METR 4350 / ESCI 5350 – Mesoscale Meteorology
Review for the Final Exam
Time and Location: Tuesday, May 9, 2017 from 2:00 – 4:30 pm in McEniry 203
Test-taking Tips:
1. Use pictures and graphs with appropriate labels to help answer questions.
2. Provide units of measurement and/or an appropriate label for each numerical answer.
3. When asked to provide an explanation, describe your reasoning using simple
meteorological language. Use complete sentences.
4. Show your work. You can earn partial credit if correct work is shown.
5. Review your homework problems.
6. Study together. What you may not understand, your classmates may.
Definition of Mesoscale
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Re-read Chapter 1 in your text.
Know the origin of the term “mesoscale”.
Know the definition of “mesoscale” that will be used in this class.
Be prepared to give 5-10 examples of meteorological phenomena that are mesoscale.
Know the three (3) primary forcing mechanism of mesoscale weather.
Be prepared to explain why mesoscale forecasting is often considered one of the greatest
challenges in meteorology.
Mesoscale Fronts
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Re-read Chapter 5 in your text.
Know the basic structural characteristics of all synoptic-mesoscale fronts.
Be prepared to discuss why fronts are important for mesoscale weather.
Be prepared to sketch and identify regions of convergence/divergence and ascent/descent
in a typical upper-level jet streak.
5. Be prepared to discuss how the location and orientation of an upper level jet streak and a
surface front can act to enhance or suppress deep convection.
6. Know the common characteristics, structure, and significance of the dryline.
7. Be prepared to describe the physical process that influence a dryline’s eastward
propagation during the day and westward propagation during the night.
8. Know the importance of drylines interacting with fronts.
9. Know what processes result in dryline bulges.
10. Know the basic structural characteristics of gust fronts.
11. Know what processes produce gust fronts.
12. Know the basic structure and evolution of sea-breeze fronts during a diurnal cycle.
13. Know the basic characteristics of coastal fronts, including the factors that influence their
formation and their mesoscale significance.
14. Know the basic characteristics of topographically-induced fronts, including the factors
associated with their formation and their mesoscale significance.
15. Be prepared to identify and locate a dryline, gust front, sea-breeze front, coastal front, or
topographically-induced front from surface maps of wind, temperature, moisture,
pressure, and/or radar reflectivity.
Deep Convective Initiation
1. Re-read Chapters 4 and 7 in your text.
2. Be prepared to briefly describe the concept of convective initiation and its importance,
particularly to mesoscale meteorology.
3. Know the five (5) sub-regions of the boundary layer in a typical diurnal cycle.
4. Be prepared to discuss and/or sketch the boundary layer evolution during a given day.
5. Be prepared to identify each of the five sub-regions from a plotted sounding.
6. Be prepared to discuss the physical processes associated with the two (2) primary
methods by which boundary layer convection (via thermals) is generated.
7. Know what horizontal convective rolls (HCRs) are, in what type of synoptic environment
they form, and how they help initiation of deep convection.
8. Know what open and closed convective cells are, and in what type of synoptic
environments they form.
9. Know several examples of non-homogeneous surfaces, and how they can influence
mesoscale convective initiation.
10. Know what atmospheric features are required for the initiation of mesoscale convection,
including what processes can often alter the atmosphere over the course of several hours,
increasing the likelihood of convective initiation.
Deep Convection: Classification
Re-read Chapter 8.1 – 8.4.2 in your text.
Be prepared to discuss the three (3) stages in the lifecycle of a single-cell storm.
Know how single cells are linked to multicell and supercell storms.
Know the defining characteristics and basic components of a typical multicell storm.
Be prepared to discuss the role of a gust front in the lifecycle of a typical multicell storm.
Know the three (3) most common types of multicell storms.
Know the defining characteristics and basic components of any supercell storm.
Know the basic differences between classic supercells, high-precipitation (HP) supercells,
low-precipitation (LP) supercells, and shallow supercells.
