Nexrad Limitations; Radar Intensity - Garmin Pilot User Manual

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NEXRAD Limitations

Certain limitations exist regarding the NEXRAD radar displays. Some, but not all, are
listed for the user's awareness:
• NEXRAD base reflectivity does not provide sufficient information to determine
cloud layers or precipitation characteristics (hail vs. rain). For example, it is not
possible to distinguish between wet snow, wet hail, and rain.
• Radar base reflectivity is sampled at the minimum antenna elevation angle. An
individual radar site cannot depict high altitude storms at close ranges, and has
no information about storms directly over the site.
• Radar coverage in Canada is only available in the southern 1/4 of the country.
NeXrad i
Colors are used to identify the different NEXRAD echo intensities (reflectivity)
measured in dBZ (decibels of Z). "Reflectivity" (designated by the letter Z) is the
amount of transmitted power returned to the radar receiver. The dBZ values increase
as returned signal strength increases. Precipitation intensity is displayed using colors
corresponding to the dBZ values.
WINDS ALOFT
Winds Aloft data shows the forecasted wind speed and direction at the surface
and at selected altitudes. Altitudes can be displayed in 3,000-foot increments up to
39,000 feet MSL.
Winds Aloft are displayed using wind barbs. The wind barbs indicate wind speed
and direction and always point in the direction that the wind is coming from. The wind
speed is depicted using flags at the end of the wind barb. A short wind flag is 5 knots,
a long wind flag is 10 knots, and a filled triangle is 50 knots. Wind barbs are also color
coded to indicate wind speed.
The wind barbs always point in the direction that the wind is coming from. The wind
speed is depicted using flags at the end of the wind barb. A short wind flag is 5 knots,
a long wind flag is 10 knots, and a triangle flag is 50 knots.
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NTeNsiTy

Radar Intensity

Garmin Pilot for iOS User's Guide 190-01501-00 Rev. C