Exam 2 Flashcards
On average how many tornadoes occur in the US each year
1400
What percentage of the world’s tornadoes occur in the US?
75%
Within which state was the deadliest tornado in US history?
Illinois
Supercell updrafts typically appear as
Rain free cloud bases
Mammatus clouds are typically associated with
a. Large hail
b. Damaging wind
c. Tornadoes
d. None of the above
d. none
Which type of supercell typically produces the most tornadoes?
Classic supercells
What creates horizontal roll that gets suck up into the storm
Wind shear
Creation of a wall Cloud
Sometimes rotates
Lowered cloud based beneath the updraft
Air hits ground, spreading out, some rotation, that air is going underneath the updraft and get sucked up, cand create wall cloud
The Forward flank downdraft creates the wall cloud
Tornado → what kind of flank draft
rear flank downdraft
Shelf clouds –
mcs
Tornado outline
(ice skating metaphor) put hands up → spin faster
Cold air sinking and hitting ground, creating horizontal vortex along the surface
Titled and stretched
The rotation in tornadoes forms through what two processes?
Tilting and stretching
Tornadoes typically develop from
Wall clouds
Which of the following is most closely tied to tornadogenesis
Rear-flank downdraft
What is the rotating updraft with a supercell thunderstorm called?
mesocyclone
What’s the deciding ingredient on whether a thunderstorm will be severe or not?
a. Sufficient moisture
b. Evapotranspiration
c. Significant wind shear
c. Significant wind shear
Pic of cloud, like a long line, could be curvy, darkness like a spaceship about to overhead
a. Hinge cloud
b. Wall
c. Pole
d. Countertop
e. Shelf Cloud
e. Shelf Cloud
As a cloud like a shelf cloud passes overhead, what should you prepare to feel?
a. A blast of very warm humid air
b. Nothing, this cloud ill pass over you and barely kick up a breeze
c. A violent rapidly-rotating, tornado like wind will accompany this cloud and cause a lot of damage
d. A gusty burst of cooler air
d. A gusty burst of cooler air
Which of following isn’t a requirement for a thunderstorm to be considered severe?
a. Frequent cloud-to-ground lightning
b. Hail largenr than 1 inch in diameter
c. Thunderstorm winds
a. Frequent cloud-to-ground lightning
Below are the conditions on a day in May. the NWS did NOT forecast severe thunderstorms on this day. whY>?
a. The lifted index was +4
b. Wants a lifted index that’s negative
c. The dewpoint temperature was 71F
d. There was a cold front that was coming through the region
e. The winds near the surface were 10 mph while the winds in the middle atmosphere were 60 mph
a. The lifted index was +4
If all the energy from a single lightning bolt could be captured, how long could this electricity power your house?
6 hours
In which direction does the bright flash of light that you see during lightning strike travel?
From ground to the cloud
Value of the lifted index
Know that parcel line on right is negative, unstable, storms
Vice versa
The atmosphere is said to be unstable if parcel’s temp is warmer than the surrounding environmental temperature
True or false
true
A negative lifted index indicate an unstable atmosphere
True or false
true
The stratosphere is defined by a large temp inversion. Is the stratosphere a stable or unstable layer in the atmosphere
Stable
Which body of water is the primary moisture source for thunderstorms in the midwest
Pacific
Atlantic
Great lakes
Gulf of mexico
Mahomet aquifer
Gulf of mexico
Which is the cloud base?
LCL: lifting condensation level
LFC: level of free convection
EL: equilibrium level
LCL: Lifting Condensation Level
What is the top of the cloud?
LCL: lifting condensation level
LFC: level of free convection
EL: equilibrium level
Equilibrium level
What is the bubbly part of the cloud?
LCL: lifting condensation level
LFC: level of free convection
EL: equilibrium level
LFC: level of free convection
Which will be found at the highest pressure?
LCL: lifting condensation level
LFC: level of free convection
EL: equilibrium level
Lifting condensation level
Which will be found at the lowest pressure?
