日环食精密预测公报第五号

前言

　　这是2010年日环食精密预测公报第五号，为最终预测公报，以中文和英文编制。本报的预测方法较上报没有显著变化。公报中提及的预报资料可在http://7timer.y234.cn/V3/product.php?language=zh_cn&product_id=2, http://www.fnmoc.navy.mil和http://www.ecmwf.int查阅。对于任意地点的数值预报可查阅http: //7timer.y234.cn/V3/product.php?language=zh_cn&product_id=1。本服务的RSS种 子为http://7timer.y234.cn/V3/wordpress/?feed=rss2&cat=47。

分析

　　各模式之间的预测已经趋于一致，均显示南支槽正集结于由长江中游至川西高原一带，与其关联的湿区在环食带上延伸至东经116度。1030百帕等值线触及北纬30度，但近地面风场显示届时冬季风已减弱。FNMOC NOGAPS指出能见度不足10公里的区域包含四川盆地和长江中游一带，EFS认为环食带出现显著降雨的概率接近0%。

观测

　　以下是环食带一线部分城市13日17时的气象观测资料：

• 瑞丽：阴到多云间晴，能见度约20公里；
• 大理：晴，能见度接近30公里；
• 重庆：有雾，能见度约3公里；
• 南阳：大致天晴，能见度逾20公里；
• 济南：晴，能见度约23公里；
• 青岛：晴，能见度约15公里。

预报

　　鉴于各模式基本吻合，本报的不确定性减为极小。本报同时参考了地面气象站及卫星的观测结果。

• 云南地区、四川南部：大致晴间少云，能见度较好；
• 重庆地区：有雾，能见度较差，但高地上可能有阳光；
• 十堰、南阳一带：晴间多云，但可能为卷云，能见度偏低到中等；
• 山东地区：多云，但可能为卷云，能见度中等。

　　一片卷云区正集结在青藏高原东部，预计未来48小时内将迅速东移，可能对华中、华东和辽东的部分地区造成影响，建议这一地区的观测者随时注意这一片云区的动态；日食期间，南支槽预计将移动至云南东部、贵州和湖北西南部，预计这一带的东部邻近地区天气将不佳。

预报分析

　　2月28日前。

2010 Annular Solar Eclipse PFS Bulletin No. 5

FOREWORD

This is 2010 Annular Solar Eclipse PFS Bulletin No. 5, the final forecast update before the eclipse, issued in both English and Chinese. No major changes were made on the forecast philosophy since last bulletin. The forecast diagrams mentioned below may be found at http://7timer.y234.cn/V3/product.php?language=en&product_id=2, http://www.fnmoc.navy.mil and http://www.ecmwf.int. Numeric forecast for various locations may be found at http://7timer.y234.cn/V3/product.php?language=en&product_id=1. RSS feed of this service is available at http://7timer.y234.cn/V3/wordpress/?feed=rss2&cat=46.

ANALYSIS

The three global models, NCEP GFS at JAN14/00Z, ECMWF at JAN 12/12Z, and FNMOC NOGAPS JAN 13/18Z now show an almost consistent forecast: a significant westerly trough over central Yangtze Valley and Western Sichuan Plateau with an associated wet area south of the annularity path to 116E over east. The 1030hPa contour reaches 30N, but the near-surface wind forecast suggests the winter monsoon has weaken at that time. NOGAPS suggested that the visibility of most part of Myanmar, Sichuan Basin, Central Yangtze Valley and nearby area would be poor. EFS suggested a minimum chance of rain along the annularity path.

OBSERVATION

Here is a list of the weather on Jan. 13 of some major cities along the annularity path:

• Mandalay, Myanmar: sunny, visibility around 8 km.
• Ruili, China: overcast to broken clouds, visibility around 20 km.
• Dali, China: sunny, visibility near 30 km.
• Chongqing, China: mist and fog, visibility around 3 km.
• Nanyang, China: mainly sunny, visibility over 20 km.
• Jinan, China: sunny, visibility around 23 km.
• Qingdao, China: sunny, visibility around 15 km.

FORECAST

The divergence between the models is minimum, therefore, the uncertainty of this forecast is reduced to minimum. This forecast also makes use of ground-based observation and satellite data.

Local forecasts are listed below.

