Tables


Table 1
Summary of Atlantic tropical cyclone data for the years 1950-1991 with data from Neumann et al. (1987) and Jarvinen et al. (1984). The numbered columns indicate the seasonal total of NS (named storms), NSD (named storm days), H (hurricanes), HD (hurricane days), IH* (intense or major hurricanes), IHD* (intense hurricane days), HDP* (hurricane destruction potential), and NTC* (net tropical cyclone activity). Note that the data with an asterisk are bias-corrected values following the analysis of Landsea (1993).
Year NS NSD H HD IH* IHD* HDP*NTC*
1950 1398 1160 715.75200243
1951 10 58 8 36 25.00113121
1952 7 40 6 23 33.757097
1953 14 64 6 18 35.5059121
1954 11 44 8 32 28.5091127
1955 12 829 47513.75158198
1956 8 30 4 13 22.253969
1957 8 38 3 21 25.256686
1958 1056 730 48.2594140
1959 11 41 7 22 23.756099
1960 7 30 4 18 210.7572101
1961 11 71 8 48 620.75170222
1962 5 22 3 11 00.002633
1963 9 52 7 37 2 5.50103116
1964 12 716 4359.75139168
1965 6 40 4 27 16.257386
1966 1162 742 37.00121140
1967 8 58 6 36 13.259897
1968 7 26 4 10 00.001841
1969 17 84 12 40 32.75110157
1970 10 24 5 7 21.001865
1971 13 63 6 29 11.006595
1972 4 21 3 6 00.001428
1973 7 334 1010.252452
1974 732 414 24.254676
1975 8 43 6 20 3 2.255492
1976 8 45 6 26 21.00 6585
1977 6 14 5 7 11.00 1846
1978 11 40 5 14 23.50 4086
1979 8 44 5 22 25.75 7396
1980 11 60 9 38 27.25126135
1981 11 61 7 2233.75 63114
1982 51626 11.25 1837
19834 14 3 4 10.25 832
198412 51 5 18 10.75 4277
198511 51 7 21 34.00 61110
19866 23 4 10 00.00 2338
19877 37 3 5 10.50 1148
198812 47 5 24 38.0081121
198911 66 7 32 2 10.75108140
19901468 828 1 1.00 57104
19918 224 82 1.252359


