Dvorak Intensity Analysis: Pattern types

1. Curved Band2. Shear3. Central Dense Overcast (CDO)4. Eye

Examples of Curved Band Pattern

Curved Band – Tropical Storm IRENEGOES-12 Visible image 1315 UTC 11 Aug 2005

Curved Band – Tropical Storm KATRINA1645 UTC 24 Aug 2005

Curved Band – Tropical Storm OPHELIAMODIS Truecolor image 1700 UTC 28 Sep 2011

Examples of Shear Pattern

Shear Pattern – Tropical Storm HARVEY2045 UTC 5 Aug 2005

Shear Pattern – Tropical Storm HARVEY1245 UTC 5 Aug 2005

Shear Pattern -- Tropical Depression “ pre- KATIA”1510 UTC 29 Aug 2011

Note: also may be classified as Curved Band pattern, at this early stage

Examples of Central Dense Overcast (CDO) Pattern

CDO pattern – Tropical Storm IRENE1115 UTC 14 Aug 2005

CDO Pattern – Hurricane IRENE1845 UTC 15 Aug 2005

CDO Pattern – Tropical Storm KATRINA1715 UTC 25 Aug 2005

CDO Pattern – Tropical Storm Katrina1815 UTC 25 Aug 2005

Note: first classified as hurricane (65 kt) just after this image (21 UTC Advisory)

CDO – Tropical Storm PHILIPPEMODIS truecolor image 1535 UTC 26 Sep 2011

CDO Pattern – Hurricane Katrina2045 UTC 26 Aug 2005

CDO Pattern – Hurricane KATRINA2015 UTC 26 Aug 2005

Examples of Eye Pattern

Eye Pattern – Hurricane IRENE1445 UTC 16 Aug 2005

Eye pattern – Hurricane KATRINA1715 UTC 28 Aug 2005

Note: Cat 5 hurricane intensity at this time

Eye Pattern – Hurricane KATRINA1845 UTC 28 August 2005

Eye Pattern – Hurricane GUSTAVMODIS Visible image 1910 30 Aug 2008

Eye Pattern -- Hurricane DEANNOAA-18 AVHRR Visible image 1852 UTC 19 August 2007

Eye Pattern – Tropical Storm Ophelia1440 UTC 29 Sep 2011

Note: this is referred to as a “banding eye” defined as the inner cloud minimum area of an extensive spiral band.

Eye Pattern -- Hurricane FELIXGOES visible image at 1 km res -- 2015 UTC 3 Sep 2007

Note: very small eyes are sometimes referred to as “pinhole” eyes