• In Myanmar: mainly sunny with a few clouds, with some haze in valley.
• In Yunnan, China: mainly sunny with a few clouds and good visibility.
• Around Chongqing, China: mist and fog, with low visibility, but sunshine is possible on highlands.
• Around Shiyan and Nanyang, China: broken clouds, but likely to be cirrus, with low to fair visibility.
• In Shandong, China: cloudy, but likely to be cirrus, the visibility shall be fair.

REVIEW UPDATE

Before Feburary 28.

日环食精密预测公报第四号

前言

　　这是2010年日环食精密预测公报第四号，以中文和英文编制。本报的预测方法较上报没有显著变化。公报中提及的预报资料可在http://7timer.y234.cn/V3/product.php?language=zh_cn&product_id=2, http://www.fnmoc.navy.mil和http://www.ecmwf.int查阅。对于任意地点的数值预报可查阅http: //7timer.y234.cn/V3/product.php?language=zh_cn&product_id=1。本服务的RSS种子为http://7timer.y234.cn/V3/wordpress/?feed=rss2&cat=47。

分析

　　NCEP GFS在1月12日06Z初始化的预报显示南支槽正集结于东经103度、北纬28度周围，与其关联的湿区在环食带上延伸至东经116度。1030百帕等值线触及北纬30度，但近地面风场显示届时冬季风已减弱。

　　ECMWF在1月12日00Z初始化的预报则给出了一个较GFS的预报偏西5度左右的南支槽；从地面图上观察，ECMWF认为冬季风较GFS略强一些。

　　FNMOC NOGAPS在1月12日06Z初始化的预报给出了介于GFS和ECMWF预报之间的南支槽，中心大致位于东经100度，北纬28度左右；1030百帕等值线触及北 纬25度。NOGAPS同时指出四川盆地及周边地区的能见度将会低于10公里。同一时刻的EFS认为预报区域内环食带上降水概率接近0%。

　　可以看出：中南半岛北部将有一西风槽，大陆上的冬季风正在减弱，但对于这一对系统的位置/强弱，三个模式分歧较大。

预报

　　由于各模式分歧显著，因此本报的不确定性保持中等。如果GFS正确（即南支槽较偏东、冬季风很弱），则云南西部天气较好，西南地区大部、华南和华中的部分地区天气不佳。但从历史统计上来看，ECMWF的准确率较GFS高一点，而且相对而言ECMWF和NOGAPS的预报比较接近，因此本报偏重于这两者的预报，采取了较偏西的南支槽以及偏强一些的冬季风。请注意：由于目前网络上绝大多数的天气网站都采用的是GFS，鉴于上述理由，它们的预报和本报的分歧可能较大。

• 云南地区、四川南部：大致多云，但如果南支槽较偏东则有望少云或晴天；
• 重庆地区：有雾；
• 十堰、南阳一带：可望天晴，能见度一般，适宜观测；
• 山东地区：可望天晴或少云，但灰霾可能会对观测造成一定影响。

下次更新

　　1月14日北京时间12时作最终预报更新。

2010 Annular Solar Eclipse PFS Bulletin No. 4

FOREWORD

This is 2010 Annular Solar Eclipse PFS Bulletin No. 4, issued in both English and Chinese. No major changes were made on the forecast philosophy since last bulletin. The forecast diagrams mentioned below may be found at http://7timer.y234.cn/V3/product.php?language=en&product_id=2, http://www.fnmoc.navy.mil and http://www.ecmwf.int. Numeric forecast for various locations may be found at http://7timer.y234.cn/V3/product.php?language=en&product_id=1. RSS feed of this service is available at http://7timer.y234.cn/V3/wordpress/?feed=rss2&cat=46.

ANALYSIS

NCEP GFS JAN12/06Z's forecast shows a significant westerly trough around 103E 28N, the associated wet area reaches 116E over the annularity path. Over the east, the 1030hPa contour reaches 30N, but the near-surface wind forecast suggests the winter monsoon has weaken at that time.

ECMWF JAN12/00Z's forecast shows the same westerly trough over western China, but is about 3-5 degrees west of GFS's forecast. Meanwhile, ECMWF gives a slightly stronger winter monsoon persisting over East China.

