The polar vortex is a large area of cold air that circulates around the Arctic.
November 24, 2025
high
definition
Meteorological concept describing a circumpolar area of cold air used in forecasts and climate discussions.
The Madden–Julian Oscillation (MJO) is an eastward-moving pulse of clouds, rainfall, winds and pressure that propagates through the tropics.
November 24, 2025
high
definition
The MJO is an intraseasonal tropical climate pattern that can modulate global weather.
Lake-effect snow commonly produces heavy snowfall in regions downwind of large lakes, such as areas adjacent to the Great Lakes.
November 24, 2025
high
process
Lake-effect snow occurs when cold air moves over relatively warmer lake waters, enhancing precipitation downwind.
Lake-effect snow is a meteorological phenomenon in which snow develops in relatively narrow bands downwind of a lake and can produce locally heavy snowfall that substantially increases totals in some areas while nearby locations receive little or no snow.
November 10, 2025
high
process
Explains how localized, intense snow bands form near lakes and cause uneven snowfall distribution.
Nor'easters can produce coastal flooding, heavy rain, strong winds, high surf, inland flash flooding, and beach erosion.
October 12, 2025
high
temporal
General hazard profile associated with nor'easter storms.
The National Weather Service issues coastal flood warnings and wind advisories to alert communities about imminent coastal flooding and hazardous winds.
October 12, 2025
high
temporal
Typical operational warnings used by the U.S. National Weather Service during coastal storm events.
Swells generated by tropical cyclones (including hurricanes) can propagate to distant coastal areas and create life-threatening surf and rip currents.
high
hazard
Coastal impacts from tropical cyclones
Heavy rainfall from tropical cyclones can cause flash flooding in affected coastal regions.
high
hazard
Flooding risk associated with tropical cyclone rainfall
A tornado must have wind speeds of at least 200 miles per hour to be classified as EF-5, which is the highest rating on the Enhanced Fujita Scale.
high
definition
Tornado intensity classification criteria
Hurricanes generate ocean swells that can reach coastlines and create life-threatening surf and rip currents.
high
process
Meteorological hazards associated with tropical cyclones affecting coastal areas.
Outer bands of hurricanes can produce heavy rainfall that increases the risk of flash flooding in impacted regions.
high
process
Hydrological impacts of tropical cyclone rainbands on vulnerable areas.
A nor'easter is a type of coastal storm in the northeastern United States that commonly brings heavy rain and strong winds.
high
descriptive
Typical impacts and characterization of nor'easter storms affecting New England.
Mount Washington is known for extreme and severe weather and is nicknamed "Home of the World's Worst Weather."
high
descriptive
Reputation and characterisation of Mount Washington's climate conditions.
Disruption of the stratospheric polar vortex is a natural process that occurs almost every winter or every few winters.
medium
process
Characterizes the typical frequency of stratospheric polar vortex disruptions.