Updrafts/Downdrafts rising and sinking air The atmosphere can be unstable for updrafts but stable for downdrafts, stable for updrafts but unstable for downdrafts, stable for both, or unstable for both.
Updraft - A small-scale current of rising air. If the air is sufficiently moist, then the moisture condenses to become a cumulus cloud or an individual tower of a towering cumulus or Cb.
Updraft Base - Alternate term for a rain-free base.
Updrafts and downdrafts are some of the main causes of in-flight turbulence in planes, and are one reason airlines try to avoid regions of bad weather. Extreme cases, known as downbursts and microbursts are responsible for many airplane crashes.
Updraft - Warm moist air which rises and condenses into a visible cumulus or cumulonimbus cloud. Once the cloud forms, it depends on the updraft for continuance and further development.
Updraft - a relatively small-scale current of air with marked upward motion
Upslope Flow - air that flows toward higher terrain and, hence, is forced to rise ...
Updraft Base Alternate term for a rain-free base.
Upper-Level Disturbance A disturbance in the upper atmospheric flow pattern which is usually associated with clouds and precipitation.
UPDRAFT
A small scale current of air with vertical motion. If there is enough moisture, then it may condense, forming a cumulus cloud, the first step towards thunderstorm development.
Updraft: A current of air that has a marked upward vertical motion. Updrafts keep cloud particles suspended in the air.
updraft—A localized upward current of air.
upper front—A front aloft not extending to the earth's surface.
Tilted Updraft
A thunderstorm updraft which is not purely vertical but instead exhibits a slanted or tilted character. It is a sign of vertical wind shear, a favorable condition for severe storm development.
Tipping-Bucket Rain Gage ...
Updraft- An upward current of air, usually within a thundercloud.
Veering Winds- Winds that shift in a clockwise direction, a shift caused by a high-pressure system.
Visibility- The greatest distance at which one can see and identify objects.
UPDRAFT - Rising air in the atmosphere. Thunderstorms can have very fast updrafts.
UPGRADE - A promotion in status of a storm system, usually a tropical system. Example, the tropical storm was UPGRADED to a hurricane.
(or tilted updraft) A thunderstorm or cloud tower which is not purely vertical but instead exhibits a slanted or tilted character. It is a sign of vertical wind shear, a favourable condition for severe storm development.
Tornado ...
The prevailing updraft which initiated the cloud's growth is now replaced by the downdraft.
Barber poleA thunderstorm updraft with a visual appearance including cloud striations that are curved in a manner similar to the stripes of a barber pole.
It typically marks the location of the thunderstorm updraft. Tornadoes may develop from wall clouds attached to the rain-free base, ...
Compare with beaver tail, which is a form of inflow band that normally attaches to the storm's main updraft (not to the wall cloud) and has a base at about the same level as the updraft base (not the wall cloud).
Lee WaveThe wavelike effect, characterized by severe updrafts and downdrafts, that occurs in the lee of a mountain range when rapidly flowing air is lifted up the steep front of a mountain range. Compare mountain wave.
Forming in the area of a thunderstorm updraft, or inflow area, it exhibits rapid upward movement and cyclonic rotation. It usually develops before strong or violent tornadoes. WARM To have or give out heat to a moderate or adequate degree.
The WER is a sign of a strong updraft on the inflow side of a storm, within which precipitation is held aloft. When the area of low reflectivity extends upward into, and is surrounded by, the higher reflectivity aloft, it becomes a BWER.
This feature is associated with a strong updraft and is almost always found in the inflow region of a thunderstorm. It cannot be seen visually.BOVCBase of OvercastBow EchoA radar echo which is linear but bent outward in a bow shape.
The first type is known as a single cell storm usually composed of a convective cloud containing one updraft and one downdraft segment.
It is usually located south or southwest of the visible precipitation area, and marks the strongest updraft in the thunderstorm. The wall cloud develops as the strong updraft draws in surface moisture from several miles away.
supercell"An often dangerous convective storm that consists primarily of a single, quasi-steady rotating updraft, ...
A strong convective updraft is a distinguishing feature of this storm in its early phases. A strong downdraft in a column of precipitation marks its dissipating stages.
*Supercell - A thunderstorm with a persistent rotating updraft. Supercells are rare, but are responsible for a remarkably high percentage of severe weather events - especially tornadoes, extremely large hail and damaging straight-line winds.
Higher values are favorable for a rotating updraft (greater than 400).
Bounded Weak Echo Region (BWER) A radar feature that identifies where the strongest updraft is located in a supercell thunderstorm.
CAPE is directly related to the maximum potential vertical speed within an updraft; thus, higher values indicate greater potential for severe weather.
Raindrops, and even hailstones, can be supported by updrafts of a velocity greater than the terminal velocity, which is not very difficult for the smaller drops. This plays a role in the complex phenomena of the cumulonimbus.
Violent updrafts and at or below freezing temperatures throughout the atmosphere, from surface to high aloft, discourage the melting of snow and ice into rain. Intense snowfall rates often occur during these situations.
Supercell - A severe thunderstorm whose updrafts and downdrafts are in near balance for several hours. Supercells often produce large hail and tornadoes.
Temperature - The measurement of how hot or cold something is.
Supercell - A severe thunderstorm whose updrafts and downdrafts are in near balance allowing the storm to maintain itself for several hours. Supercells often produce large hail and tornados.
Cumuliform clouds Clouds that exhibit significant vertical development; often produced by updrafts in convection currents.
Cumulonimbus clouds (Cb) Thunderstorm clouds that form as a consequence of deep convection in the atmosphere.
Supercell storm An enormous severe thunderstorm whose updrafts and downdrafts are nearly in balance, allowing it to maintain itself for several hours. It can produce large hail and tornadoes.
CAPE - Convective Available Potential Energy. The amount of energy that is used by thunderstorms to create the updraft; similarly positive buoyant energy (PBE).
Cumulus Stage - The initial stage in thunderstorm develop- ment in which the growing cumulonimbus is dominated by strong updrafts.
Cup Anemometer - See Anemometer.
hail: precipitation composed of chunks of ice that form atop cumulonimbus clouds and fall as soon as they become too heavy for the cloud updrafts to hold.
Acronym for Bounded Weak Echo Region. Refers to radar echo signatures with low reflectivity in the center, surrounded by higher reflectivity. It is associated with strong updrafts and is found in the inflow region of a thunderstorm.
Hail- precipitation in the form of balls of ice produced by liquid precipitation, freezing and being coated by layers of ice as it is lifted and cooled in strong updrafts of thunderstorms.
Violent updrafts in the cloud carry the particles in freezing air, allowing the frozen core to accumulate more ice. When the piece of hail becomes too heavy to be carried by upsurging air currents it falls to the ground.
Updraft A relatively small-scale, upward moving current of air. Upper air That portion of the atmosphere which is above the lower troposphere. Generally applied to levels above 850 mb.
updrafts), convection is sometimes used to imply only upward vertical motion. convective adjustment A numerical procedure applied in many atmospheric models to approximate the vertical nonradiative heat transport.
 See also: Storm, Cloud, Thunderstorm, Thunder, Air
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