• | Premium

    The ECMWF meteogram feature shows "cloud base". For my location it often shows values above 30k feet, while the expected base of the cumulus clouds (according to "clouds" shown lower in the same meteogram) is 2k to 4k feet.
    Can this be explained or improved?![0_1491987518642_ecmwf-aonang.jpg](Uploading 100%) ![0_1491987544303_ecmwf-aonang.jpg](Uploading 100%)

  • Moderator

    same indications for my location (Greece).
    The height of cloud base (or ceiling) is a new parameter provided by ECMWF and is the height of the level where cloud fraction is more than 50% (5 or more octas). Cu or CB clouds rarelly exceed 50% (coverage of the sky). As is a new parameter I don't take it as "operational". Also I spoted the same for height of conv. cloud tops.

  • Administrator

    Can you try to put the screenshot here

  • Administrator

    We have basically two types of cloud bases one is used in meteogram for pilots, other is in map. I have to check with @TZ for details

  • Administrator

    @willottevanger Hi, you mentioned cumuls clouds - we do not have forecast of cumulus clouds. In meteogram you can see two clouds predictions. First is the cloud base according to ECMWF parameter with the same name. Second is the grayscale visualisation in the bottom part of meteogram. It is based on relative humidity in various altitudes, so you can estimate clouds thickness and their vertical distribution. These clouds parameters consider only large scale convective clouds, not small cumuli.

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