Hail-Spike - A radar signature that can occur when severe hail is present in a thunderstorm. The signature is seen as a narrow line of weak reflectivity beyond the thunderstorm. Its occurrence is due to the way the radar pulse is scattered in many directions when it reaches large hailstones. This phenomenon is also referred to as the three-body scatter spike.

Crepuscular Rays - The meteorological term used to describe rays of sunshine that poke through holes in the cloud cover. They oftentimes have a celestial quality to them.

Sundog - A colored luminous spot produced by refraction of light through ice crystals. Sun dogs are seen as bright spots that appear on either side of the sun. This optical phenomenon is also referred to as parhelion. They are most commonly seen during the winter season.

Evaporation - The process by which water changes phase from a liquid to a vapor. Energy from the sun and wind are the main drivers of evaporation. 80% of evaporation occurs over the oceans, while the remaining 20% occurs over land. The highest evaporation rates occur when the relative humidity is low on a hot and windy day.

Isotach - A line of equal wind speed on a weather map. The most common use for isotachs is finding the location of upper level jet streams and jet streaks. For example, the polar jet stream in the northern hemisphere is located by analysing isotachs at around 30,000 ft. Isotachs in the polar jet stream can indicate winds speeds of over 200 mph at times.

Rainbow - An arc of concentric colored bands formed by refraction that occurs when sunlight passes through raindrops. Anytime you see it raining while the sun is out, there will almost always be a rainbow. Just position yourself with your back to where the sun is shining and you will find it.

Land Breeze - A land breeze is an off shore wind, meaning the wind blows from the land out to sea. It occurs at night when the land becomes sufficiently colder than the air over the water. Land breezes are most likely to occur on clear, calm nights. The opposite of a land breeze is a sea breeze.