LAPS Hurricane Analysis and Forecasting of Dennis and Katrina Steve Albers, Isidora Jankov, John McGinley, Yuanfu Xie, J-Y Kim, S. G. Gopalakrishnan, John Gamache and Sim Aberson
LAPS • Aimed at fine scale analysis where error covariances are not well known • Analysis is data dominated: detailed where data exists, smooth where data is sparse; blended to background where data is absent • Multi-step procedure
Slide 0 LAPS III Configuration Data Data Ingest Intermediate data files variances Error Covariance covariances Trans LAPS GSI STMAS3D Trans Post proc1 Post proc2 Post proc3 Model prep WRF-ARW MM5 WRF-NMM Probabilistic Post Processing Ensemble Forecast
ANALYSIS QUESTIONS Dennis: Can data, such as, aircraft measured doppler winds adjust the 3D winds and height with appropriate weights on observations and constraints. Katrina: How much can an analysis benefit from drop sonde and radar data?
GFS 850mb wind
fdfdfd GOES/POES Soundings Cloud-Drift Winds ACARS Temperature ACARS/Radar Wind
pre-balanced 850mb wind with obs. 5 July 2005 2100 UTC
Balanced 850 wind and heights.
AOML 0.5 - 3.0km doppler radar winds July 5, 2005 2100 UTC
AOML 3km radar & dropsonde winds July 5, 2005 2200UTC
Analysis with Radar and Dropsondes 750mb July 5, 2005 2200UTC
ANALYSIS CONSIDERATIONS • Increased time window to bring in more radar data with the dropsondes • Decreased minimum radius of influence to capture smaller scale wind maxima? • Increase vertical radius of influence - particularly if we bring in flight level winds
Balanced-GFS temperature W-E Xsect through Dennis
Dennis Height Perturb. X-sect
Dennis Balanced W-E wind and omega Xsect.
ADDITIONAL DEVELOPMENTS * Cyclostrophic term is being reweighted in the balance package to strengthen height/temperature perturbation in accordance with gradient wind relationship. - Important for tight circulations in tropics. * Improved cloud analysis contribution to the balance package. - Parameter adjustments to improve low cloud depiction.
11n satellite with 850mb wind overlay
Katrina 18 UTC 27 August MSLP and drop sondes Aircraft radar reflectivity utilized in the analysis
Katrina Balance package testing (higher/lower weights on wind/heights) Favoring wind analysis Favoring height analysis 950 mb pre-balanced (green) and balanced (orange) heights (dm).
Katrina Pre-balanced 950-mb wind speed and height. Balanced 950-mb wind speed and height.