What was the weatherman's issue with yesterday's weather?

The weatherman's issue with yesterday's weather is that he couldn't account for it. This suggests that the weather behaved in an unexpected manner, and the weatherman struggled to reconcile the actual weather conditions with the forecasts or models he typically relies on. When someone cannot account for something, it implies a lack of understanding or an inability to explain the circumstances surrounding it, which indicates a problem or challenge in accurately forecasting or explaining the weather.