Weather Service for Olympic Sailing

Qingdao is one of the most beautiful coastal cities in China . It is located in the southeastern coastal area of Shandong Peninsula , and is surrounded by Jiaozhou Bay to the west and Yellow Sea to the south. Qingdao administers seven districts (Shinan, Shibei, Sifang, Licang, Laoshan, Chengyang, Huangdao) and five cities, i.e. Pingdu, Laixi, Jimo, Jiaozhou, Jiaonan, cover ing a total area of 10654 square kilometers (119°30′E ～ 121° 00' E, 35° 35' N ～ 37° 09' N) .

Figure 1 Location of Qingdao

Figure 2 Outline map of Qingdao 's districts

In general, Qingdao has higher topography in the east than in the west . T he south and the north part of the city is hunching while the middle is sunken. There are 3 mountain groups in Qingdao . Located in the southeast part of the city, Laoshan Mountain has steep peaks, the main of which is 1,133 meters above sea level. T he zigzag coastal lines r ang e along caps and bays , with a total length of 862.64 kilometers (including island s coastal lines). There are 32 b ays distributed along the sea shore, among which, Fushan Bay is the venue of 2008 Beijing Olympic Games Sailing Competition .

Figure 3 Topography map of Qingdao
Figure 4 Venue of sailing competition	Figure5 Location of competition fields and buoys

Located in the monsoon area of northern temperate zone, and on the coast of Yellow Sea, Qingdao has half monsoon climate and half marine climate . Its climate has a character of “no severe hot weather in summer and no bitter cold weather in winter”. Compared with inland area , the air temperature of Qingdao in winter is higher , and sweltering weather is less in summer. The air temperature experiences slower increase in spring and slower decrease in a utumn. Higher humidity, moderate precipitation, and the coincidence of wet season and warm season make a favorable climate.

Air temperature
The annual average temperature of Qingdao is 12.7 ℃ . T he hottest month of Qingdao is August , which has average temperature of 25.3 ℃ , and hold high temperature record of 38.9 ℃ ( on August 8, 1981 ) . January has the lowest temperature , which is -0.5 ℃ on average , and holds low temperature record of -14.3 ℃ ( on January 30, 1980 ) .

Figure 6 Monthly average temperatures of Qingdao (between 19 7 1 and 2000 )

Precipitation
The a verage annual precipitation of Qingdao is 662.1mm , while rainfall is mainly concentrated between June and September. August sees the largest monthly precipitation of 151.1mm , and 10.2 rainy days on average. In September, the monthly precipitation is 62.7mm , while the number of rainy days is 6.5 averagely.。

Figure7 Average monthly precipitation of Qingdao (between 19 7 1 and 2000 )

Relative humidity
The a nnual average relative humidity of Qingdao is 71% . Between June and August, the a verage r elative humidity is 8 4 %, making up the dampest and hottest season of Qingdao . I n August, the average relative humidity is 82% , and it decreases to 70% in September.

Figure8 Monthly average relative humidity of Qingdao (between 19 7 1 and 2000 )

Wind
Southeasterly wind prevails in summer half year of Qingdao , while northerly wind dominates winter half year. The annual average wind speed is 5.2m /s. In August and September , which have smallest wind speed, the monthly average wind speeds are both 4.5m /s.

Figure 9 Monthly average wind speed of Qingdao (between 19 7 1 and 2000 )

Temperature
The monthly average a ir temperature in August is 25.3 ℃ , and 21.8 ℃ in September. D aily average , maximum and minimum temperature all drop slowly d uring the se two months. D aily minimum temperature is commonly seen before sunrise at about 6:00, and the maximum temperature always be reached during noon time at about 13:00 .

Figure 10 Average daily air temperature in August(between 19 7 1 and 2000 )

Figure 11 Average daily air temperature in September ( between 19 7 1 and 2000 )

Figure 12 Average hourly air temperature in August and September (between 2003 and 200 7 )

Precipitation
The average monthly precipitations in August and September are 151.1mm and 62.7mm respectively, but they both fluctuate greatly year by year. For August, the largest monthly precipitation is 482.2mm (in 2007), while the smallest precipitation is only 29.2mm (in 2002); For September, the largest monthly precipitation , 482.2mm , occurred in 1970, and in September of 1957 , there was no rainfall .

