Download Homework #2: Synoptic Discussion Review

METR 4245 / ESCI 5251 – Advanced Synoptic Meteorology
Homework 2
Due Wednesday, September 7, 2016 at 2:00 pm
Further Map Analysis and Discussion of Synoptic Weather Conditions:
Again, let’s pretend you are a forecaster at the Greenville-Spartanburg NWS office, and your
next task on the day shift is to synthesize the most recent 12Z observations and then discuss the
synoptic evolution over the past 12 hours (i.e., since 00Z). You will be using the same
observations, soundings and analyzed maps from your first homework, as well as some
additional relevant observations. When a meteorologist prepares a forecast or changes shift,
they regularly provide a discussion of the previous and current weather (in written and/or oral
form) in order to explain their forecast of a given system’s evolution. It’s time to prepare your
discussion! You may wish to consult your lecture notes from this (and previous) course(s).
1. Surface Analysis: Using your 12Z surface analysis, locate and label any warm, cold,
stationary, or occluded fronts that you believe exist. Discuss and justify any selected
frontal locations. Describe the relationship between the surface wind barbs and the
isobars in most locations around any prominent high and low pressure systems. What
physical processes (i.e., forces) cause such a relationship?
2. 850mb Analysis: Using your 12Z analysis, lightly shade regions of prominent warm air
advection (in red) and cold air advection (in blue). Where are these locations relative to
the prominent high/low pressure centers (or troughs/ridges)? Describe the relationship
between the wind barbs and the geopotential height contours in most locations around the
prominent high/low pressure systems (or troughs/ridges). What causes this relationship?
3. 700mb Analysis: Using your 12Z analysis, lightly shade the regions of prominent moist
air advection (in red) and dry air advection (in blue). Where are these locations relative
to the prominent high/low pressure centers (or troughs/ridges)?
4. 500mb Analysis: Using your 12Z analysis, lightly shade the regions of prominent warm
air advection (in red) and cold air advection (in blue). Where are these locations relative
to the prominent high/low pressure centers (or troughs/ridges)?
Obtain the 500mb map of analyzed absolute vorticity at 12Z from the website. Why are
there so few negative values of absolute vorticity on the map? Lightly shade the regions
of prominent positive absolute vorticity advection (using black hatches). Identify (by
magnitude and location) two positive absolute vorticity maxima. What is the primary
type of vorticity associated with each maximum: shear or curvature vorticity?
5. 250mb Analyses: Using your 12Z analysis, identify prominent regions of speed
convergence (light red shading), confluence (red hatches), speed divergence (light green
shading), and diffluence (green hatches). Where are these locations relative to the wind
maxima?
6. Radar Observations: Obtain the radar reflectivity summaries from the course website.
Where are the prominent precipitation bands relative to the surface pressure systems and
any fronts? Discuss the relationship between the prominent rainband locations and the
regions of high dewpoint temperatures at the surface and moist air advection at 700 mb.
7. Rawinsondes: What event(s) occurred at Jackson, MS during the 12 hours between the
two soundings? Discuss any significant differences in the temperature, dewpoint, and
wind profiles, as well as the stability indices, between the two times. Are the differences
consistent with the occurrence of such event(s)? Explain.
8. Synoptic System Vertical Structure: Discuss the vertical structure of the prominent
synoptic system (i.e., compare the analyzed fields of geopotential height, temperature,
dewpoint, and winds at the various pressure levels). Do any prominent synoptic features
tilt a particular direction with height? How does the intensity of these features change
with height? How does this vertical structure change over the 12-hour period?
9. Synoptic System Evolution: How would you expect the prominent synoptic weather
system to evolve in the next 12 hours? In what direction would the system move? How
would the fronts move and evolve? Would the system intensify, weaken, or remain
steady? How would the vertical structure change? Explain your reasoning behind the
response to each question.
Note: The best professional forecasters provide detailed discussion to supplement their well
analyzed maps. Each main task listed above contains multiple parts. Make sure you
complete each task and answer each sub-question fully. Use complete sentences. This
assignment will be evaluated on the quality and depth of your discussion as well as the
correctness of your physical explanations.