9. Be prepared to sketch the basic structure and air flow patterns associated either with a
mature single-cell, a mature multicell, or a mature supercell storm.
10. Know the basic environmental and motion characteristics of single-cell, multicell, and
supercell storms (and how they differ).
11. Know the likelihood and type of severe weather in association with typical single-cell,
multicell, and supercell storms.
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Deep Convection: Physical Processes
1. Re-read Chapter 2 and 3.1 in your text.
2. Know the two (2) most important basic parameters in determining convective storm type.
3. Know the basic definition of buoyancy and its influence on an air parcel.
4. Know the three contributions to total buoyancy.
5. Know how CAPE and CIN are calculated and their relevance to deep convection.
6. Know how the neglect of moisture buoyancy will affect CAPE and CIN values.
7. Know the relevance of water-loading in deep convection.
8. Know how to calculate the maximum updraft velocity in a storm from a sounding.
9. Know how updraft diameter can influence updraft magnitude.
10. Know how the vertical distribution of CAPE and the amount of environmental moisture
can influence updraft magnitude due to entrainment effects.
11. Know the two primary processes that initiate a downdraft.
12. Know how to calculate DCAPE and its relevance to deep convection.
13. Know how to calculate the maximum downdraft velocity in a storm from a sounding.
14. Know the basic definition of vertical wind shear.
15. Be prepared to construct a hodograph if given the observed vertical profile of wind.
16. Know how to estimate the vertical shear through a given layer from the hodograph.
17. Be prepared to describe the vertical shear profile [e.g., shape (straight, curved, or some
combination), magnitude, type (speed or directional), and significant features].
18. Know how to estimate storm motion from a hodograph.
19. Know how to construct a storm-relative hodograph.
20. Be prepared to sketch typical hodographs for single-cell, multicell, and supercell storms.
21. Know the three (3) factors that influence cold pool (or gust front) motion.
22. Know how buoyancy gradients along a cold pool can generate horizontal vorticity.
23. Know how environmental vertical shear can generate horizontal vorticity.
24. Be prepared to discuss (and sketch a simple figure) why convection on the downshear
side of a cold pool will often develop into deep convection, while convection on the
upshear side is often suppressed.
Deep Convection: Forecasting Parameters
1. Review the SPC document on forecast parameters.
2. Know the respective forecast roles of the Storm Prediction Center and any given local
NWS forecast office in regard to mesoscale forecasting.
3. Know how SBCAPE, MLCAPE, MUCAPE, CIN, LI, Bulk Shear, BRN, SREH, EHI,
SCP, and STP are calculated, as well as their range of values, typical values, and any
forecast criteria regarding storm type and/or severe weather.
4. Know the strengths and weaknesses of each of the forecast parameters listed above.
5. Be prepared to use the CAPE – shear phase space diagram as well as the above
parameters and/or a hodograph to forecast the type of convection (single cell, multicell,
and/or supercell) and the possibility of severe weather.
6. Know how to effectively use the collection of parameters to make a mesoscale forecast of
deep convection.
7. Know which parameters are used to make forecasts for a given mesoscale event (i.e.
general deep convection, storm type, supercell intensity, and tornadoes)
Supercell Processes
1. Re-read Chapter 8.4.3 – 8.4.5 in your text.
2. Know the location within a typical synoptic-scale system where supercells often develop
3. Know the typical CAPE, CIN, and hodograph characteristics most often observed in the
supercell environment.
4. Be prepared to discuss (and possibly sketch) the basic radar reflectivity structure of a
supercell during its early, intermediate, or mature stage.
5. Know the three (3) processes that occur during a supercell’s early stage.
6. Know the two (2) processes that occur during the supercell’s intermediate stage.
7. Know the three (2) processes that occur during a supercell’s mature stage.
8. Be prepared to describe (and possibly sketch) the important steps, physics, and/or
characteristics involved in one of the above seven (7) processes.
9. Know the distinction between crosswise and streamwise horizontal vorticity, including its
relevance to the development of a low-level mesocyclone.
