Hurricane Field Program

2019

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Program Overview

On this page you can find detailed descriptions of the overview plan for the season, information about each product, and the data to go along with it. The 2019 Hurricane Field Program is a project under the Intensity Forecasting Experiment. This page is organized by the lifecycle stages of the storm from genesis to end stage.

About the Intensity Forecasting Experiment: Developed in partnership with NOAA’s Environmental Modeling Center and its Hurricane Center, the Intensity Forecast Experiment is intended to improve our understanding and prediction of hurricane intensity change by collecting observations that will aid in the improvement of current operational models and the development of the next-generation operational hurricane model, the Hurricane Weather Research and Forecasting model.ย Observations also will be collected for NESDIS’ย Ocean Winds Experimentย in a variety of tropical wind regimes as ‘ground truth’ for remote sensing equipment.

Operations

Instrument Descriptions

Data Management Plan

Genesis Stage

Favorable Air Mass Experiment

  • Investigators

    Ghassan Alaka (PI), Jon Zawislak, Jason Dunion, Alan Brammer (CSU/CIRA), Chris Thorncroft (Univ. at Albany-SUNY)
  • Project Goal

    To investigate the favorability in both dynamics (e.g., vertical wind shear) and thermodynamics (e.g., moisture) for tropical cyclogenesis in the environment near a pre-tropical depression, especially the downstream environment [IFEX Goals 1, 3].
  • Observational Applications

    Observations resulting from this science goal have the potential to improve operational forecasts of tropical cyclone formation by identifying characteristics of the large-scale environment near the disturbance. Aircraft observations may provide more details about the thermodynamic and dynamic vertical structure that cannot be measured by satellites. These observations can be stratified into developing and non-developing categories to determine critical differences that are associated with tropical cyclogenesis. Further, these observations may translate into refinement of satellite-based guidance to better determine whether or not a particular disturbance will develop into a tropical cyclone.
  • Science

    Requirements

    Pre-genesis disturbances (pre-TDs), including NHC-designated โ€œInvestsโ€

    Motivation

    The environment near a pre-TD is critical to the favorability for tropical cyclogenesis to occur. The probability of cyclogenesis for a given pre-TD is dependent upon thermodynamics (e.g., moisture) and dynamics (e.g., vertical wind shear) in the adjacent air mass. Increased observations of lower-tropospheric humidity in the near-disturbance environment would shed light upon critical moisture thresholds important (or necessary) for tropical cyclogenesis and would help correct moisture biases in numerical weather prediction models. The downstream environment is most important for cyclogenesis predictions because that is the environment that a pre-TD moves into.

     

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  • Flight Pattern

    Find here a detailed description of intended flight patterns for the experiment.

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Pouch Evolution During Genesis

  • Investigators

    Ghassan Alaka (Co-PI), Jon Zawislak (Co-PI), Mark Boothe (Co-PI, Naval Postgraduate School, NPS), Michael Montgomery (Co-PI, NPS), Tim Dunkerton (Co-PI, Northwest Research Associates, NWRA), Blake Rutherford (CoPI, NWRA)
  • Project Goal

    To investigate the importance of the pouch, including the shear sheath, which tends to indicate a tropical storm, and its relationship to a low-level circulation and organized deep convection within the pouch [IFEX Goal 3]. In 2019, this experiment has the potential to also be flown collaboratively with the National Science Foundation supported Organization of Tropical East Pacific Convection (OTREC) Experiment.
  • Observational Applications

    Observations within this science goal have the potential to improve operational forecasts of tropical cyclone formation by identifying key characteristics of the pouch evolution in developing and non-developing storms. These tendencies can be quantified and incorporated into statistical genesis probabilities issued by the National Hurricane Center. Further impact on genesis forecasts can be made through model evaluation efforts, which have been historically lacking due to the sparse record of in-situ measurements of developing storms [IFEX Goal 1]. Of particular focus is on whether models replicate the location of pouch centers in the low and middle troposphere, and whether they represent well the observed thermodynamic environment encompassing the pouch.
  • Science

    Requirements

    Pre-genesis disturbances (pre-TDs), including NHC-designated โ€œInvestsโ€

    Motivation

    A longstanding challenge for hurricane forecasters, theoreticians, and numerical weather forecast systems is to distinguish tropical waves that will develop into hurricanes from tropical waves that will not develop. The Naval Postgraduate School (NPS) Montgomery Research Group (MRG) has been tracking pouches in the Atlantic since 2008 in numerical models. Airborne observations provide much-needed data for analysis of processes critical for TC genesis, as well as an opportunity to compare our much-used numerical models with reality.

