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Weather Info > Upper-Level Weather Information [Refresh] [中文]

Location: King's Park (45004). Source of Data: Univerisity of Wyoming

Stability Indices

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 08:00 HKT on 24/8/2017 (Raw observations)

Major Stability IndexValueDegree of Instability
K Index:27.40
Lifted index:-3.51
Totals totals index:39.70
Convective Inhibition:-0.27
Vertical Wind Shear (925-200 hPa):35 knots


Other Stability Indices - Show


  1. These purely quantitative indices may not fully reflect the situation in all layers of the atmosphere and each has its weaknesses. Hence such indices should be used as a general guide only. You may also click on the relevant links for a description on those indices.
  2. Under the influence of tropical cyclones, unstable weather may occur at lower levels of the above indices, i.e. the threshold is reduced.
  3. Such analysis may not be suitable in autumn and winter when cold fronts cross Hong Kong.

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 08:00 HKT on 24/8/2017

PressureHeightTemperatureDew PointRelative HumidityWind DirectionWind Speed
1000.0 hPa66 m28.0°C25.8°C88 %0° (N)0 km/h
925.0 hPa758 m23.4°C21.8°C91 %165° (SSE)43 km/h
850.0 hPa1494 m19.2°C15.9°C81 %165° (SSE)46 km/h
700.0 hPa3139 m10.4°C0.4°C50 %175° (S)54 km/h
500.0 hPa5890 m-2.3°C-14.3°C39 %170° (S)31 km/h
300.0 hPa9770 m-27.1°C-35.1°C47 %115° (ESE)11 km/h
200.0 hPa12560 m-49.5°C-57.5°C39 %45° (NE)31 km/h
100.0 hPa16750 m-75.9°C-86.9°C16 %70° (ENE)72 km/h

Skew-T Diagram

The latest available Skew-T diagram is shown below. Visit this site for a description on how to interpret the information presented.

Sorry, but no data was available in the past three runs [36 hours]

Last Accessed: Thu Aug 24 2017 14:36:55 HKT
Last Modified: Tue Dec 24 2013

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