The Impact of Satellite Data on Real Time Statistical Tropical Cyclone Intensity Forecasts Joint Hurricane Testbed Project Mark DeMaria, NOAA/NESDIS/ORA, Fort Collins, CO Michelle M. Mainelli, NOAA/NCEP/TPC, Miami, FL Lynn K. Shay, University of Miami, MPO/RSMAS, Miami, FL John A. Knaff, CSU/CIRA, Fort Collins, CO James P. Kossin, UW/SSEC/CIMSS, Madison, WI Presented At The Inter-Departmental Hurricane Conference March, 2003 Miami, FL

Project Overview Goal: To determine if satellite data (GOES and satellite altimetry) can improve the intensity forecasts from the statistical-dynamical SHIPS model Method: Parallel version of SHIPS with satellite input was run in real-time for 2002 Atlantic season –Parallel version also developed for East Pacific, and run after the season with operational input Evaluation: Compare operational and parallel SHIPS forecasts for Atlantic and east Pacific

The SHIPS Model Statistical-dynamical model predicts tropical cyclone max winds hr Climatology, persistence, SST and atmospheric (vertical shear, momentum fluxes, etc) predictors –Reynold’s SST, NCEP global forecasting system Empirical decay for portion of track over land Run 4 times per day, initiated by the ATCF Track from adjusted 6-hour old NHC official forecast –LBAR track when no official forecast available Developed from sample

Parallel Version of SHIPS Predictors from GOES Imagery –% IR brightness temperature < -20 C, R= km –Std. Dev. of IR temp, R= km Predictors from satellite altimetry data –Ocean Heat Content (OHC) exceeding 50 KJ/cm2 averaged along the forecast track Method developed by Shay/Mainelli Atlantic only Developed using sample Predicts correction to operational SHIPS forecast Dependent data suggest ~5% max improvement at 48 hr

Sample GOES Imagery and OHC Analysis Hurricane Floyd 14 Sept 1999 OHC 26 Sept 2002

2002 Evaluation “New” NHC verification rules –Depressions, subtropical included –Extra-tropical, wave, remnant-lows excluded Only Decay-SHIPS forecasts considered since many storms were affected by land Verification samples –Atlantic real-time forecasts (Dolly-TD14) –Atlantic re-runs (all storms) No GOES or OHC, GOES only, OHC only, GOES+OHC –East Pacific re-runs (all storms) No GOES, GOES –Re-runs used all operational input Very similar, but not identical to real-time forecasts

Verification of Real-Time 2002 Atlantic Forecasts

Improvement of Parallel vs. Operational SHIPS (Real-time 2002 Atlantic Forecasts) N:

Contributions from GOES/OHC (Atlantic Forecast Re-runs) N:

Verification of Re-Run 2002 East Pacific Forecasts

Improvement of Parallel vs. Operational SHIPS (Re-Run 2002 East Pacific Forecasts)

Conclusions Atlantic –Real-time h SHIPS improved by up to 5% Statistically significant at 90% level hr –GOES and OHC both contribute to improvement –Some degradation at day 4 and 5 East Pacific –Real-time h SHIPS improved by up to 8% Statistically significant at 90% level hr –Some degradation at day 4 and 5 Suggestions to JHT: –Study individual forecasts in more detail –Add 2002 cases to developmental sample –Run in parallel again in 2003

Future Plans On average, SHIPS model has skill out to 72 hours (10-15% over SHIFOR, ) Wide variation in performance from storm to storm Primary limitations –Upper-end of rapid intensification kt range Add recon data to SHIPS (new JHT proposal) –“False Alarm” storms Lack of thermodynamic information? Analyze new hyperspectral (AIRS) tropical soundings

Operational SHIPS forecasts for Alberto 2000 and Lili 2002