Figure 13 Monthly precipitations of August and September
T en-day P recipitation s during August and September : the second ten-day of August has the largest precipitation ( 70.7mm ), and the last ten-day of September has smallest precipitation ( 14.2mm ) . The number of r ainy days within every ten-day during August and September: from August to the first ten-day of September, there are average ly 3 rain ing events every ten-day ; for each of the last two ten-day of September, there are 1 ～ 2 rain ing event s .
Figure 14 Precipitation and number of rainy days of every ten-day during August and September (between 19 7 1 and 2000 )
Relative humidity The weather of Qingdao is controlled by West Pacific Subtropical High during summer, when damp and hot southerl y prevail s . In August and September, the monthly average relative humidity is 82% and 70% respectively, and the daily average relative humidity decrease s slowly. Humidity has great influence on body comfort. People may feel damp and hot sometimes during Beijing 2008 Olympic Games Sailing Competition (in August); However during 2008 Paralympic Games Sailing Competition (in Sepember), the weather will be comfortable and cool. R elative humidity generally fluctuat es reversely with temperature . In the afternoon, as the temperature reaches its maxima , the relative humidity gets its minimum value, and when the temperature is the lowest in the early morning and at night, the relative humidity gets its maximum value . In August and September, the maximum relative humidity always occurred at about 6:00; and the minimum relative humidity occurred in afternoon at about 13:00~15:00.
Figure 15 Daily average relative humidity in August and September (between 19 7 1 and 2000 ) Figure 16 Average hourly relative humidity in August and September (between 2005 and 200 7 )
Wind The monthly average wind speeds are both 4.5m /s for August and September . Southeasterly wind prevails in August, while northerly and southerly winds prevail in Sep t ember.
Figure 17 Daily average wind speed of August and September (between 19 7 1 and 2000 )

Figure 18 Wind rose of August and September ( The color bar indicates average wind speed. The direction and length of the radials indicate wind direction and frequency respectively. The dash concentric circles denote frequency, which starts by 1% and has interval of 2%. Figures in center denote frequency of calm wind . )
During daytime in August and September, wind speed rise to over 3.5m /s after 9:00. In August, the maximum wind speed occur s in the afternoon during 13:00 ～ 15:00 , when hourly average wind speed can reach 4.3m /s; In S e ptember, the maximum wind speed occurs between 14:00 and 15:00, with maximum hourly wind speed of 4.4m /s. After that time , wind speed decrease gradually, and reaches 3.5m /s at 21:00.
Figure 19 Average hourly wind speed in August and September (between 19 97 and 200 6 )
The so-called sea and land breeze circulation is the most impo r tant local wind system of Qingdao . During daytime, the incoming heat from the sun lift s the warmed air on land generating sea breeze , which blows from sea to land ; A fter sunset, land is cooled more faster, off-shore air flow will occur blowing from land to sea -- land breeze. In general, land breeze is much weaker than sea breeze.
Figure 20 Sketch maps of sea and land breeze
The period of Beijing 2008 Olympic Games Sailing Competition ( August, 9 ～ August,23 ) is part of the mid summer season of Qingdao. According to statistics of meteorological data from 1971 to 2007, there may be a moderate or lower intensity rain ing event every 3 days. Thunderstorms occur once a week averagely , and they always strike in afternoon. The occurrences of fog and gust wind have low probability . Every 5 to 6 years, Qingdao is affected by tropical cyclone, companied by gust wind, torrential rain and sto r m surge. The probability of hail and high temperature(≥ 35 ℃ ) is ex t remely low. During Beijing 2008 Paralympic Games Sailing Competition (September 6 ～ September 17) , probability of the above high impact weather s is relatively lower. Rainfall may occur once 4 ～ 5 days, and the occurrence probabilit ies of fog, tropical cyclone, thunder storm and gust wind are extremely low.

Buoy observations of competition venue in August and September of 2007 are listed below ：
Wind

Figure21 Wind rose of August and September
( The color bar indicates average wind speed. The direction and length of the radials indicate wind direction and frequency respectively. The dash concentric circles denote frequency, which starts by 1% and has interval of 2%. Figures in center denote frequency of calm wind . )

Figure 22 Daily average wind speeds in August and September

Figure 23 Average hourly wind speeds in August and September

Temperature

Figure24 Daily average air temperature in August and September

Figure 25 Average hourly air temperature in August and September

Humidity

Figure26 Daily average relative humidity in August and September

Figure27 Average hourly relative humidity in August and September

         Weather service at Olympic Sailing Center
         • Weather and sea state briefing: every morning, weather and sea state forecast of t he day and next 2 days are issued to Sailing Sub-Committee and teams from all countries .
        • On notice/information board : real time weather and sea state information and hourly forecast for competition venue are posted 3 times a day; Forecast for the next 7 days is posted once a day; High impact weather warning and its rescindment are posted at first time.
        • Face to f ace service: at the Meteorology and Hydrology Office in the Olympic Sailing Center , weather experts are always ready to answer questions from any department of Sailing Sub-Committee , and from coaches and athletes o f all countries.
        • Hotline: 66562690

Weather service website for Olympic and Paralymtic sailing competition

R eal time weather information and other service products are provided for the Beijing 2008 Olympic Games Sailing Competition and the Beijing 2008 Paralympic Games Sailing Competition .

Chinese ：http://afqx.qingdao.gov.cn

English ：http://afqx.qingdao.gov.cn/english

Public weather service

To satisfy the needs of city operation department, the public, and tourists from home and abroad arriving Qingdao during sailing competitions of Olympic Games and Paralympic games, Qingdao Meteorological Bureau issue s e veryday the following public weather service information .

Weather information	Time of issuance	Access
3-6 h forecast	6:00 , 9:00 , 12:00 , 15:00, 18:00	Web , 12121 , SMS , etc.
24 h forecast	6:00 , 11:00 , 16:00	TV , radio, newspaper, Web, 12121 , MS, etc.
F orecast of next 3 days	6:00, 16:00	TV, radio, Web, etc.
F orecast for scenic sites	6:00, 16:00	TV, newspaper, Web, etc.
Weather index forecast	6:00, 16:00	TV, newspaper, Web, etc.
F orecast for international tourist cities	6:00, 16:00	Web, etc.
F orecast of next 7 days	15:00	12121, Web, etc.
Nowcasting and Very Short –Range forecast	Non-fixed	TV, radio, 12121, SMS, Web , etc
Weather warning signal	Non-fixed	TV, radio, 12121, SMS, Web , etc

Appendix 1 : D aily average value s of main weather element s during Olympic Sailing Competition ( August 9 ～23)
( Between 1971 and 2007)

Date	Ps( hPa )	Tavg (℃)	Tmax (℃)	Tmin (℃)	EHT (℃)	ELT (℃)	RH(％)	WSP(m/s)	WDR
9	998.4	25.8	28.9	23.5	32.5	20	83.2	4.5	SE
10	998.5	25.7	28.8	23.6	32.2	19.9	82.3	4.4	SE,S
11	998.8	25.8	28.9	23.7	33.2	19.4	84.2	4.4	S
12	998.6	26.0	28.8	23.9	33	20.6	84.0	4.3	SE
13	998.7	26.0	29.2	23.6	32.8	18.2	81.9	4.6	N
14	998.9	25.6	28.8	23.2	33.5	18.5	81.9	4.5	N
15	999.0	25.6	28.4	23.6	32.1	18	83.0	4.1	SSE
16	999.2	25.2	28.2	22.9	31.4	16.7	84.2	4.0	SE
17	999.7	25.3	28.5	23.1	33.6	17.8	81.3	4.3	SE,S,NNW
18	1000.0	25.1	28.5	22.8	32	18.7	81.2	4.1	N
19	999.6	25.2	28.8	22.3	33	17.3	80.2	4.1	SE,NNW
20	999.3	24.9	28.2	22.4	32.3	17	81.2	4.1	S
21	999.7	25.1	28.6	22.4	33.3	19.2	78.2	4.1	N
22	1000.1	25.0	28.5	22.3	34.4	17.7	76.8	4.4	N
23	1000.7	24.8	28.1	22.0	32.2	16.8	76.6	4.3	N,S

Ps--station pressure
Tavg--average air temperature
Tmax--average maximum air temperature
Tmin--average minimum air temperature
EHT-- extremely high temperature
ELT-- extremely low temperature
RH--relative humidity
WSP--average wind speed
WDR-- Prevailing wind direction

Appendix 2：Daily average values of main weather elements during Paralympic Sailing Competition (September 6～17)
(Between 1971 and 2007)

Date	Ps( hPa )	Tavg (℃)	Tmax (℃)	Tmin (℃)	EHT (℃)	ELT (℃)	RH(％)	WSP (m/s)	WDR
6	1003.3	23.3	26.7	20.6	29.9	16.3	75.3	4.1	N
7	1003.8	23.1	26.4	20.5	32	15.4	76.8	4.1	N
8	1004.2	23.3	26.8	20.6	33.2	16.4	75.6	4.2	S
9	1004.1	22.6	26.0	19.9	30.9	14.6	74.7	4.2	NNW
10	1004.5	22.6	26.2	19.7	31.1	13.8	71.5	4.1	NNW
11	1004.6	22.5	26.4	19.8	30.2	15.6	69.5	4.4	NNW
12	1005.3	22.4	26.0	19.5	30.9	14.5	68.4	4.2	N
13	1005.9	22.2	25.8	19.4	29.9	15.7	70.1	4.1	NNW
14	1006.3	22.0	25.7	19.2	28.6	14.6	70.3	4.2	NNW
15	1006.6	21.7	25.2	18.8	28.1	13.9	70.2	3.8	S
16	1006.5	21.9	25.7	18.9	29	13.5	71.9	4.0	S
17	1006.0	21.6	25.1	18.8	27.9	13.2	70.6	4.2	N

Appendix 3：Unit conversion tables
3.1 Temperature conversion table

℃	°F	℃	°F	℃	°F	℃	°F
10	50.0	20	68.0	30	86.0	40	104.0
9	48.2	19	66.2	29	84.2	39	102.2
8	46.4	18	64.4	28	82.4	38	100.4
7	44.6	17	62.6	27	80.6	37	98.6
6	42.8	16	60.8	26	78.8	36	96.8
5	41.0	15	59.0	25	77.0	35	95.0
4	39.2	14	57.2	24	75.2	34	93.2
3	37.4	13	55.4	23	73.4	33	91.4
2	35.6	12	53.6	22	71.6	32	89.6
1	33.8	11	51.8	21	69.8	31	87.8
0	32.0	10	50.0	20	68.0	30	86.0

Conversion f ormulae ：°F ＝ 1.8× ℃ +32 ℃ ＝ 0.556 × ( °F-32)

Length conversion table

	meter	foot	yard	mile
meter	1	3.28	1.09	0.62×10 -3
foot	0.305	1	0.333	0.19×10 -3
yard	0.914	3	1	0.57×10 -3
mile	1609	5280	1760	1

Velocity conversion table

	kilometer/hour	meter/second	mile/hour	knot
kilometer/hour	1	0.278	0.622	0.54
meter/second	3.6	1	2.24	1.94
mile/hour	1.61	0.447	1	0.868
knot	1.85	0.515	1.15	1

Appendix 4: Timetable of sunrise and sunset in August and September of 2008

Date	Sunrise	Sunset	Date	Sunrise	Sunset
1-8-2008	5:08	19:05	1-9-2008	5:32	18:29
2-8-2008	5:09	19:04	2-9-2008	5:33	18:27
3-8-2008	5:10	19:03	3-9-2008	5:34	18:26
4-8-2008	5:11	19:02	4-9-2008	5:35	18:24
5-8-2008	5:11	19:02	5-9-2008	5:36	18:23
6-8-2008	5:12	19:00	6-9-2008	5:37	18:21
7-8-2008	5:13	18:59	7-9-2008	5:37	18:20
8-8-2008	5:14	18:58	8-9-2008	5:38	18:19
9-8-2008	5:14	18:58	9-9-2008	5:38	18:17
10-8-2008	5:16	18:56	10-9-2008	5:40	18:16
11-8-2008	5:16	18:55	11-9-2008	5:40	18:14
12-8-2008	5:17	18:54	12-9-2008	5:41	18:12
13-8-2008	5:18	18:53	13-9-2008	5:42	18:11
14-8-2008	5:19	18:52	14-9-2008	5:42	18:10
15-8-2008	5:19	18:50	15-9-2008	5:43	18:08
16-8-2008	5:20	18:49	16-9-2008	5:44	18:07
17-8-2008	5:21	18:49	17-9-2008	5:44	18:05
18-8-2008	5:22	18:47	18-9-2008	5:46	18:04
19-8-2008	5:23	18:46	19-9-2008	5:46	18:02
20-8-2008	5:23	18:45	20-9-2008	5:47	18:00
21-8-2008	5:24	18:43	21-9-2008	5:48	17:59
22-8-2008	5:25	18:42	22-9-2008	5:48	17:58
23-8-2008	5:26	18:40	23-9-2008	5:49	17:56
24-8-2008	5:26	18:40	24-9-2008	5:50	17:55
25-8-2008	5:27	18:38	25-9-2008	5:50	17:53
26-8-2008	5:28	18:37	26-9-2008	5:52	17:52
27-8-2008	5:29	18:35	27-9-2008	5:52	17:50
28-8-2008	5:29	18:34	28-9-2008	5:53	17:49
29-8-2008	5:31	18:33	29-9-2008	5:54	17:47
30-8-2008	5:31	18:31	30-9-2008	5:55	17:45
31-8-2008	5:32	18:29