Illuminated Cloud Bottoms

After another day of heavy rain and 1/2 inch hail, there were breaks in the clouds near sunset. There were clearer skies to the west, so once the Sun's elevation was less than the cloud layer, light streamed across the valley and lit up the bottoms of the clouds around me. Here's one shot with the MMT observatory on the peak of Mt. Hopkins in the middle distance, a bit of virga can be seen dropping from the foreground clouds to the right, while the cumulus clouds lower right are way off in the distance, in Mexico. Canon 20D - 1/60th, 149mm @ f/4.5, ISO 100