Status:Ongoing analysis Material from: Linus, Mohamed


1. Impact

On 15-16 Southern Florida was hit by extreme rainfall. Miami reported 215 mm/48h.

2. Description of the event

The plots below show analyses of MSLP and 6 hour rainfall from 13 November 00UTC to 17 November 00UTC, every 12th hour.

The plot below shows the 48-h total precipitation from NEXRAD for 15-16 November.

3. Predictability


3.1 Data assimilation


3.2 HRES

The plots below show 48-hour precipitation (15 November 00UTC - 17 November 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 Miami. While having a lot of rainfall in the region, the control forecasts missed the local maximum over southern Florida, butt he concatenated 6-hour forecasts agree well with NEXRAD.

3.3 ENS

The plots below shows EFI and SOT for 3-day precipitation (15 November 00UTC - 18 November 00UTC)  from different initial dates. (2-day EFI is not available.)

The plot below shows the forecast evolution plot for 48-hour precipitation (15 November 00UTC - 17 November 00UTC)  a 0.25x0.25 box centred on Miami. Mean of observations - green hourglass, Concatenated 6-hour forecasts - green dot, ENS control –red, ENS blue box-and-whisker, Model climate (to be added) – cyan box-and-whisker. Ensemble mean as black diamonds. Triangle marks the maximum in the model climate based on 1800 forecasts. The observation in Miami was 215 mm and the area mean from NEXRAD was 179 mm.

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

  • The ensemble seems to have captured the risk for the event ~7 days before but had problems with the mesoscale structure of the rainfall.

6. Additional material