APPENDIX A

Table 1: Summary verifications of the authors prior three seasonal forecasts of Atlantic TC activity (1999-2001).

Update Update Update
1999 5 Dec 19987 April 4 June6 August Obs.
No. of Hurricanes 9 9 9 9 8
No. of Named Storms 14 14 14 14 12
No. of Hurricane Days 40 40 40 40 43
No. of Named Storm Days 65 65 75 75 77
Hurr. Destruction Potential(HDP) 130 130 130 130 140
Major Hurricanes (Cat. 3-4-5)4 4 4 4 5
Major Hurr. Days 10 10 1010 15
Net Trop. Cyclone Activity 160 160 160 160 193
Update Update Update
2000 8 Dec 1999 7 April 7 June4 August Obs.
No. of Hurricanes 7 7 8 7 8
No. of Named Storms 11 11 12 11 14
No. of Hurricane Days 25 25 35 30 32
No. of Named Storm Days 55 55 65 55 66
Hurr. Destruction Potential(HDP) 85 85 100 90 85
Major Hurricanes (Cat. 3-4-5)3 3 4 3 3
Major Hurr. Days 6 6 8 6 5.25
Net Trop. Cyclone Activity 125 125 160 130 134
Update Update Update
2001 7 Dec 20006 April 7 June7 August Obs.
No. of Hurricanes 5 6 7 7 9
No. of Named Storms 9 10 12 12 15
No. of Hurricane Days 20 25 30 30 27
No. of Named Storm Days 45 50 60 60 62
Hurr. Destruction Potential(HDP) 65 65 75 75 71
Major Hurricanes (Cat. 3-4-5)2 2 3 3 4
Major Hurr. Days 4 4 5 5 5
Net Trop. Cyclone Activity 90 100 120 120 142

Table 2: Alteration of Atlantic basin tropical cyclone climatology when the base period is changed from 1950-1990 to 1950-2000.

1950-1990 1950-2000 Difference
No. of Hurricanes 5.8 5.9 0.1
No. of Named Storms 9.3 9.6 0.3
No. of Hurricane Days 23.7 24.5 0.8
No. of Named Storm Days 46.9 49.1 2.2
Hurr. Destruction Potential(HDP) 71.7 72.7 11.0
Major Hurricanes (Cat. 3-4-5)2.2 2.3 0.1
Major Hurr. Days 4.7 5.0 0.3
Net Trop. Cyclone Activity 100 100 0