ATSANI continues to weaken. At 8 am, ATSANI was centred about 870 km (470 NM) ESE of Tokyo.

艾莎尼繼續減弱。在上午 8 時，艾莎尼集結在東京東南偏東約 870 公里 (470 海里)。

ATSANI is the 82nd name in the tropical cyclone name list. It was contributed by Thailand, meaning lightning flash. This name replaces MORAKOT which caused extensive destruction in Taiwan in 2009.

艾莎尼為熱帶氣旋名稱列表中第 82 個名字，由泰國提供，意思為閃電。此名取代於同一位置，並於 2009 年重創台灣的颱風莫拉克。

ATSANI will move ENE along the northern periphery of the subtropical ridge. It is expected to decelerate after t+24 or t+36 as the ridge weakens south of the storm, reducing the steering force it receives.

艾莎尼將沿副熱帶高壓脊北部向東北偏東移動。24 至 36 小時後，副高處於艾莎尼以南的部分將西徹，令風暴所在之處的流場減弱，這將使風暴減速。

Current T-number 現時的 T 號碼: T3.5/4.0/W1.0/24 HRS

ATSANI has weakened over the past 24 hours, but its structure remains tight. Gradual weakening is expected in the remainder of the forecast period. As ATSANI enters the baroclinic zone, extratropical transition should start near t+24 and is expected to be complete by t+48.

艾莎尼於過去 24 小時減弱，但其結構仍然緊密。預料風暴將於餘下時間逐漸減弱。隨著艾莎尼進入斜壓區，預料它將於 24 小時後開始溫帶氣旋轉化，並於 48 小時後完成。

No threat to Hong Kong is expected within the next 72 hours.

預料艾莎尼於未來的 72 小時將不會對香港構成影響。

2015/08/25 (Tue 二), afternoon 下午 (or earlier 或更早)

ATSANI is now recurving. At 8 am, ATSANI was centred about 660 km (360 NM) NE of Iwo Jima.

艾莎尼正開始轉向。在上午 8 時，艾莎尼集結在硫磺島東北約 660 公里 (360 海里)。

ATSANI is the 82nd name in the tropical cyclone name list. It was contributed by Thailand, meaning lightning flash. This name replaces MORAKOT which caused extensive destruction in Taiwan in 2009.

艾莎尼為熱帶氣旋名稱列表中第 82 個名字，由泰國提供，意思為閃電。此名取代於同一位置，並於 2009 年重創台灣的颱風莫拉克。

ATSANI will turn NE along the northwestern periphery of the subtropical ridge, and will then accelerate towards the ENE. It is expected to decelerate after t+48 as the ridge weakens south of the storm, reducing the steering force it receives.

艾莎尼將沿副熱帶高壓脊西北部轉向東北移動，隨後向東北偏東加速。48 小時後，副高處於艾莎尼以南的部分將西徹，令風暴所在之處的流場減弱，這將使風暴減速。

Current T-number 現時的 T 號碼: T4.5/4.5/S0.0/24 HRS

ATSANI weakened slightly over the past 24 hours. Slight increase in vertical wind shear and lower ocean heat content will cause the storm to weaken slowly over the next 72 hours. Extratropical transition is expected to be complete by t+72.

艾莎尼於過去 24 小時稍為減弱。隨著海洋熱含量下降及垂直風切變略為上升，預料艾莎尼將於未來 72 小時慢慢減弱。艾莎尼將於 72 小時後轉化為溫帶氣旋。

No threat to Hong Kong is expected within the next 72 hours.

預料艾莎尼於未來的 72 小時將不會對香港構成影響。

2015/08/24 (Mon 一), afternoon 下午 (or earlier 或更早)

ATSANI has weakened into a category 2 typhoon and decelerated over the past 12 hours. At 8 am, ATSANI was centred about 440 km (240 NM) NE of Iwo Jima.

艾莎尼減弱為二級颱風，並於過去 12 小時減速。在上午 8 時，艾莎尼集結在硫磺島東北約 440 公里 (240 海里)。

ATSANI is the 82nd name in the tropical cyclone name list. It was contributed by Thailand, meaning lightning flash. This name replaces MORAKOT which caused extensive destruction in Taiwan in 2009.

艾莎尼為熱帶氣旋名稱列表中第 82 個名字，由泰國提供，意思為閃電。此名取代於同一位置，並於 2009 年重創台灣的颱風莫拉克。

ATSANI is now crossing the subtropical ridge axis, and will recurve to the northeast in the next 36 hours. It will then accelerate along the northern periphery of the ridge. Some numerical model forecasts are calling for a rapid deceleration towards the end of the forecast period, as the storm becomes embedded within the mid-latitude trough.

艾莎尼正橫過副熱帶高壓脊脊線，預料將於未來 36 小時轉向東北移動，隨後沿副高北端加速。部分數值模式預報顯示預測後期風暴將嵌入西風槽中並明顯減速。

Current T-number 現時的 T 號碼: T4.5/5.0/W1.0/24 HRS

ATSANI has weakened significantly over the past 24 hours. Slight increase in vertical wind shear and lower ocean heat content will cause the storm to weaken gradually over the next 72 hours. Extratropical transition is expected to be complete by t+96.

艾莎尼於過去 24 小時明顯減弱。隨著海洋熱含量下降及垂直風切變略為上升，預料艾莎尼將於未來 72 小時逐漸減弱。艾莎尼將於 96 小時後轉化為溫帶氣旋。

No threat to Hong Kong is expected within the next 72 hours.

預料艾莎尼於未來的 72 小時將不會對香港構成影響。

2015/08/23 (Sun 日), afternoon 下午 (or earlier 或更早)

ATSANI has weakened over the past 24 hours. At 8 am, ATSANI was centred about 530 km (290 NM) E of Iwo Jima.

艾莎尼於過去 24 小時減弱。在上午 8 時，艾莎尼集結在硫磺島以東約 530 公里 (290 海里)。

ATSANI is the 82nd name in the tropical cyclone name list. It was contributed by Thailand, meaning lightning flash. This name replaces MORAKOT which caused extensive destruction in Taiwan in 2009.

艾莎尼為熱帶氣旋名稱列表中第 82 個名字，由泰國提供，意思為閃電。此名取代於同一位置，並於 2009 年重創台灣的颱風莫拉克。

ATSANI will move NW along the southwestern periphery of the subtropical ridge over the next 12 to 24 hours. The ridge will then weaken and allow ATSANI to recurve to the northeast.

艾莎尼將於未來 12 至 24 小時沿副熱帶高壓脊西南部向西北移動，隨後副高減弱，艾莎尼將轉向東北移動。

Current T-number 現時的 T 號碼: T5.5/6.0/W0.5/24 HRS

As seas become cooler, ATSANI is expected to weaken throughout the forecast period.

隨著海溫下降，預料艾莎尼將於預測期內逐漸減弱。

No threat to Hong Kong is expected within the next 72 hours.

預料艾莎尼於未來的 72 小時將不會對香港構成影響。

2015/08/22 (Sat 六), afternoon 下午 (or earlier 或更早)

ATSANI briefly intensified into a category 5 typhoon yesterday but has weakened since then. At 8 am, ATSANI was centred about 930 km (500 NM) ESE of Iwo Jima.

艾莎尼昨天曾短暫增強為五級超級颱風，但隨後減弱。在上午 8 時，艾莎尼集結在硫磺島東南偏東約 930 公里 (500 海里)。

ATSANI is the 82nd name in the tropical cyclone name list. It was contributed by Thailand, meaning lightning flash. This name replaces MORAKOT which caused extensive destruction in Taiwan in 2009.

艾莎尼為熱帶氣旋名稱列表中第 82 個名字，由泰國提供，意思為閃電。此名取代於同一位置，並於 2009 年重創台灣的颱風莫拉克。

ATSANI will move NW along the southwestern periphery of the subtropical ridge over the next 36 hours. The ridge will weaken later and ATSANI will recurve along its western periphery.

艾莎尼將於未來 36 小時沿副熱帶高壓脊西南部向西北移動。預測副高將於稍後減弱，艾莎尼將沿該脊西部轉向。

Current T-number 現時的 T 號碼: T6.0/6.5/W0.5/24 HRS

ATSANI has developed a large eye, but convections to its north have thinned over the past 12 hours. Slight weakening is expected at first; as seas become cooler, its rate of weakening will increase at later taus.

艾莎尼發展出一大型風眼，但其北端的對流於過去 12 小時轉薄。預料初時艾莎尼會稍為減弱，隨後因海溫降低，減弱速度將加快。

No threat to Hong Kong is expected within the next 72 hours.

預料艾莎尼於未來的 72 小時將不會對香港構成影響。

2015/08/21 (Fri 五), afternoon 下午 (or earlier 或更早)

ATSANI is moving NW steadily and has intensified into a super typhoon. At 8 am, ATSANI was centred about 1370 km (740 NM) ESE of Iwo Jima.

艾莎尼穩定向西北移動，並增強為一超級颱風。在上午 8 時，艾莎尼集結在硫磺島東南偏東約 1370 公里 (740 海里)。

ATSANI is the 82nd name in the tropical cyclone name list. It was contributed by Thailand, meaning lightning flash. This name replaces MORAKOT which caused extensive destruction in Taiwan in 2009.

艾莎尼為熱帶氣旋名稱列表中第 82 個名字，由泰國提供，意思為閃電。此名取代於同一位置，並於 2009 年重創台灣的颱風莫拉克。

ATSANI will move NW along the southwestern periphery of the subtropical ridge over the next 48 hours. The ridge will weaken later and ATSANI will recurve along its western periphery.

艾莎尼將於未來 48 小時沿副熱帶高壓脊西南部向西北移動。預測副高將於稍後減弱，艾莎尼將沿該脊西部轉向。

Current T-number 現時的 T 號碼: T6.5/6.5/D1.0/24 HRS

ATSANI continues to display an excellent structure and its eye has warmed quite a bit over the past 12 hours. Environmental conditions are still conducive to storm development; ATSANI is expected to reach category 5 soon. As it moves further north, it will reach cooler seas and should start to weaken.

艾莎尼結構極佳，其風眼於過去 12 小時明顯變暖。由於大氣環境仍有利熱帶氣旋發展，預料艾莎尼即將增強為五級颱風。隨著風暴進一步北上，它將進入較冷的洋面並開始減弱。

No threat to Hong Kong is expected within the next 72 hours.

預料艾莎尼於未來的 72 小時將不會對香港構成影響。

2015/08/20 (Thu 四), afternoon 下午 (or earlier 或更早)

ATSANI has intensified into a category 3 typhoon. At 8 am, ATSANI was centred about 1840 km (990 NM) ESE of Iwo Jima.

艾莎尼已增強為三級颱風。在上午 8 時，艾莎尼集結在硫磺島東南偏東約 1840 公里 (990 海里)。

ATSANI is the 82nd name in the tropical cyclone name list. It was contributed by Thailand, meaning lightning flash. This name replaces MORAKOT which caused extensive destruction in Taiwan in 2009.

艾莎尼為熱帶氣旋名稱列表中第 82 個名字，由泰國提供，意思為閃電。此名取代於同一位置，並於 2009 年重創台灣的颱風莫拉克。

As the subtropical ridge extension between GONI and ATSANI weakens and the ridge builds to the east of ATSANI, the storm should move NW steadily in the next 72 to 96 hours. The ridge may weaken beyond that, contributing to a poleward turn.

隨著天鵝及艾莎尼之間的副熱帶高壓脊延伸減弱而副高於艾莎尼以東伸展，艾莎尼將於未來 72 小時穩定向西北移動。預測後期副高或會減弱，令艾莎尼的移向漸轉偏北。

Current T-number 現時的 T 號碼: T5.5/5.5/D1.0/24 HRS

ATSANI is displaying a very symmetric structure. With superb environmental conditions (warm sea temperatures, very low vertical wind shear and decent divergence) along its forecast track, ATSANI is expected to intensify into a major typhoon in the next 72 hours. The storm may weaken later due to a reduction in ocean heat content.

艾莎尼的結構非常對稱。由於艾莎尼沿途大氣環境極佳，海溫高、垂直風切變極低且輻散良好，預料艾莎尼將於未來 72 小時增強為一股強勁颱風，隨後或因海洋熱含量降低而開始減弱。

No threat to Hong Kong is expected within the next 72 hours.

預料艾莎尼於未來的 72 小時將不會對香港構成影響。

2015/08/19 (Wed 三), afternoon 下午 (or earlier 或更早)

ATSANI has intensified into a typhoon. At 8 am, ATSANI was centred about 950 km (520 NM) WSW of Wake Island.

艾莎尼已增強為颱風。在上午 8 時，艾莎尼集結在威克島西南偏西約 950 公里 (520 海里)。

ATSANI is the 82nd name in the tropical cyclone name list. It was contributed by Thailand, meaning lightning flash. This name replaces MORAKOT which caused extensive destruction in Taiwan in 2009.

艾莎尼為熱帶氣旋名稱列表中第 82 個名字，由泰國提供，意思為閃電。此名取代於同一位置，並於 2009 年重創台灣的颱風莫拉克。

The subtropical ridge extension between GONI and ATSANI is about to weaken, and ATSANI will start to move NW in the next 24 hours along the southwestern periphery of the subtropical ridge.

天鵝及艾莎尼之間的副熱帶高壓脊延伸即將減弱，預料艾莎尼將於 24 小時內開始沿副高西南部向西北移動。

Current T-number 現時的 T 號碼: T4.5/4.5/D1.0/24 HRS

ATSANI has developed a banding eye. With superb environmental conditions (warm sea temperatures, very low vertical wind shear and decent divergence) along its forecast track, ATSANI is expected to intensify at above climatological rate in the next 48 to 72 hours, and stay as a strong typhoon through t+120.

艾莎尼發展出一雲捲風眼。沿途大氣環境極佳，海溫高、垂直風切變極低且輻散良好，預料艾莎尼將於未來 48 至 72 小時以高於氣候平均值的速度增強，其後維持較高強度。

No threat to Hong Kong is expected within the next 72 hours.

預料艾莎尼於未來的 72 小時將不會對香港構成影響。

2015/08/18 (Tue 二), afternoon 下午 (or earlier 或更早)

ATSANI has intensified into a severe tropical storm. At 8 am, ATSANI was centred about 800 km (430 NM) SW of Wake Island.

艾莎尼已增強為強烈熱帶風暴。在上午 8 時，艾莎尼集結在威克島西南約 800 公里 (430 海里)。

ATSANI is the 82nd name in the tropical cyclone name list. It was contributed by Thailand, meaning lightning flash. This name replaces MORAKOT which caused extensive destruction in Taiwan in 2009.

艾莎尼為熱帶氣旋名稱列表中第 82 個名字，由泰國提供，意思為閃電。此名取代於同一位置，並於 2009 年重創台灣的颱風莫拉克。

ATSANI is dipping south due to the southward extension of the subtropical ridge between GONI and ATSANI. As that extension weakens and another extension builds to the east of ATSANI, the storm will start to turn NW near t+36. It will then move NW steadily along the southwestern periphery of the subtropical ridge.

受天鵝及艾莎尼之間的副熱帶高壓脊南部延伸影響，艾莎尼略為南移。隨著該延伸減弱及副高於艾莎尼以東南伸，預料艾莎尼將於約 36 小時後開始轉向西北，隨後繼續沿副高西南部向西北移動。

Current T-number 現時的 T 號碼: T3.5/3.5/D1.0/24 HRS

ATSANI will enjoy very favourable environmental conditions (warm sea temperatures, very low vertical wind shear and decent divergence) along its forecast track. Intensification at faster than climatological rate is expected, and ATSANI will very likely become an intense typhoon at the end of the forecast period.

艾莎尼沿途大氣環境極佳，海溫高、垂直風切變極低且輻散良好，預料它將以高於氣候平均值的速度增強，並很大機會於預測後期成為一強勁颱風。

No threat to Hong Kong is expected within the next 72 hours.

預料艾莎尼於未來的 72 小時將不會對香港構成影響。

2015/08/17 (Mon 一), afternoon 下午 (or earlier 或更早)

17W has intensified into a tropical storm, and was named ATSANI. At 8 am, ATSANI was centred about 690 km (370 NM) SW of Wake Island.

17W 已增強為熱帶風暴，被命名為艾莎尼。在上午 8 時，艾莎尼集結在威克島西南約 690 公里 (370 海里)。

ATSANI is the 82nd name in the tropical cyclone name list. It was contributed by Thailand, meaning lightning flash. This name replaces MORAKOT which caused extensive destruction in Taiwan in 2009.

艾莎尼為熱帶氣旋名稱列表中第 82 個名字，由泰國提供，意思為閃電。此名取代於同一位置，並於 2009 年重創台灣的颱風莫拉克。

ATSANI is currently under the influence of competing steering forces from the subtropical ridge to its north and the near-equatorial ridge to its southeast, and the storm has essentially been motionless in the past 24 hours. ATSANI will remain slow-moving in the next 48 hours, and should accelerate NW once the near-equatorial ridge weakens and the subtropical ridge extends south to the east of the storm.

艾莎尼正受北面副熱帶高壓脊及東南面赤道高壓脊的共同影響，因淨流場微弱而於過去 24 小時幾乎停留不動。預料艾莎尼將於未來 48 小時繼續移動緩慢，隨後赤道高壓減弱，加上副高從艾莎尼東面南伸，風暴得以向西北加速移動。

Current T-number 現時的 T 號碼: T2.5/2.5/D1.0/24 HRS

ATSANI will enjoy very favourable environmental conditions (warm sea temperatures, very low vertical wind shear and decent divergence) along its forecast track, and numerical models are consistently predicting it to intensify rapidly after t+72. It will potentially become a very strong typhoon at the end of the forecast period.

預料艾莎尼沿途大氣環境極佳，海溫高、垂直風切變極低且輻散良好，數值模式已多報預測艾莎尼將於 72 小時後大幅增強。在此環境下，艾莎尼有望於預測後期成為一強勁颱風。

No threat to Hong Kong is expected within the next 72 hours.

預料艾莎尼於未來的 72 小時將不會對香港構成影響。

2015/08/16 (Sun 日), afternoon 下午 (or earlier 或更早)

Tropical disturbance 98W has also intensified into tropical depression 17W. At 2 pm, 17W was centred about 610 km (330 NM) SW of Wake Island.

熱帶擾動 98W 亦已增強為熱帶低氣壓 17W。在下午 2 時，17W 集結在威克島西南約 610 公里 (330 海里)。

N/A 不適用

Similar to 16W, 17W is also surrounded by the subtropical ridge to the north. However 17W is closer to the ridge to its southeast than 16W, and is expected to move very slowly in the next 48 hours due to competing forces from the ridges. That southeastern ridge is expected to reorientate near t+48, reducing the cancellation forces it exerts on 17W and allowing the storm to accelerate towards the WNW or NW.

跟 16W 情況一樣，17W 以北亦為副熱帶高壓脊所控制，但 17W 比 16W 更接近處於東南面的脊場，由於兩脊流場抵銷，預計 17W 於未來 48 小時移動非常緩慢。預測該東南脊場之形態將於 48 小時後有所改變，其抵銷力度減弱，從而令 17W 向西北偏西或西北加速移動。

Current T-number 現時的 T 號碼: T1.5/1.5/INT OBS

17W is enjoying very decent divergence aloft, and with suitable sea temperatures the storm is expected to intensify gradually over the next 72 hours.

17W 附近輻散強勁，預料將於未來 72 小時在溫暖洋面上穩步增強。

No threat to Hong Kong is expected within the next 72 hours.

預料 17W 於未來的 72 小時將不會對香港構成影響。

2015/08/15 (Sat 六), afternoon 下午 (or earlier 或更早)