JPATS Weather - NETC
JPATS Weather - NETC
JPATS Weather - NETC
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<strong>JPATS</strong> AVIATION WEATHER BOOKLET<br />
Figure 5-8 — NEXRAD Doppler Radar Composite<br />
A direct relationship exists among the strength of the radar echoes, the presence of aircraft icing,<br />
and the intensity of turbulence. Stronger radar echoes are associated with more severe<br />
thunderstorms.<br />
The following weather radar information is of particular interest to pilots:<br />
1. A thunderstorm with radar echo tops indicated above 35,000 feet often contains extreme<br />
turbulence and hail.<br />
2. Hazardous weather associated with scattered echoes can usually be circumnavigated.<br />
However, if the lines or areas are reported as broken or solid and are of moderate to strong<br />
intensity, hazardous weather can be avoided only if the aircraft is radar equipped.<br />
3. Severe clear air turbulence and hail may be experienced between thunderstorms if the<br />
separation between echoes is less than 30 miles.<br />
Ground-based weather radar is the most valuable to a pilot when there are numerous<br />
thunderstorms that are obscured by multiple cloud layers. However, echoes can change shape,<br />
character, and intensity in a matter of minutes when updrafts reach velocities of over 6000 feet<br />
per minute. Therefore, radar information received before takeoff may be worthless by the time<br />
thunderstorms are encountered.<br />
A pilot with airborne weather radar should remember that radar does not eliminate the hazards of<br />
the thunderstorm. It merely helps to locate the most severe conditions. Since the radarscope<br />
indicates only precipitation areas within thunderstorms, hazards can be encountered even in soft<br />
spots. Thunderstorms having frequent, vivid lightning discharges are especially dangerous.<br />
Airborne weather radar should be used as an avoidance rather than penetration tool. The pilot<br />
should take time to properly evaluate scope indications and watch for trends in order to avoid the<br />
most intense echo patterns. The pilot without airborne weather radar should make no attempt to<br />
find soft spots on the basis of any radar information that is not current up-to-the-minute.<br />
5-8 Version 3.2/Dec 08
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