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2. Description of the event
The evaluation of the cold temperatures rainfall will focus on 24-hour rainfall on 16 April 00UTC - 17 Aprl 00UTC in a 0.25x0.25 box centred on Dubai (centre point 25.2N, 55.3E).
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The plots below show analyses of T850 and z500 from 30 March 13 April to 5 17 April.
3. Predictability
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Regarding events of 14th, which caused 19 fatalities in Oman (compared to 1 in UAEreported for the UAE event on 16th) the plots below show the ecPoint 99th percentile from leads of 8, 4 and 2 days in advance. We don't have many measurements, but very dramatic floodwater videos, and data we do have, suggest that 100-500mm very probably fell in a short period of time in hills/mountains north of the crosshairs marker on the plots. Here there is again a signal well in advance (though at a lower level than for 16th events given that this is the 99th percentile). This signal grew markedly in forecasts from 4 to 2 days in advance. For comparison, the last plot below shows the equivalent 99th percentile from the raw ENS output (=max in the ENS here). As is usual for a high percentile, raw ENS values are generally notably less than ecPoint, and much more noisy. Just locally the raw ENS can give a much higher value than ecPoint, if for example there is a marked outlier, as shown by the CDF example.
Day 8 ecPoint forecast (95th 99th percentile) for Oman floods (14 April) - crosshairs denote the centroid of the casualty reports (the wadi rises northwards from here)
Day 4 ecPoint forecast (95th 99th percentile) for Oman floods (14 April)
Day 2 ecPoint forecast (99th percentile) for Oman floods (14 April)
Day 2 RAW ENS forecast (95th 99th percentile) for Oman floods (14 April)
CDF example for where ENS > ecPoint for 99th percentile.
3.4 Monthly forecasts
3.5 Comparison with other centres
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