1. Tropical cyclone activity
1.1 Tropical cyclones ending during the month
|
NWP
|
NEP
|
NAT
|
NI
|
SWI
|
AUS
|
TOTAL
|
| Total number ending
during the month
|
3
|
4
|
0
|
0
|
0
|
0
|
7
|
|
| Name
|
Identifier
|
Basin
|
Start Date
|
End Date
|
1-minute MSW
|
10-minute MSW
|
| Mindulle
|
10W
|
NWP
|
23 June
|
04 July
|
125
|
90
|
| Tingting
|
11W
|
NWP
|
25 June
|
04 July
|
75
|
85
|
| -
|
02E
|
NEP
|
02 July
|
03 July
|
25
|
-
|
| -
|
01C
|
NEP
|
05 July
|
05 July
|
25
|
-
|
| Blas
|
03E
|
NEP
|
12 July
|
15 July
|
50
|
-
|
| Kompasu
|
12W
|
NWP
|
13 July
|
16 July
|
45
|
45
|
| Celia
|
04E
|
NEP
|
19 July
|
25 July
|
70
|
-
|
|
Basin name abbreviations:-
NWP : North-West Pacific (west of 180°E)
NEP : North-East Pacific (east of 180°E)
NAT : North Atlantic
NI : North Indian (west of Malay Peninsula)
SWI : South-West Indian (west of 90°E)
AUS : Australian (east of 90°E)
1-minute MSW: Maximum sustained wind (knots) averaged over 1
minute (JTWC Hawaii, NHC Miami, CPHC Hawaii)
10-minute MSW: Maximum sustained wind (knots) averaged over 10
minutes (JMA Japan, Southern Hemisphere RSMCs and TCWCs)
Note: Although 1-minute average winds should be stronger than
10-minute average, this may not be the case here since estimates are
obtained from different warning centres.
1.2 Tropical cyclones still active at the end of the month
| Name
|
Identifier
|
Basin
|
Start Date
|
| Namtheun
|
13W
|
NWP
|
24 July
|
| Darby
|
05E
|
NEP
|
26 July
|
| -
|
06E
|
NEP
|
29 July
|
| Alex
|
01L
|
NAT
|
31 July
|
|
2. FORECAST ERROR STATISTICS
The Met Office global Numerical Weather Prediction model produces a
6-day forecast every 12 hours. The performance of the model in forecasting
this month's tropical cyclones is assessed below. Mean error statistics
for each storm that ended during the month are presented together with
a final table of statistics for all storms ending this month. Verification
is performed at 24 hour intervals up to forecast time T+120. Some mean
error statistics for last year's storms are included for the purposes
of a comparison. The present global model has a resolution of 0.83°x
0.55°x 38 levels. This is equivalent to a horizontal resolution
of 93km x 62km at the equator.
Click here for details of the TC verification
technique and an explanation of error statistics and their sign conventions.
2.1 Individual Tropical Cyclone Summaries
Name: MINDULLE Identifier: 10W
Basin: NORTH-WEST PACIFIC
Start date: 23.06.2004 End date: 04.07.2004
1-minute MSW: 125 knots 10-minute MSW: 90 knots
Table of Mean Error Statistics
| |
T+0 |
T+24 |
T+48 |
T+72 |
T+96 |
T+120 |
| Possibly Verified
|
22
|
20
|
18
|
16
|
14
|
12
|
| Detection Rate
(%)
|
100
|
100
|
100
|
100
|
100
|
100
|
| Mean DX
|
-7
|
-36
|
-108
|
-214
|
-314
|
-350
|
| Mean DY
|
-7
|
-22
|
-27
|
-125
|
-241
|
-341
|
| Mean AT
|
-20
|
-64
|
-17
|
12
|
-151
|
-346
|
| Mean CT
|
-18
|
-12
|
-22
|
-133
|
-298
|
-258
|
| Track skill (%)
|
****
|
11
|
23
|
-8
|
****
|
****
|
| Mean DPE
|
65
|
149
|
220
|
390
|
504
|
668
|
| 2003 DPE *
|
54
|
150
|
251
|
359
|
498
|
643
|
| Intensity skill
(%)
|
****
|
50
|
33
|
25
|
43
|
-33
|
|
* DPE for all storms in the 2003 season in the NWP basin
A plot of the storm's observed track and forecasts.
