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:

HRD Debrief for missions into Hurricane Edouard – 1 October 2014

HRD researchers discussed the results from the 8 P-3, 1 G-IV, and 3 Global-Hawk missions into Hurricane Edouard. The agenda for the discussion was:
  1. Brief overview of all missions (Joe Cione)
  2. Overview of Doppler radar composites (Sim Aberson)
  3. Pre-storm ocean and ocean winds (Eric Uhlhorn)
  4. Model evaluation experiment – 20140915H1 (Jason Dunion)
  5. Model evaluation experiment – 20140915I1 (Eric Uhlhorn)
  6. HS3/NOAA Global Hawk operations – 20140914-15 (Rob Rogers)
  7. Model evaluation experiment – 20140915N1 (Altug Aksoy)
  8. Model evaluation experiment – 20140916H1 (Jason Dunion)
  9. Coyote USA – 20140916H1 (Joe Cione)
  10. Ocean winds – 20140916I1 (Sim Aberson/Paul Chang)
  11. Model evaluation experiment – 20140917H1 (Evan Kalina)
  12. Coyote USA – 20140917H1 (Joe Cione)
  13. HS3/NOAA Global Hawk operations – 20140916-17 (Rob Rogers)
  14. Post-storm ocean and glider comparison 20140919I1 (Eric Uhlhorn)
  15. Caribbean Survey Ocean Glider/North Brazil Current Ring Experiment 20140919I1 (Johna Rudzin, RSMAS)
  16. Media (Erica Rule)
  17. Open discussion (all)

Slides from the debrief are available at:

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10th Anniversary of Hurricane Jeanne


Infrared satellite picture of Hurricane Jeanne at Florida landfall (NOAA)

On the night of Sept. 25, 2004, Hurricane Jeanne made landfall at Sewall’s Point, FL, just three weeks after Hurricane Frances came ashore near the same location.  It was the last of four hurricanes to affect Florida that year, being preceded by Charley, Frances, and Ivan.


Hurricane Jeanne’s track (Wikipedia)

Jeanne began as a tropical wave which organized into a tropical depression prior to passing through the Lesser Antilles.  Once west of the islands, it was upgraded to a tropical storm and then a hurricane after it made landfall in Puerto Rico.  It skimmed along the north shore of Hispañola, which weakened it back down to a depression as it dumped tremendous rains on the mountains there.  Over 3000 people died from flash floods and landslides.  Turning north and moving over the Turks and Caicos, Jeanne seemed destined to recurve out to sea and do no more harm.  But a high pressure ridge to its north stalled and then forced it into a clockwise loop.  During this maneuver, Jeanne regained strength and began heading westward.  As it struck Florida, the hurricane achieved its peak power, with maximum sustained winds of 120 mph (195 km/hr).  Once ashore, Jeanne turned northwest and traveled up Florida and across Georgia before incorporating into a cold front as an extratropical low.  All along its track, Jeanne produced heavy rains and flooding.



Hurricane Jeanne near its peak. MODIS satellite (NASA)

Damage from Jeanne was hard to assess since clean-up after Frances had not been complete. One estimate of US$7 billion would make Jeanne the 15th costliest hurricane on record.  It was certainly the final sour note in Florida’s hurricane sonata for that year.

HRD participated in ten NOAA missions into Jeanne, after it had made its loop and began to intensify.  Some of the research to come out of Jeanne:

