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TC Watch / 熱帶氣旋 > Selected TC Review / 重要熱帶氣旋回顧 > 201329W (KROSA 羅莎) [Refresh 更新]

201329W (KROSA 羅莎) - Profile 檔案

(First draft issued on December 15, 2013; final version issued on December 26, 2013)
(初稿於 2013 年 12 月 15 日發出,最後版本於 2013 年 12 月 26 日上載)

Brief profile of KROSA 羅莎小檔案:

JTWC number 聯合颱風警報中心 (JTWC) 號碼 29W
International number 國際編號 1329
Period of existence 生存時期 (JTWC) 2013/10/29 08 HKT - 2013/11/04 20 HKT
Lifetime 壽命 (JTWC) 6.50 days 日
Maximum 1-minute wind (JTWC) JTWC 一分鐘平均最高中心風速 100 knots 節 (Category 3 Typhoon 三級颱風)
Minimum pressure (JTWC) JTWC 最低氣壓 948 hPa 百帕
Highest TC signal by HKO (if applicable)
香港天文台發出最高熱帶氣旋警告信號
1 (Standby Signal 戒備信號)
Closest point of approach by HKO (if applicable)
香港天文台所示之最接近距離 (如適用)
S 220 km (real-time warning 實時報告 / TC report 熱帶氣旋報告)
Time of closest approach by HKO (if applicable)
香港天文台所示之最接近時間 (如適用)
2013/11/03 18 HKT (real-time warning 實時報告) / 14 HKT (TC report 熱帶氣旋報告)
Lowest pressure recorded at HKO (if applicable)
香港天文台錄得的最低氣壓 (如適用)
1010.2 hPa 百帕 (2013/11/02 14:06 HKT)

TC signals for Hong Kong & Track 香港曾經生效的熱帶氣旋警告和路徑圖:

Table 表:

Signal
信號
Date and time
日期和時間
Distance from HK
與香港的距離
Predicted movement
預測移動方向和速度
Max. 10-min winds
中心最高十分鐘平均風速
2013/11/01 (FRI) 15:20 HKT SE 530 km W/WNW at 16 km/h 120 km/h (65 knots, CAT. 1 / T)
2013/11/03 (SUN) 22:50 HKT S 270 km SW at 25 km/h 75 km/h (40 knots, TS)

Figure 圖:

(Track courtesy of Lorenzo. Data from HKO. 鳴謝 Lorenzo 提供路徑圖,資料取自天文台)

TC Track

Percentile Ranks 百分等級:

Percentile ranks are only available for cyclones that necessitated at least the No. 3 Strong Wind Signal. 百分等級只適用於曾令天文台發出三號強風信號 (或更高) 的熱帶氣旋。

IR imagery animation 紅外線雲圖動畫:

TC track from HKWW 本站的熱帶氣旋路徑圖:

TC Track

TC track from HKO 天文台的熱帶氣旋路徑圖:

TC Track

TC Track

Past HKWW Bulletins on KROSA 本站有關羅莎的發佈

Please click here for bulletins on KROSA. 請按這裡

Storm Formation and Development 氣旋形成和發展

Unless otherwise stated, all times below are in Hong Kong Standard Time (UTC+8)
除非特別註明,下文時間均為香港標準時間 (協調世界時加 8 小時)

KROSA is the last tropical cyclone that necessitated TC warning signal this year.

A tropical disturbance developed in the northwestern Pacific in the end of October. It gathered strength and intensified into tropical depression 29W at 8 am October 29. Under the influence of the subtropical ridge, 29W was forecast to move W to WNW in general towards Luzon in the next two days, followed by a westward movement in the South China Sea. Numerical models show discrepancies in the predicted strength of the subtropical ridge, leading to somewhat different forecast tracks, although they generally predicted 29W to enter the South China Sea in early November.

Situated to the south of the subtropical ridge, 29W moved west on October 29. The cyclone was in an area of low to moderate vertical wind shear, and intensified gradually that day. The JMA upgraded 29W into a tropical storm at 2 am October 30 and named it KROSA. This name was contributed by Cambodia, meaning the bird crane.

