Thunder Storms with no Thunder

We are currently staying at the Yonok foundation in Lampang Thailand for our orientation. Our day generally consists of waking up having breakfast, taking a break, learning Thai, taking a break, learning cultural ques and sorts, lunch (for an hour), more language with a break, and then ending around 4. We then have free time to explore the campus univeristy we are on or go into the city of Lampang. Today our evening excursion to the outdoor market started with a "mini bus" ride into town. Within 10 min of walking into the outdoor market I already bought a pair of orange sunglasses for 50 baht (just under $2.00). Pim found us searching for more goodies in the first isle. By the time we got to the third isle stands were frantically packing up. At first I just thought that for some reason that vendor had dome something illegal and some sort of regulating police was coming, then I realized everyone was doing the same thing (maybe 40 min had passed since the market opened) and Allison told me to look up. Behind us dark clouds were moving in and within walking to the end of the isle the sky was dark. There was no rain at first, but you would tell it was coming. We waited for the rest of the group, Pim and the mini bus while everything was quickly packed up. The regular shoppers hopped on their motorbikes as fast as they could into the busy street making it impossible to cross (luckily our minibus driver was coming to us so we didn't have to cross). The wind was blowing and dust was everywhewre and then the rain came with lightning that lit the whole sky, but no thunder that we could hear. And that was our first experience with the rain in Lampang. Our night ended early and we headed back to the university.