FNMOC NOGAPS JAN12/06Z's forecast gives a westward westerly trough located between the ECMWF's prediction and GFS's prediction, centred at 100E, 28N. NOGAPS also expect a strong but weakening winter monsoon persisted over east, with 1030hPa contour reaches as south as 25N. NOGAPS also notes low visibility (<10km) may be applied at Sichuan Basin and at the annularity path over Yangtze Valley. FNMOC EFS JAN12/06Z's forecast suggests minimum chance for significant rainfall along the annularity path.

For analyses of the models above, we can depict: a westerly trough lies at somewhere over the northern Indo-China Peninsula, and a winter monsoon is weakening over mainland China; however there is still considerable divergence over the location of the westerly trough between the models.

FORECAST

Since the divergence between the models is still quite significant, the uncertainty of this forecast remains moderate. The situation varies over the models. If GFS gets it right (on an eastward trough and a weak winter monsoon), then we can expect a fair weather over the west of Yunnan, but generally poor sky around Sichuan Basin and some parts of Central and South China. However, statistically ECMWF has a better performance, and what is more, NOGAPS also suggests a slow moving trough, so in this forecast the author consider the situation of a slow moving trough and a slow weaken monsoon. It should point out that many weather websites employ GFS, which is somehow against the philosophy of this forecast, as their numeric model, so there can be significant difference between this forecast and the weather information from the internet.

Local forecasts are listed below.

• In Myanmar: mainly clear with a few clouds, with some haze in valley. More clouds to the northeast.
• In Yunnan, China: mainly cloudy along the annularity path; however, if the westerly trough moves faster than expected (or close to GFS's forecast), then there will be a good chance for a less cloudy or even sunny weather.
• Around Chongqing, China: foggy.
• Around Shiyan and Nanyang, China: sunny weather possible with fair visibility for solar observation at low elevation.
• In Shandong, China: sunny or less cloudy weather possible, but the visibility may be low for solar observation at low elevation.

NEXT UPDATE

Brief final update around January 14 0400 UTC.

日环食精密预测公报第三号

前言

　　这是2010年日环食精密预测公报第三号，以中文和英文编制。本报的预测方法较上报有一定变化。公报中提及的预报资料可在http://7timer.y234.cn/V3/product.php?language=zh_cn&product_id=2, http://www.fnmoc.navy.mil和http://www.ecmwf.int查阅。对于任意地点的数值预报可查阅http: //7timer.y234.cn/V3/product.php?language=zh_cn&product_id=1。本服务的RSS种子为http://7timer.y234.cn/V3/wordpress/?feed=rss2&cat=47。

分析

　　NCEP GFS在1月10日06Z初始化的预报显示南支槽正在东经105-107度上活动，与其关联的湿区在环食带上延伸至东经116度。1030百帕等值线触及北纬30度，但近地面风场显示届时冬季风已减弱。

　　ECMWF在1月10日00Z初始化的预报则认为南支槽在100-102度左右，较GFS偏西约5度；从地面图上观察，ECMWF给出了一个稍微偏强的冬季风。

　　FNMOC NOGAPS在1月10日06Z初始化的预报给出了更偏西的南支槽，中心大致位于东经95度，北纬25度左右，延伸至川西高原；1030百帕等值线触及北纬25度。NOGAPS同时指出四川盆地和郑州一带的能见度将会低于10公里。同一时刻的EFS认为云南大部、四川及重庆在15日白天出现显著降水的概率介于0-20%之间。

　　可以看出：中南半岛北部将有一西风槽，大陆上的冬季风正在减弱，但对于这一对系统的位置/强弱，三个模式分歧较大。

预报

　　由于各模式分歧显著，因此本报的不确定性升至偏高。如果GFS正确（即南支槽较偏东、冬季风很弱），则云南西部天气较好，但从云南东部开始的环食带天气皆不佳。但从历史统计上来看，ECMWF的准确率较GFS高一点，而且相对而言ECMWF和NOGAPS的预报比较接近，因此本报偏重于这两者的预报，采取了较偏西的南支槽以及偏强一些的冬季风。请注意：由于目前网络上绝大多数的天气网站都采用的是GFS，鉴于上述理由，它们的预报和本报的分歧可能较大。

• 云南地区、四川南部：大致多云或阴天，可能有几阵雨，靠东的地区降雨概率更大些；
• 重庆地区：有雾和毛毛雨；
• 十堰、南阳一带：可望天晴或少云，能见度一般，适宜观测；
• 山东地区：可望天晴，但灰霾可能会对观测造成一定影响。

