Development of objective forecast guidance on tropical cyclone rapid intensity change

Recent (past ~15 years) advances in our understanding of tropical cyclone (TC) intensity change processes using aircraft data are summarized here. The focus covers a variety of spatiotemporal scales, regions of the TC inner core, and stages of the TC lifecycle, from preformation to major hurricane status. Topics covered include (1) characterizing TC structure and its relationship to intensity change; (2) TC intensification in vertical shear; (3) planetary boundary layer (PBL) processes and air–sea interaction; (4) upper-level warm core structure and evolution; (5) genesis and development of weak TCs; and (6) secondary eyewall formation/eyewall replacement cycles (SEF/ERC). Gaps in our airborne observational capabilities are discussed, as are new observing technologies to address these gaps and future directions for airborne TC intensity change research.

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A View of Tropical Cyclones from Above: The Tropical Cyclone Intensity Experiment

Bulletin of the American Meteorological Society ◽

10.1175/bams-d-16-0055.1 ◽

2017 ◽

Vol 98 (10) ◽

pp. 2113-2134 ◽

Cited By ~ 43

Author(s):

James D. Doyle ◽

Jonathan R. Moskaitis ◽

Joel W. Feldmeier ◽

Ronald J. Ferek ◽

Mark Beaubien ◽

...

Keyword(s):

Tropical Cyclone ◽

Lower Stratosphere ◽

Inner Core ◽

Horizontal Resolution ◽

Intensity Change ◽

Naval Research ◽

Atmospheric Conditions ◽

Tropical Cyclone Intensity ◽

High Definition ◽

Cyclone Intensity

Abstract Tropical cyclone (TC) outflow and its relationship to TC intensity change and structure were investigated in the Office of Naval Research Tropical Cyclone Intensity (TCI) field program during 2015 using dropsondes deployed from the innovative new High-Definition Sounding System (HDSS) and remotely sensed observations from the Hurricane Imaging Radiometer (HIRAD), both on board the NASA WB-57 that flew in the lower stratosphere. Three noteworthy hurricanes were intensively observed with unprecedented horizontal resolution: Joaquin in the Atlantic and Marty and Patricia in the eastern North Pacific. Nearly 800 dropsondes were deployed from the WB-57 flight level of ∼60,000 ft (∼18 km), recording atmospheric conditions from the lower stratosphere to the surface, while HIRAD measured the surface winds in a 50-km-wide swath with a horizontal resolution of 2 km. Dropsonde transects with 4–10-km spacing through the inner cores of Hurricanes Patricia, Joaquin, and Marty depict the large horizontal and vertical gradients in winds and thermodynamic properties. An innovative technique utilizing GPS positions of the HDSS reveals the vortex tilt in detail not possible before. In four TCI flights over Joaquin, systematic measurements of a major hurricane’s outflow layer were made at high spatial resolution for the first time. Dropsondes deployed at 4-km intervals as the WB-57 flew over the center of Hurricane Patricia reveal in unprecedented detail the inner-core structure and upper-tropospheric outflow associated with this historic hurricane. Analyses and numerical modeling studies are in progress to understand and predict the complex factors that influenced Joaquin’s and Patricia’s unusual intensity changes.

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Precipitation Properties Observed during Tropical Cyclone Intensity Change

Monthly Weather Review ◽

10.1175/mwr-d-15-0065.1 ◽

2015 ◽

Vol 143 (11) ◽

pp. 4476-4492 ◽

Cited By ~ 45

Author(s):

George R. Alvey III ◽

Jonathan Zawislak ◽

Edward Zipser

Keyword(s):

Tropical Cyclone ◽

Passive Microwave ◽

Intensity Change ◽

Rapid Intensification ◽

Relative Importance ◽

Tropical Cyclone Intensity ◽

Cyclone Intensity ◽

East Pacific ◽

Intensity Changes ◽

Strong Convection

Abstract Using a 15-yr (1998–2012) multiplatform dataset of passive microwave satellite data [tropical cyclone–passive microwave (TC-PMW)] for Atlantic and east Pacific storms, this study examines the relative importance of various precipitation properties, specifically convective intensity, symmetry, and area, to the spectrum of intensity changes observed in tropical cyclones. Analyses are presented not only spatially in shear-relative quadrants around the center, but also every 6 h during a 42-h period encompassing 18 h prior to onset of intensification to 24 h after. Compared to those with slower intensification rates, storms with higher intensification rates (including rapid intensification) have more symmetric distributions of precipitation prior to onset of intensification, as well as a greater overall areal coverage of precipitation. The rate of symmetrization prior to, and during, intensification increases with increasing intensity change as rapidly intensifying storms are more symmetric than slowly intensifying storms. While results also clearly show important contributions from strong convection, it is concluded that intensification is more closely related to the evolution of the areal, radial, and symmetric distribution of precipitation that is not necessarily intense.