  • Environmental Ingredients for Supercells and Tornadoes within Hurricane Ivan Adam K. Baker, Matthew D. Parker, Matthew D. Eastin Weather and Forecasting Volume 24, Issue 1 (February 2009) pp. 223-244
  • On Momentum Transport and Dissipative Heating during Hurricane Landfalls Jun A. Zhang, Ping Zhu, Forrest J. Masters, Robert F. Rogers, Frank D. Marks Journal of the Atmospheric Sciences Volume 68, Issue 6 (June 2011) pp. 1397-1404
  • A Comparison of Adaptive Observing Guidance for Atlantic Tropical Cyclones S. J. Majumdar, S. D. Aberson, C. H. Bishop, R. Buizza, M. S. Peng, C. A. Reynolds Monthly Weather Review Volume 134, Issue 9 (September 2006) pp. 2354-2372
  • Eye and Eyewall Traits as Determined with the NOAA WP-3D Lower-Fuselage Radar Carl E. Barnes, Gary M. Barnes Monthly Weather Review Volume 142, Issue 9 (September 2014) pp. 3393-3417
  • Tropical Cyclone Destructive Potential by Integrated Kinetic Energy Mark D. Powell, Timothy A. Reinhold Bulletin of the American Meteorological Society Volume 88, Issue 4 (April 2007) pp. 513-526
  • THIRTY YEARS OF TROPICAL CYCLONE RESEARCH WITH THE NOAA P-3 AIRCRAFT Sim D. Aberson, Michael L. Black, Robert A. Black, Joseph J. Cione, Christopher W. Landsea, Frank D. Marks Jr., Robert W. Burpee Bulletin of the American Meteorological Society Volume 87, Issue 8 (August 2006) pp. 1039-1055
  • A Parametric Model for Predicting Hurricane Rainfall Manuel Lonfat, Robert Rogers, Timothy Marchok, Frank D. Marks Jr. Monthly Weather Review Volume 135, Issue 9 (September 2007) pp. 3086-3097
  • On the Limits of Estimating the Maximum Wind Speeds in Hurricanes David S. Nolan, Jun A. Zhang, Eric W. Uhlhorn Monthly Weather Review Volume 142, Issue 8 (August 2014) pp. 2814-2837
  • Estimating Maximum Surface Winds from Hurricane Reconnaissance Measurements Mark D. Powell, Eric W. Uhlhorn, Jeffrey D. Kepert Weather and Forecasting Volume 24, Issue 3 (June 2009) pp. 868-883
  • Turbulence Structure of the Hurricane Boundary Layer between the Outer Rainbands Jun A. Zhang, William M. Drennan, Peter G. Black, Jeffrey R. French Journal of the Atmospheric Sciences Volume 66, Issue 8 (August 2009) pp. 2455-2467
  • Wavelet Analyses of Turbulence in the Hurricane Surface Layer during Landfalls Ping Zhu, Jun A. Zhang, Forrest J. Masters Journal of the Atmospheric Sciences Volume 67, Issue 12 (December 2010) pp. 3793-3805
  • Air–Sea Enthalpy and Momentum Exchange at Major Hurricane Wind Speeds Observed during CBLAST Michael M. Bell, Michael T. Montgomery, Kerry A. Emanuel Journal of the Atmospheric Sciences Volume 69, Issue 11 (November 2012) pp. 3197-3222

HRD Monthly Science Meeting of September 2014

September’s Science meeting had 5 presentations:

  1. Jie Tang (CMA/STI):  The Transition of Turbulent Cascade in the Near-surface Layer of Landfalling Typhoons
  2. Brad Klotz:  Expanding the MSI metric to scatterometer surface winds
  3. Shirley Murillo:  Science Research Opportunities
  4. Robert Rogers: Convective and vortex-scale interactions during the rapid intensification of Hurricane Earl (2010)
  5. Sandy Delgado:  Reanalysis of the 1954-1963 Atlantic Hurricane Seasons

The presentations are available on the anonymous ftp site at:


25th Anniversary of a ‘hairy hop’ into Hurricane Hugo


NOAA 42 radar display of Hugo’s eyewall

On September 15, 1989, NOAA 42 “Kermit” flew a research mission into Hurricane Hugo, east of Barbados, that became what old-time Hurricane Hunters called a “hairy hop”.  This referred to a hurricane flight where the turbulence was so severe as to put the mission in jeopardy.

The day before the two NOAA P-3 Orion research planes had deployed to Barbados to intercept Hugo while it was still east of the Lesser Antilles.  In addition, several Air Force Reserve Hurricane Hunter C-130s had similarly deployed to carry out reconnaissance on the storm.  The plan was for NOAA 42 to enter the storm first, followed by NOAA 43 “Miss Piggy” and the USAF aircraft, designated Teal 57.  On approach to the storm there was a temporary outage of the lower fuselage radar, blinding the crew as to the structure and strength of the storm they were approaching.  Jeff Masters, the Flight Director, and Frank Marks, the Lead Scientist, decide to enter the storm at 1500 feet, an altitude much lower than the usual 5-10 thousand feet.  The hope was to gather energetics information close to the top of the boundary layer.  However, since this was the first plane to enter this storm, the crew had no idea how strong the eyewall turbulence would be.  Once the radar was working again, NOAA 42 was just minutes from penetrating the storm.  The eye appears to be just 12 miles across.


