Advection - The transfer of an atmospheric property by wind. The most common entities that meteorologists look at when diagnosing areas of advection are temperature and moisture.

Skew-T - A Thermodynamic Diagram on which temperature, dew point, and winds are plotted for the various levels in the atmosphere. Meteorologists receive the data needed to construct a skew-t diagram from weather balloon launches. Skew-t charts are a great way to diagnose how stable or unstable the atmosphere is on a given day.

Cloud Street - Clouds that are aligned in rows that are parallel to the direction of the wind. Cloud streets are oftentimes composed of cumulus clouds.

Hard Freeze - A hard freeze occurs When temperatures fall below 28 degrees for a period of four or more hours. A hard freeze kills most vegetation and marks the official end of the growing season.

Rain - Precipitation that falls to earth in liquid drops that are greater than 0.5 mm in diameter. Liquid drops that are smaller than .5 mm are categorized as drizzle. The largest raindrop that has ever been measured occurred in September of 1995 in Brazil as well as in July of 1999 in the Marshall Islands. At both these sites the raindrops were measured at a whopping 8.6 mm (.338 in) diameter!

Astronomical Twilight - Is defined to begin in the morning, and to end in the evening when the center of the Sun is geometrically 18 degrees below the horizon. Before the beginning of astronomical twilight in the morning and after the end of astronomical twilight in the evening, scattered light from the Sun is less than that from starlight and other natural sources. Before and after astronomical twilight, the sky is absolutely dark.

Blue Moon - Term used when a full moon occurs twice in the same calendar month. It happens once every 2.7 years. An alternate definition is when the moon actually has a bluish tint to it caused by smoke or dust particulates in the atmosphere.