As I have made my living for the last 28 years flying mainly at night, and despite what a spokesman from my company told the NTSB that there was less weather at night, I have had to deviate around thunderstorms, fly through stuff that I wish I hadn't due to the limitations of the equipment etc. There is an old saying about airborne radar...one peek is worth a thousand sweeps. We try our best to avoid the build ups but when a cell is dying and at high altitude it is made up of mainly ice crystals (but NOT ALWAYS) which do not reflect the radar beam. New generation radars are not as good as the old kinds that would alter your gene structure if it was left powered on the ground. I have gone high, I have gone a LONG way around, I have gritted my teeth and held on and wondered at why I chose this profession. The very best weather radar interpreter I ever flew with was an old Braniff Captain. He had a knack for where it was flyable and not. Learned a lot from him. For instance, flying level at 370 and the weather ahead was springtime Kansas/Nebraska storms that stretched from Minnesota to Mexico. He played with the radar, looked out the window and told me to ask for FL180, we did and flew under the anvils until on the other side of the line...ATC said we were the only plane that didn't deviate and we didn't get a bump or drop on us.
Most airliners have less electronic equipment than a lot of the newer GA airplanes. XM weather and the ability to pull up and look at the overall stuff is not available to me in my airliner.