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  • Observatory launches trial service of “Mean-sea-level Pressure” extended forecast

  • Tuesday, 30th July 2019

The Hong Kong Observatory launched a new trial service of “Mean-sea-level Pressure” extended forecast on the Extended Outlook (Beta version) webpage today (30 July 2019). Displaying the probability forecast of mean-sea-level pressure (hereafter pressure) for the next 14 days as a time series chart, the new service allows the public to easily keep track of the pressure evolution trend and make necessary preparation at the earliest instance possible. In general, pressure will fall significantly when a tropical cyclone moves close. When an intense cold surge affects Hong Kong the pressure will rise considerably.

Members of the public can access the “Mean-sea-level Pressure” extended forecast from the Observatory’s homepage, or via the following link:
https://www.hko.gov.hk/probfcst/tempfcst.htm(desktop version)
https://www.hko.gov.hk/m/probfcst/tempfcst.htm(mobile version)

The “Mean-sea-level Pressure” extended forecast chart will also be added to “MyObservatory” mobile app later.

Two cases of using “Mean-sea-level Pressure” extended forecast are given below:

Figure 1
Case (1): Pressure probability forecast chart associated with Super Typhoon Mangkhut in September 2018 -- pronounced signal with finite chance for pressure to drop drastically on 16 September way below the normal climate range (gray lines), hinting that Mangkhut might be closest to Hong Kong and bring extreme low pressure to the territory by then.
Figure 2
Case (2): Pressure probability forecast chart associated with the intense cold surge in January 2016 -- pronounced signal with good chance for pressure to rise rapidly around 24-25 January way above the normal climate range (gray lines), hinting that the intense cold surge might reach Hong Kong and bring extreme low temperatures to the territory by then.