support Staff 3 Posted by Julie on 05 Mar, 2021 07:19 PM

   

   Hi Doug,

   I think you would have to look through the NOAA documentation to find that out.

   Thanks,
   Julie

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6. Julie closed this discussion on 05 Mar, 2021 07:19 PM.