Precipitation Display

METEOROLOGY FLIGHT PLANNING

CHAPTER TWO

Figure 2-12 Oklahoma NEXRAD Display

While older weather radar show only basic displays, the NEXRAD system can display derived

products, such as composite reflectivity. This is the type of precipitation display most commonly

used in flight planning. A wind profile screen can also be displayed.

Precipitation Display

NEXRAD presentations show precipitation levels in the area scanned by the radar system. The

NEXRAD does not measure the rate of precipitation directly; rather, it measures the energy

return from the precipitation particles. The image seen on the screen is actually a computer-

generated compilation of returned energy shown in varying colors. This display is referred to as

the reflectivity presentation.

The intensity of precipitation can be determined by using the graduated scale shown in the legend

area of the screen (Figure 2-11). The maximum radar return strength at the time of the

presentation is listed above the scale. This is measured in "dbz," or strength in decibels, of the

energy received by the radar. Through use of this scale, precipitation strength can quickly be

deciphered for a given area by comparing the color of the area to the color-coded legend. Higher

precipitation levels are farther down the color scale. During flight planning, a pilot should

carefully analyze the higher intensity areas in relation to the planned route of flight or operating

area.

DATA DISPLAYED ON WEATHER IMAGERY PRODUCTS

2-13