Status: Ongoing analysis Material from: Linus, Mohamed
1. Impact
In the end of May, Canterbury in New Zeeland was hit by severe rainfall resulting in flooding.
2. Description of the event
The plots below show analyses of MSLP and 6-hour forecasts of precipitation from 28 May 00UTC to 31 May 12UTC, 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 29-31 May, from different initial dates.
3.3 ENS
The plots below show EFI for 3-day precipitation valid 29-31 May, from different initial times.
The plots below show EFI for 3-day mean integrated water vapor flux (atmospheric river) valid 29-31 May, from different initial times.
The plot below shows the evolution of the 3-day precipitation starting on 29 May, 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). The ensemble median was constantly above the 99th percentile of the model climate in forecasts initialised from from 24 May 12UTC and onwards.
3.4 Monthly forecasts
The plots below shows the weekly anomaly of precipitation for the week 24-30 May. Note that the event happened in the end of the week, and the first plot below was issued almost one week before the event.
3.5 Comparison with other centres
3.6 Glofas flood forecasts
The plots below show hydrographs for a point near Christchurch.
