Meridional flow - Meridional flow is a term that describes the direction of the upper level wind flow with respect to the Earth. When the upper level winds oscillate from north to south often, a meridional flow pattern is present. The opposite of meridional flow is zonal flow. In zonal flow, the upper level winds move in a more west to east fashion.

Gust front - The leading edge of gusty winds flowing out of a thunderstorm. Gust fronts form when rain-cooled air masses accelerate downward and out ahead of a thunderstorm. When a gust front passes through, temperatures fall as winds increase.

Funnel Cloud - A funnel-shaped cloud, composed of condensed water droplets, that rotates as it extends down from the base of a cumulonimbus cloud. When a funnel cloud reaches the ground, it becomes a tornado. At the point it becomes a tornado, a debris cloud or dust whirl will be visible at the base.

Rawinsonde - An instrument attached to a weather balloon that measures atmospheric pressure, temperature, humidity, and wind speed/direction at different layers of the atmosphere. As the instrument rises through the atmosphere, the data is sent via radio waves to a receiver on the ground. Rawinsondes are launched all over the world at specified times. The data from these launches is used in initializing the numerous forecast models.

Anomalies - Departures of temperature, precipitation, or other weather elements from long-term averages. Any abnormal trend in the weather can be called an anomaly.

Anticyclone - Another word for a high pressure system. Anticyclones occur when air piles up aloft due to convergent upper level wind flow. This raises the pressure readings at the surface, thereby creating a surface high pressure system.

Cumulus - Puffy white clouds that typically have flat bases and have a limited amount of vertical growth. If they start to grow vertically they can morph into cumulonimbus clouds, at which point they can spawn a thunderstorm.