Introduction
The purpose of these pages is to allow those new and unfamiliar to the
composite reflectivity imagery and the storm attribute table learn how
to use it
effectively. It has been put together using credible web
sites on radar interpretation throughout the Internet.
Remember that all
information retrieved from radar algorithms should be used as
a guide, as it is not the exact truth. The link between a
weather radar
and a thunderstorm is full of obstacles. This opens a margin of error.
Nonetheless, output from a radar should not be taken lightly either.
The several strengths and weaknesses of using composite
reflectivity imagery and the storm attribute table follow.
Strengths
- Composite
reflectivity is able to determine the highest value per
attribute in storms. This saves time since the radar operator does not
have to go filing through radar images.
- Compared
with the base radar products, the structure of a thunderstorm
may be able to be determined.
- A
list of storm attributes is available for a quick reference to a
cell's data. The potential that a storm cell is severe can also be
inferred. This information is available for any thunderstorm cell
identified and marked by the radar.
Weaknesses
- Low-level
base reflectivity signatures are hidden by the upper layers
of reflectivity. This makes it difficult to see hooks, which
are better
seen on the lower tilts of base reflectivity sweeps.
- The
vertical height of the reflectivity is unknown directly. Some
information may be able to be obtained regarding dBZ and height from
the storm attribute table however.
- An
echo aloft in the atmosphere is hard to differentiate from actual
precipitation reaching the surface. Anvil clouds on
thunderstorms are
notorious for creating a fake area of precipitation on radar.
- Anomalous
propagation and ground clutter can fog the product. Instead
of just precipitation, weather radar also detects smoke, migrating
areas of birds, sunrises and sunsets (seen as a narrow spike extending
outward from the site of the radar), and some airplanes, among other
unexplainable things.
Please
submit any questions or comments to Jordan
Gerth, development at wiscwx dot com.
CLOSE
WINDOW
Jordan Gerth,
May 2007