Broken Forecast: Science Fiction

The forecast broke on a fine, sunny Sunday while Margaret was on a picnic in the park with her best friend and their children. The husbands of course, had chosen to go to a ballgame together. At first, she didn't even understand what was happening. There were strange spots appearing on top of the sandwiches, moist spots. Had she somehow gotten the mix of the bread wrong? It was only when she felt the raindrops striking her face that she understood. The unthinkable had happened. The forecast had broken. Fine sunny weather, it had promised, all through Sunday. Ideal weather for a picnic. But when she tilted her head up and pushed back her hat, the sky above them had suddenly gone far from sunny. Storm clouds had swept in out of nowhere, and the fine rain pelting them lightly--

Inspiration: checking the weather forecast for tonight
Story Potential: Low
Notes: Of itself, not that interesting.