Our extended sunny streak will get a brief interruption as some moisture thrown off from a dying hurricane Fabio will drift across the region, but it is unlikely it will produce any showers. It will serve to stall any more warming, with Fridays highs still just reaching the low 90s. Once that cloudiness passes through the sun will return on Saturday, and a building ridge of high pressure will send the temperatures soaring into the upper 90s over the weekend, and likely into the low 100s by the first of next week.

So why can you hear so many more radio stations at night than during the day? Actually, you can blame the sun and the ionosphere for the change at night. 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. Without anything else to help, you would be limited to those kinds of distances. Tomorrow, I’ll tell you how the ionosphere helps out.