Reading the Coded Surface Bulletin
The coded surface bulletin describes the locations of high and low pressure centers, surface frontal systems, and surface troughs. The particular type of feature is represented by capital letters and is followed by a series of four or five digit numbers. For pressure centers the strength of the high or low is given in whole millibars and is followed by a string containing the latitude and longitude of the feature. The first two digits indicate the latitude in degrees north, while the last two or three represent the longitude in degrees west. Both values are rounded to whole degrees. Fronts and troughs are described through a series of latitude and longitude points; additionally, fronts are followed by their intensity.
Here's an example (Decode this bulletin) :
The valid time of the analysis in the format MMDDHH where:
The Z at the end indicates that this is Zulu or UTC time.
HIGHS 1029 34128 1036 4975 1036 4073 ...
Describes the strength and location of high pressure centers. The first value is the central pressure in millibars. The second value is the location in whole degrees latitude and longitude. In the example above,
LOWS 971 59144 1010 3787 1011 3388 ...
Describes the strength and location of low pressure centers. In this example,
The remainder of the message provides the location of all fronts and troughs in whole degrees latitude and longitude and also describes the intensity of fronts.
OCFNT WK 60144 59137 55131 51129 49129
This is a weak (WK) occluded front (OCFNT) extending from 60N 144W through 59N 137W, 55N 131W, 51N 129W, ending at 49N 129W.COLD MDT 49129 44130 41131 38134 35136 33141
This is a moderate (MDT) cold front extending from 49N 129W through 44N 130W, 41N 131W, 38N 134W, 35N 136W, ending at 33N 141W.TROF 3887 3988 4090
This is a trough (or trof as labeled on the surface map) extending through 38N 87W, 39N 88W, and 40N 90W. Note that troughs do not have an intensity label.All possible frontal types and intensities are provided in the table below.