Summer thunderstorm season is underway here in the Upper Midwest, and that means that there will be lots of static crashes on the radio on the days when active weather is moving through Minnesota and surrounding states. The most affect HF bands are 160 meters, 80/75 meters, and 40 meters. When the storms are nearby, the bands will also be dominated by noisy crashes caused by lightning.
Sometimes the stations will be taken offline if severe weather is directly in their vicinity. These service outages can be expected throughout the summer, especially early summer. The stations will return to service as soon as conditions warrant.
Users who live in areas where thunderstorms are uncommon may not be familiar with how disruptive they can be to HF communications. However, these storms are a normal part of seasonal variation in the central United States and you may find that some days conditions are just not good enough on one or more HF bands.