Table 2
Data for the 13 predictors for each year from 1950 to 1991 used to make the 1 June forecast of subsequent Atlantic tropical cyclone activity. Note that data in columns 4, 5, 6, 7, 12, and 13 are expressed in terms of standardized deviations and that data in columns 8, 9, and 10 are departures from the long-term (1950-1991) means.
Four-month extrapolated Previous
Aug-Sep
Previous
Aug-Nov
Feb - May
U50
ms-1
U30
ms-1
[U50 - U30]
ms-1
RsRgDxPDxT
Year1 2 3 4 5 6 7
1950 -3.00 -3.00.00-.121.09 .521.55
1951 -4.00 -18.00 14.001.71-.65 .81 -.62
1952 -22.00 -26.00 4.00.52.67 1.47 -.21
1953 -1.00 -18.00 17.00.96.42 1.30 -.24
1954 -22.00 -30.00 8.00.23-.14 .09 -.28
1955 .00 -8.00 8.00.63.66 1.71 .75
1956 -20.00 -30.00 10.001.03.43 .21 -1.25
1957 -2.00 -1.00 1.00.50-.34 .58 .62
1958 -12.00 -29.00 17.00.601.04 .94 .50
1959 -7.00 -1.00 6.001.48-.73 -.17 -.95
1960 -8.00 -30.00 22.00.27.13 .90 .81
1961 -3.00 -5.00 2.00.251.06 2.03 2.98
1962 -12.00 -30.00 18.00.50-.73 .03 1.48
1963 -12.00 -1.00 11.00.30.75 .18 .68
1964 -4.00 -12.00 8.00-.101.20 .25 1.16
1965 -17.00 -31.00 14.00.62-.66 -.07 .76
1966 -7.00 -1.00 6.00.78-.16 .56 1.34
1967 -8.00 -26.00 18.00.36-.13 -.50 -.32
1968 -22.00 -14.00 8.00.75-.49 -.60 -.43
1969 -2.00 -2.00 .00-.811.30 .22 .27
1970 -12.00 -31.00 19.00.40-.29 .27 .64
1971 -3.00 -3.00 .00-.44-.21 -1.16 -1.77
1972 -12.00 -30.00 18.00-.17-.38 -1.15 -1.18
1973 -1.00 -5.00 4.00-1.09-.87 -.52 -.80
1974 -14.00 -31.00 17.00-.71.45 -1.20 -.92
1975 -7.00 -1.00 6.00-.02-.06 -1.14 -.09
1976 -6.00 -26.00 20.00.08-.54 -1.62 -.23
1977 -21.00 -14.00 7.00-.48-.58 .01 1.22
1978 -1.00 -12.00 11.00-.73-.49 -.41 -.23
1979 -17.00 -31.00 14.00-.34-.71 -.58 .49
1980 -5.00 -2.00 3.00-.90.57 -.88 -.43
1981 -12.00 -29.00 17.00-.32.38 -.21 .33
1982 -18.00 -1.00 17.00-.42-.91 -1.10 -.81
1983 -2.00 -18.00 16.00-.89-.60 .13 .26
1984 -20.00 -14.00 6.00-1.22-1.31 -.07 -.10
1985 -1.00 -7.00 6.00-1.21.06 -.47 -.83
1986 -14.00 -28.00 14.00-.50.14 -1.82 -1.61
1987 -21.00 -3.00 18.00.02-.48 .12 -.37
1988 -3.00 -18.00 15.00-.611.39 -.21 -.55
1989 -21.00 -31.00 10.00.44.36 .29 .51
1990 -2.00 -2.00 .00.15.20 .54 1.65
1991 -12.00-29.00 17.00-.79-.57-1.34 -1.16

Table 2: Continued

Year Apr-May (Apr-May)-(Jan-Feb) Apr-May (Apr-May)-(Jan-Feb)
SLPA ZWA SST DtSST SOI DtSOI
mb ms-1 10 -2C 10 -2C 10-1 10-1
8 9 10 11 12 13
1950 -.30 1.50-93.00 41.0010.80.00
1951-.20 1.50 34.00 64.00-9.50-18.70
1952-.20-2.50 26.00 -43.00.509.00
1953-.30 -.50 83.00 48.00-13.20-10.40
1954-.10 -1.50-99.00 -106.004.504.60
1955-.10 -.50 -84.00 -42.003.10-1.40
1956-.20 -.50 -62.00 47.0012.601.10
1957.401.20 83.00 112.00-5.80-6.50
1958-1.20 -3.50 68.00 -55.00-4.008.30
1959.00 .2034.00 -3.004.2016.10
1960-.20 -2.50 5.00 12.006.006.70
1961.70 -2.00 13.00 -2.004.903.60
1962.20-3.70 -50.00 -28.005.70.00
1963-.10 .00 20.00 60.004.90-.70
1964.30 .40-67.00 -106.004.107.30
1965-.30 4.00 58.00 84.00-5.40-3.70
1966.00 .50 3.00 -100.00-6.901.80
1967.30 2.10 -12.00 34.00-2.90-16.30
1968.601.80-47.00 37.005.70-.70
1969-1.20 -4.40 92.00 13.00-6.904.00
1970-.20 -.80 19.00 -63.00-1.0010.50
1971.20 .50 -61.00 67.0014.405.60
1972 .00 1.50 68.00 88.00-14.60-19.80
1973.50-4.40- 17.00 -147.00.509.80
19741.20 3.30 -53.00 70.0010.00-8.20
1975.40 1.30 -57.00 -2.009.309.90
1976.70 2.20 -33.00 93.001.60-10.40
1977.50 .90 12.00-42.00-8.80-11.00
1978-.20 -1.30-38.00-76.004.2019.50
1979.001.50 32.0024.00-.30-1.10
1980.10 .20 46.00-13.00-7.20-8.70
1981-.80 2.10 -24.00-8.001.602.70
1982.20 3.40 48.0035.00-4.70-9.00
1983-1.10 2.50145.00-88.00-5.0028.60
1984.30 -2.50 3.0023.00.80-2.20
1985.30 .30 -70.0018.007.807.00
1986-.504.30 13.0068.00-2.50-.20
1987-1.102.60 123.008.00-21.60-11.10
1988.00-1.60-78.00-138.003.507.40
1989.901.60 -35.0070.0014.00.00
1990-.10.00 45.0045.005.5018.50
1991.504.20 60.0040.00-12.50-15.00


Table 3
Linear correlation coefficients (r) for each of the eight measures of seasonal TC activity with each of the 13 seasonal predictors. (Note other results are presented as r2 or r)
QBO NS NSD H HD IH* IHD* HDP* NTC*
U50 0.450.450.370.380.400.250.370.41
U30 0.380.370.330.310.240.090.260.28
[ U50 - U30 ]-0.51-0.49-0.53-0.48-0.32-0.23-0.41-0.44
AFRICA Rs 0.000.120.100.230.100.220.230.18
Rg 0.510.610.580.600.690.600.640.70
DxP 0.350.440.370.440.550.610.500.57
DxT 0.190.380.320.470.480.570.500.51
Caribbean and ENSO SLPA -0.14-0.12-0.180.00-0.070.08 0.00-0.04
ZWA -0.38-0.23-0.30-0.18-0.22-0.18-0.19-0.26
SST -0.22-0.24-0.22-0.31-0.29-0.28 -0.31-0.31
DtSST -0.110.00-0.070.00-0.23-0.12-0.05-0.12
SOI 0.230.230.200.280.240.270.260.29
DtSOI 0.220.040.110.000.160.05-0.010.10


Table 4
Regression weights for the nonjackknifed LAD regression procedure prediction equations (the bs). Empirical weights for composite functions of QBO, African surface data, and Caribbean/ENSO for the jackknifed LAD regression equations (the a's).
b0 b1 b2 b3
NS 12.378141 .165112.631170 -.271436
NSD 68.855472 1.040898 .798522 -19.513325
H 9.754466 .138935 .507379 -2.588458
HD 41.268825 .651320 3.880723 -13.128793
IH* 2.519881 -.025233 -.405885 .018736
IHD* 6.338632 .152666 -1.601894-1.063583
HDP* 112.9476601.512232 8.571396-34.827567
NTC* 146.76692.0802 -2.2472-17.0237

Table 4: Continued

NS NSD H HD IH* IHD* HDP* NTC*
QBO
a11.00001.00001.00001.0000 1.0000 1.00001.00001.0000
a2-0.0714 -0.0729 -0.3662 -0.3971 0.4160 -0.2182-0.3153 -0.1021
a3-0.9199 -1.2538 -2.1072 -2.0173 0.2899 -0.7551-1.8143 -1.1884
AFRICA
a41.0000 1.0000 1.00001.0000 1.00001.00001.00001.00 00
a52.4308 8.4673 0.5335 0.5796 -2.4883-1.03171.3122 -7.7489
a6-.04778 1.0972 -1.3485 -0.4836 -2.4395-1.61120.2809 -5.4734
a7-0.6367 7.2463 0.8690 1.4982 -0.6668-.99432.7448 -9.3565
ENSO
a81.00001.00001.00001.00001.0000 1.00001.00001.0000
a9-0.1987 -0.0294 0.06667 -0.0667 5.8344 -0.6537-0.0889 -0.0824
a100.0713 0.0054 -0.0012 -0.0055 -0.6297 0.0103-0.0016 0.0098
a11-0.0430 0.0002 0.0016 0.0113 0.0171 0.016670.0088 0.0024
a120.7902 -0.0037 -0.0521 -0.1327 -1.4853 -0.1748-0.1166 -0.0687
a13-0.4711 0.0437 0.0631 0.12580.1546 0.25210.1199 0.1416


