Well…
For day time stuff think about the following:
1. It’s so bright outside that the explosion isn’t going to seem as “hot”, so instead of being totally blown out (whiter) you will want to bring the tendril detail back down and maybe use curves to give it a warmer look. (add some red gamma and take away a little blue gamma) also use the screen mode instead of add this way it will be less likely to blow out.
2. If you look at day time explosions they do emit light so an exta ground matte with some increased orange brightness may help sell.
3. Some camera shake definely is good.
Something to think about.
Andrew Kramer
http://www.VideoCopilot.net