Deep-layer mean wind
Average wind over a deep layer of the atmosphere, giving a representative steering wind.
Usually only the mean wind is forecast, unless the gusts are expected to be a significant feature.
where α is the mean wind direction, and each point of the compass is replaced by the number of observations of wind from that direction. Compare resultant wind, wind rose, prevailing wind direction.
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The model assumes that a pollutant plume is carried downwind from its emission source by a mean wind and that concentrations in the plume can be approximated by assuming that the highest concentrations occur on the horizontal and vertical midlines ...
In Australia, it is described as a sudden increase of the mean wind speed which lasts for several minutes at least before the mean wind returns to near its previous value.StabilityAn indication of how easily a parcel of air is lifted.
Mountainadoes, when carried by the mean wind, can produce strong horizontal shears and wind gusts that are much more damaging than the general prevailing wind speeds.
Eddy velocity Difference between the instantaneous wind velocity at a point and the mean wind velocity taken over a given time interval. Also called fluctuation velocity.
At mid to high latitudes in the upper part of the troposphere (above roughly 5 km ), the mean wind flow exhibits a broadly west-to-east motion - this applies in both hemispheres.
Overturning, quasi-two-dimensional circulations parallel to mean wind in the layer they occupy in which individual particles move downwind in a helical motion.
Dispersion can be the result of molecular diffusion, turbulent mixing, and mean wind shear. The displacement or advection of polluted air by the mean wind is usually called transport rather than dispersion.
Supercells usually move to the right of the mean wind. These are called "right movers" and they are favored with veering winds. Occasionally, these thunderstorms will move to the left of the mean wind. These thunderstorms are called "left movers".
The mean wind velocity and its standard deviation are useful statistics with considerable meaning. The range of velocities is another statistic, or the interquartile range of velocities.
It was more precisely defined as the ratio of the range in wind gusts (maximum minus minimum) divided by the mean wind speed.
This thermal wind is equivalent to the mean wind between the layer it represents i.e., the 1000-500 mb thermal wind represents the mean wind between 1000 and 500 mb, and it "flows" between contours of 1000-500 mb thickness.
Derecho characterized by a short curved squall line oriented nearly perpendicular to the mean wind direction with a bulge in the general direction of the mean flow. Downburst activity occurs along the bulging portion of the line.
Progressive Derecho: They are characterized by a short curved squall line oriented nearly perpendicular to the mean wind direction with a bulge in the general direction of the mean flow.
MRF-Based 8-day Guidance - Based on the MRF model output statistics the Guidance gives a temperature forecast (max and min) with actual values (e.g. high of 50 low of 40) for the next 7 days plus probability of precipitation, and mean wind speed ...
thunderstorms in the warm air in front of a squall line, although they can sometimes be embedded in a squall line. Because they can last for hours, they are known as quasi-steady-state storms. As they usually track to the right of the mean wind, ...
STORM MOTION VECTOR - Speed and direction of storm motion, due to environmental mean winds. Also may be called STORM MEAN VECTOR.
 See also: Wind, Air, Temperature, Surface, Water
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