meteo wind Merge pull request #42 from fire2a/weather-docs

Update weather.md

Author: fdobad

site/Cell2FireW/data_preparation.md

@@ -67,7 +67,7 @@ Scott&Burgan
 * FireScenario was deprecated by "Live & Dead Fuel Moisture Content Scenario [1=dry..4=moist]"
 * There's no need to be consistent with the timestamps, but isoformat `YYYY-MM-DDTHH:MM:SS` should be followed
 * WIP: unifying weather formats, relying on column names instead of order to read them
-* Cell2Fire wind angle is reversed from normal metereological data, check [wind direction](weather) for more details.
+* Cell2Fire wind angle follows metereological convention, check [wind direction](weather) for more details.
 
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site/Cell2FireW/weather.md

@@ -8,30 +8,32 @@ has_toc: false
 ---
 
 # Wind direction 
-
-Wind direction is generally indicated by the direction from which the wind originates. For example, a north or northerly wind blows from the north to the south.
-
-## Wind direction in meteorology
-
-It is measured in degrees, from 0º to 360º, rotating clockwise in the horizontal plane. 
-
-* Values close to 1º and 360º indicate north wind
-* 90º indicate east wind
-* 180º south wind
-* 270º west wind.
-
-## Wind direction Cell2Fire
-
-In Cell2Fire, the wind is also measured in degrees from 0° to 360°, rotating clockwise in the horizontal plane.
-
-* Values close to 0° or 360° indicate south wind
-* 90° indicate west wind
-* 180° north wind
-* 270° east wind 
-
-
-| Metereological | Cell2FireW | 
-| --- | --- |
-| ![meteo](img/meteo_angulos.png)| ![angulos](img/Cell2Fire_angulos.png)  |
-
+How wind direction should be indicated in weather files depends of which version of the simulator or QGIS plugin you use.
+
+## Wind direction in Cell2FireW version 1.0.0 or greater
+
+Following the <b>meteorological standard, wind direction is indicated by the direction from which the wind originates</b>. For example, a north or northerly wind blows from the north to the south. The wind direction is measured in degrees, from 0º to 360º, rotating clockwise in the horizontal plane. 
+
+<div style="text-align: justify;">
+  <table>
+    <tr>
+      <td style="text-align: center;"><img src="img/meteo_angulos.png" alt="meteo" width="50%"></td>
+      <td style="text-align: center;"><br>Values close to 0º and 360º indicate north wind<br>90º indicate east wind<br>180º south wind<br>270º west wind.</td>
+    </tr>
+    </table>
+</div>
+
+## Wind direction in Cell2FireW versions prior to 1.0.0
+
+In previous versions of Cell2FireW, the wind direction was dictated by the direction <b>towards</b> which the wind is blowing.
+It is also measured in degrees from 0° to 360°, rotating clockwise in the horizontal plane, but 0° means "South".
+
+<div style="text-align: justify;">
+  <table>
+    <tr>
+      <td style="text-align: center;"><img src="img/Cell2Fire_angulos.png" alt="meteo" width="50%"></td>
+      <td style="text-align: center;"><br>Values close to 0º and 360º indicate south wind<br>90º indicate west wind<br>180º north wind<br>270º east wind.</td>
+    </tr>
+    </table>
+</div>