Assignment 7. Convective Storm Matrix. Due March 25. 20 points
Questions
1. Construct the following diagrams using copies of the forms available in the Convective Storm Matrix module: (question1a_us.pdf, question1a_brn.pdf, question1b.pdf, and question1c.pdf ). Use the worksheet (matrixws.pdf) to record observations.
(A) A shear/buoyancy diagram that describes whether each simulation is best characterized by ordinary cells, multiple cell systems, or supercells. For shear parameters, you may use the length of the hodograph (Us) or the BRN shear. For buoyancy, you may use CAPE or LI. For the purpose of this diagram, we will define "Ordinary Cell" simulations as those for which the initial cell grows and decays without significant new cell redevelopment, "Multiple Cell System" simulations as those for which there is significant redevelopment of ordinary cells throughout the simulation, but without supercell structures present, and "Supercell" simulations as those which include supercell structures, and may or may not also include other ordinary cells.
(B) A storm type versus BRN diagram, noting the range of BRN values associated with primarily ordinary cells, multiple cell systems, and supercells, as defined in A above.
(C) A shear/buoyancy diagram that indicates which simulations produce the strongest low-level mesocyclones (as determined from 0.4 km view of the matrix). This diagram defines the environments most likely to produce supercell-type tornadoes for the present simulations.
Turn in the worksheet and 3 diagrams. Use the diagrams and/or the matrix itself to help you answer the rest of the questions. Write the answers in your own words- don't just parrot the "expert answers".
2. Describe and briefly explain the storm type versus shear and buoyancy relationships revealed by your shear/buoyancy diagram.
3. Examining the matrix views, describe the influence of variations to the buoyancy (stability) profiles on overall storm structure and evolution?
4. For a given hodograph and magnitude of vertical wind shear, what is the role of dry mid-level air on storm evolution?
5. What is the role of shear depth in controlling resulting storm structure?
6. What is the role of hodograph curvature in controlling resulting storm structure and evolution for strongly-sheared environments?
7. What values of BRN are most likely to be associated with supercell storms? Are there cases with BRNs well within the supercell range for which supercells do not occur? Explain why.
8. Can you find other significant storm structures as you further explore the matrix? Look for shallow (mini) supercells, HP supercells, and storm systems conducive to producing straight-line winds, such as bow echoes. Note which simulations display these structures.