Weather Forecastings

High-pressure system (H)

A weather system where the regional pressure is higher than in surrounding areas, resulting in fair and stable weather with clear skies.

Low-pressure system (L)

An area of low atmospheric pressure characterized by inclement weather, clouds, wind, and precipitation.

Coriolis Effect

The effect of Earth's rotation on the direction of winds, causing winds in a high-pressure system to flow clockwise in the Northern Hemisphere and counterclockwise in a low-pressure system.

Isobars

Lines on a weather map that connect points of equal atmospheric pressure.

Reflectivity

A radar measurement of precipitation intensity based on the energy reflected back to the radar by precipitation particles.

Radar Velocity

A Doppler radar feature that measures the motion of targets directly toward or away from the radar antenna.

Satellite IR

Infrared satellite imagery that measures the heat energy radiated from Earth's surface to assess cloud top temperature and identify weather systems.

NWS (National Weather Service)

The agency responsible for providing weather forecasts, warnings, and advisories to the public.

Advisory

A weather notification indicating that conditions can be troublesome but are not life-threatening, requiring caution.

Watch

A weather alert issued when conditions are favorable for a hazardous event to occur, advising preparedness.

Warning

An urgent weather notification indicating that dangerous weather is currently occurring or imminent, requiring immediate action.

Heat Index

A measure that combines actual air temperature with relative humidity to represent how hot it feels to the human body.

Wind Chill

A measure that combines actual air temperature with wind speed to represent how cold it feels to the human body.

Heating Degree Days (HDD)

A measure used to quantify heating demand based on how much the average daily temperature falls below 65°F.

Cooling Degree Days (CDD)

A measure used to quantify cooling demand based on how much the average daily temperature rises above 65°F.

CAPE (Convective Available Potential Energy)

A measure of atmospheric instability that indicates the potential energy available for thunderstorms.

Inversions

Weather conditions where temperature increases with height, creating a stable layer of air that can suppress cloud formation.