Date/Time Sat Diameter (km) Ring % Tb diff (K) Score Meaning JTWC estimate
20111225T091723 ssmis16 34.5 100.0% 33.1 -48.1 n/a   36.5 kts
20111225T104628 ssmis18 34.5 78.1% 16.2 -16.2 n/a   35.7 kts
20111225T203640 ssmis17 12.2 65.8% 0.0 -0.0 n/a   26.6 kts
20111226T084535 ssmis16 212.4 11.0% 1.7 -1.7 n/a   25.0 kts
20111226T091137 ssmis17 212.4 17.8% 1.5 -1.5 n/a   25.0 kts
20111226T110055 ssmis18 190.1 NaN% NaN NaN n/a   25.0 kts
20111226T202458 ssmis17 212.4 NaN% NaN NaN n/a   25.0 kts
20111227T090055 ssmis17 201.2 7.9% 1.1 -1.1 n/a   22.6 kts

Key:

Diameter values indicate the estimated surface eyewall diameter (the MI eyewall edge diameter minus 10 km).

Diameter values are red if Ring % <= 65, yellow/brown if Ring % <= 85 and green if Ring % > 85.

"Ring %" is the percentage of the "ring" (eyewall inner boundary) that is 1) colder than the "hot spot" (warmest eye pixel) in the eye by 20K, or 2) the percentage that is a) colder than 232K and b) colder than the "hot spot" by 10K, whichever is greater.

"Tb diff" is the difference between the "hot spot" (warmest eye pixel) and the warmest pixel on the eyewall.

Scores are listed as negative, and not used, when the JTWC or NHC estimated Vmax is <50 kts in order to rule out weak but highly symmetric TCs.