12. Typhoon MEGI (Lawin/18w)                        Print this Article
>> August 14-22, 2004

Megi: contributed by South Korea, is the catfish--a large fish found mainly in rivers, lakes, etc and which has long whiskers around its mouth.


Typhoon Megi was the fourth of eight significant tropical cyclones to form during August. After Megi formed in the Northwest Pacific, JTWC issued warnings on tropical cyclones without a break through the rest of the month. Megi formed well to the east of the Philippines, moved north- westward through the Ryukyu island chain before recurving northeastward towards South Korea and Japan. Despite peaking at only minimal typhoon intensity, Megi had quite a significant impact on both these nations.

Storm Origins

At 2200 UTC on 11 August an area of convection persisted approximately 260 nm west of Guam and was included in JTWC's STWO with the development potential being assessed as poor. Animated enhanced infrared satellite imagery indicated a possible LLCC in connection with this convection. An upper-level analysis showed moderate diffluence aloft and moderate wind shear over the area. The potential for develop- ment remained poor through the 12th and much of the 13th. At 13/0600 UTC the system was relocated to a position approximately 65 nm south of Guam, and then repositioned again at 13/2300 UTC to a point 60 nm to the north-northwest of Guam. A recent QuikScat pass indicated that the LLCC had consolidated significantly over the previous 12 hours with stronger winds within the deep convection. On this basis, a TCFA was issued at this time. The disturbance was upgraded to Tropical Depression 18W at 14/0000 UTC.

Synoptic History

Tropical Depression 18W formed approximately 150 nm northwest of Guam and initially tracked west-northwestward at 8 kts under the influence of a mid-level steering ridge to its northeast. This heading persisted through the 14th while the forward speed accelerated. There was little change in intensity and deep convection had become less organized by 14/1800 UTC. At this time animated enhanced infrared satellite imagery suggested multiple LLCCs, meaning that the system resembled a monsoon depression. The system appeared to have become a little more consolidated by 15/0000 UTC, as depicted in satellite imagery, but remained at depression status through the 15th.

At 0000 UTC on 16 August Tropical Depression 18W was centred 490 nm south-southeast of Okinawa and continuing on its westward journey at a slower pace of 7 kts. The storm still had not become any better consolidated at this time. However, both JTWC and JMA upgraded the system to a tropical storm and it was named Megi. From there, Megi strengthened slowly, reaching 45 kts at 16/1800 UTC after turning northwestward six hours earlier. This new heading was caused by Megi's reaching the end of the subtropical ridge at the same time an upper- level trough was moving eastward over eastern China.

Tropical Storm Megi was accelerating north-northwestward at 0000 UTC on 17 August approximately 160 nm south of Okinawa. The upper-level trough began to enhance Megi's outflow and the storm responded by strengthening to 60 kts at 17/1800 UTC. Warnings issued by JTWC indicated that Megi passed 75 nm west of Okinawa at 17/1200 UTC with the island lying well within the radius of gale-force winds. Although the system was upgraded to typhoon intensity at 18/0000 UTC (by both JTWC and JMA) satellite images showed a distorted circulation as it became more involved with the upper-level trough. At this time Megi had reached its maximum intensity of 65 kts and this was to be maintained for the following 24 hours. The typhoon completed recurvature at 18/1200 UTC approximately 210 nm west-southwest of Sasebo, Japan.

At 0000 UTC on 19 August Megi was downgraded to tropical storm status as it moved north-northeastward at a quickening pace approximately 620 nm west-southwest of Misawa, Japan. Extratropical transition was well underway as its circulation crossed the southern part of the Korean peninsula, northern Kyushu and then entered the Sea of Japan. From there Megi sped across northern Honshu before completing extratropical transition off the east coast of Hokkaido. Its rapid translational speed likely limited heavy rainfall to a degree over South Korea and Japan but allowed little time for the storm to significantly weaken. JTWC issued its final bulletin at 19/1200 UTC, but JMA continued to follow the storm through their bulletins. In fact, that agency retained typhoon intensity until 19/1800 UTC, at which time Megi was demoted to severe tropical storm status. The last mention of the system as a tropical cyclone was at 20/0600 UTC when it was located southeast of Hokkaido and moving eastward at 33 kts. The resulting extratropical storm continued moving rapidly eastward, reaching a point near 42N/174E by 22/0600 UTC when it was last referenced in JMA's High Seas Bulletins.

The lowest CP estimated by JMA was 970 mb. This coincided with that agency's peak estimated intensity of 65-kts (10-min avg). During the time that Lawin (Filipino name for the system) was within PAGASA's AOR, the highest MSW estimated by that agency was 40 kts. The cyclone remained a tropical storm during the period it was within PAGASA's boundary lines, and thus was never upgraded to typhoon status. PAGASA began issuing warnings at 15/0900 UTC and ended warning coverage at 17/0600 UTC after Lawin had exited their AOR. NMCC's peak 10-min avg MSW for Megi was also 65 kts.

Meteorological Observations from Japan

The data in this section, and in the two following, was compiled and sent by Huang Chunliang. A special thanks to Chunliang for sending the information.

NOTE: I have left all the wind observations in metres per second (mps). To convert to knots, divide the mps value by 0.51444. For a quickly obtained approximation, just double the mps value. An asterisk (*) preceding an entry denotes a record-breaking value for the relevant station.

{Part I}. Landfall

According to the JMA warnings, Typhoon 0415 (MEGI) made landfall in
Tsugaru Peninsula, Aomori Prefecture, around 19/2100 UTC with a MSW of
30 m/s and a CP of 975 hPa.

{Part II}. Top-5 Storm Totals [16/1500-20/1500Z]

Ranking    Prefecture        Station        Rainfall (mm)
01         Ehime             Tomisato          610
02         Kochi             Hongawa           602
03         Miyazaki          Mikado            487
04         Kochi             Funato            445
05         Kochi             Ikegawa           424

{Part III}. Top-5 Daily Rainfall Observations

Ranking    Prefecture        Station           Rainfall (mm)
01         Ehime             Tomisato     *398 [16/1500-17/1500Z]
02         Miyazaki          Mikado        338 [16/1500-17/1500Z]
03         Kochi             Ikegawa       297 [17/1500-18/1500Z]
04         Kochi             Hongawa       289 [17/1500-18/1500Z]
05         Kochi             Funato        273 [17/1500-18/1500Z]

{Part IV}. Top-5 Hourly Rainfall Observations

Ranking    Prefecture        Station           Rainfall (mm)
01         Miyazaki          Mikado        123 [17/1210-17/1310Z]
02         Kanagawa          Hakone         96 [17/0840-17/0940Z]
03         Hyogo             Sumoto         82 [17/0810-17/0910Z]
04         Ehime             Tomisato       70 [17/0610-17/0710Z]
05         Kochi             Hongawa        64 [17/0540-18/0640Z]

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

Ranking    Station                              Peak wind (mps/dir)
01   Tobishima, Yamagata (JMA35002, Alt 58m)    34  /WSW [19/2000Z]
02   Erimomisaki, Hokkaido (JMA22391, Alt 63m)  28  /NE  [20/0130Z]
03   Izuhara, Nagasaki (WMO47800, Alt 4m)      *27.1/SSE [18/2050Z]
04   Nomozaki, Nagasaki (JMA84596, Alt 190m)    27  /SE  [18/1600Z]
05   Ryotsu, Niigata (JMA54166, Alt 2m)        *26  /SW  [19/1740Z]

{Part VI}. Top-5 Peak Gust Observations

Ranking    Station                              Peak wind (mps/dir)
01     Izuhara, Nagasaki (WMO47800, Alt 4m)    *48.7/SSE [18/2036Z]
02     Fukue, Nagasaki (WMO47843, Alt 25m)      41.2/S   [18/1723Z]
03     Akita, Akita (WMO47582, Alt 6m)          41.1/SW  [19/1839Z]
04     Sakata, Yamagata (WMO47587, Alt 3m)      39.9/SSW [19/1853Z]
05     Hachinohe, Aomori (WMO47581, Alt 27m)    39.2/SW  [20/0006Z]

{Part VII}. Top-5 SLP Observations

Ranking    Station                              Min SLP (hPa)
01         Izuhara, Nagasaki (WMO47800)        974.1 [18/2112Z]
02         Fukaura, Aomori (WMOWMO47574)       978.7 [19/1939Z]
03         Kumejima, Okinawa (WMO47929)        980.7 [17/0937Z]
04         Aomori, Aomori (WMO47575)           981.3 [19/2104Z]
05         Hachinohe, Aomori (WMO47581)        982.5 [19/2328Z]

{Part VIII} References (Japanese versions only)


Meteorological Observations from Coastal Zhejiang, China

1. Significant gust observations from the western periphery 
   of Typhoon Megi [Aug 17-18, locally]

        Shulang Lake----30.6 m/s
        Langgang----27.7 m/s
        Haijiao----27.3 m/s
        Dongtou----26.8 m/s

2. Significant rainfall observations from the western 
   periphery of Typhoon Megi [18/0000-19/0000Z]

        Dongtou----86.4 mm
        Yuhuan----62.9 mm
        Jinhua----59.2 mm

Rainfall Observations from the Republic of Korea

17/1200-18/1200Z (Only amounts >= 100 mm listed)

WANDO (34.40N 126.70E 35m)              332.5 mm
GWANGJU (35.17N 126.90E 74m)            305.5 mm
ANDONG (36.57N 128.72E 141m)            210.0 mm
JINDO RADAR (34.47N 126.32E 477m)       191.5 mm
MOKPO (34.82N 126.38E 39m)              177.0 mm
JEONJU (35.82N 127.15E 55m)             171.5 mm
JEJU (33.52N 126.53E 23m)               139.5 mm
JEJU UPPER/RADAR (33.28N 126.17E 73m)   139.0 mm
SANGJU (36.40N 128.15E 100m)            116.0 mm
CHUPUNGNYEONG (36.22N 128.00E 245m)     114.0 mm

18/0000-19/0000Z (Only amounts >= 100 mm listed)

GWANGJU (35.17N 126.90E 74m)            319.5 mm
WANDO (34.40N 126.70E 35m)              254.5 mm
ANDONG (36.57N 128.72E 141m)            237.0 mm
DAEGWALLYEONG (37.68N 128.77E 844m)     220.5 mm
JINDO RADAR (34.47N 126.32E 477m)       214.0 mm
SOKCHO (38.25N 128.57E 19m)             199.0 mm
GANGNEUNG (37.75N 128.90E 26m)          197.5 mm
MOKPO (34.82N 126.38E 39m)              195.5 mm
DONGHAE RADAR (37.50N 129.13E 37m)      187.5 mm
ULJIN (36.98N 129.42E 51m)              183.5 mm
DAEGU (35.88N 128.62E 59m)              179.5 mm
JEONJU (35.82N 127.15E 55m)             176.5 mm
POHANG (36.03N 129.38E 4m)              167.5 mm
SANGJU (36.40N 128.15E 100m)            154.0 mm
CHUPUNGNYEONG (36.22N 128.00E 245m)     144.0 mm
YEONGWOL (37.18N 128.47E 237m)          113.5 mm
DAEJEON (36.37N 127.37E 72m)            104.5 mm

18/1200-19/1200Z (Only amounts >= 100 mm listed)

DAEGWALLYEONG (37.68N 128.77E 844m)     219.0 mm
DONGHAE RADAR (37.50N 129.13E 37m)      217.5 mm
GANGNEUNG (37.75N 128.90E 26m)          209.5 mm
SOKCHO (38.25N 128.57E 19m)             169.0 mm
ULJIN (36.98N 129.42E 51m)              165.0 mm
POHANG (36.03N 129.38E 4m)              143.5 mm
DAEGU (35.88N 128.62E 59m)              108.0 mm

Damage and Casualties

News sources indicated that five people were reported dead or missing after Typhoon Megi lashed South Korea with heavy rains and strong winds. The number left homeless by the storm rose to more than 2400. Dozens of domestic flights were cancelled. Typhoon Megi left at least ten dead in Japan, where the previous month's floods had already caused 15 deaths. Most of the casualties were due to floods and landslides while two persons were lost at sea. Also, a man was killed after being struck by wind-borne advertising boarding. Shikoku and the nearby Tsushima Islands were particularly hard hit--205 mm of rain had fallen on some areas of Shikoku by 0000 GMT 20 August. Megi's landfall on northern Japan resulted in large blackouts as electricity to 130,000 homes was cut. Some 700 people were evacuated from their homes due to the heavy rains and 24 airline flights were cancelled. A group of around 165 primary school students stranded by a landslide in western Japan were success- fully rescued by helicopter.

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

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

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