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This is a very complex area.  It is very difficult to get things right.  Cycle 49r1 included substantial changes to vegetation, flux representation, etc.  It is also very challenging to balance the needs of, for example, hydrologists and fire prediction algorithms, which can be contradictory, particularly when the model has intrinsic biases for which soil moisture is only one small part of the equation.

Fig2.1.4.5-6: Forecast 24h ppn to 00Z 03Apr25, DT00Z 02Apr25.  Rain over SW France is 10-30mm.  The impact on soil moisture metric in Levels 1,2,3 between 00UTC 02Apr and 00UTC03 Apr is very minor.  There is even some drying out in the wettest areas shown at T+0 .  To change soil moisture metric appears to need a lot of rain. 

Surface water budget in a dry desert

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