Tables
Table 1: Relative errors for the 48 h forecasted vertical wind shear (VWS)
from the AVN model for selected locations and the overall average
during August
and September 1993. Errors (in ms-1) are expressed as observed
minus forecasted VWS
such that positive values indicate more VWS was observed than forecasted.
The type of observed winds (west, east, west < 10 ms-1
and west
10 ms-1) refer to the 200 mb wind flow at the particular location at the verification
time 48 h (t = 48). Number of cases are in parenthesis.
| Category | 15° N, 80° W | 15 °N, 70° W
| 20° N, 65° W | 12.5° N, 60° W
| Avg |
|
|
| All Cases (t = 48) | 5.7 (63) | 6.1 (63) | 2.2 (63) | 2.0 (63)
| 4.0 (252) |
| West (t = 48) | 7.7 (37) | 7.4 (43) | 3.5 (47) | 4.6 (30)
| 5.8 (157) |
| East (t = 48) | 2.8 (26) | 3.4 (20) | -1.6 (16)
| -0.4 (33) | 1.1 (95) |
| West < 10 ms-1 (t = 48) | 7.3 (26) | 5.2 (30) | 2.6 (24)
| 3.5 (23) | 4.7 (103) |
| West 10 ms-1 (t = 48) | 8.6 (11) | 12.5 (13) | 4.5
(23) | 8.3 (7) | 7.8 (54) |
|
Table 2: Average relative forecast errors (in ms-1) for the 48 h VWS
from the AVN model during August and September 1993 stratified by winds
observed at initialization (t = 0) and 48 h later (t = 48). Number of
cases are in parenthesis. Due to missing wind observations coinciding
with model initialization, there are 4 fewer total cases than in Table
1 (248).
| Category | East (t = 48) | West < 10 ms-1 (t = 48)
| West 10 ms-1 (t = 48) |
|
|
| East (t = 0) | 1.4 (51) | 5.8 (37) | 8.8 (6) |
| West < 10 ms-1 (t = 0) | 1.3 (33) | 5.0 (44) | 7.2 (25) |
| West 10 ms-1 (t = 0) | -2.3 (8) | 2.3 (21)
| 8.1 (23) |
|
Table 3: 1979-1988
Climatological VWS values (in ms-1) for mid-August, late
August, mid-September, and late September.
| Date | 15° N, 80° W | 15° N, 70° W
| 20° N, 65° W | 12.5° N, 60 °W
|
|
|
| Mid-August | 14.6 | 14.7 | 10.5 | 8.3 |
| Late August | 12.6 | 14.1 | 9.9 | 9.1 |
| Mid-September | 10.7 | 13.5 | 9.3 | 9.9 |
| Late September | 11.1 | 14.0 | 10.6 | 13.4 |
|
Table 4: Average relative forecast errors (in ms-1) for the 48 h VWS
of all wind stratifications at model initialization (t = 0)
using the AVN prognostic field, persistence, and climatology.
The number of cases are the same as Table 2.
| Category | AVN | Persistence
| Climatology |
|
|
| All Cases (t = 0) | 4.0 | -0.1 | 1.3 |
| West (t = 0) | 4.3 | -1.9 | 2.1 |
| East (t = 0) | 3.6 | 2.9 | 0.1 |
| West < 10 ms-1 (t = 0) | 4.3 | -1.2 | 1.2 |
| West 10 ms-1 (t = 0) | 4.2 | -3.2 | 3.8 |
|
Table 5: Average absolute forecast errors (in ms-1)
for the 48 h VWS
of all wind stratifications at model initialization (t = 0)
using the AVN prognostic field, persistence, and climatology.
The number of cases are the same as Table 2.
| Category | AVN | Persistence
| Climatology |
|
|
| All Cases (t = 0) | 5.4 | 4.8 | 4.5 |
| West (t = 0) | 5.6 | 4.7 | 4.8 |
| East (t = 0) | 5.1 | 4.9 | 4.0 |
| West < 10 ms-1 (t = 0) | 5.3 | 4.1 | 4.0 |
| West 10 ms-1 (t = 0) | 6.3 | 5.8 | 6.3 |
|