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The impact of upper tropospheric temperature change on tropical cyclone

10.5194/egusphere-egu21-13735 ◽

2021 ◽

Author(s):

Nawo Eguchi ◽

Kenta Kobayashi ◽

Kosuke Ito ◽

Tomoe Nasuno

Keyword(s):

Tropical Cyclone ◽

Lower Stratosphere ◽

Intensity Change ◽

Tropospheric Temperature ◽

Upward Motion ◽

Sea Level Pressure ◽

Upper Troposphere ◽

Ocean Coupling ◽

Cold Simulation ◽

The Impact

<p>We evaluate the impact of temperature at the upper troposphere and lower stratosphere (UTLS) on the tropical cyclone (TC) generation and its development by using the nonhydrostatic atmosphere-ocean coupling axisymmetric numerical model [Rotunno and Emanuel, 1987; Ito et al., 2010]. In the case of cold simulation at UTLS, the maximum wind and the minimum sea level pressure are increased and decreased than the control run, respectively. The magnitude of intensity change is the approximately 4 times larger than the change estimated from the MPIs (Maximum Potential Intensity [Bister and Emanuel,1998; Holland, 1997]). Further, during the development phase, the cold air mass intrudes to the middle troposphere from the upper troposphere at the center of TC, which is not seen in the warm case, leading the atmosphere unstable and enhanced the upward motion and then the TC got stronger.</p>

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Operational Perspectives on Tropical Cyclone Intensity Change Part 1: recent advances in intensity guidance

Tropical Cyclone Research and Review ◽

10.1016/j.tcrr.2019.10.002 ◽

2019 ◽

Vol 8 (3) ◽

pp. 123-133 ◽

Cited By ~ 4

Author(s):

Joseph B. Courtney ◽

Sébastien Langlade ◽

Charles R. Sampson ◽

John A. Knaff ◽

Thomas Birchard ◽

...

Keyword(s):

Tropical Cyclone ◽

Intensity Change ◽

Tropical Cyclone Intensity ◽

Cyclone Intensity ◽

Recent Advances

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Tropical Cyclone Intensity Change Prediction Based on Surrounding Environmental Conditions with Deep Learning

Water ◽

10.3390/w12102685 ◽

2020 ◽

Vol 12 (10) ◽

pp. 2685

Author(s):

Xin Wang ◽

Wenke Wang ◽

Bing Yan

Keyword(s):

Deep Learning ◽

Tropical Cyclone ◽

Environmental Conditions ◽

Environmental Variables ◽

Intensity Change ◽

Prediction Algorithm ◽

Hybrid Features ◽

Distribution Features ◽

Intensity Changes ◽

Change Prediction

Tropical cyclone (TC) motion has an important impact on both human lives and infrastructure. Predicting TC intensity is crucial, especially within the 24 h warning time. TC intensity change prediction can be regarded as a problem of both regression and classification. Statistical forecasting methods based on empirical relationships and traditional numerical prediction methods based on dynamical equations still have difficulty in accurately predicting TC intensity. In this study, a prediction algorithm for TC intensity changes based on deep learning is proposed by exploring the joint spatial features of three-dimensional (3D) environmental conditions that contain the basic variables of the atmosphere and ocean. These features can also be interpreted as fused characteristics of the distributions and interactions of these 3D environmental variables. We adopt a 3D convolutional neural network (3D-CNN) for learning the implicit correlations between the spatial distribution features and TC intensity changes. Image processing technology is also used to enhance the data from a small number of TC samples to generate the training set. Considering the instantaneous 3D status of a TC, we extract deep hybrid features from TC image patterns to predict 24 h intensity changes. Compared to previous studies, the experimental results show that the mean absolute error (MAE) of TC intensity change predictions and the accuracy of the classification as either intensifying or weakening are both significantly improved. The results of combining features of high and low spatial layers confirm that considering the distributions and interactions of 3D environmental variables is conducive to predicting TC intensity changes, thus providing insight into the process of TC evolution.