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  • Flight Pattern

    Find here a detailed description of intended flight patterns for the experiment.

    Download Pattern Description

Precipitation Module

  • Investigators

    Jon Zawislak (Co-PI), Ghassan Alaka (Co-PI), and Paul Reasor (Co-PI)
  • Goal

    To investigate the precipitation modes (e.g., stratiform or convective precipitation) that are prevalent during the genesis stage, the evolution of key characteristics (e.g., areal coverage and intensity of precipitation), and the response of the potentially developing vortex to the observed precipitation organization [IFEX Goal 3]. In 2019, this experiment has the potential to also be flown collaboratively with the National Science Foundation supported Organization of Tropical East Pacific Convection (OTREC) Experiment.
  • Observational Applications

    Observations within this science goal have the potential to improve operational forecasts of tropical cyclone formation by identifying tendencies in precipitation characteristics in developing and non-developing storms. These tendencies can be quantified and incorporated into statistical genesis probabilities issued by the National Hurricane Center. Further impact on genesis forecasts can be made through model evaluation efforts, which have been historically lacking due to the sparse record of in-situ measurements of developing storms [IFEX Goal 1]. This particular goal will require using (precipitation) tail Doppler radar data to identify whether precipitation biases exist within Hurricane Weather Research and Forecast (HWRF) model forecasts of potentially developing storms, which could subsequently feed back on the modeled (forecasted) vortex evolution.
  • Science

    Requirements

    Pre-genesis disturbances (pre-TDs), including NHC-designated โ€œInvestsโ€

    Motivation

    One of the fundamental requirements to achieve a more accurate prediction, and understanding, of tropical cyclogenesis events is an improved knowledge of the precipitation organization and the developing vortex response, in the context of environmental forcing, during the formation process. While true that the favorable environmental conditions for tropical cyclogenesis have been well accepted for decades, those conditions also frequently exist in non-developing disturbances. An understanding of the sequence of events, and thus more informed prediction, of tropical cyclogenesis is still very much constrained by our inability to describe the relative contributions of precipitation organization (e.g., deep convection vs. stratiform rain), in the context of the environmental properties, to the evolution of the developing incipient vortex. Numerical models are a convenient platform to study tropical cyclogenesis events, and are often able to reproduce them, but the processes โ€” particularly the relative roles of various precipitation modes involved โ€” that contribute to genesis have generally been unobserved. Satellites are a convenient tool for identifying precipitation properties, particularly with the availability of the Dual-frequency Precipitation Radar (DPR) on the core satellite of the Global Precipitation Measuring Mission (GPM) and multiple higher resolution passive microwave sensors (AMSR2, GMI, SSMIS), but the vortex itself is not well observed; thus the co-evolution of precipitation and vortex cannot be described using satellites alone. Dedicated aircraft missions (outside of the GRIP-PREDICTIFEX, tri-agency field program effort in 2010) have historically been too few.

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  • Flight Pattern

    Find here a detailed description of intended flight patterns for the experiment.

    Download Full Pattern Description

Early Stage

Analysis of Intensity Change Processes Experiment

  • Investigators

    Robert Rogers (Co-PI), Jon Zawislak (Co-PI), Trey Alvey (Co-PI), Jason Dunion (Co-PI), Ghassan Alaka (Co-PI), Heather Holbach (Co-PI), Xiaomin Chen (Co-PI), Josh Wadler (Co-PI, UM/RSMAS)
  • Project Goal

    The goal of this experiment is to collect aircraft observations (i.e., tail Doppler radar, lower fuselage radar, dropsonde, flight-level data, Doppler Wind Lidar, and stepped-frequency microwave radiometer) that will allow us to characterize the precipitation and vortex-scale kinematic and thermodynamic structures of tropical cyclones (TCs) experiencing moderate vertical shear. Understanding the reasons behind these structures, particularly greater azimuthal coverage of precipitation and vortex alignment, will contribute toward a greater understanding of the physical processes that govern whether TCs will intensify in this type of environment [IFEX Goal 3].
  • Observational Applications

    The data collected during this experiment will be useful for the evaluation of numerical model performance in the challenging forecasting environment of moderate vertical wind shear [IFEX Goal 1]. Radar measurements of reflectivity and vertical velocity, along with flight-level measurements of vertical velocity, can be used for the evaluation of microphysical parameterizations. Dropsonde measurements of low-level kinematic and thermodynamic structures and SFMR measurements of surface wind speed can be used to evaluate the performance of planetary boundary layer parameterizations. Select datasets can be withheld in observing system experiments (OSEs) to assess the impact of them on modeling accurately the TC structure and evolution. Finally, deep tropospheric dropsonde data can be used to assess the ability of geophysical retrievals (e.g., relative humidity) from operational satellites (e.g., instruments on NOAA-20, S-NPP) to accurately represent the characteristics of the environments moderately-sheared storms interact with.
  • Science

