Status:Ongoing analysis Material from: Linus, Esti
1. Impact
On 27 July parts of United Arabian Emirates was hit by torrential rainfall, causing around 7 fatalities. Fujairah measured 169 mm in 24 hours.
2. Description of the event
The plots below show analyses of MSLP and 6 hour rainfall from 26 July 00UTC to 28 July 12UTC, every 12th hour.
The plots below show analyses of z500 and T850 from 25 July to 28 July 00UTC, every 24 hour.
3. Predictability
3.1 Data assimilation
3.2 HRES
The plots below show observations from SYNOP (first plot), concatenated 6-hour forecasts (2nd plot) and HRES forecasts of 24-hour precipitation valid 27 July 00UTC - 28 July 00UTC, from different initial dates. The black box marks a region around Fujairah.
3.3 ENS
The plots below show EFI for 1-day precipitation 27 July, from different initial times. The latest forecasts had a strong EFI signal, and also in the medium-range there was a signal present for extreme rainfall.
The plot below shows the forecast evolution plot for 24-hour precipitation valid 27 July 00UTC - 28 July 00UTC for Fujairah (25N, 56.2E). Mean of observations - green hourglass, concatenated 6-hour forecasts - green dot, HRES –red, ENS blue box-and-whisker, Model climate – red box-and-whisker. Triangle marks the maximum in the model climate based on 1200 forecasts.
The plot below shows the same as above but for the maximum 24-rainfall with a 1x1 degree box centred on Fujairah. Here we find a nearby grid point with almost 200 mm in the ensemble.
The plots below show:
- First row: 99th percentile of the ENS for 12-h precipitation forecast at different lead times and always valid from 27th 12UTC to 28th 00 UTC 2022.
- Second row: 99th percentile of the ecPoint for 12-h precipitation forecast at different lead times and always valid from 27th 12UTC to 28th 00 UTC 2022.
- Third row: CDFs for the ENS (red) and ecPoint (blue) 12-h precipitation forecast at different lead times and always valid from 27th 12UTC to 28th 00 UTC 2022.
| T+12h | T+24h | T+48h | T+72h | T+96h | T+120h | T+144 | T+168h | |
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ENS raw 99th perc |
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ecPoint 99th perc |
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CDFs ENSraw and ecPoint |
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3.4 Monthly forecasts
3.5 Comparison with other centres
4. Experience from general performance/other cases
5. Good and bad aspects of the forecasts for the event
- Early signal in the medium-range for extreme rainfall
- HRES and ENS missed the local intensity also in the short-range for Furairah
- Extreme (>40mm/24h) local rainfall present in the vicinity of the point (fractional skill score would pick up)