Be ready for weather whiplash.  In western Washington over the next week, we will go from a minor heatwave to much cooler conditions and some light rain.  East of the Cascades, temperatures over 100F today will transition to a regime of scattered thunderstorms associated with a plume of moisture from the southwest.   In the second segment, I will tell you about the basics of regional thunderstorms and why we are so thunderstorm deficient in our region.