Key for HW7

 


  1.  
    Layer ELR (degrees C / km) Stability
    4km-5km 8 degrees C / km Conditionally unstable
    3km-4km 7 degrees C / km Conditionally unstable
    2km-3km 4 degrees C / km Absolutely stable
    1km-2km -1 degrees C / km Absolutely stable
    0km-1km -5 degrees C / km Absolutely stable
  2. In the previous problem, the layers from 0-1 km and from 1-2 km would be called temperature inversions. (Actually, we would normally say that the 0-2 km layer is a temperature inversion.)
  3. ELR = 7 degrees C per km. (How did I get this? The temperature decreased 3.5 degrees C per 500m, so it's rate is 8 degrees C per kilometer.) That makes this layer CONDITIONALLY UNSTABLE.
  4. Air mass thunderstorm activity is greatest during the warm seasons of spring and summer. It is greatest in the mid- to late-afternoon. These times are preferred because they represent the times at which air near the surface is likely the warmest, and therefore the most likely to rise.
  5. Entrainment can only weaken the updraft of a thunderstorm. As cooler, drier air is entrained into our warm, moist updraft, the updraft can only become LESS warm and LESS moist, reducing its buoyancy.
  6. There are lots of possible differences you could have listed here. You need to have mentioned at least three of these:
    Tornado watch Tornado warning
    Issued by the federal Storm Prediction Center Issued by your local Weather Service office
    Last for several hours Last for less than an hour
    Issued when conditions are favorable for tornadic thunderstorms Issued when a tornado has been observed or is almost certainly forming
    Cover areas about the size of a state Cover areas about the size of a county
    Require no action on the part of the public Require taking shelter
    Very high false alarm rate Very low false alarm rate
  7. There are several answers to this question. You need to have mentioned at least three of these:
    • We have a better understanding the meteorological conditions that lead to tornadoes.
    • The public is more aware of the dangers tornadoes represent, so they take warnings more seriously.
    • We have better radar systems, so we can issue tornado warnings earlier, giving people more time to take shelter.
    • We have better spotter networks, so we can issue tornado warnings earlier, giving people more time to take shelter.
    • We have better information systems (such as the Emergency Broadcast System), so more people get the word and are able to take shelter.
    • Houses are built to better building codes, making it more likely that people will survive a tornado.
    • Rural population is much lower.
  8. There are a couple of ways that you could go with this question.  The answer that I was hoping for is the the dry adiabatic lapse rate (DALR) and the moist adiabatic lapse rate (MALR) are applied to air parcels, whereas the environmental lapse rate (ELR) is a property of the environment.  Another way to go with this would be to point out that the DALR and the MALR are constant, whereas the ELR is a property that needs to be measured.