Forecast errors fluctuated either side of last season's average for
this storm. Early forecasts were very good , but then the model failed
to pick up on the sharp northward turn towards Taiwan at an early stage,
so producing some large errors. The model showed modest skill over CLIPER
at T+24 and T+48 and there was a left-of-track bias in forecasts.
Name: TINGTING Identifier: 11W
Basin: NORTH-WEST PACIFIC
Start date: 25.06.2004 End date: 04.07.2004
1-minute MSW: 75 knots 10-minute MSW: 85 knots
Table of Mean Error Statistics
| |
T+0 |
T+24 |
T+48 |
T+72 |
T+96 |
T+120 |
| Possibly Verified
|
16 |
14 |
12 |
10 |
8 |
6 |
| Detection Rate
(%) |
100 |
100 |
100 |
100 |
100 |
100 |
| Mean DX |
-9 |
-66 |
-152 |
-257 |
-256 |
-280 |
| Mean DY |
-15 |
-57 |
-157 |
-217 |
-254 |
-250 |
| Mean AT |
-18 |
-72 |
-188 |
-339 |
-394 |
-409 |
| Mean CT |
-8 |
-18 |
-29 |
-75 |
-56 |
-2 |
| Track skill (%)
|
**** |
20 |
30 |
20 |
**** |
**** |
| Mean DPE |
46 |
131 |
235 |
385 |
419 |
478 |
| 2003 DPE * |
54 |
150 |
251 |
359 |
498 |
643 |
| Intensity skill
(%) |
**** |
71 |
67 |
40 |
0 |
67 |
|
* DPE for all storms in the 2003 season in the NWP basin
A plot of the storm's observed track and forecasts.
The direction of motion of this storm was very well forecast, although
the model had a slow bias. Forecast errors were below last season's
at all lead times except T+72. Skill scores against CLIPER were good.
Name: - Identifier: 02E
Basin: NORTH-EAST PACIFIC
Start date: 02.07.2004 End date: 03.07.2004
1-minute MSW: 25 knots 10-minute MSW: -
A plot of the storm's observed track.
There are no verification statistics or forecast plot for this tropical
cyclone since its 1-minute averaged winds did not reach tropical storm
strength.
Name: - Identifier: 01C
Basin: NORTH-EAST PACIFIC (Central)
Start date: 05.07.2004 End date: 05.07.2004
1-minute MSW: 25 knots 10-minute MSW: -
A plot of the storm's observed track.
There are no verification statistics or forecast plot for this tropical
cyclone since its 1-minute averaged winds did not reach tropical storm
strength.
Name: BLAS Identifier: 03E
Basin: NORTH-EAST PACIFIC
Start date: 12.07.2004 End date: 15.07.2004
1-minute MSW: 50 knots 10-minute MSW: -
Table of Mean Error Statistics
| |
T+0 |
T+24 |
T+48 |
T+72 |
T+96 |
T+120 |
| Possibly Verified
|
4 |
2 |
0 |
0 |
0 |
0 |
| Detection Rate
(%) |
100 |
100 |
**** |
**** |
**** |
**** |
| Mean DX |
70 |
270 |
**** |
**** |
**** |
**** |
| Mean DY |
-39 |
-61 |
**** |
**** |
**** |
**** |
| Mean AT |
-80 |
-257 |
**** |
**** |
**** |
**** |
| Mean CT |
11 |
101 |
**** |
**** |
**** |
**** |
| Track skill (%)
|
**** |
20 |
**** |
**** |
**** |
**** |
| Mean DPE |
98 |
278 |
**** |
**** |
**** |
**** |
| 2003 DPE * |
59 |
155 |
282 |
418 |
580 |
973 |
| Intensity skill
(%) |
**** |
0 |
**** |
**** |
**** |
**** |
|
* DPE for all storms in the 2003 season in the NEP basin
A plot of the storm's observed track and forecasts.
Only a couple of T+24 forecasts were verified for this storm. These
had a slow bias resulting in large forecast errors, although skill scores
were still good.
Name: KOMPASU Identifier: 12W
Basin: NORTH-WEST PACIFIC
Start date: 13.07.2004 End date: 16.07.2004
1-minute MSW: 45 knots 10-minute MSW: 45 knots
Table of Mean Error Statistics
| |
T+0 |
T+24 |
T+48 |
T+72 |
T+96 |
T+120 |
| Possibly Verified
|
5 |
3 |
1 |
0 |
0 |
0 |
| Detection Rate
(%) |
100 |
100 |
100 |
**** |
**** |
**** |
| Mean DX |
20 |
76 |
207 |
**** |
**** |
**** |
| Mean DY |
-16 |
-100 |
-300 |
**** |
**** |
**** |
| Mean AT |
-42 |
-92 |
-360 |
**** |
**** |
**** |
| Mean CT |
5 |
-33 |
70 |
**** |
**** |
**** |
| Track skill (%)
|
**** |
-9 |
8 |
**** |
**** |
**** |
| Mean DPE |
58 |
143 |
367 |
**** |
**** |
**** |
| 2003 DPE * |
54 |
150 |
251 |
359 |
498 |
643 |
| Intensity skill
(%) |
**** |
33 |
100 |
**** |
**** |
**** |
|
* DPE for all storms in the 2003 season in the NWP basin
A plot of the storm's observed track and forecasts.
The model again had a slow bias for this storm, so was too late in
its prediction of landfall. T+24 errors were near to last season's average.
Name: CELIA Identifier: 04E
Basin: NORTH-EAST PACIFIC
Start date: 19.07.2004 End date: 25.07.2004
1-minute MSW: 70 knots 10-minute MSW: - knots
Table of Mean Error Statistics
| |
T+0 |
T+24 |
T+48 |
T+72 |
T+96 |
T+120 |
| Possibly Verified
|
9 |
7 |
5 |
3 |
1 |
0 |
| Detection Rate
(%) |
100 |
100 |
100 |
100 |
100 |
**** |
| Mean DX |
-10 |
-14 |
-74 |
-160 |
-469 |
**** |
| Mean DY |
0 |
34 |
55 |
48 |
44 |
**** |
| Mean AT |
2 |
6 |
72 |
158 |
468 |
**** |
| Mean CT |
-2 |
28 |
48 |
56 |
9 |
**** |
| Track skill (%)
|
**** |
14 |
37 |
47 |
**** |
**** |
| Mean DPE |
47 |
87 |
136 |
178 |
469 |
**** |
| 2003 DPE * |
59 |
155 |
282 |
418 |
580 |
973 |
| Intensity skill
(%) |
**** |
43 |
60 |
100 |
100 |
**** |
|
* DPE for all storms in the 2003 season in the NEP basin
A plot of the storm's observed track and forecasts.
Track forecast errors were low for this hurricane - particularly up
to T+72. Skill scores against CLIPER were high and biases small. The
intensity tendency skill scores were also high.
2.2 Summary of all Tropical Cyclones
Mean error statistics for all tropical cyclones (of at least tropical
storm strength) which have ended this month are shown below.
Total number of depressions ending this month:- 7
Number of storms used in statistics below:- 5
Table of Mean Error Statistics
| |
T+0 |
T+24 |
T+48 |
T+72 |
T+96 |
T+120 |
| Possibly Verified
|
56 |
46 |
36 |
29 |
23 |
18 |
| Detection Rate
(%) |
100 |
100 |
100 |
100 |
100 |
100 |
| Mean DX |
0 |
-21 |
-109 |
-223 |
-300 |
-327 |
| Mean DY |
-11 |
-31 |
-66 |
-138 |
-233 |
-311 |
| Mean AT |
-22 |
-66 |
-71 |
-94 |
-208 |
-367 |
| Mean CT |
-8 |
-4 |
-12 |
-93 |
-200 |
-172 |
| Track skill (%)
|
**** |
14 |
27 |
9 |
**** |
**** |
| Mean DPE |
59 |
139 |
217 |
366 |
473 |
605 |
| 2003 DPE * |
55 |
149 |
249 |
355 |
491 |
612 |
| Intensity skill
(%) |
**** |
52 |
50 |
38 |
30 |
0 |
|
* DPE for all Northern Hemisphere storms in 2003 season
Comments :
Overall, track forecast errors were near to last season's average for
this month's storms. A modest amount of skill was shown over CLIPER
and there was a slow bias in forecasts. The intensity tendency skill
score for the month's storms was 39%.
