Geoscience Reference
In-Depth Information
Appendix 3
Synoptic weather maps
The synoptic weather map provides a generalized
view of weather conditions over a large area at a given
time. The map analysis smooths out local pressure and
wind departures from the broad pattern. Such maps
are usually prepared at six- or twelve-hourly intervals.
Maps are generally prepared for mean sea-level pressure
(or of height contours for the 1000 mb pressure surface)
and at standard isobaric - 850, 700, 500, 300 mb, etc.
The MSL pressure map typically shows isobars at 4 or
5 mb intervals, surface fronts and weather information.
Weather phenomena shown on the map are as
follows:
REFERENCES
Pouncy, F. J. (2003) A history of cloud codes and symbols.
Weather
58, 69-80.
Stubbs, M. W. (1981) New code for reporting surface
observations - an introduction.
Weather
36, 357-66.
temperature
type and height of cloud base
dew-point
present weather
wind direction
past weather (last six hours)
wind speed
pressure tendency
pressure
pressure change (last three hours)
cloud amount
visibility
These data are presented in coded or symbolic form for
each weather station. The plotting convention ('station
model') is illustrated in Figure A3.1. The basic weather
symbols are illustrated in Figure A3.2, and the synoptic
code is given in Table A3.1.