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Tropical Cyclone Outflow-Layer Structure and Balanced Response to Eddy Forcings

Journal of the Atmospheric Sciences ◽

10.1175/jas-d-16-0117.1 ◽

2017 ◽

Vol 74 (1) ◽

pp. 133-149 ◽

Cited By ~ 9

Author(s):

Sarah D. Ditchek ◽

John Molinari ◽

David Vollaro

Keyword(s):

Heat Flux ◽

Tropical Cyclone ◽

Momentum Flux ◽

Layer Structure ◽

Secondary Circulation ◽

Intensity Change ◽

Upper Troposphere ◽

Eddy Heat Flux ◽

Momentum Fluxes

Abstract The ERA-Interim is used to generate azimuthally averaged composites of Atlantic basin tropical cyclones from 1979 to 2014. Both the mean state and the eddy forcing terms exhibited similar radial–vertical structure for all storm intensities, varying only in magnitude. Thus, only major hurricanes are described in detail. Radial inflow and outflow extended beyond the 2000-km radius. Warm anomalies reached 2000 km in the outflow layer. Composite eddy momentum fluxes within the outflow layer were 2.5 times larger than mean momentum fluxes, highlighting the importance of outflow–environment interactions. A balanced vortex equation was applied to understand the role of eddy heat and momentum fluxes. Dominant terms were the lateral eddy heat flux convergence, lateral eddy momentum flux, and eddy Coriolis torque. Each acted to enhance the secondary circulation. The eddy momentum flux terms produced about twice the response of heat flux terms. The circulation created by the eddy Coriolis torque arises from a vertical gradient of mean storm-relative meridional wind in the upper troposphere at outer radii. It is produced by background inertial stability variations that allow stronger outflow on the equatorward side. Overall, the fluxes drive a strengthened secondary circulation that extends to outer radii. Balanced vertical motion is strongest in the upper troposphere in the storm core. A method is proposed for evaluating the role of environmental interaction on tropical cyclone intensity change.

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Normalized Convective Characteristics of Tropical Cyclone Rapid Intensification Events in the North Atlantic and Eastern North Pacific

Monthly Weather Review ◽

10.1175/mwr-d-17-0239.1 ◽

2018 ◽

Vol 146 (4) ◽

pp. 1133-1155 ◽

Cited By ~ 14

Author(s):

Michael S. Fischer ◽

Brian H. Tang ◽

Kristen L. Corbosiero ◽

Christopher M. Rozoff

Keyword(s):

Tropical Cyclone ◽

North Atlantic ◽

North Pacific ◽

Forecast Skill ◽

Passive Microwave ◽

Intensity Change ◽

Rapid Intensification ◽

Brightness Temperatures ◽

The North ◽

The North Atlantic

The relationship between tropical cyclone (TC) convective characteristics and TC intensity change is explored using infrared and passive microwave satellite imagery of TCs in the North Atlantic and eastern North Pacific basins from 1989 to 2016. TC intensity change episodes were placed into one of four groups: rapid intensification (RI), slow intensification (SI), neutral (N), and weakening (W). To account for differences in the distributions of TC intensity among the intensity change groups, a normalization technique is introduced, which allows for the analysis of anomalous TC convective characteristics and their relationship to TC intensity change. A composite analysis of normalized convective parameters shows anomalously cold infrared and 85-GHz brightness temperatures, as well as anomalously warm 37-GHz brightness temperatures, in the upshear quadrants of the TC are associated with increased rates of TC intensification, including RI. For RI episodes in the North Atlantic basin, an increase in anomalous liquid hydrometeor content precedes anomalous ice hydrometeor content by approximately 12 h, suggesting convection deep enough to produce robust ice scattering is a symptom of, rather than a precursor to, RI. In the eastern North Pacific basin, the amount of anomalous liquid and ice hydrometeors increases in tandem near the onset of RI. Normalized infrared and passive microwave brightness temperatures can be utilized to skillfully predict episodes of RI, as the forecast skill of RI episodes using solely normalized convective parameters is comparable to the forecast skill of RI episodes by current operational statistical models.

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