M. Fiorino :: IHC 61 st NOLA Performance of the ECMWF High- Resolution Global Model during the 2006 Northern Hemisphere Season and Impact on CONsensus Mike Fiorino 1 National Hurricane Center Miami, FL 7 March CDR USN(RC), CNE-C6F DET 802 Atlanta M. Fiorino :: 61 st IHC New Orleans, LA Full Disclosure n was seconded to ECMWF 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 M. Fiorino :: IHC 61 st NOLA 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 M. Fiorino :: IHC 61 st NOLA 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 M. Fiorino :: 61 st IHC New Orleans, LA LANT 2006 :: BLUF huge trend in ECMWF skill with d+3/4/5 >> peers d+3 d+5 ECMO06 > ECMO12 > CONU > OFCL 72-h V max - Mean Abs Error - Bias M. Fiorino :: 61 st IHC 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 M. Fiorino :: 61 st IHC New Orleans, LA WPAC 2006:: BLUF ECMWF ~ peers except > d+3/4/5 ECMO12 as at the level of incompetence d+3 JTYM06 > ECMO12 > M. Fiorino :: 61 st IHC 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) M. Fiorino :: 61 st IHC New Orleans, LA ECMWF BUFR trackers Data flow latency ~ 0.5 h GTS UKMO TOC FNMOC NCEP/NCO ECMWF NHC JTWC M. Fiorino :: 61 st IHC 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 h n JTWC forecast process starts +7.0 need CON by h n on time model trackers 6.5 h n late model trackers > 6.5 h M. Fiorino :: 61 st IHC 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 M. Fiorino :: IHC 61 st NOLA 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 M. Fiorino :: 61 st IHC 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 best model error compensation M. Fiorino :: 61 st IHC 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 M. Fiorino :: 61 st IHC 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 2006but will improve CON in all basins at the medium range M. Fiorino :: IHC 61 st NOLA Feb 2005 Commander Fiorino, whats your forecast for my 2005 WESTPAC season? COMPACFLT Meteorologist It wont be like 2004 Captain M. Fiorino :: 61 st IHC New Orleans, LA NHEM TC activity anomalies 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 M. Fiorino :: IHC 61 st NOLA sometimes the magic works, and sometimes it doesnt 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