Upper Air Analyses. Assignment 5. Due March 2

Purpose: (1) to analyze 500 mb geopotential height and temperature; (2) examine the structure of a upper level trought on synoptic time and spatial scales.

Review the information on manual analyses of upper air charts in the Djuric text.

Charts at 500 mb will be analyzed for the following times:

00z 24 February 04
12z 24 February 04

Required Equipment: #2 pencil; red pencil; eraser.

Manual analyses of height and temperature on constant pressure surfaces require:

knowledge of the typical errors likely in upper air observations
application of the dyamical principles of synoptic meteorology (e.g., geostrophic and gradient wind balance, thermal wind relationship)
use of conceptual models of the structure of synoptic weather systems
compliance with the traditions of synoptic manual analyses (e.g., contour intervals, color, and labeling conventions)

Analyses will be evaluated in terms of neatness and on how well the aforementioned factors are applied.

1. For 0000 UTC 24 February:

a. Contour in regular pencil, geopotential height at 500 mb in 60 m intervals beginning at 5520 m. Use the plotting conventions discussed in class. Underline suspect observations, if present, that do not conform to your analysis. Label ridge and trough axes, if present.
b. Contour in red pencil, temperature at 500 mb in 5C intervals beginning at -25C. Label temperature maxima and minima.

2. Repeat for 1200 UTC 24 February

3. Based on your analyses, discuss the temporal and spatial evolution of the height and temperature fields at 500 mb across the United States.

estimate the speed and direction of movement of the trough over the western U.S. over the 12 h period.
how did the amplitude and orientation of the major weather features change with time?