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http://intra.ecmwf.int/daily/d/dreport/2015/06/24/sc/

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1. Impact

In the days around 20 June 2015 a  heatwave affected southern Pakistan and eastern India. The temperatures in Karachi reached 43 degrees. However, it is believed that the high humidity and lack of winds made the effects of the heat worse.

http://www.bbc.co.uk/news/science-environment-33288311

2. Description of the event

The figures below show analyses of z500 and t850 (left) and 2-metre temperature and 30-metre wind (right) valid for 20 June 12 UTC.


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The plot below shows the time-series of observations (blue) for Karachi (25N, 67.2E) for 4 days. The HRES forecast from 19 June 00UTC is included (blue). The heatwave peaked on 20 June with 43 degrees and the minimum temperature the night after was 34 degrees.

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3. Predictability

  

3.1 Data assimilation

 

3.2 HRES

The HRES forecast is included in the observation plot above.


3.3 ENS

The plot below shows the Ensgram for Karachi from 20 June 12 UTC (the earlier Ensgrams had been removed when the investigation started). For the Sunday, both the daily maximum almost reaches the 99th percentile of the climate while the minimum temperature is above. We also see that the wind speed is much lower than normal.

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3.4 Monthly forecasts


3.5 Comparison with other centres

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