下次更新

　　1月12日北京时间24时，或当预报方法有显著变化时。

2010 Annular Solar Eclipse PFS Bulletin No. 3

FOREWORD

This is 2010 Annular Solar Eclipse PFS Bulletin No. 3, issued in both English and Chinese. There are some changes on the forecast philosophy. The forecast diagrams mentioned below may be found at http://7timer.y234.cn/V3/product.php?language=en&product_id=2, http://www.fnmoc.navy.mil and http://www.ecmwf.int. Numeric forecast for various locations may be found at http://7timer.y234.cn/V3/product.php?language=en&product_id=1. RSS feed of this service is available at http://7timer.y234.cn/V3/wordpress/?feed=rss2&cat=46.

ANALYSIS

NCEP GFS JAN10/06Z's forecast shows a significant westerly trough over 105-107E at 25N-35N, the associated wet area reaches 116E over the annularity path. Over the east, the 1030hPa contour reaches 30N, but the near-surface wind forecast suggests the winter monsoon has weaken at that time.

ECMWF JAN10/00Z's forecast shows the same westerly trough over western China, but is about 5 degrees west of GFS's forecast. Meanwhile, ECMWF gives a slightly stronger winter monsoon persisting over East China.

FNMOC NOGAPS JAN10/06Z's forecast gives an even more westward westerly trough, centred at 95E, 25N and extend to West Sichuan Plateau. NOGAPS also expect a strong but weakening winter monsoon persisted over east, with 1030hPa contour reaches as south as 25N. NOGAPS also notes low visibility (<10km) may be applied at Sichuan Basin and Zhengzhou nearby area. FNMOC EFS JAN10/06Z's forecast suggests a chance for significant rainfall at 0-20% is expected along the annularity path over Yunnan, Sichuan and Chongqing.

For analyses of the models above, we can depict: a westerly trough lies at somewhere over the northern Indo-China Peninsula, and a winter monsoon is weakening over mainland China; however there is significant divergence over the location and strength of the westerly trough between the models.

FORECAST

Since the divergence between the models is significant, the uncertainty of this forecast increases to moderate to large. The situation varies over the models. If GFS gets it right (on an eastward trough and a weak winter monsoon), then we can expect a fair weather over the west of Yunnan, but generally poor sky around Sichuan Basin and along the annularity path over east. However, statistically ECMWF has a better performance, and what is more, NOGAPS also suggests a slow moving trough, so in this forecast the author consider the situation of a slow moving trough versus a slow weaken monsoon. It should point out that many weather websites employ GFS, which is somehow against the philosophy of this forecast, as their numeric model, so there can be significant difference between this forecast and the weather information from the internet.

Local forecasts are listed below.

• In Myanmar: partly cloudy, with some haze in valley. More clouds to the northeast.
• In Yunnan, China: mainly cloudy or overcast along the annularity path, may be a few rain patches. Rains more likely over east of 102E.
• Around Chongqing, China: foggy with drizzles.
• Around Shiyan and Nanyang, China: sunny or less cloudy weather possible with fair visibility for solar observation at low elevation.
• In Shandong, China: sunny weather possible, but the visibility may be low for solar observation at low elevation.

NEXT UPDATE

January 12 at 1600 UTC or when changes apply on forecast philosophy.

日环食精密预测公报第二号

纵览

　　这是2010年日环食精密预测公报第二号，以中文和英文编制。距离日环食尚有7天，本预测的可信度为较高。公报中提及的预报资料可在http://7timer.y234.cn/V3/product.php?language=zh_cn&product_id=2, http://www.fnmoc.navy.mil和http://www.ecmwf.int查阅。对于任意地点的数值预报可查阅http://7timer.y234.cn/V3/product.php?language=zh_cn&product_id=1。本服务的RSS种子为http://7timer.y234.cn/V3/wordpress/?feed=rss2&cat=47。