10. Know the three most common reasons why a supercell dissipates.
11. Know how supercell motions are estimated from a sounding (or hodograph) before cells
develop, and why such estimates are useful. How do the new and old methods differ?
12. Know the basic differences between supercells that evolve in environments with straight
hodographs and supercells that evolve in environments with curved hodographs.
Tornadoes
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Re-read Chapter 10.1 in your text.
Know the basic history and breakdown of the original F-scale.
Know how (in a very basic sense) the intensity of any given tornado is determined.
Know why the enhanced F-scale was developed.
Be prepared to discuss the basic spatial and temporal patterns of the U.S. tornado
climatology, including its annual cycle and long-term trends.
6. Be prepared to discuss the three (3) different scales of motion regarding tornadoes, the
structures observed at each scale, and which can be regularly observed with radar.
7. Be prepared to sketch and discuss the common tornado damage pattern.
8. Be prepared to discuss the various methods used to document the tornado core over the
past several decades.
9. Know a basic definition for the swirl ratio, and know how tornado structure changes as
the swirl ratio increases.
10. Be prepared to sketch and discuss the five regions of air flow in the conceptual model of
a tornado.
11. Be prepared to describe and/or sketch the local environmental difference and physical
processes involved in one of the two (2) leading theories as to how tornadoes form in
supercells, including the storm-scale circulations common to both theories.
12. Be prepared to discuss the physical processes by which tornadoes are believed to develop
in non-supercell convection.
13. Know the two (2) additional forecast parameters that are useful in forecasting tornado
formation, including why they are useful.
Squall Lines **
1. Know the definition of a Mesoscale Convective System (MCS).
2. Know the definition and basic environmental characteristics of a squall line.
3. Be prepared to sketch, discuss, and contrast the radar and kinematic structures as well as
the basic characteristics of trailing stratiform (TS), leading stratiform (LS), and parallel
stratiform (PS) squall lines.
4. Be prepared to sketch and discuss the three (3) primary flows in a classic squall line, as
well as the four (4) associated mesoscale pressure features.
5. Be prepared to discuss the different evolutions expected for squall lines embedded within
weak and strong vertical shear environments.
6. Be prepared to discuss and sketch a simple diagram illustrating the physical processes
associated with the formation of the either the ascending front-to-rear flow or the
descending rear-to-front flow (rear inflow jet).
7. Know the different forcing associated with strong and weak rear inflow jets, as well as
descending and elevated rear inflow jets.
8. Be prepared to discuss one or both of the two (2) proposed mechanisms for book-end
vortex development.
9. Know how the Coriolis force influences the book-end vortices.
10. Know the key structural features of bow echoes.
11. Be prepared to discuss the definition of a derecho event and how one develops.
12. Know the common locations for squall line tornadoes and their basic characteristics.
13. Know common forecast rules associated with squall line development, motion, and the
onset of derechos.
Thermally-driven Circulations **
1. Know the definition and basic characteristics of the land-sea breeze.
2. Be prepared to sketch and discuss the basic structure and evolution of the land-sea breeze
through a daily cycle.
3. Know the forecast considerations associated with land-sea breezes.
4. Know the definition of slope flows and valley flows, as well as the physical processes
associated with the development of each.
5. Be prepared to sketch and discuss the basic structure and evolution of slope-valley flows
through a daily cycle.
6. Be prepared to discuss the definition, basic characteristics, physical processes, and
mesoscale circulations associated with urban heat islands.
Microbursts **
1. Know the basic field-campaign-derived climatology of microbursts.
2. Be prepared to discuss the four (4) forcing terms in the vertical momentum equation and
how they can initiate or influence microburst evolution
3. Be prepared to sketch and discuss the 2-D or 3-D conceptual model of a microburst
4. Know the definitions and environmental differences between a wet and dry microburst.
5. Be prepared to discuss and contrast the physical processes responsible for wet and dry
microbursts.
6. Know the basic forecast guidelines for wet and dry microbursts.
** Topic will be covered on the Final Exam