Climatological or Synoptic Characteristic

Table 2. The mean climatological (black) and synoptic (red) characteristics at the start of the 24 h period of RI for each TC in the 1989-1997 ATLNST stratification. Mean statistics were computed for the following subsets of the ATLNST stratification: (1) All TCs; (2) RI TCs ; and (3) SI TCs. The difference (D) between the mean value computed for the RI and SI stratifications is also shown for each characteristic. A single or double asterisk was placed beside a D value if the results of a 2-sided t-test indicated that this difference was statistically significant at either the 95% (*) or 99% (**) level.

Characteristic

All

RI

SI

D

JDAY

243.9

245.0

245.4

-0.4

TIME (UTC)

15.9

12.3

17.1

-4.8 (*)

LAT (°N)

21.7

21.4

19.8

1.6

LON (°W)

64.4

64.3

65.2

-0.9

MSSW (kt)

46.1

68.3

34.1

34.2 (**)

CP (mb)

998.9

985.5

1006.4

-20.9 (**)

DML (m)

42.1

42.9

49.8

-6.9

DTL (km)

783.4

831.4

730.1

101.3

SPD (kt)

10.3

10.6

9.8

0.8

HDG (°)

317

307.1

303.8

3.3

SST (°C)

28.0

28.2

27.9

0.3

SHRD (kt)

13.1

9.4

17.6

-8.2 (**)

SHRS (kt)

5.4

4.0

7.1

-3.1 (*)

RVOR(10^-6S^-1)

0.2

0.3

0.3

0.0

REFC (ms^-1d^-1)

1.6

0.6

2.4

-1.8 (*)

U200 (10^-6S^-1)

4.0

0.4

7.5

-7.1 (*)

D200 (10^-6S^-1)

20.5

24.9

17.8

7.1

T200 (°C)

-55.7

-55.5

-55.8

0.3

Characteristic	All	RI	SI	D
JDAY	243.9	245.0	245.4	-0.4
TIME (UTC)	15.9	12.3	17.1	-4.8 (*)
LAT (°N)	21.7	21.4	19.8	1.6
LON (°W)	64.4	64.3	65.2	-0.9
MSSW (kt)	46.1	68.3	34.1	34.2 (**)
CP (mb)	998.9	985.5	1006.4	-20.9 (**)
DML (m)	42.1	42.9	49.8	-6.9
DTL (km)	783.4	831.4	730.1	101.3
SPD (kt)	10.3	10.6	9.8	0.8
HDG (°)	317	307.1	303.8	3.3
SST (°C)	28.0	28.2	27.9	0.3
SHRD (kt)	13.1	9.4	17.6	-8.2 ()**
SHRS (kt)	5.4	4.0	7.1	*-3.1 ()**
RVOR(10^-6S^-1)	0.2	0.3	0.3	0.0
REFC (ms^-1d^-1)	1.6	0.6	2.4	*-1.8 ()**
U200 (10^-6S^-1)	4.0	0.4	7.5	*-7.1 ()**
D200 (10^-6S^-1)	20.5	24.9	17.8	7.1
T200 (°C)	-55.7	-55.5	-55.8	0.3