A few clouds in the afternoon have a very slight chance of producing thunderstorms on Saturday, but it is much more likely any storms will be limited to areas to our east. A weak low pressure system will move onshore Saturday, moving the focus of any storms to our east, and completely out of the area by Sunday. Temperatures will slowly drop, hitting the mid-90s on Saturday, and bottoming out to the upper-80s by the middle of next week. So if you are looking for fireworks this weekend, you will have to be satisfied with the man-made variety. But don’t light them off yourself…they are illegal in most areas of the state.

I got the following question from a late-night listener: “Here’s something that has always puzzled me. How come I can hear so many more radio stations at night than I can during the day time? Are there just a lot more on the air then, or do they turn up their power, or is there some other explanation?”

No, no, and yes to your questions, in that order.  There aren’t more stations on late at night. In fact, many sign off during the late hours. As for power, there are many radio stations that are required to turn DOWN their power after hours, because they will interfere with other stations far away on the same frequency at night, whereas during the day the signal won’t go as far. So there must be some other explanation.

Actually, you can blame the sun and the ionosphere. The ionosphere is that portion of the atmosphere above the stratosphere (about 50 to 600 miles above the earth’s surface) that contains a high concentration of ions. The sun I think you already know about.

Radio waves can only travel in a straight line, and because the earth is curved, most stations can only be heard about 60 miles away because the earth gradually curves under and away from those signals. But the ionosphere can act as a backboard, bouncing the signal back down the earth at a much farther distance, hundreds or even thousands of miles away. I once picked up a station in Minnesota while driving in Seattle.

But this bouncing will only work effectively after the sun goes down. That’s because radiation coming from the sun interacts in the ionosphere to create (surprise!) ions. These ions have the nasty habit of eating radio waves, instead of allowing them to be reflected. Thus, while the sun shines, the ionosphere dines, and we don’t get to pick up Rush live from New York. We need a satellite for that.