19. Typhoon TOKAGE (Siony/27w)                   Print this Article
>> October 12-23, 2004

Tokage: contributed by Japan, is the word for 'lizard.'

Storm Origins

At 0000 UTC 12 October JTWC issued a TCFA for an area of convection located approximately 480 nm east-southeast of Guam. At this time, animated multi-spectral and enhanced infrared satellite imagery revealed that deep convection was increasing around a partially-exposed LLCC. An upper-level analysis indicated that the system was located underneath the axis of a near-equatorial ridge and in an area of low wind shear and favourable diffluence. The system developed into Tropical Depression 27W at 12/1200 UTC, the storm moving in a west-northwesterly direction at 15 kts and centred at that time 200 nm east of Guam.

Synoptic History

JTWC upgraded Tropical Depression 27W to a 35-kt tropical storm at 1800 UTC 12 September when the system had moved to within 50 nm northeast of Guam and a little over 20 nm southeast of Rota. The tropical cyclone subsequently moved westward, passing very near Rota, and then away from the islands. At 13/0000 UTC JMA upped their MSW to 40 kts (10-min avg) and promoted the system to tropical storm intensity, naming the system Tokage from the list of international code names. Tropical Storm Tokage slowed as it moved westward and was upgraded to a 75-kt typhoon at 13/1800 UTC when centred some 970 nm southeast of Okinawa.

After the MSW had reached 80 kts at 0000 UTC 14 October, Tokage ceased strengthening for a short while and briefly turned onto a west- southwesterly heading. The storm's path then gradually curved onto a northwesterly heading at 14/1800 UTC and the typhoon began to strengthen again, reaching an intensity of 100 kts at 15/0000 UTC. Whilst an eye feature was visible in microwave imagery, this had so far eluded multi- spectral satellite imagery. Maintaining 100-kt winds, Typhoon Tokage continued moving in a general northwesterly fashion, reaching a position 750 nm south-southeast of Okinawa, Japan at 15/1200 UTC. At this stage, Tokage decelerated and by 15/1800 UTC its forward speed was down to 4 kts.

Finally, a small eye appeared in multi-spectral satellite imagery at 0000 UTC 16 October when Typhoon Tokage was still sporting a MSW of 100 kts some 695 nm south-southeast of Okinawa. The storm turned to a more poleward track as a major shortwave trough over Japan temporarily weakened the subtropical ridge. Meanwhile, strengthening resumed and at 17/0000 UTC Tokage reached its peak intensity of 125 kts--just shy of super typhoon status. At this time, typhoon-force winds extended out 30 nm in the northern semicircle and up to 50 nm in the southern semi- circle while the radius of gales lay up to 180 nm in all but the south- east quadrant, where they reached as far as 200 nm. Weakening began at 17/1200 UTC as the storm made one last excursion towards the west- northwest, thence turning towards the northwest on the first leg of its recurvature towards Okinawa and Japan. The MSW had fallen to 115 kts at this time, and at 17/1800 UTC the eye had become a rather weak, ragged feature.

At 0000 UTC 18 October Typhoon Tokage was approximately 290 nm south of Kadena AB, Okinawa, and was tracking northwestward at 11 kts around the western periphery of the subtropical ridge to the east. The next in the series of shortwave troughs was expected to move across the Yellow Sea and weaken the ridge which was enticing Tokage onto a northeastward track towards Japan. The intensity of the storm had fallen to 105 kts at 18/0000 UTC and to 95 kts at 18/0600 UTC. Multi-spectral satellite imagery revealed that the eyewall had collapsed at this time, but the eyewall had reformed around the centre by 18/1200 UTC. Tokage turned northward at 18/1800 UTC and was positioned 160 nm south-southwest of Okinawa, Japan, with the MSW down slightly to 90 kts. By 19/0000 UTC Typhoon Tokage was accelerating north-northeastward with the intensity down to 80 kts--the storm was then located approximately 85 nm south- southwest of Okinawa. Tokage made its closest approach to Okinawa at around 19/0600 UTC when it was passed 20 nm to the south-southeast. The storm turned to the northeast as it continued to accelerate and weaken, and by 1800 UTC the intensity had dropped to 65 kts. The system was beginning to undergo extratropical transition at this time.

Tokage was downgraded to a 60-kt tropical storm at 0000 UTC 20 October as it tracked towards the north-northeast at 28 kts approximately 265 nm southwest of Kyoto, Japan. The system weakened quickly as cooler sea surface temperatures, drier air and high vertical wind shear all took their toll. In addition, the ex-typhoon made landfall over Tosa-Shimizu, near the southern tip of Shikoku, Japan. At this time, JMA estimated the MSW at 80 kts (10-min avg) with a CP of 950 hPa. In fact, winds were not lowered below typhoon intensity until 20/1200 UTC, when JTWC dropped their MSW to 40 kts. By then, the storm's centre was located 130 nm west of Tokyo. Tokage was downgraded to a tropical depression at 20/1800 UTC and the final warning was issued at this time by JTWC. JMA maintained Tokage as a tropical entity until 21/0000 UTC when the system was declared extratropical. The extratropical remnants of Tokage continued to move rapidly northeastward across the North Pacific, crossing the International Dateline shortly before 23/0000 UTC.

JMA's estimated peak 10-min avg MSW and lowest CP were 85 kts and 940 hPa, respectively. The CWB of Taiwan's peak MSW was also 85 kts, whereas NMCC's highest MSW was 100 kts. PAGASA applied the name Siony during the time Typhoon Tokage was located within that agency's AOR, and their highest estimated intensity was 95 kts (10-min avg).

Damages and Casualties

According to news reports, Tokage was the worst storm to strike Japan since Typhoon Mireille in 1991. A total of 69 deaths were attributed to high winds, flooding and mudslides caused by Tokage. Seventeen persons were still unaccounted for several days after the storm. A total of 18,000 people were forced to evacuate their homes. The storm also caused the cancellation of 1000 flights, affecting 127,000 passengers.

Huang Chunliang Report

Following is the report compiled and sent by Huang Chunliang of Fuzhou City, Fujian Province, China. A special thanks to Chunliang for compiling and sending the information. (To convert wind velocity in metres/second (m/s) to knots, divide m/s by 0.51444, or for an approximation, simply double the m/s value.)

{Part I}. Landfalls (based on the JMA warnings)

1. Severe Typhoon 0423 (TOKAGE) made landfall near 
   Tosa-Shimizu City, Kochi Prefecture, around 
   20/0400 UTC with a MSW of 40 m/s and a CP of 
   955 hPa.

2. Severe Typhoon 0423 (TOKAGE) made landfall near 
   Muroto City, Kochi Prefecture, around 20/0600 
   UTC with a MSW of 40 m/s and a CP of 955 hPa.

3. Severe Typhoon 0423 (TOKAGE) made landfall near 
   Izumisano City, Osaka Prefectuve, around 
   20/0900Z with a MSW of 35 m/s and a CP of 
   970 hPa.

{Part II}. Top-5 Storm Total [17/1500-21/1500Z] Obs

Ranking    Prefecture        Station           Rainfall (mm)
01         Tokushima         Fukuharaasahi     550
02         Tokushima         Asahimaru         545
03         Ehime             Tomisato          542
04         Kochi             Funato            525
05         Oita              Umi               503

{Part III}. Top-5 Daily Rainfall Obs

Ranking    Prefecture        Station           Rainfall (mm)
01         Tokushima         Fukuharaasahi     470 [19/1500-20/1500Z]
02         Tokushima         Asahimaru         449 [19/1500-20/1500Z]
03         Ehime             Tomisato         *441 [19/1500-20/1500Z]
04         Kochi             Funato            426 [19/1500-20/1500Z]
05         Kochi             Yanase            411 [19/1500-20/1500Z]

{Part IV}. Top-5 1-hr Rainfall Obs

Ranking    Prefecture        Station           Rainfall (mm)
01         Kochi             Geisei            87 [20/0450-20/0550Z]
02         Tokushima         Asahimaru         74 [20/0330-20/0430Z]
03         Mie               Miyagawa          73 [20/0600-20/0700Z]
04         Hyogo             Sumoto            72 [20/0530-20/0630Z]
05         Kochi             Funato            71 [20/0210-20/0310Z]
05         Kochi             Kubokawa          71 [20/0220-20/0320Z]

{Part V}. Top-5 Peak Sustained Wind (10-min avg) Obs

Ranking    Station                                      Peak wind (mps)
01         Murotomisaki, Kochi (WMO47899, Alt 185m)     44.9 [20/0550Z]
02         Nagi, Okayama (JMA66127, Alt 212m)          *34   [20/0800Z]
03         Unzendake, Nagasaki (WMO47818, Alt 678m)    *33.5 [20/0300Z]
04         Okinoerabu, Kagoshima (WMO47942, Alt 27m)    29.0 [19/0900Z]
05         Akyoshidai, Yamaguchi (JMA81196, Alt 240m)  *28   [20/0500Z]

{Part VI}. Top-5 Peak Gust Obs

Ranking    Station                                      Peak wind (mps)
01         Unzendake, Nagasaki (WMO47818, Alt 678m)    *63.7 [20/0352Z]
02         Murotomisaki, Kochi (WMO47899, Alt 185m)     59.0 [20/0515Z]
03         Maitsuru, Kyoto (WMO47750, Alt 2m)          *51.9 [20/1127Z]
04         Tsuyama, Okayama (WMO47756, Alt 146m)       *50.4 [20/0813Z]
05         Sasebo, Nagasaki (WMO47812, Alt 4m)         *49.3 [20/0157Z]

{Part VII}. Top-5 SLP Obs

Ranking    Station                             Min SLP (hPa)
01         Okinoerabu, Kagoshima (WMO47942)    949.4 [19/1137Z]
02         Nago, Okinawa (WMO47940)            950.8 [19/0732Z]
03         Naze, Kagoshima (WMO47909)          951.0 [19/1502Z]
04         Naha, Okinawa (WMO47936)            952.4 [19/0558Z]
05         Yakushima, Kagoshima (WMO47836)     956.3 [19/2101Z]

{Part VIII} References (Japanese versions only)


Note: "*" = record-breaking values for relevant stations.

(Report written by Kevin Boyle with significant contributions by Huang Chunliang)

Source: Gary Padgett's Monthly Tropical Cyclone Summary - October 2004

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