Earthquake clouds

On Monday 31, early morning, I looked up the sky from my Bangkok home and saw small ribbed pattern of clouds facing southwest. I knew that it 's getting tremors from earthquake. That night, a lot of people in Bangkok reported of their spotting that same clouds but there was no news of an earthquake. Not until Tuesday June 1, when there was a news of a 6.7 scale earthquake in Andaman sea, southwest direction from Bangkok. We did not feel the tremor in Bangkok. Interestingly, I think the cloud is a sure warning sign of an impending earthquake. I have spotted this coincidence twice already.