Status:Ongoing analysis Material from: Linus, Tim,
1. Impact
On 16 April the United Arab Emirates was hit by record breaking rainfall. Evidently many places recorded over 100mm. Some had 1.5 years worth of rain in one day (e.g. Dubai airport where the total was 142mm). The rain actually began before 04UTC Tue, and media indicate that the two highest totals 'during Tuesday' (24h rainfall) were 259.5mm in Khatam Al Shaklah in Al Ain and 239mm in Kalba, in Sharjah. The former represents an all-time UAE area record daily rainfall (records go back 75 years). Unsurprisingly there were major impacts, from the rain, the gusty winds (and even hail) as discussed, for example, in an ITV news bulletin here, and these are continuing today - see e.g. here.
On the days before Oman as also hit by severe rainfall (e.g. here). Media reported the main fatalities (17 in recent reports) were centred on a region about 100km S of the capital, Muscat, which itself lies on the north coast of the country, to the SE of the Straits of Hormuz.
https://www.bbc.co.uk/news/world-middle-east-68831408
2. Description of the event
The evaluation of the cold temperatures 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).
The plots below show analyses of MSLP and 6 hour rainfall from 14 April 00UTC to 17 April 00UTC, every 12th hour.
The plots below show analyses of T850 and z500 from 30 March to 5 April.
3. Predictability
3.1 Data assimilation
3.2 HRES
The plots below show 24-hour precipitation (16 April 00UTC - 17 April 00UTC) in observations (first plot) concatenated short forecasts (second plot) and ENS control forecasts with different lead times. The box marks 0.25x0.25 degree centred on Dubai.
The plots below show forecasts from DestinE.
The plots below show forecasts from AIFS.
3.3 ENS
The plots below shows EFI and SOT for 1-day precipitation (16 April) from different initial dates.
The plot below shows the forecast evolution plot for 24-hour precipitation for Dubai on 16 April.
Observation - green hourglass
Analysis - green dot
ENS control–red
DestinE4.4km - purple dot
ENS - blue box-and-whisker
AIFS - pcyan dot
Model climate – cyan box-and-whisker
Ensemble mean as black diamonds. Triangle marks the maximum in the model climate based on 1800 forecasts.
Signs of a rainfall extreme was seen from 6 April - 10 days before the event in the ensemble (median passed the model climate maximum).
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