Knowledge Expectations for METR 4433
Purpose: This document
describes the principal concepts, technical skills, and fundamental understanding
that all students are expected to possess upon completing METR 4433 Mesoscale
Meteorology. Individual instructors may
deviate somewhat from the specific topics and order listed.
Pre-requisites: Grade of C
or better in METR 4133 and METR 4424. Students should have a good understanding
of the structure, dynamics, physics and thermodynamics of the atmosphere prior
to starting this course.
Goal of the Course: This
course teaches the structure and dynamics of convective and mesoscale phenomena,
including mesoscale convective systems, severe thunderstorms, tornadoes,
low-level jets, mountain waves and hurricanes. For most of these phenomena, the
course discusses their general behaviors and characteristics, the dynamics of
their formation and development, and the types of weather and hazards they
produce, and in some cases their prediction. Specific topics and expected
knowledge and understanding by the students after taking the course are given
1. Scale analysis and definition of scales
able to perform scale analysis on the atmospheric equations of motion.
Know the typical magnitude and relative importance of terms in the
equations for the corresponding scales.
the methods for categorizing atmospheric motion into various scales, and
the general characteristics of such motion.
2. Dryline and mesoscale low-level jet
the definition, spatial structure, and climatology of dryline. Understand
the physical processes responsible for the formation and movement of
dryline and the role of dryline in initiating convection.
the definition and climatology of mesoscale low-level jet, and its role in
moisture and heat transport in precipitating events. Understand the
theories on the formation of nocturnal low-level jet.
4. Convection, single-cell storms and microburst
the basic types of convective storms and their key characteristics, including
their morphology, typical weather, and life cycles.
the forces responsible for initiation, enhancement and suppression of the
storms. Be able to apply the parcel theory to single cell storm
development and estimate the maximum updraft speed based on environmental CAPE.
the definitions, key features and hazard, and the conceptual model and
life cycle of downbursts/microbursts.
Know how they affect aircraft during takeoff and landing.
convective systems, including multicell storms, squall lines and mesoscale
multicell storms, know the ways by which multicell storms propagate.
Understand the dynamic processes responsible for cell regeneration and its
the source of cold pool in convective storms, understand its propagation
along the ground in the form of density currents. Be able to derive and
interpret the equation of cold pool / density current propagation and
understand how cold pool propagation affects storm motion.
the definition and general characteristics of squall lines. Know the
conceptual models of squall lines that describe that typical internal
circulation, thermal and perturbation pressure patterns and the
distribution of precipitation in the systems.
the ways by which squall lines form and understand the favorable
environmental conditions that support long-lived squall lines.
the phenomenon, characteristics, and significance of bow echoes. Know and
understand the conceptual models of bow echo. Be able to describe the typical
life cycle of bow echoes, and explain the formation of bookend vortices.
the typical environment favorable for bow echoes, including shear and
instability. Know the behaviors of derechos as a special form of bow
the criteria for mesoscale convective complexes (MCC), their physical
characteristics, associated weather and typical time evolution.
6. Supercell storms and tornadoes
the distinguishing characteristics of supercell storms from other types of
able describe the typical internal flow structure of supercell storms and
be able to identify them according to radar echo patterns. Be able to explain the reason for such
the 3D conceptual models of tornadic supercells. Be able to use the
vorticity equation to explain the origin and intensification of updraft
the phenomena, classification, damage as well as climatology of tornadoes.
Know the kinematics and thermal structure inside tornadoes. Know the
typical life cycles of tornadoes.
the generation of mid-level rotation and role of mid-level mesocyclones in
tornadogenesis. Understand the theories for the generation of low-level
rotation and tornadogenesis. Know the typical way that supercell storms
transition into their tornadic phase.
and be able to use diagnostic pressure equation to explain the enhancement
of rotating updraft, and why storms often split and how the hodograph
curvature affects the behaviors of split cells.
able to define various forms of vorticity, helicity and the Bulk
Richardson number using both physical terms and equations. Understand and
be able to explain the effects of these and other environmental parameters
on storm types and storm behavior.
how to use bulk Richardson number and various forms of helicity as the
predictors of storm types, and their strength and weakness of these
parameters for such a task.
7. Mesoscale rainbands, horizontal convective
rolls and land-sea breezes
the phenomena of rainbands and the conditional symmetric instability as a
possible mechanism for their formation.
the phenomena of horizontal convective rolls (HCR) and their role in
convective initiation. Understand the theories of HCR formation.
the causes and behaviors of land-sea breezes and their role in modulating
8. Mesoscale rainbands, horizontal convective
rolls and land-sea breezes
Mountain waves and flows
- Orographic precipitaiton
the phenomena and climatology of hurricanes, the key factors and the
necessary conditions for hurricanes formation. Know the flow and
thermodynamic structures of hurricanes and the associated weather and
the CISK and air-sea interaction theories of hurricane formation.