Table 5
Agreement coefficient r, probability P of no relationship, and r2 values from a cross-validated LAD regression procedure for the 1 June hindcasts.
r P r2
NS .514 .70 x 10-7.425
NSD.660 .46 x 10-10.688
H .617 .10 x 10-8.595
HD .703 .46 x 10-11.736
IH*.637 .34 x 10-8.703
IHD*.614 .38 x 10-8.654
HDP*.711 .60 x 10-11.751
NTC*.718 .27 x 10-10.760


Table 6
Example of year-to-year verification of the forecast of intense hurricane days.
YearForecast VerificationResidual
(Forecast - Verification)
195015.4415.75-0.31
19515.005.000.00
19523.753.750.00
19535.505.500.00
19543.888.50-4.62
195513.7513.750.00
19562.502.250.25
19575.255.250.00
19583.608.25-4.65
1959-4.643.75-8.39
19604.5010.75-6.25
196114.8620.755.89
19623.180.003.18
19635.505.500.00
196411.229.751.47
19653.076.25-3.18
19667.007.000.00
19675.823.252.57
19680.000.000.00
19695.172.752.42
19701.511.000.51
19711.321.000.32
19724.400.004.40
19732.502.500.00
19745.014.250.76
19751.672.25-0.58
19761.001.000.00
19776.591.005.59
19780.883.50-2.62
19792.325.75-3.43
19805.487.25-1.77
19816.933.753.18
1982-0.751.25-2.00
19830.250.250.00
19840.750.750.00
19855.144.001.14
1986-0.950.00-0.95
19870.500.500.00
19887.468.00-0.54
19896.3610.75-4.39
19905.091.004.09
19911.251.250.00


Table 7
Same as Table 4 for revised IH*,IHD*, HDP*, and NTC* for 1 December of the previous year forecast (Gray et al. 1992a) and for 1 August of the current year forecast (Gray et al. 1993).
1 December 1 August
b0 b1 b2 b0 b1 b2 b3
IH* 2.7590 0.03160.35922.9998 0.01340.7450-0.2895
IHD* 6.40860.03811.12864.8060 0.10854.9325-0.5685
HDP* 86.6214 0.457218.9744 85.83511.615430.9894-4.0380
NTC* 123.6108 0.453417.7062122.81901.480511.3101-0.6185
IH*IHD* HDP* NTC*
1 December
a1 1.00001.00001.00001.0000
a2-0.0146-1.98581.77801.8000
a3-1.1649-7.4296-1.2600-2.4990
a41.00001.00001.00001.0000
a53.79873.83042.11802.8690
1 August
a1 1.00001.00001.00001.0000
a22.44830.19530.55011.0556
a3-0.87570.92890.64941.0129
a41.00001.00001.00001.0000
a50.68910.22200.18641.8147
a61.00001.00001.00001.0000
a70.1660 0.28630.49661.7093
a80.47633.04521.977513.7971
a91.46241.27023.327421.7751


Table 8
Comparison of hindcast skill measured by agreement coefficient for previous work based on differing forecast starting points. Note that the IH*, IHD*, HDP* have been recalculated to adjust for the bias in the tropical cyclone data base found by Landsea (1993). Values for the bias-removed data not available in our previous papers are shown in parenthesis for a proper comparison against the 1 June values.
1 June of
current year
1 December of
previous year
(Gray et al. 1992a)
1 August or current
year
(Gray et al. 1993)
NS0.514 0.440 0.447
NSD0.6600.5140.608
H 0.6170.4470.472
HD 0.7030.4910.505
IH* 0.6370.465 0.586
IHD*0.6140.452 0.540
HDP* 0.7090.4440.549
NTC* 0.7180.5320.581