XN000022-1981-07-12 — Page 9

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SUNDAY, JULY 12, 1981

SIGNAL 10

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THIS IS THE HIGHEST SIGNAL AND MEANS THAT HURRICANE FORCE WINDS ARE EXPECTED OR BLOWING WITH SUSTAINED SPEED REACHING UPWARDS FROM 64 KNOTS. GUSTS MAY EXCEED 120 KNOTS.

THIS SIGNAL IS HOISTED AS SOON AS THERE ARE

DEFINITE INDICATIONS THAT THE SUSTAINED WIND SPEED ANYWHERE NEAR SEA LEVEL IN HONG KONG IS LIKELY TO EXCEED 63 KNOTS.

WHAT YOU SHOULD DO

AS WHEN NO. 9 IS UP, STAY WHERE YOU ARE WELL PROTECTED. BOTH SIGNALS 9 AND 10 IMPLY THAT THE CENTRE OF A SEVERE TROPICAL STORM OR A TYPHOON WILL COME CLOSE TO HONG KONG. IF THE EYE PASSES OVER THERE WILL BE A LULL LASTING FROM A FEW MINUTES TO SOME HOURS BUT BE PREPARED FOR A SUDDEN RESUMPTION OF DESTRUCTIVE WINDS FROM A DIFFERENT DIRECTION.

IT IS IMPORTANT TO REALISE THAT WHILST THE TROPICAL CYCLONE WARNING SIGNALS GIVE WARNINGS OF WINDS EXPECTED OR BLOWING NEAR SEA LEVEL OVER OPEN WATER AND SIMILARLY EXPOSED AREAS, THEY DO NOT SPECIFICALLY WARN OF OTHER DANGERS WHICH MAY RESULT FROM THE TROPICAL CYCLONE. THESE INCLUDE FLOODING IN LOW LYING AREAS AS A RESULT OF A STORM SURGE WHICH MAY CAUSE THE SEA LEVEL TO RISE CONSIDERABLY HIGHER THAN IS NORMAL, AND THE DESTRUCTIVE EFFECTS OF VERY HEAVY RAIN WHICH USUALLY ACCOMPANIES TROPICAL CYCLONES. THIS RAIN CAN CAUSE FLOODING, LANDSLIPS AND GROUND SUBSIDENCE. SMALL STREAMS CAN TURN INTO RAGING TORRENTS WITHIN A SHORT PERIOD BRINGING DANGER TO ANYONE WITHIN THEIR VICINITY. ROCKS MAY DISLODGE FROM HILLSIDES AND THERE MAY BE MUDSLIPS.

IT IS THEREFORE OF PARAMOUNT IMPORTANCE THAT MEMBERS OF THE PUBLIC LISTEN TO BROADCAST WEATHER BULLETINS TO OBTAIN INFORMATION ON ALL EXPECTED ADVERSE WEATHER SO THAT THEY MAY TAKE APPROPRIATE PRECAUTIONS AGAINST VIOLENT WIND, HEAVY RAIN AND STORM SURGES.

TROPICAL CYCLONE WARNING BULLETINS ARE BROADCAST EVERY HALF HOUR AND AT TWO MINUTES TO THE HOUR WHEN ANY OF THE SIGNALS 8 TO 10 IS DISPLAYED.

MEMBERS OF THE PUBLIC ARE ADVISED TO LISTEN TO WEATHER BROADCASTS AND NOT TO TELEPHONE THE ROYAL OBSERVATORY DURING TROPICAL CYCLONE CONDITIONS AS THE TELEPHONE LINES MUST BE KEPT OPEN FOR THE DISSEMINATION OF WARNINGS AND OTHER URGENT OPERATIONAL REQUIREMENTS. INSTEAD, THEY SHOULD, IF REQUIRED, CALL 5-456381 WHICH IS OPERATED ROUND THE CLOCK BY THE HOME AFFAIRS DEPARTMENT DURING TROPICAL CYCLONE CONDITIONS.

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