分析

　　NCEP GFS在1月8日06Z初始化的预报指出：在1月15日，850百帕湿度场上华中、云南大部分地区较干燥。1020线至北纬25度左右，1030线控制华北及辽东半岛。ECMWF在1月8日00Z初始化的预报则认为1020线可南达北纬20度，1030线较GFS的预报要偏南一些2-3个纬度，对冬季风的估计较GFS稍强一些。FNMOC EFS集合预报则给出了一个稍微缓和的冬季风，1020线达北纬20度，但1030线则仅控制华北地区，同时认为从瑞丽到南阳的环食带在15日白天有显著降水的概率为接近10%。可以看出：届时将有显著但趋弱的冬季风控制我国大部分地区。

预报

　　各模型在冬季风强度的预报上已经接近，因此本预报的不确定性降为较小。地域预报给出如下，请随时留意随着时间的推移和观测数据的更新带来的预报修正。

• 云南地区（含环食带掠过的临近地区，如攀枝花等）：大致天晴，向东的云量可能会有所增加，但影响日食观测的概率不大；
• 重庆地区：预计为大雾天气，但高地上可能会有阳光；
• 南阳一带：大致天晴，根据现在的情况来看，城区一带的能见度在15公里以上，对低仰角的观测较为有利；
• 山东地区：大致天晴，预计城市地区的能见度在10-15公里左右，可能对日食观测较为有利。

下次更新

　　1月10日北京时间23时或更早。

2010 Annular Solar Eclipse PFS Bulletin No. 2

OVERVIEW

This is 2010 Annular Solar Eclipse PFS Bulletin No. 2, issued in both English and Chinese. There is 7 days away from the event, uncertainty for this forecast is small. The forecast diagrams mentioned below may be found at http://7timer.y234.cn/V3/product.php?language=en&product_id=2, http://www.fnmoc.navy.mil and http://www.ecmwf.int. Numeric forecast for various locations may be found at http://7timer.y234.cn/V3/product.php?language=en&product_id=1. RSS feed of this service is available at http://7timer.y234.cn/V3/wordpress/?feed=rss2&cat=46.

ANALYSIS

NCEP GFS JAN08/06Z's forecast shows a significant dry area over Yunnan and Central China on the height of 850mb humidity shows there is a large dry area over Central China and western Indo-China Peninsula. The Mean Sea Level Pressure shows the 1020hPa contour reaches 25N, indicating a mild winter monsoon persisting over mainland China. However, there is no notable feature on 500hPa geopotential height forecast.

ECMWF JAN08/00Z's forecast shows a mild to strong winter monsoon is persisting over Central China as the 1020hPa reaches near 20N, the southern limit of 1030hPa contour is about 2-3 degrees south of the GFS's prediction. Again, no notable feature is shown on 500hPa geopotential height forecast.

FNMOC EFS JAN08/00Z's forecast suggests a weakening winter monsoon with 1020hPa reaches 20N but 1030hPa near 35N. It also suggests a chance of significant rainfall (generally less than 10%) along the path from Ruili to Nanyang at the day time of January 15.

For analyses of the models above, we can depict a persisting but probably mild and/or weakening winter monsoon over mainland.

FORECAST

Since the models have came to a rough agreement on the strength of winter monsoon, the uncertainty of this forecast is reduce to small. Local forecasts are listed below. Please be aware that the forecast philosophy may trim as there is still 7 days to go for the event.

• In Myanmar: sunny, with some haze in valley.
• In Yunnan, China: generally sunny, a few or some clouds to the east, but the cloud amount may still allow an enjoyable observation along the annularity path.
• Around Chongqing, China: foggy, but sunshine is likely over highlands.
• Around Nanyang, China: mainly sunny, the visibility is estimated to be 15 km or better, allowing a reasonably good sky for low elevation observation.
• In Shandong, China: mainly sunny, the visibility is estimated to be about 10-15 km or better, it is possible for observers to get the "fire ring" at horizon.

NEXT UPDATE

January 10 at 1500 UTC or earlier.

