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:

HRD Scientists participate in World Weather Open Science Conference (WWOSC), Montreal, Canada – 16-21 August 2014

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Drs. Rob Rogers and Sundararaman Gopalakrishnan (Gopal) attended World Weather Open Science Conference (WWOSC-2014) and presented results of their research. Gopal presented a talk on “Global to Local Scale Hurricane Forecasting System” and Rob Rogers presented a talk entitled “Convective and Vortex-Scale Interactions during rapid intensification of Hurricane Earl (2010)”. The conference presentations are supported by High Impact Weather Prediction Project (HIWPP).

Their presentations are available on the ftp site at: ftp://ftp.aoml.noaa.gov/pub/hrd/blog/seminars/2014/WWOSC_2014.zip

10th Anniversary of Hurricane Frances


NASA MODIS satellite photo of Hurricane Frances at its peak intensity

On September 5, 2004, Hurricane Frances, the second hurricane to make landfall in Florida that record-breaking year, came ashore at Sewall’s Point.  Frances had followed Hurricane Charley in striking Florida by 23 days and was followed in turn by Hurricane Jeanne, hitting the same point three weeks later.  Hurricane Ivan completed the quadruple whammy on Florida a mere ten days after Jeanne.

Frances began as a African Easterly Wave on August 21, and became a classic Cape Verde-type hurricane as it trekked across the Atlantic’s Main Development Region gaining strength and organization.  Frances reached its peak intensity as it moved north of the island of Hispanola, with winds of 145 mph (233 km/hr).  It rampaged through the Bahama Islands as it slowly weakened, knocking out power to three quarters of the residents and causing some US$300 million in damage.  At the north end of the archipelago, the hurricane turned northwestward for its encounter with the Florida shore.  It struck in the early morning hours of Sept. 5th bringing Category-2 winds and heavy rain.  It picked up speed over Florida but managed to cause damage throughout most of central Florida, especially in areas already affected by Charley.  It dipped its toes briefly in the Gulf of Mexico before making another Florida landfall in the panhandle.  It moved northward before merging with an extratropical trough over the Ohio Valley.

Frances’ damage bill is estimated to be some US$9 billion, and caused 7 deaths directly and 42 indirectly.

NOAA flew 14 missions into Hurricane Frances, mostly Coupled Boundary Layer Air-Sea Transfer (CBLAST) and Synoptic Surveillance experiments.

Scientific articles by HRD personnel using Hurricane Frances data

  • Aberson, S. D., 2010:  10 years of hurricane synoptic surveillance (1997-2006).  Mon. Wea. Rev., 138, 1536-1549.
  • Aberson, S. D., 2008:  Large forecast degradations due to synoptic surveillance during the 2004 and 2005 hurricane seasons.  Mon. Wea. Rev., 136, 3138-3150.
  • Black, P. G., E. A. D’Asaro, W. M. Drennan, J. R. French, P. P. Niiler, T. B. Sanford, E. J. Terrill, E. J. Walsh and J. A. Zhang, 2007: Air-sea exchange in hurricanes:  Synthesis of observations from the Coupled Boundary Layer Air-Sea Transfer Experiment.  Bull. Amer. Met. Soc.,  88, 357-374.
  • Lonfat, M., R. Rogers, T. Marchok, and F. D. Marks Jr., 2007:  A parametric model for predicting hurricane rainfall.  Mon. Wea. Rev., 135, 3086-2097.
  • Lorsolo, S., J. L. Schroeder, P. Dodge, and F. Marks Jr., 2008:  An observational study of hurricane boundary layer small-scale coherent structures.  Mon. Wea. Rev., 136, 2871-2893.
  • Majumdar, S. J., S. D. Aberson, C. H. Bishop, R. Buizza, M. S. Peng, and C. A. Reynolds, 2006:  A comparison of adaptive observing guidance for Atlantic tropical cyclones.  Mon. Wea. Rev., 134, 2354-2372.
  • Powell, M. D., E. W. Uhlhorn, and J. D. Kepert, 2009:  Estimating maximum surface winds from hurricane reconnaissance measurements.  Wea. Forecast., 24, 868-883.
  • 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.
  • Zhang, J. A., P. Zhu, F. J. Masters, R. F. Rogers, and F. D. Marks, 2011:  On momentum transport and dissipative heating during hurricane landfalls.  J. Atmos. Sci., 68, 1397-1404.
  • 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 hurricane Allen (1980) and Hugo (1989).  Mon. Wea. Rev., 139, 1447-1462.

