Speaking to a full house, Jim explained the weather related propagation modes most associated with VHF/UHF. By knowing the signs, an operator might pick the best time to be on the air. The main modes of propagation for the higher bands described by Jim were Sporadic E and Tropospheric Ducting and although weather related, the two modes have different properties. Being able to differentiate means the operator could possibly know what to expect and what results might be obtainable.
Various weather situations were explained and how they impact propagation. Jim pointed out that by listening for beacon signals one might know when paths are open and in which direction. Some discussion followed about the part the Jet Stream plays in controlling the weather and how the highs affected could propagate signals for long distances.
Jim then gave a brief look at modern forecasting methods and how a certain percentage of reliability is achieved, especially for businesses that could be affected by unexpected weather extremes.