Status: Ongoing analysis Material from: Linus


 


1. Impact

In January 2021 Singapore saw two major precipitation. The cases were reported in ECMWF User Forum: Severe Monsoon Surge in January over Singapore . This page shows evaluation for the first event on 1-3 January. The page for the second event can be found here: 202101 - Rainfall - Singapore Part 2

2. Description of the event

Accumulation of precipitation over Singapore from 1 January to 30 January 2021 from observations (black) and forecasts for the observation sites.



The plots below show analyses of MSLP and 6-hour forecasts of precipitation from 30 December 00UTC to 4 January 00UTC, every 12 hour.


3. Predictability

  

3.1 Data assimilation

 

3.2 HRES

The plots below show observations and HRES forecasts of 72-hour precipitation valid 1-3 January, from different initial dates. 


3.3 ENS

The plots below show EFI for 3-day precipitation valid 1-3 January, from different initial times.

The plot below shows the evolution of the 3-day precipitation starting on 1 January, in the box outlined in the plots above. The plot includes HRES (red dot), ENS control (purple dot), ENS distribution (blue box-and-whisker) and model climate (red box-and-whisker). 


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


6. Additional material














  • No labels

4 Comments

  1. NEA MSS

    The EFI plots look very useful. The plots show a muted signal even over the South China Sea at the start, but gradually towards the surge day we can start to see from the box-and-whisker below that most of the ENS members are going for higher precipitation and the EFI signal starts to become significant. It is also interesting to note from the box-and-whisker the variability in the HRES forecast from around 28 December. Is the box-and-whisker plot available as part of the charts catalogue?

    1. Linus Magnusson

      The box-and-whisker can be seen as a concatenation of Ensgrams for symbols valid at the same date. But it is not available in this form currently.

  2. NEA MSS

    Would like to point out also that duing the northeast monsoon season, the sea areas are usually more active. This explained for the strong land-sea contrast from the HRES 3-day precipitation. (On a side note, we couldn't reply to comments or insert images on the forecast forum. Had feedback on the Atlassian community but wondered whether it is due to restricted user access rights)

    1. Rebecca Emerton

      Thank you for the additional comments! There was a technical issue with the comment permissions on the Forecast User Forum, which has now been fixed so it should be possible to comment on the page (and all pages).