Signal No. 9 Increasing Gale or Storm



Increasing Gale or Storm Signal No. 9  (Traditional Chinese: 九號烈風或暴風風力增強信號), colloquially as Signal No. 9 (Traditional Chinese: 九號風球), is a tropical cyclone warning signal issued by National Meteorology Bureau of the Imaginary Lands of Nicholas (NMBILN). It is the second lowest stage of all tropical cyclone warning signals, the next higher one is Signal No. 10 Hurricane, the next lower one is Signal No. 8 Gale or Storm. It has only been issued 3 times since 2012.

When the light system was still in place, Signal No. 9 was indicated by a series of flashing lights at the top of the lighthouse in a harbour. The sequence of the lights are "Green", "Green", "Green".

When a severe tropical storm or a weak typhoon makes a landfall in the warning area, this signal is typically issued.

Meaning
The official meaning of Increasing Gale of Storm Signal No. 9 is that "there has been storm winds (88 - 117 km/h) blowing in the area, and is expected to persist and/or to strengthen". Gales may exceed hurricane strength (118 km/h) frequently, occasionally exceeding 200 km/h.

Signal No. 9 is not always issued even if storm winds are occurring in the area, as signal no. 8's definition includes storm winds as well. It is critical that the gale winds are increasing (strengthening) to warrant a signal no. 9.

Signal No. 9 is often seen as a precursor to the highest tropical cyclone signal, Signal No. 10 Hurricane.

For this signal to be in force, a majority of the anemometer stations must record a 10-minute sustained wind speed over 88 km/h, and the wind speeds have an overall trend of increasing. Each anemometer station is assigned a weighting when factoring the wind speed, this weighting is dependent on the local population. If the weighting is over half of that area's population for the stations recording over 88 km/h of wind speed, a Signal No. 9 may also be warranted. Likewise, if the majority recorded over 117 km/h (hurricane winds), then the signal would be "upgraded" to Signal No. 10 Hurricane; the signal would be "downgraded" to Signal No. 8 Gale or Storm if the majority is recording winds less than 88 km/h, and/or the winds are no longer increasing in strength.

Precautions and Impacts
According to the Cyclone Safety Act, when a Signal No. 9 is in force, the precaution measurements largely follow that of Signal No. 8:
 * All classes from all educational institutes are cancelled.
 * All firms providing non-essential services are to be closed.
 * Television broadcasting companies / radio channels are required to reserve at least one channel in the area to continuously air the newest updates of the storm. (Signal No. 9 only)
 * Only government public services and other certified businesses can remain open.
 * Ferry services are suspended.
 * Boats are securely berthed at typhoon shelters.
 * All public transport services, excluding underground metro sections and selected bus routes, are suspended.
 * Bridges are closed.
 * Roads remained open, but travelling is strongly not recommended.
 * Taxis may provide limited service, at driver's own discretion.
 * Seaports are closed.
 * Trading is suspended in stock exchanges.
 * Airports remain opened, but most flights are likely to be cancelled or delayed.

Extremes

 * Longest Duration: Severe Typhoon Kay-Dooblurvay, 1 day 51 mins (16:27, 12 Jun - 17:18, 13 Jun)
 * Shortest Duration: Super Typhoon Eigen, 5 hrs 17 mins (20:28, 08 Aug, 01:45, 09 Aug)
 * Year with the Most Signal 9: 2012