This has been an interesting (and still is!) tropical cyclone. Started in the Pacific, rather small and looking not too offensive has deepened and it has been said (still needs to be assessed if true) the category of super-typhoon, just before hitting Okinawa (29th September). Now the typhoon is travelling to the main Japanese mainland east coast.
There are lots of photos on the press. The following is the aftermath of Jelawat in Okinawa:
More photos (worth a look if you are on Facebook!) have been posted by the USA KAdena Airbase
What about ECMWF forecasts?
The forecast from the 25th September indicated the typhoon to intensify and head for Japan. The forecast trajectory matches quite well the observed trajectory as observed on various websites (needs more objective verifications!). The panels on the right are constructed recording the forecast typhoon characteristics as though sitting on the typhoon and travelling with it (Lagrangian specification). Interestingly, for Thursday 27th the Ens forecast indicates a 5% probability of having a super-typhoon (black shading; needs to carefully check the Thursday boxes on the top right panel ). The HighRes forecast is always an outlier (black line in the middle and bottom panel on the right. These two panel show wind and central pressure of the typhoon, respectively)
Forecast base date: 25th September
A more recent forecast shows the progression of the typhoon, which will decay after affecting the East Coast of Japan. Please note (bottom left panel) that after t+120 not many members are tracked (ie the tropical cyclone is weakened and disappeared).
Forecast base date 27th September
Torrential rains and flash floods affected Andalusia and Murcia on Friday 28th September. The rain came after an extensive period of drought. The press talks about 600 people evacuated and six casualties.
Photos on the press showed people evacuated with boats and mud and water covering streets and the ground floors of buildings:
How did ECMWF forecasts do?
The Extreme Forecast Index (EFI) showed high values three days in advance. The following pdf shows on the left panel the EFI (shading). The red colour indicates the areas where the EFI has its maximum value (EFI=1). The model climate on the right panel tells us the amount of precipitation for the 99th percentile of the climate, which in the area of the flood is between 10 and 20 mm/24h (green shading):
The EPSgram for a location on the Spanish South-east coast indicates (left panel below) that the accumulated precipitation for a 24 hour period are for the majority of the Ensemble Members well above the climate (thin green line). In fact the forecast for Friday 28th, shows that from the 25th percentile upwards, the accumulated amounts are above the 99th percentile of the climate:
Ensemble Cumulative Distribution Functions
The file on the right shows the EPS distribution for the same location as the EPSgram. The top panel is the feature we are interested in and it shows the Cumulative Distribution Function (CDF) for the 10 forecast runs all verifying on the 28-29th (accumulated) September. The climate is in black. All the forecast runs indicated that there would be more rain than it would be expected if we took the climate as forecast. A particular shift to the right happens for the d+3 forecast range with a bunch of curves that move to the right suggesting very large extreme values (>50mm/24h). There is some spread in the EPS members as to what it should be the amounts of precipitation: for example following the red curve one notices values from >10mm/24h to >60mm/24h: they are obviously associated to a different probability of happening!
First of all, the following plot shows the observations (as they are from GTS). Top row is the threee individual 24h periods, borttom are the 48h and 72h accumulations. Sunday the rain was mostly in the southern areas, by Monday it moved to north, and Tuesday it stayed there but the amounts were less extreme. The 72h total shows up as over 100m even with this sparse coverage (especially in the flood affected region). Orange corresponds to 30-50 mm, red to 50-75 mm and purple to 75-100 mm.
On the following plots always 8 model runs appear (if available verifying on the corresponding period) starting from top left going to the right. The 1st and 3rd rows are ECMWF, the 2nd and 4th rows are UKMO forecasts. The bottom right corner shows the observations. The colour scheme is the simila in the forecasts and the observation. Orange corresponds to 30-50 mm, red to 50-75 mm and purple to 75-100 mm.
- For Sunday the MetOffice is better, the EC timing is quite bad, the rain goes too far north (execpt one UKMO run, which missed the event completely).
- For Monday it is more mixed, first the EC forecasts are better, showing consistently the large precip, even if too far north. Later, closer to the event, the EC forecasts are surprisingly bad, the precip is way too far north, and also not enough.
Nadine's future remains as uncertain as it was in the previous forecasts for both its intensity and its track. The extra-tropical tracker again shows two possible movement: eastward and westward.
According to the high-resolution forecast Nadine will move north-eastwards behaving as tropical-like feature. Then it will penetrate inland into the Iberian peninsular dying quickly or merging with a bigger trough.
GFS in its last run from 06UTC predicted a little bit different behaviour of Nadine: again north-eastwards motion, more easterly track, earlier in the forecast and living longer inland causing torrential rain in Portugal and Spain.
Comparing day 6 forecast from the main centres we will see how different they are.
The possibility of Nadine hitting the Iberian peninsular seems to be well captured in EFI forecast of 10-metre wind gusts. The SOT valued are also quite big.