NOAA 42’s G meter

They slammed into an updraft/downdraft/updraft triplet which wrenched the aircraft violently from 20 mph up, to 22 mph down, to 45 mph up again, all while the horizontal winds peak at 185 mph (298 km/hr)!  Then force on the plane goes from 3 g’s downward to 6 g’s up (1 g = the force of gravity).  Even items which were fastened down, such as a 200 pound life raft, are torn loose and sent careening around the cabin.  Even worse, one of the aircraft’s four engines spouts flames.  Just then they enter the calm of Hugo’s eye.  The pilots pull the plane out of its dive 880 feet above the raging ocean surface, a loss of 620 feet in just seconds.  To add to their predicament, the navigator Sean White spots a de-icing boot dangling loose over the engine next to the one on fire.


NOAA 42’s trashed interior

NOAA 42 begins to orbit the small eye of Hugo, desperately trying to avoid entering its fierce winds again.  They hope to quell the engine blaze and then gain altitude to exit the storm at a safer altitude.  The aircraft begins the tricky business of dumping excess fuel in order to lighten the plane and allowing it to climb further.  They also eject all of the heavy bathythermograph probes they had on board to measure sea temperatures. After reaching 5000 feet, Teal 57 arrives in the eye and flies near NOAA 42 to inspect for damage.  Finding nothing major, the Air Force plane begins a series of eyewall penetrations looking for a ‘soft spot’ for NOAA 42 to exit by. NOAA 43 arrives in the eye and monitors the other aircraft from 15,000 feet.  When they are finally ready to exit, the crew finds that the dangling de-icing boot has fallen off without further injury to its engine.  They follow Teal 57 out through the northeast eyewall, found to be the weakest spot, and exit the storm while encountering just manageable turbulence.  They return to Barbados with no injuries.

But NOAA 42 is out of commission for the rest of the 1989 hurricane season.  NOAA 43 continues to monitor the hurricane as it rampages through the Caribbean, kiling 72 people and racking up over US$4 billion in havoc, and finally makes landfall at Charleston, SC.  HRD crews are at the Charleston and Wilmington NWS offices recorded the radar data for future research as the storm plowed through the Carolinas causing US$5 billion in damages and 35 deaths.

NOAA 42 crew on Sept. 15th : Aircraft Commander Lowell Genzlinger, Pilot Gerry McKim, Flight Director Jeff Masters, Flight Engineer Steve Wade, Navigator Sean White, Radio Operator Tom Nunn, System Engineers Al Goldstein and Terry Schricker, Radar Technician Neil Rain, Lead Scientist Frank Marks, Radar Scientist Peter Dodge, Doppler Radar Scientist Bob Burpee, Air-Sea Scientist Pete Black, Dropsonde Scientist Hugh Willoughby, Observer Jim McFadden, reporter Janice Griffith of the Barbados Sun.

Hurricane Hugo was a landmark storm in general and for researchers in particular.  Some research papers by HRD personnel about Hugo:

  • Black, M. L., R. W. Burpee, and F. D. Marks Jr., 1996:  Vertical Motion Characteristics of Tropical Cyclones Determined with Airborne Doppler Radial Velocities.  J. Atmos. Sci., 53, 1887–1909.
  • Black, R. A., and J. Hallett, 1999:  Electrification of the Hurricane. J. Atmos. Sci., 56, 2004–2028.
  • DeMaria, M., and J. Kaplan, 1994:  A Statistical Hurricane Intensity Prediction Scheme (SHIPS) for the Atlantic Basin.  Wea. Forecasting, 9, 209–220.
  • Demaria, M., and R. W. Jones, 1993:  Optimization of a Hurricane Track Forecast Model with the Adjoint Model Equations.  Mon. Wea. Rev., 121, 1730–1745.
  • DeMaria, M., J. Kaplan, and J.-J. Baik, 1993:  Upper-Level Eddy Angular Momentum Fluxes and Tropical Cyclone Intensity Change.  J. Atmos. Sci., 50, 1133–1147.
  • Dorst, N. M., 2007:  The National Hurricane Research Project: 50 Years of Research, Rough Rides, and Name Changes.  Bull. Amer. Meteor. Soc., 88, 1566–1588.
  • Eastin, M. D., P. G. Black, and W. M. Gray, 2002:  Flight-Level Thermodynamic Instrument Wetting Errors in Hurricanes.  Part I: Observations. Mon. Wea. Rev., 130, 825–841.
  • Franklin, J. L., S. E. Feuer, J. Kaplan, and S. D. Aberson, 1996: Tropical Cyclone Motion and Surrounding Flow Relationships: Searching for Beta Gyres in Omega Dropwindsonde Datasets. Mon. Wea. Rev., 124, 64–84.
  • Franklin, J. L., and M. DeMaria, 1992:  The Impact of Omega Dropwindsonde Observations on Barotropic Hurricane Track Forecasts. Mon. Wea. Rev., 120, 381–391.
  • Gopalakrishnan, S. G., F. M. Jr., J. A. Zhang, X. Zhang, J.-W. Bao, and V. Tallapragada, 2013:  A Study of the Impacts of Vertical Diffusion on the Structure and Intensity of the Tropical Cyclones Using the High-Resolution HWRF System.  J. Atmos. Sci., 70, 524–541.
  • Houston, S. H., W. A. Shaffer, M. D. Powell, and J. Chen, 1999: Comparisons of HRD and SLOSH Surface Wind Fields in Hurricanes: Implications for Storm Surge Modeling.  Wea. Forecasting, 14, 671–686.
  • Jones, R. W., and Mark DeMaria, 1999:  Further Studies of the Optimization of a Hurricane Track Prediction Model Using the Adjoint Equations.  Mon. Wea. Rev., 127, 1586–1598.
  • Marks, F. D., P. G. Black, M. T. Montgomery and R. W. Burpee, 2008: Structure of the eye and eyewall of Hurricane Hugo (1989). Mon. Wea. Rev., 136, 1237–1259.
  • Powell, M. D., P. P. Dodge, and M. L. Black, 1991: The landfall of Hurricane Hugo in the Carolinas: surface wind distribution. Wea. and Forecasting, 6, 379-399.
  • Powell, M. D., 1993:  Wind Measurement and Archival under the Automated Surface Observing System (ASOS):  User Concerns and Opportunity for Improvement.  Bull. Amer. Meteor. Soc., 74, 615–623.
  • Powell, M. D., P. P. Dodge, and M. L. Black, 1991:  The Landfall of Hurricane Hugo in the Carolinas: Surface Wind Distribution.  Wea. Forecasting, 6, 379–399.
  • Roux, F., and F. D. Marks Jr., 1996:  Extended Velocity Track Display (EVTD):  An Improved Processing Method for Doppler Radar Observations of Tropical Cyclones.  J. Atmos. Oceanic Technol., 13, 875–899.
  • Samsury, C. E., and E. J. Zipser, 1995:  Secondary Wind Maxima in Hurricanes: Airflow and Relationship to Rainbands.  Mon. Wea. Rev., 123, 3502–3517.
  • Velden, C. S., C. M. Hayden, W. P. Menzel, J. L. Franklin, and J. S. Lynch, 1992:  The Impact of Satellite-derived Winds on Numerical Hurricane Track Forecasting.  Wea. Forecasting, 7, 107–118.
  • Willoughby, H. E., R. W. R. Darling, and M. E. Rahn, 2006:  Parametric Representation of the Primary Hurricane Vortex.  Part II:  A New Family of Sectionally Continuous Profiles.  Mon. Wea. Rev., 134, 1102–1120.
  • Willoughby, H. E., and M. E. Rahn, 2004:  Parametric Representation of the Primary Hurricane Vortex. Part I:  Observations and Evaluation of the Holland (1980) Model.  Mon. Wea. Rev., 132, 3033–3048.
  • Willoughby, H.E., 1998:  Tropical Cyclone Eye Thermodynamics.  Mon. Wea. Rev., 126, 3053–3067.
  • Willoughby, H. E., 1991:  Reply.  J. Atmos. Sci., 48, 1209–1212.
  • Zhang, J. A., F. D. Marks, M. T. Montgomery and S. Lorsolo, 2011: An estimation of turbulent characteristics in the low-level region of intense Hurricanes Allen (1980) and Hugo (1989). Mon. Wea. Rev., 139, 1447-1462.
  • Zhang, J. A., and M. T. Montgomery, 2012:  Observational Estimates of the Horizontal Eddy Diffusivity and Mixing Length in the Low-Level Region of Intense Hurricanes.  J. Atmos. Sci., 69, 1306–1316.

HRD Debrief for missions into Tropical Storm/Hurricane Cristobal – 5 September 2014

HRD researchers discussed the results from the 8 P-3 and 2 G-IV missions into Tropical Storm/Hurricane Cristobal. The agenda for the discussion was: