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Cooperative Institute for Meteorological Satellite Studies / University of Wisconsin-Madison
Tropical Cyclones
Advanced Dvorak Technique (ADT)

The Advanced Dvorak Technique (ADT) utilizes longwave-infrared, temperature measurements from geostationary satellites to estimate tropical cyclone (TC) intensity. The ADT is based upon the operational Dvorak Technique developed by Vern Dvorak of NOAA over 30 years ago. This step-by-step technique relies upon the user to determine a primary cloud pattern and measure various TC cloud top parameters in order to derive an initial intensity estimate. Various rules regarding TC development and intensity change over time are employed to guide the user in the scene selection process and govern the rate in intensity change over a given time period.
 
The Dvorak Technique continues to be the standard method for estimating TC intensity where aircraft reconnaissance is not available (all tropical regions outside the North Atlantic and Caribbean Sea), however it has several important limitations and flaws. The primary issue centers upon the inherent subjectivity of the storm center selection and scene type determination proceedures. Secondly, learning the Dvorak Technique and its regional nuances and adjustments can take a significant time to master. Finally, the technique was developed more or less empirically by Dvorak and his colleagues, without the aid of computer analysis, to determine statistical relationships between various environmental parameters and intensity.
 
The ADT (and its predecessors the ODT and AODT) sought to alleviate many of the limitations found within the Dvorak Technique and previous objective algorithms based upon methods outlined by Dvorak. The ADT currently utilizes an objective storm center determination scheme and cloud pattern determination logic to remove the subjectivity aspect from the intensity estimation process. It also can be applied to all phases of the TC lifecycle; something that previous objective schemes could not do. Finally, the ADT makes use of statistical analysis results obtained from a 10+ year sample of North Atlantic storms, along with a significant sample of West and East Pacific storms, covering the entire spectrum of TC intensities to derive a regression-based intensity value estimate for various phases of the TC lifecycle.
 
The ADT is a powerful but easy-to-use TC intensity estimation guidance tool possessing an accuracy on par with estimates obtained by experienced TC forecasters using the Dvorak Technique.
 
Link to real-time ADT estimates here.

 
ADT flowcharts : Overview | Scene Selection | Intensity Calculations


Products Archives
Version 8.1.4
ADT Users Guide
2014 Storms
2013 Storms
2012 Storms
2011 Storms
2010 Storms
2009 Storms
2008 Storms
2007 Storms
2006 Storms
2005 Storms
2004 Storms
2003 Storms
Publications Performance
IR-WV Differencing Technique Article
(PDF from AMS website)
(Olander and Velden, 2009)

ADT Article
(PDF from AMS website)
(Olander and Velden, 2007)

History of the Dvorak Technique
(PDF)
(Velden et. al., 2006)

Latitude Bias Article
(PDF)
(Kossin and Velden, 2004)

Original ODT Article
(Velden et. al., 1998)

Statistics for version 8.1.3
coming soon

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