| ← Back to Weather Content | Return to Index | Forward to Weather Articles → |
Weather Terms
| Terms below are my own definitions based on experience or knowledge gained over the years. |
| Lightning A discharge of static electricity that can move through the air and heat it to 5 times hotter than the sun. |
| Tornado A violently rotating column of air connected from the base of a thunderstorm to the ground, see also Enhanced Fujita Scale |
| Funnel Cloud A rotating column of air connected from the base of a thunderstorm, but hasn't reached the ground |
| Fujita Scale The original scale used until around 2007 that measured a tornado's strength from F0 to F5 by its winds. |
| Enhanced Fujita
Scale The later scale used since 2007 that measured a tornado's strength from EF-0 to EF-5 by the damage it leaves behind. |
| Hail Chunks of ice that fall from a strong or severe thunderstorm made of frozen water droplets clumped together, generally happens in the spring and summer months |
| Groupel Softer hail formed when temperatures are around 40 degrees |
| Thunderstorm An often small or brief weather disturbance that produces rain, thunder and lightning. |
| Thundersnow Thunder (and sometimes lightning) during an often-potent winter storm, tends to have more potent lightning and thunder as a result |
| Nor'easter Area of low pressure with a cold core that moves up the Northeast coast, delivering rain and/or snow and winds from the Northeast. |
| Clipper Fast-moving low pressure system that originates from Canada and moves southeast, can bring rain, snow or severe weather |
| Colorado Low Fast-moving low pressure system that originates from Colorado, east of the Rocky Mountains moving generally east |
| Atmospheric River Steady stream of rain and thunderstorms, often originating from Hawaii (Pineapple Express), generally moves into California |
| Saffir Simpson Scale The scale used to measure a Hurricane's strength from Category 1 to Category 5 |
| Hurricane Vast area of swirling thunderstorms that forms over warm water, has sustained winds of at least 74 mph, right-front quadrant usually has worst activity, can produce tornadoes as it makes landfall and heavy rain, called Typhoons in the Eastern Pacific and Cyclones in the Southern Hemisphere |
| Landfall Point when a hurricane's eye fully comes onshore. |
| Eye The calm center of a Tropical Storm or Hurricane |
| Eye Wall The eye's outer edge in a Tropical Storm or Hurricane |
| Tropical Cyclone Generic term used to describe a warm core, closed circulation of thunderstorms in the ocean, applies to hurricanes, tropical storms and tropical depressions |
| Post-Tropical Cyclone A tropical system that loses the tropical characteristics, generally weakens after making landfall, but can also be from merging with another storm system |
| Extra-Tropical A tropical cyclone that transitions to the change in air masses |
| Sub-Tropical A tropical cyclone with tropical and extra-tropical characteristics |
| Tropical Storm Swirling complex of thunderstorms in the ocean with sustained winds of at least 39 mph, may have an eye, grows from Tropical Depression, given a name, can produce tornadoes and heavy rain |
| Tropical Depression Unnamed swirling complex of thunderstorms in the ocean |
| Main Development
Region Area where tropical systems are likely to develop |
| Wind An invisible stream of air often generated by high and low pressure. |
| Wind Gust Short burst of wind |
| Wind Shear Winds changing speed or direction with height in the atmosphere, great for tornado development, bad for hurricanes |
| Santa Ana Hot, dry and fast-moving winds moving down a mountain, often in California during their dry season, can lead to wildfires, called Diablo or Chinook Winds elsewhere |
| Bomb Cyclone A cold core weather system that drops at least 24 millibars in 24 hours |
| Flood Rising water from a water source, either due to rainfall or a blockage. |
| Rain Water droplets falling from the sky due to a cold front |
| Showers Water droplets falling from the sky due to a cumulous cloud |
| Drizzle Very light rain, almost non-existant |
| Virga Precipitation that falls but doesn't reach the ground, often due to dry air |
| Freezing Rain Supercooled rain drops that reach a layer of air at or below 32 degress that freezes on contact with cold surfaces |
| Fog Clouds at or near the ground as a result of a temperature inversion (cold air near the surface and warm air above) |
| Freezing Fog Clouds at or near the ground with temperatures at or below freezing |
