Now that it's thunderstorm season here in New Hampshire, it would be nice to be able to find out what the vertical wind shear is like at the altitudes that affect thunderstorm formation, to guess whether they'll form. Once cumulus clouds have started to form, it's usually easy to see by just looking up. But when planning one's day in the morning, there often aren't big enough clouds yet.
Can anyone direct me to an easy-to-use source for this?