Determining Cloud Tops

[bookworm]

Originally Posted by IO540

I heard there are forecast skew-Ts available from GFS directly, from

http://www.arl.noaa.gov/ready/cmet.html

but I haven't found them yet.

Choose your location and then choose the model you want from the "Sounding" menu.

Looking at a skew-t or tephigram, you get an idea of the cloud cover at a given level from:

Difference between the temp and the DP:

<1C means 7-8 octas cloud
1-2C means 6-7 octas cloud
2-3C means 4-5 octas cloud
3-5C means 2-4 octas cloud
>5C means clear

For those with less experience than you IO540, it's worth pointing out that that is a very crude rule of thumb. It's certainly true that, all else equal, the closer the temp and dewpoint, the more likely you'll find cloud. But you'll overestimate stratiform cloud that way and underestimate the tops of cu.