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In general, analysis of IFS model performance suggests:

• CONTROL-10/HRES errors in forecast positions of tropical cyclones are on average less than 200 km at Day3 and less than 350 km at Day5.
• Broadly, the IFS models tend on average to move tropical cyclones rather too slowly (by about 1-2 km h^-1).
• Strike probabilities seem to be a little high.  This applies to TCs in existence at T+0, but in in view of some conflicting results this topic is currently undergoing further investigation (Nov 18).  ECMWF plans to start verifying the 'activity' product soon.
• The IFS models handle rapid intensification of tropical cyclones rather poorly.  It is quite common to see an under-estimate of the speed of intensification during periods of intensification.
• CONTROL-10/HRES errors in central pressure are erratic.  They have a relatively small average bias though tend to over-deepen the central pressure.  The ENS Control run is generally not deep enough by around 15 hPa.   
• There is on average an under-estimation of maximum winds in the circulation, particular during periods of rapid intensification.
• Results are mixed regarding genesis of tropical cyclones:

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Fig8.1.10.3.2: IFS model forecast location error of tropical cyclones (CONTROL-10/HRES - blue; Ensemble Mean (EM) - Yellow)  and ENS spread (Red dots).  The diagram indicates that in 2016 the average location error and spread at:

• Day3: CONTROL-10/HRES location error about 180km; EM location error about 190km; ENS spread about 190km.
• Day5: CONTROL-10/HRES location error about 340km; EM location error about 320km; ENS spread about 310km.

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Fig8.1.10.3.3: An illustration of what can happen when the model resolution is increased.  CONTROL-10/HRES model performance Aug-Nov 2015 using test runs (~9km resolution - Red;  ~16km resolution - Blue), both without ocean coupling. On average, ~9km resolution forecast location error is slightly better to about Day5 but marginally worse from Day5 to Day7.  However, beyond about Day5 the low sample size makes statistics unreliable and ~9km resolution is unlikely to be significantly different to ~16km resolution. Users should note that this diagram is included to illustrate that  resolution changes have a significant impact.

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• the threat area in eastern USA is broadened.
• there is less chance that the hurricane track will curve northwards off the eastern seaboard.
• the southern flank of the threat extends southward into Florida.
• CONTROL-10/HRES (and ENS mean) make more progress westwards into USA.

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