Vaisala IRIS - Figure 67 Typical Shear Line Example

Post-Frontal Wind
Pre-Frontal Wind
Figure 67 Typical Shear Line Example
The SLINE product can detect sudden wind shifts and provide advance warning of their
approach, with best estimates of the arrival time and the expected speed and direction of
the new wind.
1. Select Type > SLINE.
2. To load an existing product, select File > Open
3. In Data:Display, select V Shear.
4. In EL Angle, define the elevation angle of data you want to display.
Wind shears associated with gust fronts and microbursts are usually low-level
phenomena, so angles of 1° or less are typically used to detect these.
You may select 1 or 2 angles. If you select 2 angles, make sure both are above the
threshold to be included in the shear line.
5. Define Rng / Az Filter.
The first number defines the range length scale for the SHEAR product, in km. This
distance determines the size of the skip that the SHEAR product can tolerate when
dierencing over missing data. It also specifies the length of the radial smoother, which
is applied before the XY smoother.
The second number is the azimuth length scale in degrees.
The skipping and azimuth range length are analogous to the range filter.
Chapter 5 – Configuring and Scheduling Optional IRIS Products
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