Reply to Cloud bases are higher than cloud tops? on Sat, 12 Nov 2022 00:35:41 GMT

Thomas Evans 3 — Sat, 12 Nov 2022 00:35:41 GMT

@stitch
Thanks, I would think if the tops are convection tops, they be much higher, it also does not match the forecast strip, see picture. Seems the forecast strip shows clouds around 3000’, and this doesn’t match the map view.

Reply to Cloud bases are higher than cloud tops? on Fri, 11 Nov 2022 20:33:56 GMT

stitch — Fri, 11 Nov 2022 20:33:56 GMT

I believe what you are viewing is the ECMWF model describing two differing cloud types.

From ECMWF model parameter database:
The cloud base is referred to as "cloud ceiling" - The height above the Earth's surface of the base of the lowest layer of cloud with a covering of more than 50% of the model grid box. Cloud ceiling is a measurement used in the aviation industry to indicate airport landing conditions.

This parameter is calculated by searching from the second lowest model level upwards, to the height of the level where cloud fraction becomes greater than 50% and condensate content greater than 1.E-6 kg kg-1.
https://apps.ecmwf.int/codes/grib/param-db/?id=260109***

And, Cloud Top is referred to as "Height of convective cloud top".
The height above the Earth's surface of the top of convective cloud produced by the ECMWF Integrated Forecasting System convection scheme, at the specified time. The convection scheme represents convection at spatial scales smaller than the grid box.
https://apps.ecmwf.int/codes/grib/param-db/?id=228046

From you example, it could be that the convective cloud forecast providing the "Cloud Top" display is for isolated Cumulus cloud, say' which covers a spatial area 50%.

Just my guess!!!