日环食精密预测公报第一号

纵览

　　这是2010年日环食精密预测公报第一号，以中文和英文编制。距离日环食尚有10天，本预测的可信度为中等。公报中提及的预报资料可在http://7timer.y234.cn/V3/product.php?language=zh_cn&product_id=2, http://www.fnmoc.navy.mil和http://www.ecmwf.int查阅。对于任意地点的数值预报可查阅http://7timer.y234.cn/V3/product.php?language=zh_cn&product_id=1。本服务的RSS种子为http://7timer.y234.cn/V3/wordpress/?feed=rss2&cat=47。

分析

　　NCEP GFS在1月5日06Z初始化的预报指出1月15日，在淮河流域和云贵高原西部各有一条高空槽，但850百帕湿度场则认为华中大部分地区较干燥。1030线控制全国大部分地区，表明一股强烈的冬季风正在影响我国。

　　ECMWF在1月5日00Z初始化的预报指出1月15日，华中由一股中等至偏强的冬季风控制，云贵高原上空有一条南支槽，但较GFS预报的要偏东约5个经度。1030线控制了辽东半岛及长江流域以北的地区。

　　我们可以看出，届时将有一股显著的冬季风影响我国，在黄海上空有急流，在云贵高原附近有明显的南支槽。

预报

　　由于GFS和ECMWF在冬季风的强度以及南支槽的具体位置上存在分歧，本预报的不确定性为中等。地域预报给出如下，请随时留意随着时间的推移和观测数据的更新带来的预报修正。

• 云南地区：向东云量逐渐增多，在大约东经102度开始可能会对观测造成显著影响；根据近地面气象要素预测和过去几年的情形来看，大理一带可能为晴间多云至多云的天气；
• 重庆地区：雾，有微量降水，向东北方向云量可能有减少的趋势；
• 南阳一带：大致天晴，根据近地面气象要素预测和过去几年的情形来看，城区一带的能见度可能在15公里或更好些，利于观测日食；
• 山东地区：大致天晴，根据近地面气象要素预测和过去几年的情形来看，城区附近能见度大约为10公里左右。如果GFS的预测较准确，则东部地区环食带内的能见度可以大幅提高。

下次更新

　　1月8日北京时间23时或更早。

2010 Annular Solar Eclipse PFS Bulletin No. 1

OVERVIEW

This is 2010 Annular Solar Eclipse PFS Bulletin No. 1, issued in both English and Chinese. There is 10 days away from the event, uncertainty for this forecast is moderate. The forecast diagrams mentioned below may be found at http://7timer.y234.cn/V3/product.php?language=en&product_id=2, http://www.fnmoc.navy.mil and http://www.ecmwf.int. Numeric forecast for various locations may be found at http://7timer.y234.cn/V3/product.php?language=en&product_id=1. RSS feed of this service is available at http://7timer.y234.cn/V3/wordpress/?feed=rss2&cat=46.

ANALYSIS

NCEP GFS JAN05/06Z's forecast on 500hPa geopotential heights of JAN15/06Z revealed two moderate westerly troughs over western Yunnan-Guizhou Plateau and Huai Valley. However, the forecast on 850mb humidity shows there is a large dry area over Central China and western Indo-China Peninsula. The Mean Sea Level Pressure shows the 1030hPa contour well-controls most of China, indicating a strong winter monsoon persisted.

ECMWF JAN05/00Z's forecast on 500hPa geopotential heights of JAN15/00Z shows a mild to strong winter monsoon is persisting over Central China. A significant westerly trough stays at Yunnan-Guizhou Plateau, but about 5 degrees east of GFS's. The 1030hPa reaches Liaodong Peninsula and Yangtze Valley.

For analyses of the models above, we can depict the existence of a significant winter monsoon over mainland with a rapids zone over the Yellow Sea, and a significant westerly trough over somewhere in the Yunnan-Guizhou Plateau.

FORECAST

Since there are notable divergences over the strength of winter monsoon and the exact position of westerly trough, the uncertainty for this forecast is moderate. Local forecasts are listed below. Please be aware that the forecast philosophy may change as there is still 10 days to go for the event.

• In Myanmar: clear, with some haze in valley.
• In Yunnan, China: more cloud to east, the cloud can be heavy for observation to the east of, probably, 102E.
• Around Chongqing, China: fog with drizzles, but can be cloudy over northeast.
• Around Nanyang, China: mainly clear, according to near ground forecast and observation over past five years, the visibility may be 15 km or better, allowing a reasonably good sky for sun at low elevation.
• In Shandong, China: mainly clear, according to near ground forecast and observation over past five years, the visibility may be about 10 km. If GFS is right on a strong winter monsoon, then the visibility over Central and East China can be much better.

NEXT UPDATE

January 8 at 1500 UTC or earlier.