1962
THE NEW ZEALAND GAZETTE.
[No. 76

TABLE No. 2.—CONDITION SIGNALS.
Two Upper Symbols of Hoist.

Forming. Two Direction Stationary Recurving. Filling up.
centres. unknown. or very slow.

TABLE No. 3.—RADIUS AND INTENSITY SIGNALS.
The Lowest of Three Symbols.
Radius of Position Circles :
120' 60'

Unknown. Severe. Unknown. Severe. Deepening.

Radius of Position Circles :
30'

Unknown. Severe. Exceptional Continental Position
velocity. depression. uncertain.

TABLE No. 4.—TIME-SIGNALS.
Single Symbol at Masthead.

Yesterday Yesterday This This
morning. afternoon. morning. afternoon.

TABLE No. 5.—GALE SIGNALS.
One Symbol at Yardarm.

Annam Coast. Gulf of Formosa Formosa to Yangtse to Gulf of Sea of Japan.
Tongking to Channel. Yangtse. Shantung Pechili and
Swatow. Promontory. Yalu Gulf.

North of East Coast South of
Hokushu. of Japan. Kiushu.

It is important that seamen should realize that the position
of the centre of the typhoon as signalled is the position ac-
cording to the data possessed by the Observatory at the time
of the issue of the warning. That data may be as much as
12 hours old. Thus, if the time-signal indicates that the
warning was issued “This morning,” it may be that the
position corresponds to data concerning yesterday afternoon.
If the signal “Deepening” is made, it indicates that there
is reason to believe that the barometric gradient and, con-
sequently, the intensity of the typhoon are increasing.
If the signal “Exceptional velocity” is made, it indicates
that there is reason to believe that the rate of progression is
25 per cent. or more greater than the average rate.
If the signal “Position uncertain” is made, it indicates
that the data possessed is unreliable and that the position
signalled is a mere probability.
The several tracks which a typhoon may follow in the
several months are very varied, and the velocity of progression
is liable to be erratic. It is not safe to count on a typhoon
maintaining a velocity indicated by previous position of its
centre. The velocity is liable to increase very suddenly.
Seamen are recommended to study from available sources
the tracks and average velocities for the month and locality
concerned. In the absence of more exact information the
following table of velocities in knots for the several latitudes
may be useful.

BEFORE RECURVING. AFTER RECURVING.

LATITUDE. Ordinary Limits. Mean. Exceptional Velocity as signalled. Maximum recorded. Ordinary Limits. Mean. Exceptional Velocity as signalled. Maximum recorded.

5° to 15° 5 to 12 9 11 22 .. .. .. ..
15° ,, 20° 5 ,, 14 10 12½ 24 5 to 17 10 13 22
20° ,, 25° 7 ,, 16 11 13 19 14 ,, 23 17 21 30
25° ,, 30° 7 ,, 13 11 13 15 11 ,, 23 18 23 47
30° ,, 35° .. .. .. 10 11 ,, 36 20 25 42
35° ,, 40° .. .. .. 16 12 ,, 36 21 26 50
40° ,, 45° .. .. .. .. 17 ,, 36 21 26 48
45° ,, 50° .. .. .. .. 12 ,, 36 21 26 52
50° ,, 55° .. .. .. .. 12 ,, 37 21 26 49

Seamen should realize that, whatever may be the probability
of a certain velocity in a given case, there is always the
possibility that it may be greatly exceeded. The safest guide
is to make allowance for extreme velocity.

TYPHOON SIGNAL.

Time
Latitude Direction
Longitude Radius,&c.

A severe typhoon within 30 miles of lat. 26° N., long. 120° E.,
travelling N.E. Warning issued this morning.

DEPRESSION SIGNAL.

Time
Latitude Direction
Longitude Radius,&c.

A continental depression in lat. 56° N., long. 109° E., travelling
E.S.E. Warning issued yesterday morning.

TYPHOON SIGNAL.

Time
Latitude Condition
Longitude Radius,&c.

A typhoon within 60 miles of lat. 20° N., long. 122° E., splitting
in two. Warning issued this afternoon.