| Super Fog Fog mixed with wildfire smoke, reducing visability to just a few feet |
| Avalanche Snow cascading down a mountain due to a weakness in the mountain's snow layer. |
| Blizzard Blowing or falling snow that reduces visability to 3/4 of a mile or less for 3 hours or more with winds at or above 35 mph. |
| Snow Ice crystals that bond together high in the clouds and fall to the ground. |
| Ice Storm A weather event where freezing rain accumulation reaches at least 0.5" |
| Drought Little-to-no rainfall, typically in areas that are more known for getting rain. |
| Monsoon Yearly change in an area's weather, can be wet or dry, common in the desert Southwest |
| Volcano An often tall, cone-shaped mountain with a hole at its peak that can shot ash, molten rock and lava into the air and/or downhill. Can greatly affect weather patterns and global temperatures |
| Cumulus Clouds Clouds resembling cotton wool and often dubbed "fair weather" clouds |
| Cumulonimbus Clouds Thunderstorm clouds that tower high into the sky, often pointed at one end at the top |
| Pyro Cumulus Clouds Clouds made from intense wildfires, often produces Fire Whirls or Firenados |
| Cirrus Clouds Wispy clouds made from ice crystals and are often higher up than other clouds. |
| Altocumulus Clouds Similar to Cumulus clouds, except smaller and more abundant. |
| Supercell The most dangerous of all thunderstorms, can produce tornadoes if the conditions are right, can be HP (high precipitation) or LP (low precipitation) |
| Squall Line A line of severe thunderstorms that often bring strong wind, heavy rain and sometimes quick spin-up tornadoes in its "kinks" |
| Mesocyclone A part of a supercell that allows the storm to rotate |
| Anvil The very top of a thunderstorm where the cloud is pointed in one direction |
| Scud Pieces of cloud often drawn up into a storm that indicates strengthening |
| Mesoscale Convective
System (MCS) Complex of thunderstorms in different stages of their life cycle moving in one direction |
| Multivortex Tornado Tornado with several smaller "satellite" tornadoes moving around it that are often erratic. |
| Dust Devil Swirling winds that form from the ground up, often on clear hot, dry days |
| Steam Devil Swirling winds that form from the ground up, often on cold days with water warmer than the air |
| Fire Whirl/Firenado Swirling winds that form from the ground up during dry days involving wildfires |
| Dryline A weather boundary separating warm, moist air from warm, dry air, typically forms between a warm front and a cold front |
| Cold Front A weather boundary that cools the air behind it, and sometimes ahead of it with thunderstorms, often depicted blue with spikes |
| Warm Front A weather boundary that warms the air below it, often accompanied by a cold front and depicted red with bumps |
| Occluded Front A weather boundary that forms as a mixture of a warm and cold front, often making the weather system more potent, typically depicted purple |
| Warm Sector The area between a warm and cold front where severe weather is most likely |
| Barametric Pressure A measurement of air pressure, with low pressure indicating some sort of storm. |
| Dew Point Literally the temp needed to get dew to form, also a measurement of moisture in the air, higher dew point increases humidity |
| Feels Like The temperature your body feels it is, can be higher or lower than air temperature, sometimes called "Wind Chill" or "Heat Index" |
| Watch Weather bulletin for favorable weather conditions for the watch's category (tornadoes for a Tornado Watch, etc), often issued hours in advance and lasts for several hours |
| Warning Weather bulletin for a weather event happening or about to happen for those it involves, often issued 30 minutes in advance, usually lasts 30 minutes, can be longer if the conditions persist |
| National Weather
Service The part of the Weather Bureau responsible for issuing warnings for storms. |
| Storm Prediction
Center The part of the Weather Bureau responsible for issuing predictions in advance of possible severe weather. |
| Weather Prediction
Center The part of the Weather Bureau responsible for precipitation in weather events |
| Tornado Alley An area in the Midwest where tornadoes are most common during the Spring and Summer months (generally in Illinois, Indiana, Kansas, Texas and Oklahoma) |
| Dixie Alley An area in the Southern US where tornadoes are most common during the fall and winter (generally in Alabama, Mississippi and Georgia) |