HRD seminar – Paul Reasor & Altug Aksoy, AOML/HRD – 15 May 2014

Paul and Altug each presented a seminar:

  • “Evaluation of shear-relative hurricane structure from the HWRF model” – Paul Reasor


This talk will present a composite-based analysis of shear-relative hurricane structure from the HWRF model. The model’s representation of shear-relative precipitation and kinematic structure are evaluated using a recently-published composite of such structure diagnosed from airborne Doppler radar. Results stratified by shear magnitude, motion direction and vortex intensity are examined in addition to the total-case composite. Differences between the model and observed shear-induced asymmetries, including the vortex tilt, are interpreted in the light of differences in the typical environmental and symmetric vortex properties of the respective databases. Given the availability of HWRF model output at regular intervals, the talk is concluded with a composite-based examination of the relationship between temporal changes in vortex tilt and changes in hurricane structure and intensity.

A video recording of Reasor’s presentation is available on the anonymous ftp site:

  • “Model Sensitivity in Idealized, Ocean-Coupled Hurricane Simulations: Perturbations of Environment, Structure, and Model Physics Parameters” – Altug Aksoy


Idealized simulations are important tools to investigate in detail the dynamical evolution of a tropical cyclone for various environmental and/or structural characteristics. We present here a systematic sensitivity analysis using an idealized version of the Hurricane Weather Research and Forecasting (HWRF) model. The tropical cyclone environment is initialized with the tropical moist sounding of Dunion (2011, J. Climate). The westerly 850-200-hPa vertical wind shear is thermally balanced in the meridional direction. The zonal wind field is adjusted to yield a vertically integrated westward mean flow typical of Tropical Atlantic hurricanes. Lateral boundaries are forced with the same initial environmental profiles as in the computational domain interior to minimize imbalances. Coupling with a one-dimensional column ocean model introduces ocean cooling due to surface wind stress and modifies surface fluxes. The ocean column is initialized with prescribed temperature and salinity profiles that exhibit hurricane-season Tropical Atlantic characteristics with a deep, well-mixed upper ocean. The initial vortex is a wavenumber-0 composite of thousands of hurricane reconnaissance (dropwindsonde and tail Doppler radar) observations and historical height-radius cross-sections of steady-state, category-one Tropical Atlantic hurricanes over water. An analysis of the 5-day control simulation obtained in this manner will be presented first.

Model sensitivity to perturbations in parameters that include magnitude of zonal shear, vertically integrated atmospheric mean flow (storm speed), initial SST, environmental low-level and mid-level moisture and temperature, initial intensity, initial radius of maximum wind (RMW), as well as model parameters that control horizontal diffusion, vertical eddy diffusivity, and exchange coefficients of surface momentum and heat flux is then investigated, especially focusing on the quasi-steady-state regime that is observed in the 48-96 hours of the control simulation. Detailed analyses of parameter-model correlations, simulation spread, and response function will be presented for a systematic evaluation of model sensitivity. Suggestions will be made for calibrating the range of parameter values to improve the signal-to-noise ratio for the possibility of multiple, simultaneously perturbed parameters. Implications for ensemble-based data assimilation will be discussed.

A video recording of Altug’s presentation is available on the anonymous ftp site:

A video recording of the Q&A of both presentations is available on the anonymous ftp site:

AOML and HRD researchers at 31st AMS Conference on Hurricanes and Tropical Meteorology, San Diego, CA – 31 March – 4 April 2014

Sixteen HRD scientists participated in the recent 31st AMS Conference on Hurricanes and Tropical Meteorology, being authors or co-authors on 34 presentations and 9 posters.  Roughly 750 presentations (442 oral presentations in 70 sessions and 308 posters in 2 session) were submitted to the conference.

Of the 496 TC-related presentations and posters at the conference, 130, or about 26%, used data sets developed at HRD. There were 4 dedicated sessions to HFIP with 36 presentations, plus another 25-30 presentations sprinkled through the rest of the program that reported on HFIP and IFEX related work. It was also clear that HFIP research influenced a number of other presentations through recognition of the importance of evaluating numerical model system developments.

Recordings of the 34 presentations and the abstracts for the 9 posters AOML and HRD researchers presented (or were co-authors) at the Conference are available online from the AMS website.  Links to some of the posters can also be found below:

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HEDAS Analyses of a Rapidly Evolving Eyewall of a Major Hurricane – Fabian (2003) – Sim Aberson, NOAA/AOML/HRD, Miami, FL; and S. D. DitchekA. Aksoy, and K. J. Sellwood

Model Sensitivity to Perturbations of Environment, Structure, and Model Parameters in Idealized, Ocean-Coupled Tropical Cyclone Simulations – Altug Aksoy, NOAA/AOML and Univ. of Miami/CIMAS, Miami, FL; and B. W. KlotzJ. ZhangE. Uhlhorn, and J. J. Cione

Observing System Simulation Experiments to evaluate the impact of remotely sensed data on hurricane prediction – Robert Atlas, NOAA/AOML, Miami, FL; and T. Vukicevic, L. Bucci, B. Annane, A. Aksoy, J. Delgado, X. Zhang, and S. Gopalakrishnan

Sensing Hazards with Operational Unmanned Technology: NOAA’s multi-year plan to deploy the NASA Global Hawk aircraft for high impact weather – Michael L. Black, NOAA/AOML, Miami, FL; and G. A. Wick and R. E. Hood

A Study on the Asymmetric Rapid intensification of Hurricane Earl (2010) Using the HWRF system – Hua Chen, NOAA/AOML, Key Biscayne, FL; and S. Gopalakrishnan

The truth about 26C and the relative roles of the ocean and atmosphere at the hurricane air–sea interface – Joseph J. Cione, NOAA/HRD, Miami, FL

Quadrant distribution of tropical cyclone inner-core kinematics in relation to environmental shear – Jennifer C. DeHart, University of Washington, Seattle, WA; and R. A. Houze Jr. and R. F. Rogers

The Tropical Cyclone Diurnal Cycle – Jason Dunion, University of Miami/CIMAS-NOAA/HRD, Miami, FL; and C. D. Thorncroft and C. S. Velden

Correlation Between Named Storm Genesis Locations and Seasonal Atlantic Tropical Cyclone Activity: A Possible Link to Seasonal SAL Frequency – Evan B. Forde, NOAA/AOML/CSND, Miami, FL; and M. L. Black and J. Dunion

The Research HWRF system: Looking beyond the 10-m Wind Speed for Improved Storm Predictions – Sundararaman Gopalakrishnan, NOAA/AOML/HRD, Miami, FL; and X. Zhang, T. Quirino, V. Tallapragada, F. Marks, and R. Atlas

A Robust Observation Operator and Associated Background Covariances to Assimilate Microwave Radiances into Cloud-permitting Models – Ziad S. Haddad, JPL, Pasadena, CA; and J. Steward, T. Vukicevic, and S. Hristova-Veleva

Analysis of Shear-Relative Asymmetries in Tropical Cyclone Eyewall Slope Using Airborne Doppler Radar Data – Andrew Todd Hazelton, Florida State Univ., Tallahassee, FL; and R. F. Rogers and R. E. Hart

Climatological depiction of hurricane structure from passive microwave and scatterometer observations: Using the 12-year JPL Tropical Cyclone Information System (TCIS) to create composites and establish reliable statistics – Svetla Hristova-Veleva, JPL, Pasadena, CA; and B. Stiles, T. P. Shen, F. J. Turk, Z. Haddad, S. Gopalakrishnan, T. Vukicevic, Z. Wang, P. P. Li, B. W. Knosp, Q. A. Vu, and B. H. Lambrigtsen

Interhemispheric teleconnections from Atlantic Warm Pool heat source in intermediate and simple models – Xuan Ji, University of California Los Angeles, Los Angeles, CA; and J. D. Neelin, S. K. Lee, and C. R. Mechoso

Assessing the relationship between the large-scale and inner-core estimates of vertical shear – John Kaplan, NOAA/AOML/HRD, Miami, FL; and P. Reasor and M. DeMaria

Further Improvement of SFMR Surface Wind Speeds in Heavy Precipitation – Bradley W. Klotz, NOAA/AOML – Univ. of Miami/CIMAS, Miami, FL; and E. W. Uhlhorn, R. A. Black, and S. Lorsolo

Analysis of hurricane morphology, internal waves and boundary layer rolls observed from satellite SAR images – Xiaofeng Li, Global Science and Technology, Inc., College Park, MD; and Z. Zhao, B. Liu, J. Zhang, X. yang, W. Pichel, and M. DeMaria

Understanding Hurricane Sandy’s Track and Intensity Changes – Frank Marks, NOAA/AOML/HRD, Miami, FL

Tropical Cyclone Predictions over Indian Seas: Super Storm Phailin and beyond – U. C. Mohanty, Indian Institute of Technology Bhubaneswar, Bhubaneswar, Odisha, India; and K. K. Osuri, S. Pattanayak, S. Gopalakrishnan, D. Niyogi, Y. V. Ramarao, V. Tallapragada, and F. D. Marks Jr.

Role of Land Surface Processes on land falling Tropical Cyclones and Monsoon Depressions over the Indian Region – Krishna K. Osuri, Indian Institute of Bhubaneswar, Orisha, India; and U. C. Mohanty, S. Pattanayak, S. Gopalakrishnan, and D. Niyogi

On the limits of measuring the maximum wind speeds in hurricanes – David S. Nolan, Univ. of Miami/RSMAS, Miami, FL; and J. A. Zhang and E. W. Uhlhorn

Dynamic storm surge prediction with one-way coupled mesoscale modeling system – Sujata Pattanayak, Indian Institute of Technology Bhubaneswar, Bhubaneswar, Odisha, India; and U. C. Mohanty, K. K. Osuri, S. Gopalakrishnan, and D. Niyogi

Hurricane measurements and modeling for offshore wind farm development – Mark Powell, NOAA/AOML/HRD, Tallahassee, FL; and S. Murillo and S. Cocke

Evaluation of shear-relative hurricane structure from the HWRF model – Paul Reasor, NOAA/AOML/HRD, Miami, FL; and X. Zhang and S. Gopalakrishnan

Multiscale Structure and Evolution of Earl (2010) during Rapid Intensification – Robert F. Rogers, NOAA/AOML/HRD, Miami, FL; and P. D. Reasor and J. Zhang

A Balanced Vortex approach to Improving the Initial Condition and Diagnosing Forecasts in the Hurricane Research Weather and Forecasting Model – Kathryn J. Sellwood, Univ. of Miami/CIMAS and NOAA/AOML/HRD, Miami, FL; and T. Vukicevic

Idealized Study of Land Surface Impacts on Tropical Cyclone Intensity Predictions Using the HWRF Modeling System Subashini Subramanian, Purdue University, West Lafayette, IN; and S. Gopalakrishnan, G. R. Halliwell Jr., and D. Niyogi

Evaluating Different Convective Indicators of Tropical Cyclone Rapid Intensification: The Case of Hurricane Earl (2010) – Gabriel Susca-Lopata, University of Utah, Salt Lake City, UT; and E. Zipser and R. F. Rogers

Significant Advances to the NCEP Operational HWRF Modeling System for Improved Hurricane Forecasts – Vijay Tallapragada, NOAA/NWS/NCEP/EMC, College Park, MD; and S. Trahan, Y. C. Kwon, Z. Zhang, C. Kieu, Q. Liu, W. Wang, M. Tong, D. Sheinin, E. Liu, B. Zhang, S. Gopalakrishnan, X. Zhang, L. R. Bernardet, R. M. Yablonsky, J. W. Bao, R. J. Pasch, J. L. Franklin, D. A. Zelinsky, B. Strahl, W. Lapenta, R. L. Gall, and F. Toepfer

Improved Telescopic Nesting and Accurate Storm Tracking in the NCEP Operational HWRF Model – Samuel Trahan, NCEP EMC (IMSG), College Park, MD; and Z. Zhang, Y. C. Kwon, H. Y. Chuang, V. Tallapragada, T. Marchok, X. Zhang, S. Gopalakrishnan, and G. Thompson

Use of Synthetic Profiles to Diagnose Simulated Tropical Cyclones in Regional Hurricane Models – Jonathan L. Vigh, NCAR, Boulder, CO; and C. KieuV. Tallapragada, L. R. Bernardet, and E. W. Uhlhorn

The Global Hawk Airborne Vertical Atmospheric Profiling System: Status and Initial Applications – Gary A. Wick, NOAA/ESRL/PSD, Boulder, CO; and T. Hock, M. L. Black, J. Wang, J. R. Spackman, and R. E. Hood

Dropsonde composites of asymmetric hurricane boundary layer structure in relation to environmental vertical wind shear – Jun Zhang, NOAA/AOML and Univ. of Miami/CIMAS, Miami, FL; and R. Rogers, P. Reasor, E. Uhlhorn, and F. Marks

Representing Multi-Scale Interactions in HWRF Modeling System – Xuejin Zhang, NOAA/AOML/HRD, Miami, FL; and T. Quirino, Q. Liu, R. St. Fleur, Z. Zhang, and S. Gopalakrishnan


HEDAS Vortex-Scale Data Assimilation with Aircraft and Satellite Retrieval Observations: Summary of the 2013 Atlantic Hurricane Season Results – Altug Aksoy, NOAA/AOML and Univ. of Miami/CIMAS, Miami, FL; and S. AbersonK. SellwoodB. W. KlotzT. Vukicevic, and C. S. Velden  [poster available here]

The Satellite Proving Ground at the National Hurricane Center – John L. Beven, NOAA/NWS, Miami, FL; and M. J. Brennan, H. D. Cobb III, M. DeMaria, J. Knaff, A. B. Schumacher, C. Velden, S. A. Monette, J. P. Dunion, G. J. Jedlovec, K. K. Fuell, and M. J. Folmer

Development of a Tropical Cyclone Genesis Index (TCGI) for the North Atlantic – Jason Dunion, University of Miami/CIMAS-NOAA/HRD, Miami, FL; and J. Kaplan, A. B. Schumacher, J. Cossuth, and M. DeMaria

Wave and Wind Direction Effects on SFMR Brightness Temperatures – Heather M. Holbach, Florida State University, Tallahassee, FL; and E. Uhlhorn and M. A. Bourassa

Enhancements to the SHIPS Rapid Intensification Index – John Kaplan, NOAA/AOML/HRD, Miami, FL; and C. M. Rozoff, C. R. Sampson, J. P. Kossin, C. S. Velden, and M. DeMaria [poster available here]

Adopting Model Uncertainties for Tropical Cyclone Intensity Prediction Rosimar Rios-Berrios, University at Albany, State University of New York, Albany, NY; and T. Vukicevic and B. Tang

Real-time Verification of Passive Microwave Imagery-Based Statistical Models of Tropical Cyclone Rapid Intensification – Christopher M. Rozoff, CIMSS/Univ. of Wisconsin, Madison, WI; and C. S. Velden, J. Kaplan, A. Wimmers, and J. P. Kossin

Diurnal Pulsing of Lightning in Strong Tropical Cyclones – Stephanie N. Stevenson, University at Albany – State University of New York, Albany, NY; and K. L. Corbosiero and J. P. Dunion

Observed Hurricane Wind Speed Asymmetries and Relationships to Motion and Environmental Shear – Eric Uhlhorn, NOAA/AOML, Miami, FL; and B. W. KlotzT. Vukicevic, P. Reasor, and R. F. Rogers

HRD scientists participate in HFIP Annual Review, NCWCP, College Park, MD – 19-20 February 2014

The HFIP Annual Review Meeting was held in College Park, MD, from 19-20 February, 2014. The agenda and background information are available at

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HRD Monthly Science Meeting of February 2014

February’s Science meeting had 6 presentations:

  1. Robert Black, HRD – Microphysics influences in HWRF
  2. Dr. Jun Zhang, UM/CIMAS & HRD – Using aircraft observations to improve HWRF physics
  3. Dr. Joe Cione, HRD – Difference in air-sea energy transfer in weakening and intensifying in storms
  4. Prof. Hugh Willoughby, FIU – Hurricanes in Zipfistan
  5. Dr. Hua Chen, UM/CIMAS & HRD – Role of subsidence in RI of Hurricane Earl
  6. Lisa Bucci, UM/CIMAS & HRD – OSSE Group update

The presentations are available on the anonymous ftp site as a zip archive at:

HRD Monthly Science Meeting of November 2013

November’s  Science meeting had 6 presentations:

  1. John Kaplan – Impact of Large-Scale Vertical Shear on Tropical Cyclone Rapid Intensification in the North Atlantic basin
  2. Altug Aksoy – HEDAS Cases in 2013
  3. Sim Aberson – 2013 HEDAS performance
  4. Evan Forde – Atlantic Basin Seasonal Genesis: Location & Number of Storms (1987-2008)
  5. Rob Rogers – Convective bursts and Earl’s Rapid Intensification
  6. Joe Cione – Using inner core air-sea contrast to predict short-term hurricane intensity change

The presentations are available on the anonymous ftp site as a zip archive at: