John Kaplan (NOAA/HRD), J. Cione (NOAA/HRD), M. DeMaria (NOAA/NESDIS), J. Knaff (NOAA/NESDIS), J. Dunion (U. of Miami/HRD), J. Solbrig (NRL), J. Hawkins(NRL), T. Lee (NRL), E. Kalina (CU), J. Zhang (U. Miami/HRD), J. Dostalek (CIRA), and P. Leighton (NOAA/HRD) Acknowledgements Funding support: NOAA/JHT and GOES-R Programs JHT Points of contact: E. Blake, C. Sisko, C. Landsea, T. Kimberlain, L. Avila Enhancements to the SHIPS Rapid Intensification Index

Background SHIPS rapid intensification index (RII)- provides 24-h probability of RI estimates for 25-kt, 30-kt, and 35-kt RI thresholds in Atlantic and E. Pacific basins using linear discriminant analysis (Kaplan et al. 2010) 8 Predictors used in current SHIPS RII – 6 Large scale/persistence predictors - Vertical shear ( mb), upper-level divergence (200 mb), low-level RH ( mb), potential intensity, ocean heat content, and persistence – 2 GOES inner-core predictors - Std. dev. of IR brightness T and areal-coverage of -30° C brightness T within 200 km radius SHIPS discriminant RII became operational prior to 2008 season

Verification rules: All 24-h over-water forecasts for tropical and subtropical systems (including depressions) verified using NHC final best tracks Skill of the Operational RII Forecasts

Goal- Improve Atlantic and E. Pacific operational RII using predictors from three new data sources Total precipitable water (TPW) GOES-IR predictors from principle component (PC) analysis Boundary-layer (BL) predictors from GFS fields Methodology- Select new predictors that yield largest RII skill increase when used in place of or in addition to current RI predictors and use to derive new experimental versions of RII Current JHT Project

Atlantic Experimental RII 9 total predictors 6 original operational predictors (Vertical shear, upper-level divergence, potential intensity, ocean heat content, persistence, inner-core GOES IR brightness temperature std. dev. ) 2 replacement predictors –TPW (replaces mb RH) –2 nd GOES-IR PC (replaces IR pixel count of -30 C temps) 1 new predictor –Inner-core dry air predictor Slightly modified use of potential intensity and persistence predictors

TPW Developmental Dataset -Remote Sensing Systems -14 yr dataset ( ) -1/4 degree global grid -6 hourly images (~+/- 9 hr data windows) -SSM/I, TMI (TRMM) and AMSRE-E (Aqua) -derived using the 19/22/37 GHz channels Total Precipitable Water (TPW) RII Predictor 21 Atlantic TPW predictors tested & identified Atlantic TPW Predictor chosen: % TPW pixels <45 mm (r=0-500 km, 90 deg quad centered upshear) replaces old hPa RH predictor Real-Time TPW Data Source NESDIS Operational Blended TPW

PC2 = GOES IR Principle Component (PC) RII Predictor Principle components (PCs) for motion relative imagery calculated from CIRA IR image archive ( ) IR brightness temperatures are analyzed on a cylindrical grid Standard EOF analysis was performed and first nine PCs were examined PC2 used as new RI predictor in place of areal-coverage of -30° C brightness T Storm Motion Spatial Weightings of EOF 2 Wilma 10/17/05 18 UTC

Boundary-layer RII Predictor GFS moisture and temperature analyses used to derive new thermo- dynamic boundary-layer predictors (Total of 22 predictors tested) Inner-core dry air predictor worked best (Added as a 9th predictor) q10 is the inner-core 10-m specific humidity estimated using the 1000 mb km environmental RH and T q10 layer is 10-m inner-core specific humidity estimated using km environmental layer-mean RH between 1000 mb to 500 mb Vmx is the NHC maximum surface wind Smaller values of this predictor (indicating less potential for the mixing of dry air down to surface) are favored for RI Inner-core dry air predictor = (q10 layer -q10)*Vmx

Improvement of Atlantic Experimental RII over Operational Version for Dependent Sample(N=2524)

Skill of the Atlantic Basin Independent RII Re-run Forecasts (N=503) ( Real-time data and NHC forecast tracks used RII re-derived excluding cases from each year )

E. Pacific Experimental RII 10 total predictors 9 are the same as were used in Atlantic version 1 additional predictor T= 0 h NHC maximum wind speed Potential intensity and persistence predictors handled differently than Atlantic version (i.e. like operational version)

Improvement of E. Pacific Experimental RII over Current Operational Version for Dependent Sample (N= 2422)

Skill of the E. Pacific basin independent RII re-run forecasts (N=509) (Real-time data and NHC forecast tracks used RII re-derived excluding cases from each year )

Skill of Atlantic Basin RII Re-run Forecasts for 2 Formulations of Experimental RII and Operational Version (N=503)

Skill of Operational Version of RII for Cross-Validated Samples for Lead Times of h

Summary/Future Plans Operational RII exhibited some skill (except for 35 kt RI threshold in the Atlantic basin) for the sample for both Atlantic and E. Pacific basins. Skill was considerably higher in E. Pacific. Verification of re-run forecasts showed new Experimental RII generally exhibited more skill than the current operational RII except at higher thresholds where skill was either equal to or somewhat less than current operational version (Sample size?). New experimental RII (E. Pacific formulation) will be run in parallel in 2011 in both Atlantic and E. Pacific as part of GOES-R program Future plans – extend RII to 48-h, develop/test Microwave-based (Velden et al. 2010), Lighting-based (Knaff et al 2010) and ensemble-based versions of RII (Rozoff and Kossin 2011). Provide RII as input for new RII based intensity consensus model (Sampson et al. 2011)