1. M. Fiorino :: IHC 61 st NOLA 20070307 Performance of the ECMWF High- Resolution Global Model during the 2006 Northern Hemisphere Season and Impact on CONsensus Mike Fiorino 1 michael.fiorino@noaa.gov National Hurricane Center Miami, FL 7 March 2007 1 CDR USN(RC), CNE-C6F DET 802 Atlanta

2. M. Fiorino :: 61 st IHC 20070307 New Orleans, LA Full Disclosure… n was “seconded” to ECMWF 1998-99 for their ERA-40 reanalysis project n Developed TC data assimilation techniques and TC model verification “schemes” n ECMWF is very much O2R vice R2O n Research is (wholly) driven by Operations except for the proverbial “42.9 stone” member of staff (e.g., Tim Palmer) n Operations = medium-range weather (10-15 d) = 5- d 500 AC + probability  seasonal… nothing to do with TCs…

3. M. Fiorino :: IHC 61 st NOLA 20070307 BLUF – Bottom Line Up Front a corollary BS Leverages/Losses yoU Funding from my ONR S&T Program 38 days So What? Who Cares? from Bill Gray This is all well and good Mike, but why are you doing this? One of my takeaways from the 61 st IHC…

4. M. Fiorino :: IHC 61 st NOLA 20070307 … NHEM because model (track) skill varies with (low- freq) synoptic situation … … potential for dynamical model intensity forecast skill in high resolution solutions … Answer to Bill Gray

5. M. Fiorino :: 61 st IHC 20070307 New Orleans, LA LANT 2006 :: BLUF huge trend in ECMWF skill with tau @ d+3/4/5 >> peers d+3  d+5 ECMO06 > ECMO12 > CONU > OFCL 72-h V max - Mean Abs Error - Bias

6. M. Fiorino :: 61 st IHC 20070307 New Orleans, LA EPAC 2006:: BLUF ECMWF ~ peers except > d+4/5 OCFL > all models and CONU strong error compensation GFS -CTE bias (equatorward) GFDL +CTE bias (poleward) ECMWF actually better than in previous years in EPAC persistent slow bias for WNW moving storms…

7. M. Fiorino :: 61 st IHC 20070307 New Orleans, LA WPAC 2006:: BLUF ECMWF ~ peers except > d+3/4/5 ECMO12 as at the “level of incompetence” d+3 JTYM06 > ECMO12 >

8. M. Fiorino :: 61 st IHC 20070307 New Orleans, LA Summary of 2006 NHEM Model Errors n LANT ECMWF medium-range track (MRT) skill high with low “perishability” – even +12h tracker has value bias-corrected intensity forecast shows a glimmering of skill at the medium-range – benefit of high spatial resolution? yes and no… n EPAC all models had poor skill, but ECMWF shows some MRT skill strong error compensation between GFS and GFDL due to poor vortex initialization  CON >> than individual model n WPAC better and less variation in MRT skill of the models ECMWF shows good MRT skill, but dreadful intensity errors  ??? (meteorology)

9. M. Fiorino :: 61 st IHC 20070307 New Orleans, LA ECMWF BUFR trackers – Data flow latency ~ 0.5 h GTS UKMO TOC FNMOC NCEP/NCO ECMWF NHC JTWC

10. M. Fiorino :: 61 st IHC 20070307 New Orleans, LA Timing Issues e.g., 00Z model -> 06Z forecast with 09Z initial posit n ECMWF Integrated Forecast System (IFS) +6.0 h – T l 799L91 (N400, dx~25km) 1 deterministic run +8.0 h – T l 399L62 (N200, dx~50km) 51-member EPS run +8.1 h – TC TRACKERS for DET and EPS run +8.5 h – TC trackers reach TOC/NCEP/FNMOC/NHC/JTWC n ECMWF 1deg fields at NCEP  NHC +7.0 h – 120-h 1deg DET solutions available n NHC forecast process starts +6.5 need CON by + 6.5 h n JTWC forecast process starts +7.0 need CON by + 7.5 h n “on time” model trackers ≤ 6.5 h n “late” model trackers > 6.5 h

11. M. Fiorino :: 61 st IHC 20070307 New Orleans, LA Summary of ECMWF timing and prospects for 2007 NHEM season… ECMWF trackers “late” NCEP/NHC tracker of ECMWF 1deg semi “on-time” ECMWF working to decouple TC trackers from the EPS run, may be “on time” for 2007 ECMWF working to decouple TC trackers from the EPS run, may be “on time” for 2007

12. M. Fiorino :: IHC 61 st NOLA 20070307 The Goerss Laws of CON_ or the conditions when medium-range forecast error of CON_> models 1) models have similar skill – applies in both directions… 2) error tend to be decorrelated Impact on CON…

13. M. Fiorino :: 61 st IHC 20070307 New Orleans, LA CONM – LANT 2006 ontime v late v all (CONM) 72 h ecmo06 > ecmo12 > conm >> conu  contributes to CON, but not always … sampling problem late taus: model >> peers, CON > peers, CON < best model early taus: model << peers, CON degraded

14. M. Fiorino :: 61 st IHC 20070307 New Orleans, LA CONM – EPAC 2006 ontime v late v all (CONM) ecmo06 & ecmo12 ~ other models but contributes because of error decorrelation model ~ peers, CON > best model error compensation

15. M. Fiorino :: 61 st IHC 20070307 New Orleans, LA CONM – WPAC 2006 ontime v late v all (CONM) model ~ peers, big contribution to CON at all taus big impact at d+5

16. M. Fiorino :: 61 st IHC 20070307 New Orleans, LA Summary and some Speculation… n ECMWF makes positive contribution to CON > current baseline CON at the medium-range exception was the LANT because it was much better than other members (Goerss CON rule 1) n Performance varies by basin  synoptic pattern  subtropical ridge/midlat baroclinic activity ECMWF very good for storms influenced by the midlats hi-res solution showing intensity prediction skill at the medium range, again for midlats n Speculation – ECMWF will NOT do as well in 2007 in the LANT as in 2006…but will improve CON in all basins at the medium range …

17. M. Fiorino :: IHC 61 st NOLA 20070307 Feb 2005 Commander Fiorino, what’s your forecast for my 2005 WESTPAC season? COMPACFLT Meteorologist It won’t be like 2004 Captain…

18. M. Fiorino :: 61 st IHC 20070307 New Orleans, LA NHEM TC activity anomalies 2003-2006 n 2006 ∟ 2005 n WPAC year-to- year shifts > EPAC/LANT n 2006 WPAC: strong STR – 5 hits on the PI n 2006 LANT: weaker STR, more midlat n 2006 EPAC: N tracks, synoptic-scale land effects

19. M. Fiorino :: IHC 61 st NOLA 20070307 sometimes the magic works, and sometimes it doesn’t… The Goerss Second Law of TC model skill … partly because model skill does vary with the low-freq synoptic pattern implied by the TC activity anomalies …