KROSA started to move WNW on October 30 and the track was generally north of the forecast. The official agencies shifted their forecast tracks northwards, predicting a landfall at the northern tip of Luzon instead of crossing the mountains. The predictions also called for a temporary weakening of the ridge which would put KROSA in a pressure col as it tracked across the South China Sea, which was then followed by a trajectory towards the WSW. As for KROSA's intensity, the JTWC upgraded it into a typhoon on October 31, when the storm started to develop a banding eye. A clear eye appeared on satellite images in the afternoon, which prompted other agencies to upgrade KROSA into a typhoon.

羅莎是本年最後一個令天文台發出熱帶氣旋警告信號的風暴。

一個擾動於 10 月底在西北太平洋發展,它於 29 日上午 8 時被聯合颱風警報中心升格為熱帶低氣壓 29W。受副熱帶高壓脊的影響,當時預料 29W 將於未來兩天大致向西至西北偏西移動並靠近呂宋,隨後於南海西移。數值預報模式對副高強度的預測有一定分歧,因此它們的預測路徑也不盡相同,但大致上都是預料 29W 於 11 月初進入南海。

處於副高以南的 29W 於 29 日向偏西移動。29W 一帶垂直風切變低至中等,它於當天逐漸增強。日本氣象廳於 30 日凌晨 2 時將 29W 升格為熱帶風暴,並命名為羅莎。此名字由柬埔寨提供,意思為鶴。

羅莎於 30 日向西北偏西移動,路徑普遍較預測為北,各官方氣象台開始將其預測路徑北調,由原先預料羅莎將登陸呂宋中部並橫過高山改為登陸呂宋北端。路徑預測亦顯示羅莎於南海將會因副高暫時減弱而處於鞍場中,其後轉往西南偏西移動。至於強度方面,羅莎於 31 日開始建立雲捲風眼,聯合颱風警報中心將其升格為颱風。在雲圖上風眼於當天下午漸變清晰,其他機構亦開始將其升格為颱風。

Figures 1a and 1b - Steering flow charts on October 29 and November 3
圖 1a 及 1b - 10 月 29 及 11 月 3 日的駛流圖

Figures 2a to 2b - Forecast tracks from official agencies on October 30 and November 3
圖 2a 及 2b - 官方氣象台於 10 月 30 及 11 月 3 日的預測路徑

Figure 3 - KROSA about to make landfall at Luzon
圖 3 - 羅莎即將登陸呂宋

Crossing Northern South China Sea 橫過南海北部

KROSA made landfall near the northern extreme of Luzon near 6 pm October 31. Although it avoided the most hilly part of Luzon, the temporary landfall caused the storm to lose some strength. The clear eye disappeared soon after landfall while the storm continued to move WNW. The landfall was brief and KROSA returned to sea near midnight November 1.

KROSA intensified again soon after reaching the South China Sea. The banding eye improved and became clearer on satellite images later that day. The forecasts had KROSA continuing its WNW track until it reached 20°N, after which it would turn SW as the western ridge assumed steering influence and due to the northeast monsoon.

As KROSA approached, the Observatory issued the #1 Standby Signal at 3:20 pm November 1. This is the first TC signal issued in November since BEBINCA in 2000, and the last time a TC signal was in force in November was during the influence of CIMARON in 2006. KROSA continued to move WNW steadily and was showing signs of intensification. Due to the combined effect of KROSA and the northeast monsoon, east to northeasterly winds were generally observed in the territory.

KROSA became more compact on November 2 and its eye was clearly visible in various satellite images. The subtropical ridge weakened and KROSA decelerated, while moving WNW to NW. The JTWC upgraded KROSA into a category 3 typhoon (100 knots / 185 km/h) at 2 am. Both China and Taiwan agencies estimated KROSA's strength at higher than 85 knots (157 km/h), while the JMA and HKO's estimated strengths were below 85 knots. An oil platform located at 20.2°N, 114.9°E (less than 50 km away from storm centre) recorded maximum 10-minute sustained winds of above 50 m/s (180 km/h) in the evening of November 2, hinting at possible underestimation by JMA and HKO even accounting for the altitude of the oil rig. (Note: The HKO assessed KROSA as a severe typhoon at its peak in the TC report)

Following a brief weakening, the subtropical ridge strengthened again on November 3. KROSA was in a pressure col which led to its slow movement. The storm was already less than 250 km from Hong Kong that morning, but KROSA's structure was so compact that winds in Hong Kong did not even reach strong force (except for offshore stations and on high ground). The Observatory mentioned in several bulletins that it may consider issuing the Strong Wind Signal if KROSA moved further north, but that was eventually deemed unnecessary. Local weather was initially fine under the influence of the subtropical ridge, but turned unstable as KROSA came close. There were some showers on November 2 and 3 but were generally light.

羅莎於 10 月 31 日下午 6 時左右登陸呂宋北部。雖然它避過該島最高的山脈,但短暫登陸仍然令羅莎稍為減弱。它清晰的風眼於登陸後不久消失,而風暴繼續向西北偏西移動。羅莎登陸時間頗短,它於 11 月 1 日午夜時份回到大海。

羅莎進入南海後很快便再次增強,它的雲捲風眼結構有所改善,在衛星雲圖上再度變得清晰。當時普遍預測羅莎將繼續向西北偏西移動直至到達北緯 20 度,隨後因西面副高開始引導羅莎及東北季候風的關係,羅莎將向西南移動。

隨著羅莎靠近,天文台於 1 日下午 3 時 20 分發出一號戒備信號。這是自 2000 年的貝碧嘉以來天文台首次於 11 月發出熱帶氣旋警告信號,亦是自 2006 年的西馬侖以來熱帶氣旋警告信號首次於 11 月生效。羅莎繼續穩定向西北偏西移動,並有跡象增強。受羅莎及東北季候風的影響,香港普遍吹東至東北風。

羅莎的結構於 2 日變得較為緊密,風眼於雲圖上清晰可見。副高開始減弱,羅莎因而減速,但繼續向西北偏西至西北移動。聯合颱風警報中心於凌晨 2 時將羅莎的強度訂為 100 節 (每小時 185 公里),即三級颱風強度。中國及台灣氣象當局估計羅莎的強度高於 85 節 (每小時 157 公里),而日本氣象廳及香港天文台的估計則為低於 85 節。一個於北緯 20.2 度,東經 114.9 度 (距離風暴中心小於 50 公里) 的油台於 2 日傍晚曾錄得十分鐘最高持續風速達每秒 50 米 (每小時 180 公里),即使撇除油台海拔因素後仍顯示日本氣象廳及香港天文台或低估羅莎的風力。(註:天文台於熱帶氣旋報告中將羅莎的最高強度調高為強颱風)

短暫減弱後,副高於 3 日再度增強,而羅莎仍然於鞍場中,所以移動緩慢。當天早上羅莎已於香港 250 公里範圍內,但由於它的結構緊密而尺度較小,本地風勢除離岸及高地外連強風也未達。天文台曾數次於熱帶氣旋警報中表示若羅莎繼續北移便有需要考慮改發三號強風信號,但最終並未需要發出。本地天氣方面,初時受副高影響天氣良好,但由於羅莎靠近,天氣變得不穩定,2 及 3 日有幾陣驟雨,但雨勢不大。

Figure 4 - KROSA at peak intensity
圖 4 - 羅莎到達巔峰強度

Figure 5 - Wind field associated with KROSA in the night of November 2
圖 5 - 11 月 2 日晚上羅莎的風場

Figure 6 - 500 hPa heights - KROSA was once north of the subtropical ridge, but the ridge eventually recovered and prevented KROSA from recurving
圖 6 - 500 百帕高度圖。羅莎一度處於副高以北,但該脊最終再次增強並阻止羅莎轉向

Weakening and Dissipation 減弱及消散

KROSA started to weaken on November 3 as the storm drew in drier air from the north and the sea temperatures dropped because of KROSA's stagnation. Its eye disappeared and the upper-level cloud bands were eroded during the day. The Observatory downgraded KROSA into a severe tropical storm at 1 pm. It finally moved again near sunset and was closest to Hong Kong near 6 pm, when it was 220 km to the south of the territory. KROSA turned SW sharply that night and started to accelerate. As its threat to Hong Kong decreased, the Observatory cancelled the Standby Signal at 10:50 pm.

KROSA weakened into a tropical storm in the night of November 3. By the next morning KROSA had lost almost all deep convections, leaving a totally exposed (but still intact) low-level circulation centre. At the same time, it skirted seas SE of Hainan and weakened into a tropical depression. The storm continued to move SW during that day, and degenerated into an area of low pressure early on November 5 before making landfall at Vietnam.

羅莎於南海北部捲入北方較乾燥的空氣,而且由於停滯多時,海水上翻令海溫下降,這令羅莎於 3 日開始減弱。它的風眼消失,而高層雲帶逐漸消散。天文台於下午 1 時將羅莎降格為強烈熱帶風暴。羅莎於當天日落時份終於開始移動,於下午 6 時左右最接近香港,於本港以南約 220 公里掠過。羅莎當晚轉向西南移動,並開始加速。由於它對香港的威脅逐漸減低,天文台於當晚 10 時 50 分取消一號戒備信號

羅莎於 3 日晚間減弱為熱帶風暴。4 日早上可見羅莎已幾乎失去所有深層對流,遺下一個完整但外露的低層環流中心。它於當天掠過海南以東海域,並減弱為熱帶低氣壓。羅莎繼續向西南移動,於 5 日早段於海上減弱為低壓區

Figures 7a and 7b - Radar images at 9 pm November 2 and 4 pm November 3. KROSA was weakening at that time and its size shrank considerably
圖 7a 及 7b - 11 月 2 日晚上 9 時及 3 日下午 4 時之雷達圖,可見羅莎正在減弱,尺度明顯縮小

Figures 8a and 8b - Calculated wind fields on November 2 and 3 showing the same weakening trend
圖 8a 及 8b - 11 月 2 及 3 日的估算風場圖,同樣可見羅莎減弱

Figures 9a and 9b - KROSA lost its deep convections while the low-level circulation centre moved SW
圖 9a 及 9b - 羅莎失去其深層對流,而低層環流中心向西南移動

Winds Recorded at Reference Stations 參考站所錄得的風速

(Except for special cases, this section is not available for cyclones that only necessitated the Standby Signal 除非特別情況,否則此部只當氣旋令天文台發出三號或更高信號時提供)

Charts and Figures 各項數據

Table 1: Track data from HKWW:
表一 : 香港天氣觀測站之路徑資料

YYMMDDZZ Lat Long Wind
13102818 144N1358E 025
13102900 150N1347E 030
13102906 153N1334E 030
13102912 155N1322E 030
13102918 157N1313E 035
13103000 163N1298E 045
13103006 169N1285E 050
13103012 172N1270E 055
13103018 176N1255E 060
13103100 177N1241E 065
13103106 179N1230E 075
13103112 182N1219E 080
13103118 186N1206E 075
13110100 188N1192E 075
13110106 191N1182E 075
13110112 194N1171E 080
13110118 194N1164E 085
13110200 196N1158E 090
13110206 199N1152E 095
13110212 201N1149E 090
13110218 203N1148E 080
13110300 203N1147E 070
13110306 203N1145E 065
13110312 204N1143E 050
13110318 194N1132E 045
13110400 186N1124E 040

Table 2: Maximum gust and hourly average wind speed recorded in Hong Kong from HKO:
表二 : 香港天文台公佈的各站最高每小時平均風力和陣風數據

Station Maximum Gust Maximum Hourly Mean Wind
Direction Speed (km/h) Date/Month Time Direction Speed (km/h) Date/Month Time
Bluff Head (Stanley) - 51 2/11 18:54 - 19 1/11 17:00
Central Pier N 38 3/11 08:39 NNE 23 2/11 07:00
Cheung Chau NNE 58 3/11 08:55 NNE 38 3/11 09:00
Cheung Chau Beach NE 65 2/11 20:22 NE 45 3/11 00:00
Green Island NNE 68 3/11 10:50 NNE 47 3/11 11:00
Hong Kong International Airport NE 51 3/11 12:28 NE 31 3/11 12:00
Kai Tak NNE 49 3/11 10:44 NNE 20 3/11 11:00
King's Park  NE 49 3/11 08:23 NE 20 3/11 09:00
Lau Fau Shan NNE 51 3/11 18:29 NNE 31 3/11 16:00
Ngong Ping NE 62 3/11 05:06 ENE 49 2/11 22:00
North Point NE 51 2/11 18:00 ENE 25 3/11 11:00
Peng Chau ENE 52 2/11 20:39 NE 31 3/11 16:00
Ping Chau NE 30  3/11 17:06 NNE 7 2/11 15:00
        NE 7 3/11 03:00
        NNE 7 3/11 13:00
Sai Kung  NNE 56 3/11 10:46 NNE 31 3/11 11:00
Sha Chau NNE 52  3/11 09:50 N 40 3/11 11:00
Sha Lo Wan NE 40 3/11 10:40 NE 22 3/11 12:00
Sha Tin NNE 40 3/11 12:52 NNE 20 3/11 09:00
        NNE 20 3/11 11:00
        NNE 20 3/11 12:00
Shek Kong NE 34 3/11 09:12 ENE 19 2/11 19:00
Star Ferry (Kowloon) E 36 2/11 16:15 E 16 3/11 22:00
Ta Kwu Ling  N 49 3/11 10:21 N 22 3/11 14:00
Tai Mei Tuk NE 59 3/11 12:50 NNE 36 3/11 02:00
Tai Mo Shan E 85 3/11 12:45 E 59 3/11 01:00
Tai Po Kau ENE 36 3/11 13:41 NE 14 3/11 15:00
Tap Mun N 40 3/11 11:50 N 19 3/11 10:00
Tate's Cairn  E 85 3/11 02:13 E 58 3/11 02:00
Tseung Kwan O NNE 40 3/11 10:54 N 14 3/11 08:00
Tsing Yi Shell Oil Depot - 31 3/11 08:05 - 14 3/11 08:00
- 31 3/11 13:59        
Tuen Mun Government Offices N 47 3/11 10:46 NNE 22 3/11 11:00
Waglan Island NE 62 3/11 02:27 NE 51 3/11 17:00
Wetland Park NNE 40 3/11 11:55 NE 19 3/11 12:00
Wong Chuk Hang E 52 3/11 08:31 E 20 3/11 17:00

Table 3: Rainfall (in millimetres) contributed by KROSA from HKO (figures in brackets are based on incomplete hourly data):
表三 : 香港天文台公佈的各站雨量資料 (方括號內之數據由不完整之每小時資料擷取)

Station

 1 Nov

2 Nov

3 Nov

Total(mm)
Hong Kong Observatory

0.0

Trace

0.4

0.4
Hong Kong International Airport (HKA)

0.0

Trace

1.9

1.9
Cheung Chau (CCH)

0.0

0.0

1.0

1.0
H23 Aberdeen

0.0

0.0

1.0

1.0

N05 Fanling

0.0

0.0

0.5
0.5
N13 High Island

0.0

0.0

1.0
1.0
K04 Jordan Valley

0.0

0.0

1.0
1.0
N06 Kwai Chung

0.0

0.0

0.0
0.0
H12 Mid Levels

0.0

0.0

0.0
0.0
N09 Sha Tin

0.0

0.0

0.0
0.0
H19 Shau Kei Wan

0.0

0.0

1.0
1.0
SEK Shek Kong

0.0

0.0

1.0
1.0
K06 So Uk Estate

0.0

0.0

0.0
0.0
R31 Tai Mei Tuk

0.0

0.0

0.0
0.0
R21 Tap Shek Kok

0.0

0.0

2.5
2.5
N17 Tung Chung

0.0

0.0

3.5
3.5
R27 Yuen Long

0.0

0.0

0.0
0.0

Last Accessed 最近訪問日期: Fri Nov 15 2019 06:16:58 HKT
Last Modified 最近修訂日期: Sun Oct 02 2016

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