    Requirements

    TD, TS, Category 1

    Motivation

    While some improvements in operational tropical cyclone (TC) intensity forecasting have been made in recent years (DeMaria et al. 2014), predicting changes in TC intensity (as defined by the 1-min. maximum sustained wind) remains problematic. In particular, the operational prediction of rapid intensification (RI) has proven to be especially difficult (Kaplan et al. 2010). The significant impact of such episodes has prompted the Tropical Prediction Center/National Hurricane Center (TPC/NHC) to declare it as its top forecast priority (Rappaport et al. 2009).

     

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  • Flight Pattern

    Find here a detailed description of intended flight patterns for the experiment.

    Download Full Patterns Descriptionย 

Convective Burst Structure and Evolution Module

  • Investigators

    Robert Rogers (PI), Jon Zawislak, Trey Alvey, Josh Wadler (UM/RSMAS), Michael Bell (CSU)
  • Project Goal

    The objectives are to obtain a quantitative description of the kinematic and thermodynamic structure and evolution of intense convective systems (convective bursts) and the nearby environment to examine their role in TC intensity change [IFEX Goals 1, 3].
  • Observational Applications

    The data collected during this experiment will be useful for the evaluation of numerical model performance in capturing the structure and evolution of deep convection, particularly as it evolves in a sheared environment. Radar measurements of reflectivity and vertical velocity, and cloud and precipitation probe measurements of hydrometeor type and size, can be used for the evaluation of microphysical parameterizations. Dropsonde measurements of low-level kinematic and thermodynamic structures and stepped-frequency microwave radiometer measurements of surface wind speed can be used to evaluate the performance of planetary boundary layer parameterizations. Select datasets can be withheld to assess the impact of them on TC structure and evolution in an observing system experiment (OSE) framework.
  • Science

    Requirements

    TD, TS, Category 1

    Motivation

    The objectives are to obtain a quantitative description of the kinematic and thermodynamic structure and evolution of intense convective systems (convective bursts) and the nearby environment to examine their role in TC intensity change.

    Download Full Science Description

  • Flight Pattern

    Find here a detailed description of intended flight patterns for the experiment.

    Download Pattern Description

Doppler Wind LIDAR

  • Investigators

    Lisa Bucci (PI), Kelly Ryan, Jun Zhang, G. David Emmitt (Simpson Weather Associates, Inc.), Sid Wood (Simpson Weather Associates, Inc.)
  • Goal

    The goal is to create a more comprehensive 3-D analysis of the wind field within a TC through the addition of DWL observations to existing wind observing platforms [IFEX Goals 1 & 2]. Early-stage TCs often exhibit an asymmetric distribution of rain and the DWL can add wind observations in the precipitation-free regions of a developing storm.
  • Observational Applications

    The data collected during the module will be useful for the evaluation of data impact studies which include the DWL wind profiles. The more symmetric distribution of observations could lead to better initial conditions provided to the numerical models. A more accurate representation of the TC structure could generate more reliable intensity forecasts.
  • Science

    Requirements

    TD, TS, Category 1

    Motivation

    Collect wind observations on the dry side of a TC with asymmetric precipitation distribution to provide symmetric coverage of its wind field.

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  • Flight Pattern

    Find here a detailed description of intended flight patterns for the experiment.

    Download Full Pattern Description

Gravity Waves

  • Investigators

    Jun Zhang (Co-PI), David Nolan (Co-PI, University of Miami)
  • Project Goal

    This module aims to collect observations for improving our understanding of the characteristics of gravity waves in early-stage hurricanes. The goal is to quantify how the characteristics of these waves are related to hurricane intensity and intensity change. The observational data collected in this module will also be used to evaluate the hurricane structure in hurricane model simulations [IFEX Goals 1, 3].
  • Observational Applications

    Hurricane convection produces gravity waves that propagate both upward and outward. Physics in hurricane forecast models to represent these waves remain to be evaluated and improved for improving track and intensity prediction. The flight-level data collected from this module would provide valuable information for model evaluation and physics improvement. These observational data will be analyzed to quantify the characteristics of the gravity waves in early-stage hurricanes and their relationship with storm intensity and intensity change. Such relationship would assist the operational intensity forecast in the future. Furthermore, the observational data collected from this module would benefit model initialization in hurricane forecast and research models.
  • Science

    Requirements

    TD, TS, Category 1

    Motivation

    Internal gravity waves are ubiquitous in the atmosphere and are continuously generated by deep moist convection around the globe. Gravity waves play a critical role in the dynamical adjustment processes that keep the atmosphere close to hydrostatic and geostrophic wind balance, by redistributing localized heating over larger distances. Numerical simulations showed gravity waves radiating from the eyewall region to the outer core in TCs. TC convection produces gravity waves that propagate both upward and outward. This module is designed to observe smaller scale gravity waves, with radial wavelengths of 2 to 20 km, that radiate outward from the TC core with phase speeds of 20 to 30 m s-1 . The goal is to quantify how the characteristics of these waves are tied to TC intensity and intensity change

     

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  • Flight Pattern

    Find here a detailed description of intended flight patterns for the experiment.

    Download Full Patterns Descriptionย 

Stepped Frequency Microwave Radiometer (Early)

  • Investigators

    Heather Holbach (PI)
  • Project Goal

    Improve the wind speed and rain rate estimates obtained by the P-3 and G-IV Stepped Frequency Microwave Radiometers (SFMR). For the P-3 SFMR, we aim to be able to obtain wind speed and rain rate estimates when the aircraft is not flying straight and level. For the G-IV SFMR, we aim to develop algorithm corrections to retrieve wind speed and rain rates from a higher altitude [IFEX Goal 2].
  • Observational Applications

    Improved measurements from the SFMR on the P-3 and G-IV have numerous implications for numerical modeling, operational, and research efforts. For numerical models, improved observations of the surface wind speed field will lead to better model initialization and allow for more accurate model evaluations. The operational community will benefit from more accurate surface wind speed observations allowing for improved estimates of tropical cyclone intensity and wind structure. Improvements to these quantities leads to better warnings and preparedness. Finally, SFMR data is used routinely in research studies. Therefore, all of those studies will benefit from improved wind speed and rain rate retrievals leading to more accurate results.
  • Science

    Requirements

    : TD, TS, Category 1

    Motivation

    Surface winds in a tropical cyclone are essential for determining its intensity. Currently, the Stepped-Frequency Microwave Radiometer (SFMR) is used for obtaining surface wind measurements at nadir. Due to poor knowledge about sea surface microwave emission at large incidence angles in high wind speed conditions, SFMR winds are only retrieved when the antenna is pointed directly downward from the aircraft during level flight. Understanding the relationship between the SFMR measured brightness temperatures, surface wind speed, wind direction, and the ocean surface wave field at off-nadir incidence angles would allow for the retrieval of wind speed measurements when the aircraft is not flying level. At off-nadir incidence angles the distribution of foam on the ocean surface from breaking waves impacts the SFMR measurements differently than at nadir and is dependent on polarization (Holbach et al. 2018). Therefore, by analyzing the excess brightness temperature at various wind speeds and locations within the tropical cyclone environment at various off-nadir incidence angles, the relationship between the ocean surface characteristics and the SFMR measurements will be quantified as a function of wind direction relative to the SFMR look angle and polarization.

    In addition, the proven track record of the P-3 SFMRs for providing surface wind data in tropical cyclones (Uhlhorn et al. 2007, Klotz and Uhlhorn 2014) has motivated the effort to obtain usable wind data from the G-IV SFMR. However, there is no documentation of the G-IV SFMR data and its usefulness under the current specifications of the G-IV flight patterns. To our knowledge no data from the G-IV SFMR has been released or used in any research or operational capacity. This data could potentially provide important information about the tropical cyclone wind radii as well as for mapping the environmental surface winds. The goal of this module is to validate the G-IV SFMR data with reliable, coincident P-3 SFMR data in the full spectrum of wind speeds and rain rates.

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  • Flight Pattern

    Find here a detailed description of intended flight patterns for the experiment.

    Download Pattern Description

Tail Doppler Radar (Early)

  • Investigators

    Paul Reasor (Co-PI), John Gamache (Co-PI)
  • Goal

    The goal of the Early Stage TDR Experiment is to provide real-time quality-controlled airborne Doppler-radar radial velocities, as well as Doppler wind fields in the form of three dimensional Cartesian analyses, and vertical cross-sections of analyzed wind along the inbound and outbound radial flight tracks, to EMC, NHC, and CPHC. This is not a basic science experiment, even though the results can contribute to such studies, particularly composite early tropical-cyclone com