HRD Monthly Science Meeting of June 2015

June’s science meeting consisted of 3 presentations:

  1. Joshua Wadler (Hollings scholar from U. Oklahoma) – Convective Bursts: How their structure and environments vary in shear relative quadrants
  2. Kurt Hansen (Hollings scholar from SUNY Albany) – Downdrafts in Tropical Cyclones
  3. Jun Zhang – Effects of Vertical Diffusion on Forecasts of Rapid Intensifying Storms in HWRF – preliminary results

All the presentations and posters are available on the anonymous ftp site at:

Paper examining the region closest to the ocean surface in hurricanes and typhoons released online in the Journal of Geophysical Research

Global Positioning System dropwindsondes are released by Hurricane Hunter Aircraft to measure temperature, pressure, humidity, and wind speeds. Dropwindsonde data show what the wind, temperature and moisture are like nearest the ocean surface. In this study, hurricanes in the Atlantic Ocean are compared with typhoons in the Pacific Ocean.

Important Conclusions:

1. The atmospheric region nearest the ocean surface is generally similar in typhoons and hurricanes.
2. This region in typhoons tends to be warmer and moister than that in hurricanes.
3. This helps us understand and forecast the way that heat and moisture from the ocean drives tropical cyclones.

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The paper can be accessed at

Paper on improvements to hurricane forecasts using data nearest the ocean surface released online in Monthly Weather Review

The National Hurricane Center uses the Hurricane Weather Research and Forecasting (HWRF) model to forecast where a hurricane will go, how strong it will be, how large it will be, and where the strongest winds are. This paper looks at changes in what is happening in the atmosphere closest to the ocean surface and how that can change these forecasts. NOAA Hurricane Hunter aircraft observations are compared to the HWRF forecasts. When differences between the model and the observations are found, the model is changed to greatly improve the forecasts. This technique can be used to make future versions of the model even better.

Important conclusions:

1. The differences between HWRF and NOAA Hurricane Hunter aircraft observations have been used to upgrade the model.

2. These upgrades led to large improvements in forecasts of where the hurricane will go and how strong it will be.

3. This technique can be used to make future forecast models even better.

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The paper can be accessed at

HRD & AOML researchers at 95th American Meteorological Society Annual Meeting, Phoenix, AZ – 4-8 January 2015

Screen Shot 2015-04-04 at 5.42.29 PMAbstracts and recordings of  the 13 presentations and 4 posters AOML & HRD researchers presented (or were co-authors) at the 95th AMS Annual Meeting are available online from the AMS website:


  1. Improving the Performance of the Basin Scale HWRF SystemJavier Delgado, University of Miami/CIMAS and NOAA/AOML/HRD, Miami, FL; and T. Quirino, X. Zhang, and S. Gopalakrishnan
  2. Targeting on the Research to Operational Transition with the Basin-scale HWRF Modeling SystemXuejin Zhang, NOAA/AOML/HRD, Miami, FL; and T. Quirino, S. Trahan, Q. Liu, Z. Zhang, R. St. Fleur, S. Gopalakrishnan, V. Tallapragada, and F. D. Marks Jr.
  3. A Global to Local-Scale Hurricane Forecasting SystemXuejin Zhang (for Sundararaman Gopalakrishnan), University of Miami/CIMAS and NOAA/AOML/HRD, Miami, FL; and T. Black, T. Quirino, V. Tallapragada, Z. Janjic, and T. L. Schneider
  4. Real-time Airborne Radar Data Quality Control and transmission from NOAA Aircraft for assimilation into HWRFJohn F. Gamache, NOAA/AOML/HRD, Miami, FL; and S. Otero, J. W. Hill, and P. P. Dodge
  5. NOAA’s Hurricane Forecast Improvement Project – HFIPFrank D. Marks Jr., NOAA/AOML/HRD, Miami, FL; and F. Toepfer, R. L. Gall, E. Rappaport, and V. Tallapragada
  6. Tropical Cyclone Research Utilizing the Global Hawk Unmanned AircraftJason Dunion (for Michael Black), University of Miami/CIMAS and NOAA/AOML/HRD, Miami, FL; and R. E. Hood and G. A. Wick
  7. Observing System Simulation Experiments to Assess the Potential Impact of Proposed Observing Systems on Hurricane PredictionRobert Atlas, NOAA/AOML, Miami, FL; and L. Bucci, A. Aksoy, B. Annane, R. N. Hoffman, G. D. Emmitt, Y. Xie, S. J. Majumdar, J. Delgado, and L. Cucurull
  8. Fusion of Hurricane Models and Observations: Developing the Technology to Improve the ForecastsSvetla Hristova-Veleva, JPL, Pasadena, CA; and M. Boothe, S. G. Gopalakrishnan, Z. Haddad, B. Knosp, B. Lambrigtsen, P. P. Li, M. Montgomery, N. Niamsuwan, T. P. Shen, V. Tallapragada, S. Tanelli, and F. J. Turk
  9. North Atlantic OSSEs in support of improved hurricane forecasting: Nature Run evaluationVilly H. Kourafalou, Univ. of Miami/RSMAS, Miami, FL; and G. R. Halliwell Jr., R. Atlas, H. S. Kang, M. F. Mehari, M. Le Henaff, L. K. Shay, R. Lumpkin, and G. Goni

Student presentations (HRD Hollings Scholars):

  1. An Extreme Event in the Eyewall of Hurricane FelixKelly Marie Nunez Ocasio, University of Puerto Rico, Mayagüez,, PR; and S. D. Aberson and J. Zhang
  2. A Statistical Take on the Hurricane’s Structure and Its Spatial ExtentRobert G. Nystrom, University of Illinois at Urbana-Champaign, Urbana, IL; and A. Askoy


  1. Impact of CYGNSS Data on Hurricane Analyses and Forecasts in a Regional OSSE FrameworkBachir Annane, Univ. of Miami/CIMAS and NOAA/AOML/HRD, Miami, FL; and B. McNoldy, J. Delgado, L. Bucci, R. Atlas, and S. Majumdar
  2. OSSE Evaluation of a Hyperspectral Sounder and its Potential Impact on Hurricane PredictionLisa Bucci, Univ. of Miami/RSMAS and NOAA/AOML/HRD, Miami, FL; and B. Annane, J. Delgado, and R. Atlas
  3. Wave and Wind Direction Effects on SFMR Brightness Temperatures – Heather M. Holbach, Florida State University, Tallahassee, FL; and E. W. Uhlhorn and M. A. Bourassa
  4. Improving Physical Parameterizations of the Operational Hurricane Model Using Aircraft ObservationsJun Zhang, NOAA/AOML/HRD and Univ. of Miami/CIMAS, Miami, FL; and F. D. Marks Jr., S. Gopalakrishnan, R. Rogers, and V. Tallapragada

HRD/NHC CHART Seminar – Dr. Jun Zhang, CIMAS and AOML/HRD – 13 February 2015

Dr. Zhang presented a seminar on “Improving Hurricane Model Physics using Aircraft Observations ” which is available on the NHC science presentation web site or at:


This talk addresses the important role of aircraft observations in hurricane model physics validation and improvement. As part of NOAA’s Hurricane Forecast Improvement Project (HFIP), a model  framework for improving the physical parameterizations using quality-controlled and post-processed aircraft observations is developed, with steps that include model diagnostics, physics development, physics implementation and further evaluation. Model deficiencies are first identified through model diagnostics by comparing the simulated axisymmetric multi-scale structures to observational composites. New physical parameterizations are developed in parallel based on in-situ observational data from specially designed hurricane field programs. The new physics package is then implemented in the model, which is followed by further evaluation. The developmental framework presented here is found to be successful in improving the surface layer and boundary layer parameterization schemes in the operational Hurricane Weather Research and Forecast (HWRF) model that leads to improved hurricane track and intensity forecasts.

J. Zhang presentation

J. Zhang presentation

Paper on the rapid intensification of Hurricane Earl in 2010 published in Monthly Weather Review

The paper discusses changes to the structure of Hurricane Earl (2010) as it rapidly intensified.   It found

  • Earl tilted with height before it intensified, but was upright during the intensification.
  • Strong thunderstorms played a significant role in the rapid intensification of Hurricane Earl.
  • Thunderstorms located on the inside of the eyewall are a condition favorable for intensification.
  • It is important to learn why thunderstorms form where they do to improve forecasts.
  • It is also important to observe the structure of the hurricane to better represent where these thunderstorms may occur in forecast models and improve hurricane forecasts.

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The paper can be accessed at

HRD scientists participate in HFIP RI Workshop and Annual Review, University of Miami/RSMAS – 18-20 November 2014

The HFIP Workshop on Prediction of Tropical Cyclone Rapid Intensity Change (RIC) and Annual Review Meeting were held at the University of Miami Rosenstiel School of Marine and Atmospheric Science (RSMAS), Miami, FL from 18-20 November, 2014. The agenda, presentations, and background information are available at

The goals of the Workshop on Prediction of Tropical Cyclone Rapid Intensity Change (RIC) were to:

  1. Assess current capabilities for numerical and statistical prediction of RIC, including emphasis on rapid intensification
  2. Identify short-term (0-1 year) and long-term (1-3 year) potential improvements of RIC prediction

HRD scientists Rob Rogers, John Kaplan, Sundararaman Gopalakrishnan, and Jun Zhang provided invited talks.

The HFIP Annual Workshop consisted of three parts:

  1. Reports from each of the strategic and tiger teams on activities and results from 2014 and plans for 2015
  2. A couple of reports on activities relevant to the later discussions
  3. A discussion of priorities for a reduced project

HRD Monthly Science Meeting of November 2014

November’s Science meeting had 5 presentations:

  1. Robert Rogers:  The use of airborne inner core data to aid in short-term intensity prediction
  2. Xuejin Zhang: Basin-scale HWRF Verification
  3. Jun Zhang:  Evaluating the impact of improvements in boundary-layer parameterization on hurricane intensity and structure forecasts in HWRF
  4. Zin Lhu (EMC): Idealized 18/6/2 HWRF Physics experiments in preparation for 2015 implementation
  5. Ghassan Alaka: The Intraseasonal Variability of African Easterly Waves

The presentations are available on the anonymous ftp site at:

Paper on a dataset of dropwindsonde observations in tropical cyclones released online by the Bulletin of the American Meteorological Society

A long-term (1996–2012), high-quality, high vertical resolution (∼5–15 m) GPS dropsonde dataset is created from NOAA Hurricane flights and consists of 13,681 atmospheric profiles for 120 tropical cyclones.

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The paper can be accessed at

HRD Monthly Science Meeting of October 2014

October’s Science meeting had 2 presentations:

  1. Jason Dunion:  Hurricane Edouard: TC Diurnal Cycle
  2. Jun Zhang:  The spin-up of Hurricane Earl (2010) in a HWRF forecast

The presentations are available on the anonymous ftp site at: