Thia Griffin-Elliott

Thia Griffin-Elliott

Published on: July 23, 2021

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Paper on accomplishments of NOAA’s Hurricane Field Program and future plans publishe in The Bulletin of the American Meteorological Society

This review article highlights recent research from NOAA/AOML/Hurricane Research Division’s Hurricane Field Program – Intensity Forecasting Experiment (IFEX) geared to improving our understanding and forecasting of tropical cyclones (TCs). It details the accomplishments of IFEX during the 16 years of its existence, for example

•  describing how IFEX addressed important issues like predicting rapid intensification

•  summarizing collaborations within and outside of NOAA

•  describing advancements in observations 

•  highlighting improvements in the way aircraft data are put into into the computer models

•  emphasizing advances in our understanding of how TCs work. 

Figure 1. Numbers of flights at different intensity levels by NOAA aircraft 2005-2020. The total number is shown in black, and those that occurred when the system was rapidly intensifying are in red. Before this time, the majority of flights were in the strongest hurricanes.

The article concludes by laying the foundation for the “next generation” of the hurricane field program — APHEX (Advancing the Prediction of Hurricanes Experiment) — as it broadens its scope beyond intensity forecasts to improved prediction of all TC hazards, particularly rainfall, storm-surge inundation, and tornadoes — hazards that have gained importance during the last few years after several devastating U.S. landfalling TCs.

Figure 2. Analysis of data from the P3’s Doppler radar in the tail of the aircraft from Hurricane Laura (2020) from P-3 missions during its rapid intensification. (a) wind speed [kt] at 2 km altitude (shaded), and arrows showing wind direction at 2 and 5 km altitude (black and gray, respectively). Locations of strong updrafts, indicating convection are hatched. (b) Wind speed [kt] averaged around the center of Hurricane Laura; 0 indicates Laura’s center and the ground. Both of these are using data taken between 5:30 and 9:55 pm CT 25 August. (c) and (d) show the same, but 12 h later, using data from 6:16 to 10:49 am CT 26 August. The two sets of plots show Laura’s rapid intensification before landfall. Plots like these are now available to National Hurricane Center specialists during the P3 flights.

Important Conclusions:

  1. During the past 16 years, IFEX has contributed to substantial advancements in our ability to observe, understand, and predict TC structure and intensity through more effective assimilation of airborne data into numerical models, use of these data to improve the representation of physical processes in forecast models, development of new observing technologies, and case-study and composite-based research studies that have led to new insights into tropical cyclone structure and intensity change processes.
  2. Advancements in understanding and prediction of tropical cyclones have been made possible through partnerships within and outside NOAA that have formed the foundation of IFEX. As these partnerships continue to strengthen, there is an even greater emphasis on using airborne observations to address the broad array of forecast challenges facing the tropical cyclone forecasting community.
  3. The “next generation” of IFEX and the Hurricane Field Program — APHEX (Advancing the Prediction of Hurricanes Experiment) — will maintain a similar approach to IFEX while emphasizing improvement in forecasts of all TC hazards, and prioritizing flying tropical cyclones earlier in their life cycles (pre-formation and depression stages), where the historical record of aircraft missions are lacking compared to the more mature stages, and in TCs in marginal environments for intensification where intensity change is less predictable.

Figure 3. Analysis of data from the P3’s Doppler radar in the tail of the aircraft from one pass through Hurricane Teddy on 18 September 2020. (a) 2-km radar reflectivity (dBZ) and wind velocity (barbs, kt), (b) the precipitation type classification for convective (“deep”, “moderate”, “shallow”) and more stable, layered clouds (“stratiform”), (c) radar reflectivity (shading, dBZ) and vertical velocity (contour, m/s; solid is upward motion, dashed is downward) above and below the aircraft, and (d) the speed of the wind flowing toward and away from the Teddy’s center (m/s) above and below the aircraft. In (c) and (d), the center of Teddy is in the center of the plot. The red ‘S’ indicates the start of the cross section and the red ‘E’ indicates the end, with the arrow in (a) showing the direction the plane flew through Teddy’s center. This image shows the individual thunderstorms and rainbands (high reflectivity) in the hurricane, and the wind flowing toward the center near the surface and away from the center at high altitude. This wind brings warm, moist air toward the center, and that air fuels the hurricane. Figure 1. Analysis of data from the P3’s Doppler radar in the tail of the aircraft from Hurricane Laura (2020) from P-3 missions during its rapid intensification. (a) wind speed [kt] at 2 km altitude (shaded), and arrows showing wind direction at 2 and 5 km altitude (black and gray, respectively). Locations of strong updrafts, indicating convection are hatched. (b) Wind speed [kt] averaged around the center of Hurricane Laura; 0 indicates Laura’s center and the ground. Both of these are using data taken between 5:30 and 9:55 pm CT 25 August. (c) and (d) show the same, but 12 h later, using data from 6:16 to 10:49 am CT 26 August. The two sets of plots show Laura’s rapid intensification before landfall. Plots like these are now available to National Hurricane Center specialists during the P3 flights.

For more information, contact aoml.communications@noaa.gov. The full text of the paper can be found at
https://journals.ametsoc.org/view/journals/bams/aop/BAMS-D-20-0174.1/BAMS-D-20-0174.1.xml.

Data collection for the hurricane field program would not have been possible without the incredible and heroic efforts of all the pilots, flight directors, navigators, engineers, technicians, mechanics, program managers, and leadership at NOAA/OMAO and their Aircraft Operations Center (AOC). We especially want to acknowledge the late Jim McFadden, former Chief of Programs at AOC, whose decades of leadership and dedication paved the way for the success and accomplishments of this program. IFEX also appreciates the courageous and tireless efforts of the 53rd Air Force Reserve Weather Reconnaissance Squadron and the data they provide each season, as well as the staff at the unit of the Chief, Aerial Reconnaissance Coordination, All Hurricanes. Michael Brennan, James Franklin, and Ed Rappaport at NHC, and Avichal Mehra and Vijay Tallapragada at EMC, have also been instrumental and supportive partners who guide the priorities of this program, and have allowed IFEX to benefit through piggybacking research on operationally-tasked flights. Many scientists both within and outside of NOAA —too many to fairly convey here —have played integral roles in the development, execution, and success of IFEX. Several funding sources have provided support to this project: NOAA base funds (AOC base-funds for flight hours and AOML base funds for HRD staffing and travel), CIMAS, NOAA’s Joint Hurricane Testbed (JHT), HFIP (for flight hours, expendables and travel), and the 2018 and 2019 Hurricane Supplementals (for flight hours and expendables).