3-17.
Which of the following procedures
is NOT used in discounting regional
forecasting of air-mass
thunderstorms?
1.
Dewpoint depressions of 13°C or
more at any level within the
850- to 700-hPa stratum
2.
Dry air advection in the lower
levels
3.
Freezing levels below 12,000 ft
in an unstable cyclonic flow
producing only light showers
4.
Dewpoint depressions of 15°C or
greater at the 700- to 600-hPa
levels
3-18.
Stability indexes are most valuable
in forecasting thunderstorms or
showers in which of the following
situations?
1.
When used to forecast
thunderstorm or shower activity
for individual locations
2.
When plotted and analyzed on
stability index charts for
large areas, and evaluated in
light of other synoptic
considerations
3.
When plotted and analyzed on
stability index charts and when
used alone as indicators of
probable thunderstorm activity
4.
When plotted for several
locations,
and conclusions of
possible thunderstorm or shower
activity are arrived at for
each location in light of
surrounding locations
3-19.
When Showalter Index computations
reveal an index of -4°C, what
should be indicated for
thunderstorm activity?
1.
Light thunderstorms
2.
Moderate thunderstorms
3.
Severe thunderstorms
4.
No thunderstorm activity
3-20.
The occurrence of a tornado is
possible if a Showalter Index of
1.
greater than 3°C is computed
2.
less than -2°C is computed
3.
greater than 6°C is computed
4.
less than -6°C is computed
3-21.
Which of the following statements
regarding the movement of
thunderstorms relative to upper-
level wind direction and speed is
valid?
1.
Upper-level wind direction and
speed can be used as a guide in
forecasting thunderstorm
movement,
but without a great
deal of confidence
2.
Upper-level wind direction and
speed can be used with
considerable confidence in
forecasting the direction of,
but not the speed of movement
of thunderstorms
3.
Upper-level wind direction and
speed can be used with
confidence in forecasting the
speed of movement, but not the
direction of thunderstorms
4.
The 700-hPa level winds can be
used with a considerable degree
of accuracy in forecasting both
the speed and direction of
movement of thunderstorms
3-22.
Within the 10,000- to 20,000-ft
stratum, most hail is encountered
outside the thunderstorm.
1.
True
2.
False
3-23.
Which of the following phrases
defines the Equilibrium level (EL)
as used in the Yes-No hail
forecasting technique?
1.
The top of a negative area in a
sounding where the saturation
adiabat traced from the CCL
intersects the temperature
curve
2.
The top of the lowest positive
area at the intersection of the
dry adiabat
3.
The top of a positive area in a
sounding where the saturation
adiabat traced from the CCL
intersects the temperature
curve
4.
The area between the first
positive and negative energy
areas
3-24.
When preparing hail size forecasts
by using the Skew T log P diagram,
you should trace the moist adiabat
upward from the CCL to what dry-
bulb temperature level?
1.
0°F
2.
0°c
3.
-5°F
4.
-5°C
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