The significance of each letter item is indicated below:
a. ZULU DDTTTT.
This line is the date-time at which the winds were
measured, with DD the day and TTTT the hour in local or ZULU time (Greenwich
b. The remaining lines provide data for the seven preselected yield
groups, where ddd is the effective downwind direction in degrees from grid
north and ss is the effective wind speed to the nearest kilometer per hour.
(1) ALFA dddsss is the data line for the 2-kiloton (KT) or less yield
(2) BRAVO dddsss is the data line for the more than 2-KT through 5-KT
(3) CHARLIE dddsss is the data line for the more than 5-KT through
30-KT yield group.
(4) DELTA dddsss is the data line for the more than 30-KT through
100-KT yield group.
(5) ECHO dddsss is the data line for the more than 100-KT through
300-KT yield group.
(6) FOXTROT dddsss is the data line for the more than 300-KT through
1-megaton (MT) yield group.
(7) GOLF dddsss is the data line for the more than 1-MT through 3 MT
For example, if the DELTA line of an effective downwind message reads DELTA
090025, the person using this information would know that the DELTA line is
used when the yield of the weapon is in the range from more than 30 KT
through 100 KT.
The contents of this DELTA line would indicate that the
of 90 degrees and an effective wind speed of 25 kilometers per hour.
Any one or more of the data lines of the effective downwind message may
contain only three digits when the effective wind speed is less than 8
kilometers per hour.
In this case, only the Zone 1 downwind distance is
given for the highest yield represented in that line.
device used to outline the hazard zones resulting from surface or near-
surface bursts for preselected yield groups.