Tropical cyclone activity
| Tropical cyclones ending during the month | |||||||
|---|---|---|---|---|---|---|---|
| NWP | NEP | NAT | NI | SWI | AUS | Total | |
| Total number ending during the month | 6 | 4 | 9 | 0 | 0 | 0 | 19 |
| Tropical cyclones active during the month | ||||||
|---|---|---|---|---|---|---|
| Name | Identifier | Basin | Start date | End date | 1-minute MSW | 10-minute MSW |
| Fitow | 10W | NWP | 29 August | 07 September | 85 | 65 |
| Gil | 10E | NEP | 29 August | 02 September | 40 | - |
| Henriette | 11E | NEP | 30 August | 06 September | 75 | - |
| Felix | 06L | NAT | 31 August | 05 September | 145 | - |
| Danas | 11W | NWP | 07 September | 11 September | 60 | 50 |
| Gabrielle | 07L | NAT | 08 September | 11 September | 45 | - |
| Ingrid | 08L | NAT | 12 September | 17 September | 40 | - |
| Humberto | 09L | NAT | 12 September | 13 September | 75 | - |
| Nari | 12W | NWP | 12 September | 16 September | 120 | 95 |
| Wipha | 13W | NWP | 15 September | 19 September | 135 | 100 |
| Ivo | 12E | NEP | 18 September | 23 September | 70 | - |
| - | 13E | NEP | 19 September | 20 September | 30 | - |
| - | 14W | NWP | 20 September | 21 September | 30 | - |
| - | 10L | NAT | 21 September | 22 September | 30 | - |
| Francisco | 15W | NWP | 23 September | 25 September | 45 | 45 |
| Jerry | 11L | NAT | 23 September | 25 September | 40 | - |
| Karen | 12L | NAT | 25 September | 29 September | 60* | - |
| Lorenzo | 13L | NAT | 25 September | 28 September | 65 | - |
| Melissa | 14L | NAT | 28 September | 30 September | 40 | - |
* Karen may be upgraded to a hurricane in post-season best track analysis
Basin name abbreviations:
NWP : North-west Pacific (west of 180° E)
NEP : North-east Pacific (east of 180° E)
NAT : North Atlantic
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.
Tropical cyclones still active at the end of the month
| Tropical cyclones still active at the end of the month | |||
|---|---|---|---|
| Name | Identifier | Basin | Start date |
| Juliette | 14E | NEP | 29 September |
| Lekima | 16W | NWP | 29 September |
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 0.5625°x 0.375°x 50 levels. This is equivalent to a horizontal resolution of 62km x 42km at the equator.
Individual tropical cyclone summaries
Name: FITOW Identifier: 10W
Basin: NORTH-WEST PACIFIC
Start date: 29.08.2007 End
date: 07.09.2007
1-minute MSW: 85 knots
10-minute MSW: 65 knots
| MEAN ERROR STATISTICS | ||||||
|---|---|---|---|---|---|---|
| T+0 | T+24 | T+48 | T+72 | T+96 | T+120 | |
| Possibly Verified | 21 | 19 | 17 | 15 | 13 | 10 |
| Detection Rate (%) | 100 | 100 | 100 | 100 | 100 | 100 |
| Mean DX | 26 | -45 | -93 | -97 | -49 | -44 |
| Mean DY | 14 | -6 | 10 | 19 | 64 | 63 |
| Mean AT | 9 | 17 | 90 | -3 | -37 | 1 |
| Mean CT | 17 | 0 | 8 | 45 | 148 | 138 |
| Track skill (%) | **** | 32 | 50 | 62 | **** | **** |
| Mean DPE | 65 | 120 | 188 | 251 | 337 | 384 |
| 2006 DPE * | 60 | 114 | 204 | 304 | 422 | 551 |
| Intensity skill (%) | **** | 37 | 6 | 20 | 23 | 0 |
* DPE for all storms in the 2006 season in the NWP basin
 |
Plot of the storm's observed track and forecasts |
On the whole, the turns in the track of Fitow were well predicted by the model. Track errors were below last season’s average and skill scores against CLIPER were high.
Name: GIL Identifier: 10E
Basin: NORTH-EAST PACIFIC
Start date: 29.08.2007 End date: 02.09.2007
1-minute MSW: 40 knots 10-minute MSW: - knots
| 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 | 19 | -42 | **** | **** | **** | **** |
| Mean DY | -14 | 39 | **** | **** | **** | **** |
| Mean AT | -19 | 40 | **** | **** | **** | **** |
| Mean CT | -9 | 37 | **** | **** | **** | **** |
| Track skill (5) | **** | 80 | **** | **** | **** | **** |
| Mean DPE | 49 | 87 | **** | **** | **** | **** |
| 2006 DPE * | 51 | 103 | 185 | 265 | 366 | 430 |
| Intensity skill (%) | **** | 0 | **** | **** | **** | **** |
* DPE for all storms in the 2006 season in the NEP basin
 |
Plot of the storm's observed track |
Gil only briefly became a tropical storm and only two forecasts were verified.
Name: HENRIETTE Identifier: 11W
Basin: NORTH-EAST PACIFIC
Start date: 30.08.2007 End date: 06.09.2007
1-minute MSW: 75 knots 10-minute MSW: -
| MEAN ERROR STATISTICS | ||||||
|---|---|---|---|---|---|---|
| T+0 | T+24 | T+48 | T+72 | T+96 | T+120 | |
| Possibly Verified | 12 | 10 | 8 | 6 | 4 | 2 |
| Detection Rate (%) | 100 | 100 | 100 | 100 | 75 | 0 |
| Mean DX | 12 | -12 | -100 | -268 | -520 | **** |
| Mean DY | 7 | 5 | -18 | -113 | -511 | **** |
| Mean AT | 2 | 11 | 8 | -48 | -373 | **** |
| Mean CT | 9 | 1 | -81 | -271 | -629 | **** |
| Track skill (%) | 30 | 37 | 17 | **** | **** | **** |
| Mean DPE | 58 | 118 | 210 | 315 | 732 | **** |
| 2006 DPE * | 51 | 103 | 185 | 265 | 366 | 430 |
| Intensity skill (%) | **** | 80 | -25 | 33 | 100 | **** |
* DPE for all storms in the 2006 season in the NEP basin
 |
Plot of the storm's observed track |
Early forecasts failed to turn Henriette towards the coast and resulted in some large track forecast errors, particularly at longer lead times. Skill scores were positive, but modest by T+72.
Name: FELIX Identifier: 06L
Basin: NORTH ATLANTIC
Start date: 30.08.2007 End date: 06.09.2007
1-minute MSW: 145 knots 10-minute MSW: - knots
| MEAN ERROR STATISTICS | ||||||
|---|---|---|---|---|---|---|
| T+0 | T+24 | T+48 | T+72 | T+96 | T+120 | |
| Possibly Verified | 8 | 6 | 4 | 2 | 0 | 0 |
| Detection Rate (%) | 100 | 100 | 100 | 100 | **** | **** |
| Mean DX | -2 | 9 | 14 | 33 | **** | **** |
| Mean DY | 14 | 76 | 147 | 289 | **** | **** |
| Mean AT | 2 | -6 | -17 | -51 | **** | **** |
| Mean CT | 14 | 71 | 147 | 288 | **** | **** |
| Track skill (%) | **** | 39 | 44 | 9 | **** | **** |
| Mean DPE | 22 | 89 | 149 | 298 | **** | **** |
| 2006 DPE * | 46 | 109 | 213 | 322 | 425 | 529 |
| Intensity skill (%) | **** | 0 | -50 | 0 | **** | **** |
* DPE for all storms in the 2006 season in the NAT basin
 |
Plot of the storm's observed track |
There was a slight polewards bias in forecast tracks for Felix. However, track errors were lower than last season’s average and skill scores high at T+24 and T+48.
Name: DANAS Identifier: 11W
Basin: NORTH-WEST PACIFIC
Start date: 07.09.2007 End date: 11.09.2007
1-minute MSW: 60 knots 10-minute MSW: 50 knots
| 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 | -11 | -41 | -72 | 42 | -362 | **** |
| Mean DY | -28 | -10 | 89 | 100 | -11 | **** |
| Mean AT | -38 | -99 | -81 | 24 | -426 | **** |
| Mean CT | -3 | 1 | -36 | -16 | 59 | **** |
| Track skill (%) | **** | 50 | 59 | 79 | **** | **** |
| Mean DPE | 47 | 136 | 250 | 261 | 431 | **** |
| 2006 DPE * | 60 | 114 | 204 | 304 | 422 | 551 |
| Intensity skill (%) | **** | -14 | 20 | 33 | -100 | **** |
* DPE for all storms in the 2006 season in the NWP basin
 |
Plot of the storm's observed track and forecasts |
Track forecast errors were varied dependent on lead time. However, skill scores were very high.
Name: GABRIELLE Identifier: 08L
Basin: NORTH ATLANTIC
Start date: 08.09.2007 End date: 11.09.2007
1-minute MSW: 45 knots 10-minute MSW: - knots
| 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 | 15 | -31 | -27 | **** | **** | **** |
| Mean DY | -24 | -26 | -133 | **** | **** | **** |
| Mean AT | -32 | -7 | -139 | **** | **** | **** |
| Mean CT | 9 | -19 | 8 | **** | **** | **** |
| Track skill (%) | **** | 41 | **** | **** | **** | **** |
| Mean DPE | 64 | 79 | 140 | **** | **** | **** |
| 2006 DPE * | 46 | 109 | 213 | 322 | 425 | 529 |
| Intensity skill (%) | **** | -33 | -100 | **** | **** | **** |
* DPE for all storms in the 2006 season in the NWP basin
 |
Plot of the storm's observed track |
Track forecast errors were below last season’s average for this short-lived storm.
Name: INGRID Identifier: 08L
Basin: NORTH ATLANTIC
Start date: 12.09.2007 End date: 17.09.2007
1-minute MSW: 40 knots 10-minute MSW: -
| MEAN ERROR STATISTICS | ||||||
|---|---|---|---|---|---|---|
| T+0 | T+24 | T+48 | T+72 | T+96 | T+120 | |
| Possibly Verified | 3 | 1 | 0 | 0 | 0 | 0 |
| Detection Rate (%) | 100 | 100 | **** | **** | **** | **** |
| Mean DX | 22 | 96 | **** | **** | **** | **** |
| Mean DY | 15 | 33 | **** | **** | **** | **** |
| Mean AT | -12 | -71 | **** | **** | **** | **** |
| Mean CT | 26 | 66 | **** | **** | **** | **** |
| Track skill (%) | **** | 16 | **** | **** | **** | **** |
| Mean DPE | 49 | 98 | **** | **** | **** | **** |
| 2006 DPE * | 46 | 109 | 213 | 322 | 425 | 529 |
| Intensity skill (%) | **** | 100 | **** | **** | **** | **** |
* DPE for all storms in the 2006 season in the NAT basin
 |
Plot of the storm's observed track and forecasts |
Ingrid persisted as a tropical depression for some time, but only briefly reached tropical storm status. Just one forecast was verified.
Name: HUMBERTO Identifier: 09L
Basin: NORTH ATLANTIC
Start date: 12.09.2007 End date: 13.09.2007
1-minute MSW: 75 knots 10-minute MSW: - knots
| MEAN ERROR STATISTICS | ||||||
|---|---|---|---|---|---|---|
| T+0 | T+24 | T+48 | T+72 | T+96 | T+120 | |
| Possibly Verified | 2 | 0 | 0 | 0 | 0 | 0 |
| Detection Rate (%) | 100 | **** | **** | **** | **** | **** |
| Mean DX | 30 | **** | **** | **** | **** | **** |
| Mean DY | 6 | **** | **** | **** | **** | **** |
| Mean AT | 15 | **** | -8 | **** | **** | **** |
| Mean CT | 27 | **** | **** | **** | **** | **** |
| Mean DPE | 35 | **** | **** | **** | **** | **** |
| 2006 DPE * | 46 | 109 | 213 | 322 | 425 | 529 |
* DPE for all storms in the 2006 season in the NAT basin
 |
Plot of the storm's observed track and forecasts |
Humberto spun up to hurricane status and made landfall very quickly. Hence no forecasts were verified for this storm.
Name: NARI Identifier: 12W
Basin: NORTH-WEST PACIFIC
Start date: 12.09.2007 End date: 16.09.2007
1-minute MSW: 120 knots 10-minute MSW: 95 knots
| MEAN ERROR STATISTICS | ||||||
|---|---|---|---|---|---|---|
| T+0 | T+24 | T+48 | T+72 | T+96 | T+120 | |
| Possibly Verified | 7 | 5 | 3 | 1 | 0 | 0 |
| Detection Rate (%) | 100 | 100 | 100 | 100 | **** | **** |
| Mean DX | -18 | 92 | 120 | 281 | **** | **** |
| Mean DY | -11 | -87 | -44 | 33 | **** | **** |
| Mean AT | -3 | -125 | 9 | 106 | **** | **** |
| Mean CT | -12 | 74 | 129 | 265 | **** | **** |
| Track skill (%) | **** | 4 | 35 | **** | **** | **** |
| Mean DPE | 52 | 170 | 211 | 286 | **** | **** |
| 2006 DPE * | 60 | 114 | 204 | 304 | 422 | 551 |
| Intensity skill (%) | **** | -20 | -100 | 100 | **** | **** |
* DPE for all storms in the 2006 season in the NWP basin
 |
Plot of the storm's observed track and forecasts |
Some forecasts had a slow and right-of-track bias. Track forecast errors were above last season’s average at T+24, but below at other lead times.
Name: WIPHA Identifier: 13W
Basin: NORTH-WEST PACIFIC
Start date: 15.09.2007 End date: 19.09.2007
1-minute MSW: 135 knots 10-minute MSW: 100 knots
| MEAN ERROR STATISTICS | ||||||
|---|---|---|---|---|---|---|
| T+0 | T+24 | T+48 | T+72 | T+96 | T+120 | |
| Possibly Verified | 7 | 5 | 3 | 1 | 0 | 0 |
| Detection Rate (%) | 100 | 100 | 100 | 100 | **** | **** |
| Mean DX | 21 | 44 | 100 | 110 | **** | **** |
| Mean DY | -2 | -4 | -74 | -322 | **** | **** |
| Mean AT | -8 | -44 | -111 | -305 | **** | **** |
| Mean CT | 5 | 23 | -4 | -159 | **** | **** |
| Track skill (%) | **** | 25 | 69 | **** | **** | **** |
| Mean DPE | 82 | 124 | 158 | 345 | **** | **** |
| 2006 DPE * | 60 | 114 | 204 | 304 | 422 | 551 |
| Intensity skill (%) | **** | 60 | 100 | -100 | **** | **** |
* DPE for all storms in the 2006 season in the NWP basin
 |
Plot of the storm's observed track |
Track forecast errors were variable depending on lead time. There was a slow bias in forecasts. Skill scores were positive.
Name: IVO Identifier: 12E
Basin: NORTH-EAST PACIFIC
Start date: 18.09.2007 End date: 23.09.2007
1-minute MSW: 70 knots 10-minute MSW: - knots
| 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 | -7 | -4 | 45 | 123 | 42 | **** |
| Mean DY | -15 | 64 | 94 | 67 | -211 | **** |
| Mean AT | -3 | 54 | 90 | 120 | -126 | **** |
| Mean CT | -9 | -31 | -18 | 72 | 176 | **** |
| Track skill (%) | **** | 6 | 42 | 79 | **** | **** |
| Mean DPE | 40 | 98 | 164 | 196 | 217 | **** |
| 2006 DPE * | 51 | 103 | 185 | 265 | 366 | 430 |
| Intensity skill (%) | **** | 43 | 60 | 100 | 100 | **** |
* DPE for all storms in the 2006 season in the NEP basin
 |
Plot of the storm's observed track |
Track forecast errors were below last season’s average for this storm and skill scores high at longer lead times.
Name: - Identifier: 13E
Basin: NORTH-EAST PACIFIC
Start date: 19.09.2007 End date: 20.09.2007
1-minute MSW: 30 knots 10-minute MSW: -
 |
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: 14W
Basin: NORTH-WEST PACIFIC
Start date: 20.09.2007 End date: 21.09.2007
1-minute MSW: 30 knots 10-minute MSW: -
 |
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: 10L
Basin: NORTH ATLANTIC
Start date: 21.09.2007 End date: 22.09.2007
1-minute MSW: 30 knots 10-minute MSW: -
 |
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: FRANCISCO Identifier: 15W
Basin: NORTH-WEST PACIFIC
Start date: 23.09.2007 End date: 25.09.2007
1-minute MSW: 45 knots 10-minute MSW: 45 knots
| MEAN ERROR STATISTICS | ||||||
|---|---|---|---|---|---|---|
| T+0 | T+24 | T+48 | T+72 | T+96 | T+120 | |
| Possibly Verified | 3 | 1 | 0 | 0 | 0 | 0 |
| Detection Rate (%) | 100 | 100 | **** | **** | **** | **** |
| Mean DX | 21 | 52 | **** | **** | **** | **** |
| Mean DY | 15 | 100 | **** | **** | **** | **** |
| Mean AT | -22 | -52 | **** | **** | **** | **** |
| Mean CT | 18 | 100 | **** | **** | **** | **** |
| Mean DPE | 38 | 113 | **** | **** | **** | **** |
| 2006 DPE * | 60 | 114 | 204 | 304 | 422 | 551 |
| Intensity skill (%) | **** | 100 | **** | **** | **** | **** |
* DPE for all storms in the 2006 season in the NWP basin
 |
Plot of the storm's observed track |
Francisco was short-lived and just one forecast was verified.
Name: JERRY Identifier: 11L
Basin: NORTH ATLANTIC
Start date: 23.09.2007 End date: 25.09.2007
1-minute MSW: 40 knots 10-minute MSW: -
| MEAN ERROR STATISTICS | ||||||
|---|---|---|---|---|---|---|
| T+0 | T+24 | T+48 | T+72 | T+96 | T+120 | |
| Possibly Verified | 3 | 1 | 0 | 0 | 0 | 0 |
| Detection Rate (%) | 100 | 100 | **** | **** | **** | **** |
| Mean DX | 9 | -105 | **** | **** | **** | **** |
| Mean DY | -7 | 111 | **** | **** | **** | **** |
| Mean AT | -9 | -15 | **** | |||