TABLE 3.1. Needs Summary Table – Weather Surveillance. Source: OFCM, 2006.


Current Capability

Future Need

Derived weather phenomena

Instantaneous rain rate, snow, hail, icing, turbulence, winds, microbursts, wind shear, tornado vortex signature

All of current plus clouds (base and tops), aerosols (concentration and size distribution), and lightning.

Vertical Coverage

From 1 km to 70,000 ft.a

From surface to 70,000 ft.

Horizontal Coverage

US states and territories, and surrounding water/bordersb

Same as current

Range Resolution

250 m (for Doppler moments); 1 km for reflectivity moments

Less than 100 m


From −20 to 5 dBZ

At least as sensitive as current

Scanning Mode

Clear air and severe weather volume coverage patterns; constantly increasing elevations for one complete volume scan

Optimize scanning to better cover the lowest 3 km, using negative angles if necessary


96% (WSR-88D)

At least as reliable as current capability

Data Latency

Less than 4 minutes (data latency is determined by fact that entire WSR-88D volume scan must be completed before data becomes available)

Less than 10 seconds

Update Rate

4–6 minutes for a full volume scan (reflectivity versus clear air)

1 minute or less

Dual Polarization

Planned for deployment on WSR-88D

Should be included in any new system

Radars Networked?



a More than 70 percent of the lowest 1km of atmosphere is unsampled by WSR-88D.

b DOD requires tactical radars for global deployment.

c WSR-88D reflectivity products are mosaicked; future need is for radar data from multiple sources that can be automatically fused into single operational pictures in near-real time

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