Attached is a screenshot from True Wx that clearly show that the FV3 has a strong cold bias. Note how much lower are the day by day CDDs on today's 12Z run (purple line), the first operational GFS using the FV3 vs the prior 3 runs (old GFS). Every single day of the 12Z has lower CDDs vs both the 18Z and 0Z, and all but 2 days are lower vs the 6Z. Also, note the whopping 6 fewer CDD on the 12Z just for days 1-5 vs the 6Z. I’ve been following the DD on the True Wx site for quite a while and have never seen anything close to that much change that early in the run vs the prior run. To me, this is clearly indicative of the FV3 strong cold bias remaining.
I thought it was important to document this today because this is the only opportunity to see the direct comparison of old vs new operational:
I thought it was important to document this today because this is the only opportunity to see the direct comparison of old vs new operational:
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