National Weather Service forecasters will forecast:
- "Isolated thunderstorms" when we are pretty certain that storms are going to form, but we only expect them to affect about 10% of the area. In other words, 90% of the area won't get wet.
- "Widely scattered thunderstorms", it means 20% of the area will be affected.
- "Scattered thunderstorms" means 30-50% of the area will be affected.
- "Thunderstorms likely" means 60-70% of the area will be affected.
- "Thunderstorms", we expect that 80-100% of the area will see rain.
Problems arise, however, when that isolated thunderstorm happens to develop over the most populated city in the area. When that happens, most of the people get wet, even though only a small area received rain.