Tenth Anniversary of Hurricane Charley


Hurricane Charley at landfall as seen by NWS Tampa radar


On Friday August 13, 2004, Hurricane Charley came roaring ashore at Port Charlotte, FL.  The hurricane had rapidly intensified prior to its landfall.  Also, since its track was running parallel to the southwest Florida coast, any slight variation in course would bring a large deviation of the expected landfall point.  This made Charley’s arrival something of an unpleasant surprise for many residents.

Charley had formed four days earlier south of Barbados.  It tracked south of Jamaica and struck the western tip of Cuba as a Category 3 hurricane early on the morning of August 13th.  It weakened slightly after encountering the island but after passing over the Dry Tortugas it began a rapid intensification and swerved northeastward as its winds ramped up from 110 mph (180 km/hr) to 145 mph (230 km/hr) in just three hours.  By the time Charley struck Cayo Costa, FL, its winds had peaked at 150 mph (240 km/hr).  Because it was a small hurricane, Charley cut a narrow swath of damage across Captiva Island, Punta Gorda, and Port Charlotte.  (It literally cut a narrow channel through Captiva.) Moving across Florida its strength rapidly diminished but still caused damage in Orlando and Kissimmee before moving out to sea at New Smyrna Beach.  It then went on to strike South Carolina as a Category 1 hurricane, bringing high winds and heavy rains to the Carolinas and Virginia before becoming absorbed into a front.  Charley was responsible for 15 direct deaths in Jamaica, Cuba, and the United States and caused over US$16 billion in damages.


Hurricane Charley’s forecast track at 11 PM on August 12th

There was considerable controversy after the storm.  Although the Florida landfall was within NHC’s cone of uncertainty, many people had concentrated on the ‘skinny black line’ at the center of the cone which depicted landfall in the Tampa region and were surprised by the hurricane’s turn to the northeast.  In addition, many of the high wind warnings issued for Orlando were not carried with the same alert headers as hurricane warnings and were either missed or misinterpreted by emergency managers, TV meteorologists, and the public.  Charley was the first of a record four hurricanes to strike Florida during the very active 2004 hurricane season.

Here are a list of scientific papers with HRD authors or coauthors resulting from Charley:

  • Aberson,S, D., 2008:  Large Forecast Degradations due to Synoptic Surveillance during the 2004 and 2005 Hurricane Seasons. Mon. Wea. Rev., 136, 3138–3150.
  • DiNapoli, S. M., M. A. Bourassa, and M. D. Powell, 2012:  Uncertainty and Intercalibration Analysis of H*Wind.  J. Atmos. Oceanic Technol., 29, 822–833.
  • Lonfat, M., R. Rogers, T. Marchok, and F. D. Marks Jr., 2007:  A Parametric Model for Predicting Hurricane Rainfall.  Mon. Wea. Rev., 135, 3086–3097.
  • Majumdar, S. J., S. D. Aberson, C. H. Bishop, R. Buizza, M. S. Peng, and C. A. Reynolds, 2006:  A Comparison of Adaptive Observing Guidance for Atlantic Tropical Cyclones.  Mon. Wea. Rev., 134, 2354–2372.
  • Marchok, T., R. Rogers, and R. Tuleya, 2007:  Validation Schemes for Tropical Cyclone Quantitative Precipitation Forecasts: Evaluation of Operational Models for U.S. Landfalling Cases.  Wea. Forecasting, 22, 726–746.
  • Powell, M. D., and T. A. Reinhold, 2007:  Tropical Cyclone Destructive Potential by Integrated Kinetic Energy.  Bull. Amer. Met. Soc., 88, 513-526.
  • Reynolds, C. A., M. S. Peng, S. J. Majumdar, S. D. Aberson, C. H. Bishop, and R. Buizza, 2007:  Interpretation of Adaptive Observing Guidance for Atlantic Tropical Cyclones.  Mon. Wea. Rev., 135, 4006–4029.
  • Zhu, P., J. A. Zhang, and F. J. Masters, 2010:  Wavelet Analyses of Turbulence in the Hurricane Surface Layer during Landfalls.  J. Atmos. Sci., 67, 3793–3805.

HRD Monthly Science Meeting of July 2014

July’s Science meeting had 4 presentations:

  1. Kelly M. Núñez Ocasio:  An Extreme Event in the Eyewall of Hurricane Felix
  2. Robert Nystrom:   Storm-Relative Correlation Structures
  3. Joseph Patton:  Extratropical Transition of Hurricane Sandy
  4. Robert Rogers:  Deep convection and its role in RI

The presentations are available on the anonymous ftp site at: