Tropical cyclone activity and forecasts - November 2008
Tropical cyclone activity
| NWP | NEP | NAT | NI | SWI | AUS | TOTAL | |
|---|---|---|---|---|---|---|---|
| Total number ending during the month | 3 | 1 | 1 | 2 | 1 | 1 | 9 |
| Name | Identifier | Basin | Start date | End date | 1-minute MSW | 10-minute MSW |
|---|---|---|---|---|---|---|
| Polo | 18E | NEP | 02 November | 05 November | 35 | - |
| Paloma | 17L | NAT | 05 November | 10 November | 125 | - |
| Maysak | 24W | NWP | 06 November | 10 November | 60 | 50 |
| Khai-muk | 05B | NI | 14 November | 16 November | 45 | 35 |
| Haishen | 25W | NWP | 15 November | 16 November | 40 | 35 |
| Noul | 26W | NWP | 16 November | 17 November | 40 | 40 |
| Anika | 02S | AUS | 18 November | 21 November | 50 | 50 |
| Bernard | 03S | SWI | 19 November | 21 November | 40 | 35 |
| Nisha | 06B | NI | 25 November | 27 November | 50 | 45 |
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.
Tropical cyclones still active at the end of the month
None.
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 62 km x 42 km at the equator.
Individual tropical cyclone summaries
Name: POLO Identifier: 18E
Basin: NORTH-EAST PACIFIC
Start date: 02.11.2008 End date: 05.11.2008
1-minute MSW: 35 knots 10-minute MSW: - knots
| T+0 | T+24 | T+48 | T+72 | T+96 | T+120 | T+144 | |
|---|---|---|---|---|---|---|---|
| Possibly verified | 3 | 0 | 0 | 0 | 0 | 0 | 0 |
| Detection rate (%) | 100 | 100 | **** | **** | **** | **** | **** |
| Mean DX | 26 | 11 | **** | **** | **** | **** | **** |
| Mean DY | 11 | -22 | **** | **** | **** | **** | **** |
| Mean AT | -18 | -15 | **** | **** | **** | **** | **** |
| Mean CT | 17 | -22 | **** | **** | **** | **** | **** |
| Mean DPE | 55 | 27 | **** | **** | **** | **** | **** |
| 2007 DPE * | 56 | 112 | 192 | 246 | 453 | 397 | **** |
| Intensity skill (%) | **** | 100 | **** | **** | **** | **** | **** |
* DPE for all storms in the 2007 season in the NEP basin
A plot of Polo's observed track and forecasts
Track forecast errors for this storm were a little below last season's average at 24-hours, but above the average at 48-hours.
Name: PALOMA Identifier: 17L
Basin: NORTH ATLANTIC
Start date: 05.11.2008 End date: 10.11.2008
1-minute MSW: 125 knots 10-minute MSW: - knots
| T+0 | T+24 | T+48 | T+72 | T+96 | T+120 | T+144 | |
|---|---|---|---|---|---|---|---|
| Possibly verified | 7 | 5 | 3 | 0 | 0 | 0 | 0 |
| Detection rate (%) | 100 | 100 | 100 | 100 | **** | **** | **** |
| Mean DX | -6 | -69 | -181 | -293 | **** | **** | **** |
| Mean DY | 5 | -58 | -141 | -289 | **** | **** | **** |
| Mean AT | 2 | -78 | -174 | -194 | **** | **** | **** |
| Mean CT | 10 | -38 | -65 | -369 | **** | **** | **** |
| Track skill | **** | 36 | 40 | **** | **** | **** | **** |
| Mean DPE | 45 | 119 | 234 | 418 | **** | **** | **** |
| 2007 DPE * | 63 | 102 | 151 | 179 | 228 | 265 | **** |
| Intensity skill (%) | **** | 60 | 33 | 100 | **** | **** | **** |
* DPE for all storms in the 2007 season in the NAT basin
A plot of Paloma's observed track and forecasts
Forecasts for Paloma were too slow in tracking the hurricane north and north-eastwards towards Cuba. As a consequence track errors were larger than last season's average. However, skill scores against CLIPER were high.
Name: MAYSAK Identifier: 24W
Basin: NORTH-WEST PACIFIC
Start date: 06.11.2008 End date: 10.11.2008
1-minute MSW: 60 knots 10-minute MSW: 50 knots
| T+0 | T+24 | T+48 | T+72 | T+96 | T+120 | T+144 | |
|---|---|---|---|---|---|---|---|
| Possibly verified | 4 | 2 | 0 | 0 | 0 | 0 | 0 |
| Detection rate (%) | 100 | 100 | **** | **** | **** | **** | **** |
| Mean DX | 28 | 38 | **** | **** | **** | **** | **** |
| Mean DY | 36 | -50 | **** | **** | **** | **** | **** |
| Mean AT | -1 | -62 | **** | **** | **** | **** | **** |
| Mean CT | 38 | -5 | **** | **** | **** | **** | **** |
| Mean DPE | 51 | 66 | **** | **** | **** | **** | **** |
| 2007 DPE * | 77 | 147 | 203 | 319 | 509 | 387 | **** |
| Intensity skill (%) | **** | 100 | **** | **** | **** | **** | **** |
* DPE for all storms in the 2007 season in the NI basin
A plot of Maysak's observed track and forecasts.
Track forecast errors for this storm were a little below last season's average at 24-hours, but above the average at 48-hours.
Name: KHAI-MUK Identifier: 05B
Basin: NORTH INDIAN
Start date: 14.11.2008 End date: 16.11.2008
1-minute MSW: 45 knots 10-minute MSW: 35 knots
| T+0 | T+24 | T+48 | T+72 | T+96 | T+120 | T+144 | |
|---|---|---|---|---|---|---|---|
| Possibly verified | 5 | 3 | 0 | 0 | 0 | 0 | 0 |
| Detection rate (%) | 100 | 100 | 100 | **** | **** | **** | **** |
| Mean DX | 16 | 29 | 54 | **** | **** | **** | **** |
| Mean DY | 53 | -56 | -111 | **** | **** | **** | **** |
| Mean AT | -10 | -27 | -83 | **** | **** | **** | **** |
| Mean CT | 40 | -45 | -92 | **** | **** | **** | **** |
| Track skill (%) | **** | 0 | **** | **** | **** | **** | **** |
| Mean DPE | 70 | 133 | 125 | **** | **** | **** | **** |
| 2007 DPE * | 77 | 147 | 203 | 319 | 509 | 387 | **** |
| Intensity skill (%) | **** | 33 | -100 | **** | **** | **** | **** |
* DPE for all storms in the 2007 season in the NI basin
A plot of Khai-muk's observed track and forecasts
Track forecast errors were low for this storm and landfall fairly well predicted, although a little too far to the south.
Name: HAISHEN Identifier: 25W
Basin: NORTH-WEST PACIFIC
Start date: 15.11.2008 End date: 16.11.2008
1-minute MSW: 40 knots 10-minute MSW: 35 knots
| T+0 | T+24 | T+48 | T+72 | T+96 | T+120 | T+144 | |
|---|---|---|---|---|---|---|---|
| Possibly verified | 2 | 0 | 0 | 0 | 0 | 0 | 0 |
| Detection rate (%) | 100 | **** | **** | **** | **** | **** | **** |
| Mean DX | 25 | **** | **** | **** | **** | **** | **** |
| Mean DY | 89 | **** | **** | **** | **** | **** | **** |
| Mean AT | 91 | **** | **** | **** | **** | **** | **** |
| Mean CT | -82 | **** | **** | **** | **** | **** | **** |
| Mean DPE | 90 | **** | **** | **** | **** | **** | **** |
| 2007 DPE * | 70 | 136 | 201 | 276 | 404 | 517 | **** |
* DPE for all storms in the 2007 season in the NWP basin
A plot of Haishen's observed track and forecasts
Haishen was short-lived and just one 12-hour forecast was verified.
Name: NOUL Identifier: 26W
Basin: NORTH-WEST PACIFIC
Start date: 16.11.2008 End date: 17.11.2008
1-minute MSW: 40 knots 10-minute MSW: 40 knots
| T+0 | T+24 | T+48 | T+72 | T+96 | T+120 | T+144 | |
|---|---|---|---|---|---|---|---|
| Possibly verified | 2 | 0 | 0 | 0 | 0 | 0 | 0 |
| Detection rate (%) | 100 | **** | **** | **** | **** | **** | **** |
| Mean DX | 28 | **** | **** | **** | **** | **** | **** |
| Mean DY | 0 | **** | **** | **** | **** | **** | **** |
| Mean AT | -24 | **** | **** | **** | **** | **** | **** |
| Mean CT | 10 | **** | **** | **** | **** | **** | **** |
| Mean DPE | 28 | **** | **** | **** | **** | **** | **** |
| 2007 DPE * | 70 | 136 | 201 | 276 | 404 | 517 | **** |
* DPE for all storms in the 2007 season in the NWP basin
A plot of Noul's observed track and forecasts
Noul was only briefly a tropical storm and just one 12-hour forecast was verified.
Name: ANIKA Identifier: 02S
Basin: AUSTRALIAN (SE Indian)
Start date: 18.11.2008 End date: 21.11.2008
1-minute MSW: 50 knots 10-minute MSW: 50 knots
| T+0 | T+24 | T+48 | T+72 | T+96 | T+120 | T+144 | |
|---|---|---|---|---|---|---|---|
| Possibly verified | 4 | 2 | 0 | 0 | 0 | 0 | 0 |
| Detection rate (%) | 100 | 100 | **** | **** | **** | **** | **** |
| Mean DX | -16 | -76 | **** | **** | **** | **** | **** |
| Mean DY | 18 | -95 | **** | **** | **** | **** | **** |
| Mean AT | 11 | -112 | **** | **** | **** | **** | **** |
| Mean CT | -8 | 36 | **** | **** | **** | **** | **** |
| Mean DPE | 40 | 122 | **** | **** | **** | **** | **** |
| 2007-8 DPE * | 56 | 120 | 223 | 373 | 595 | 902 | **** |
| Intensity skill (%) | **** | 100 | **** | **** | **** | **** | **** |
* DPE for all storms in the 2007-8 season in the AUS basin
A plot of Anika's observed track and forecasts
Forecasts up to 36-hours lead time were verified for this storm. Track errors were near to last season's average.
Name: BERNARD Identifier: 03S
Basin: SOUTH-WEST INDIAN
Start date: 19.11.2008 End date: 21.11.2008
1-minute MSW: 40 knots 10-minute MSW: 35 knots
| T+0 | T+24 | T+48 | T+72 | T+96 | T+120 | T+144 | |
|---|---|---|---|---|---|---|---|
| Possibly verified | 1 | 0 | 0 | 0 | 0 | 0 | 0 |
| Detection rate (%) | 100 | **** | **** | **** | **** | **** | **** |
| Mean DX | -33 | **** | **** | **** | **** | **** | **** |
| Mean DY | -67 | **** | **** | **** | **** | **** | **** |
| Mean AT | -41 | **** | **** | **** | **** | **** | **** |
| Mean CT | 57 | **** | **** | **** | **** | **** | **** |
| Mean DPE | 71 | **** | **** | **** | **** | **** | **** |
| 2007-8 DPE * | 51 | 123 | 257 | 397 | 515 | 570 | **** |
* DPE for all storms in the 2007-8 season in the SWI basin
A plot of Bernard's observed track and forecasts
Bernard only briefly reached tropical storm status and no forecasts were verified.
Name: NISHA Identifier: 06B
Basin: NORTH INDIAN
Start date: 25.11.2008 End date: 27.11.2008
1-minute MSW: 50 knots 10-minute MSW: 45 knots
| T+0 | T+24 | T+48 | T+72 | T+96 | T+120 | T+144 | |
|---|---|---|---|---|---|---|---|
| Possibly verified | 4 | 2 | 0 | 0 | 0 | 0 | 0 |
| Detection rate (%) | 100 | 100 | **** | **** | **** | **** | **** |
| Mean DX | 28 | 38 | **** | **** | **** | **** | **** |
| Mean DY | 36 | -50 | **** | **** | **** | **** | **** |
| Mean AT | -1 | -62 | **** | **** | **** | **** | **** |
| Mean CT | 38 | -5 | **** | **** | **** | **** | **** |
| Mean DPE | 51 | 66 | **** | **** | **** | **** | **** |
| 2007 DPE * | 77 | 147 | 203 | 319 | 509 | 387 | **** |
| Intensity skill (%) | **** | 100 | **** | **** | **** | **** | **** |
* DPE for all storms in the 2007 season in the NI basin
A plot of Nisha's observed track and forecasts
The development of Nisha was well signalled by the model. Once it had formed forecasts up to 36 hours ahead were verified. Track errors were low.
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: 9
Number of storms used in statistics below: 9
| T+0 | T+24 | T+48 | T+72 | T+96 | T+120 | T+144 | |
|---|---|---|---|---|---|---|---|
| Possibly verified | 34 | 17 | 6 | 0 | 0 | 0 | 0 |
| Detection rate (%) | 100 | 100 | 100 | 100 | **** | **** | **** |
| Mean DX | 3 | -22 | -162 | -293 | **** | **** | **** |
| Mean DY | 30 | -52 | -154 | -289 | **** | **** | **** |
| Mean AT | -3 | -62 | -142 | -194 | **** | **** | **** |
| Mean CT | 11 | -18 | -27 | -369 | **** | **** | **** |
| Track skill (%) | **** | 36 | 40 | **** | **** | **** | **** |
| Mean DPE | 60 | 111 | 241 | 418 | **** | **** | **** |
| 2007 DPE * | 66 | 127 | 193 | 262 | 401 | 472 | **** |
| Intensity skill (%) | **** | 76 | 33 | 100 | **** | **** | **** |
* Best track DPE for all Northern Hemisphere storms in 2007 season
There were nine storms this month, but most were fairly short lived. Only one 72-hour forecast was verified. Track errors were a little above last season's northern hemisphere average. However, skill scores against CLIPER were high. There was a slow bias in forecasts. The overall intensity tendency skill score was 71%.
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