Stability indices can be used to assess the chance of unstable weather (especially lightning and thundery showers; some of which can also be used to determine tornado possibility). The likelihood of unstable weather is indicated by the icon shown in the last column of the following table.
Data as of 20:00 HKT on 21/4/2018 (Raw observations)
|Major Stability Index||Value||Degree of Instability|
|Totals totals index:||43.80|
|Vertical Wind Shear (925-200 hPa):||61 knots|
|Index||Value||Degree of Instability|
|Convective Available Potential Energy:||78.96|
|Bulk Richardson Number:||1.37|
|CAPE active region: 416.51 hPa to 879.68 hPa|
Revised version courtesy of Sam Lau. This version is meant to provide a more accurate analysis for Hong Kong.
|Geopotential Heights & Upper Air Atmospheric Conditions|
Geopotential heights are the heights above sea level that a given set of pressures can be reached. For instance, if the geopotential height of 500 hPa is 5880 metres, it means that (at that geographic location) an ambient pressure of 500 hPa is reached when elevation is 5880 metres.
Data as of 20:00 HKT on 21/4/2018
|Pressure||Height||Temperature||Dew Point||Relative Humidity||Wind Direction||Wind Speed|
|1000.0 hPa||109 m||23.0°C||21.0°C||89 %||95° (E)||7 km/h|
|925.0 hPa||787 m||19.2°C||17.1°C||88 %||120° (ESE)||22 km/h|
|850.0 hPa||1510 m||14.8°C||14.8°C||100 %||130° (SE)||15 km/h|
|700.0 hPa||3147 m||9.0°C||2.0°C||62 %||235° (SW)||26 km/h|
|500.0 hPa||5850 m||-7.1°C||-17.1°C||45 %||255° (WSW)||65 km/h|
|300.0 hPa||9670 m||-27.7°C||-64.7°C||2 %||295° (WNW)||100 km/h|
|200.0 hPa||12450 m||-50.5°C||-73.5°C||5 %||295° (WNW)||91 km/h|
|100.0 hPa||16640 m||-77.7°C||-88.7°C||16 %||265° (W)||30 km/h|
The latest available Skew-T diagram is shown below. Visit this site for a description on how to interpret the information presented.
Last Accessed: Sun Apr 22 2018 08:52:24 HKT
Last Modified: Tue Dec 24 2013