LCL: lifting condensation level
LFC: level of free convection
EL: equilibrium level
Equilibrium level
Thunder always occurs with lightning. You may just be too far away to hear it.
true or false
true
What is the crucial ingredient for the formation of lightning such that without this ingredient, lightning does not form in thunderstorms?
Ice
dust
large rain drops (greater than 2 mm in diameter)
counterclockwise turning winds with height.
flux capacitor
ice
In what direction does the return stroke travel in the most common type of cloud-to-ground lightning strike?
from the ground to the cloud
Between the years 2001 and 2010, who or what started more forest fires?
humans
In a cloud that is capable of producing a cloud-to-ground lightning strike, where does the negative charges accumulate in the cloud?
near the top of the cloud
near the center of the cloud
near the bottom of the cloud
on the right side of the cloud
on the left side of the cloud
near the bottom of the cloud
Is the air a good conductor or electricity or a good insulator?
insulator
Which of the following correctly lists the order of events for a cloud to ground lightning strike?
dart leader, stepped leader, return stroke, second return stroke
stepped leader, dart leader, return stroke, second return stroke
dart leader, return stroke, second return stroke, stepped leader
stepped leader, return stroke, dart leader, second return stroke
stepped leader, dart leader, return stroke, second return stroke
stepped leader, return stroke, dart leader, second return stroke
What is the formal name of the cloud that produces a thunderstorm?
cumulonimbus
Which of the following is not a requirement for the National Weather Service (NWS) to determine if a thunderstorm is severe?
frequent cloud to ground lightning
hail bigger than 1 inch in diameter.
58 mph winds
tornado
frequent cloud to ground lightning
For a thunderstorm to become severe, 4 ingredients are needed. Which ingredient listed below is NOT needed?
strong wind shear
a source of moisture
a trigger mechanism
a conditionally unstable atmosphere
warm surface air temperatures (T>72F)
warm surface air temperatures (T>72F)
What is the name of the cloud at the top of a strong thunderstorm?
anvil cloud
During which of the three stages of development of an ordinary thunderstorm does the downdraft develop?
mature stage
The downdraft of a thunderstorm can be described as a current of descending air laden with precipitation falling from the storm. Are downdrafts relatively warm or cold?
cold
On radar images depicting thunderstorms, you can often see a “radar fine line - gust front”. What type of cloud is often associated with this feature?
shelf cloud
What type of cloud is typically found on the underside of an anvil in strong thunderstorms?
mammatus cloud
Which type of thunderstorm is responsible for producing the majority of tornado reports in the US?
supercell
Which is larger, the MCS (mesoscale convective system) or the supercell?
mcs
True or False: Supercell thunderstorms always rotate.
true
What is the name assigned to the rotating updraft of a supercell thunderstorm?
mesocyclone
When a tornado takes on a rope-like appearance, at what stage in the life cycle is this tornado?
shrinking and decaying stage
Tornadoes are most frequent during the month of __________ around ____ o’clock in the __________.
may 5th, afternoon
Supercell thunderstorms always rotate.
true or false
true
The “low-level jet” is an important feature of the environment within which supercells and tornadoes form. This airstream is necessary for two primary reasons - first to help create the needed wind shear and second to transport warm moist air into the storm. From what direction does the low-level jet come from?
south
What is a mesocyclone?
the rotating updraft within a supercell thunderstorm
If a tornado were to form within a supercell, from which of the following clouds would it emerge from?
wall cloud
Select the answer where the clouds are ranked from smallest to largest.
funnel cloud, wall cloud, mesocyclone, anvil
Myth or Fact: The exact location of a lightning strike can be predicted.
myth
Myth or Fact: People struck by lightning carry an electrical charge and should not be touched.
myth
Myth of Fact: If you are caught outdoors during an electrical storm one of the safest places to be is in your car.
fact
Myth or Fact: If you feel your hair stand on end during an electrical storm, crouch down low to the ground – you could be struck by lightning.
fact
Myth or Fact: A typical lightning strike is 5 km long and 2 to 3 cm wide.
fact
