 The Cooperative Institute for Meteorological <unk> Studies ( <unk> ) at the University of Wisconsin – Madison has developed the <unk> Dvorak <unk> ( <unk> ) . This is a modified version of the Dvorak technique which uses computer algorithms rather than <unk> human interpretation to arrive at a <unk> number . This is generally not implemented for tropical depressions or weak tropical storms . The China Meteorological Agency ( <unk> ) is expected to start using the standard 1984 version of Dvorak in the near future . The Indian Meteorological Department ( <unk> ) prefers using visible satellite imagery over infrared imagery due to a perceived high bias in estimates derived from infrared imagery during the early morning hours of convective maximum . The Japan Meteorological Agency ( JMA ) uses the infrared version of Dvorak over the visible imagery version . Hong Kong Observatory and JMA continue to utilize Dvorak after tropical cyclone landfall . Various centers hold on to the maximum current intensity for 6 – 12 hours , though this rule is broken when rapid weakening is obvious . 
