1
Activity 3
Tracking Thunderstorm Movement through Radar
Think About It
Date
Page F88
Page
 How can you predict
how long a thunderstorm
will last?
 How do you know
when the danger of
severe weather has
passed?
2
Activity 3
Tracking Thunderstorm Movement through Radar
Investigate
Date
Pages F89-90
Page
1a. Speculate on what
you think the blotches
near the radar location
represent.
2a. Which area has
the most intense
precipitation?
2b. How many levels
of precipitation intensity
does this area have?
3
2c. How far away is
this area from the radar
station?
2d. In which direction
is the area moving?
3a. How many levels
of intensity are now
indicated in the area
of most intense
precipitation?
3b. Describe how the
precipitation intensity
changed between 3 pm
and 4 pm.
4
4a. In which general
direction did the areas
of precipitation move
between 3 pm and 4pm?
Justify your answer
4b. What was the speed
of movement of the areas
of precipitation in
kilometers per hour?
Include a description of
the method you used to
determine the speed.
4c. Where do you expect
the areas to be located at
5 pm? Explain your answer.
4d. How do you explain
the distribution and
movement of the areas
of precipitation?
5a. How do you think
that radar detects
precipitation?
5b. How do you think
radar distinguishes heavy
versus light precipitation?
5
Activity 3
Tracking Thunderstorm Movement
through Radar
Digging Deeper
Pages F90-93
Radar
Date
Page
acronym for RAdio Detection And
Ranging; it sends out and receives
back pulses of microwave energy
To track precipitation, a radar unit
sends out and receives pulses from
precipitation targets
Rain, snow, or hail in the path of
the radar beam reflects some of
that energy back to the radar
antenna
Radar echo
the energy is electronically
processed and appears as a color
coded blotched on a computer
screen
Echo strength is calibrated on a
color scale with light green
indicating light precipitation and
dark red signaling heavy
precipitation
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Ground clutter
echo on radar from tall buildings
or smokestacks reflect radar
signals
Thunderstorm cell
is several kilometers or miles
across and passes through the
cumulus, mature and dissipating
stages
Squall lines
an elongated band of thunderstorm
cells that last for several hours
7
They form in the warm humid air along
or just ahead of a well-defined cold
front
Mesoscale
convective
complex (MCC)
a nearly circular cluster of
thunderstorm cells covering an
area that may be a thousand times
that of an individual cell
Last for 12-24 hours
They are common at night during
the warm season (MarchSeptember) over the eastern twothirds of the US
8
Supercell
a single thunderstorm cell that is
much larger and longer-lasting
than an ordinary cell
They are responsible for the most
powerful tornadoes and the
largest, most destructive hail
9
Activity 3
Tracking Thunderstorm Movement through Radar
Check Your Understanding
Date
Page F93
Page
1. What man-made or
natural features could
interfere with weather
radar?
2. How would you
calculate the speed at
which a thunderstorm
cell is moving?
3. In your own words,
describe a squall line.
4. How could you
differentiate between
a supercell and an
ordinary thunderstorm
cell?
10
Activity 3
Tracking Thunderstorm Movement through Radar
Understanding and Applying
Date
Page F93
Page
1. Explain why
thunderstorm weather
may persist at a
particular place for
many hours.
2. In what way does
a supercell thunderstorm
pose a greater hazard
than an ordinary
thunderstorm cell?
3a. How does that
predicted path of the
precipitation compare
with the actual path?
3b. How did the
predicted speed of
movement compare to
the actual speed of
movement?
c. Are the thunderstorm
cells weakening over
time or becoming
stronger? Explain.
11
Activity 3
Tracking Thunderstorm Movement through Radar
Inquiring Further
Date
Page F94
Page
1. Investigating advances
in weather forecasting
Create a poster
presentation that explains
how Doppler radar differs
from the conventional
(reflection only) type of
weather radar. Consider
the following:
a. Describe in your
own words the
Doppler principle.
b. What can Doppler
radar do that
conventional radar
can’t?
c. How does Doppler
radar help forecasters
better predict severe
weather?
d. Is your community
covered by a National
Weather Service
Doppler radar?