boulder, oct. 2011 challenges in operational nowcasting in beijing jianjie wang beijing...
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Boulder, Oct. 2011
Challenges in Operational Nowcasting in Beijing
Jianjie Wang
Beijing Meteorological Bureau, CMA
Mingxuan Chen
Institute of Urban Meteorology, CMA
Oct 24, 2011
Boulder, Oct. 2011
Impacts of sever weather to Beijing city1
2
Contents
Concluding remarks3
Performances of existing operational systems(BJ-ANC and BJ-RUC)
Boulder, Oct. 2011
Impacts of severe weather to Beijing city1
2
Contents
Concluding remarks3
Performances of existing operational systems(BJ-ANC and BJ-RUC)
Boulder, Oct. 2011
C波段（已建）
S波段（在建）
C 波段
S 波段
Complicated terrain over Beijing
Mountainous area is 62% of total territory (16800 km2)
Down townTime series on total numbers of heavy rain (R24h > 50mm) stations in May to Sep during 2008-2011(surface stations + AWS)
date
Station no.
Boulder, Oct. 2011
Gust windLightningHeavy rain
High Urban Density + Large Population + Multi-Transportation Ways+ Rapid Development
Increased Vulnerability to Weather Disasters
Due to rapid development of the city, severe weather induced hazards can trigger derivative disasters on the society and the economy of the city.
Heavy rain: —— Traffic jam on urban road and highway—— Delay of airplanes and trains—— Water logging in the low-lying places of urban area—— Mud slides in the northwestern mountainous area
Hail
Boulder, Oct. 2011
Eager demands for SW nowcasting from usersEager demands for SW nowcasting from users
Requiring accurate & reliable SW nowcasting in terms of:
Weather types (i.e., torrential rain, lightning, hail, gust wind etc) Starting time and ending time Specific location Strength (e.g., hourly rainfall amount, gust wind speed etc) Lead time (at least 3-6h ahead) …
Boulder, Oct. 2011
Impacts of severe weather to Beijing city1
2
Contents
Concluding remarks3
Performances of existing operational systems(BJ-ANC and BJ-RUC)
Boulder, Oct. 2011
Data ingest
Algorithms
Fuzzy logic
Dat QC
CINRAD radars (4 S-band & 2 C-band), AWS in 5-min, satellites (FY2D/E), rawinsondes, NWP (BJRUC)
3D reflectivity mosaic
Storm tracking
Reflectivity TREC Storm trend nowcasts Storm reflectivity nowcasts
QPE
QPF
Retrieval of low-level thermo-dynamical fields
BJANC: Bei-Jing AutoNowCasting system—developed through the cooperation of BMB and NCAR—be installed in BMB & provincial weather offices of northern China
Boulder, Oct. 2011
Used radars:
•Beijing S-band (BJRS)
•Tianjin S-band (TJRS)
•Shijiazhuang S-band (SJZRS)
•Qinhuangdao S-band (QHDRS) – added since B08
•Zhangbei C-band (ZBRC)
•Chengde C-band (CDRC) – added since B08
B08: 500km×500km
Now: 700km×700km
BJANC domain
Boulder, Oct. 2011
Statistic verification on 0-1h forecasts of QPF,and storm cell tracking from BJANC (2007-2011 summertime averaged)
Boulder, Oct. 2011
12:00 15:00 18:00 21:00 00:00 03:00 06:00 09:00
Cold start, 24h forecastCold start, 24h forecast
Warm start, 24h or 36h forecastWarm start, 24h or 36h forecast
12:00 15:00 18:00 21:00 00:00 03:00 06:00 09:00
Initiation (Initiation (UTCUTC))
3DVAR3DVAR assimilation (assimilation (UTCUTC))
rawinsondes, surface OBS, ship/buoy, AWS, AMDAR, ground based GPS_MET
BJRUC: Bei-Jing Rupid Updating Cycle system—Developed on the basis of WRF model system
D1
D3
D1
D2D3
3km, 37 level, Ptop=50hPa
Boulder, Oct. 201112
SYNOP
AMDAR
SOUND
SHIP&BUOY
Data assimilated by BJ-RUC
AWS
Ground-based GPS
Boulder, Oct. 2011
Point verification on R1h forecasts within 24h range(15 surface stations, data of 2008/06/01-2009/05/31,
referenced from Wei Dong etc.)
(a)(a)
Valid at the same time Valid not at the same time but at the same time range
Boulder, Oct. 2011
Sounding/12h
Analysis fields/6h
Surface OBS/3h
Global NWP guidance/12h
BJRUC guidance/3h
AWS OBS/5min
Radar OBS/6min
Wind profile/6min
BJANC guidance/6min
Lightning detection
Satellite OBS/30min
24-12h
6h SW starting0h
Warning issuing
Forecast on SW potential
BJT00 06 12 18 24
4 times in daily weather forecast issuing
Data support for SW forecast issuingData support for SW forecast issuing
Boulder, Oct. 2011
Date Ave. Rainfall
(mm)
Max. of R1h
(mm)
Coverage Lasting
(hour)
Synoptic forcing
July 24 73 83.7 Whole area 16 Strong
July 26 19 76.2 Partial area 6 Weak
July 29 43 50.6 Whole area 19 Strong
Aug 9 16 58.1 Partial area 7 Weak
Aug 13 22 80.2 Partial area 6 Weak
Aug 14-15 31 63.9 Whole area 20 Strong
Investigation from forecaster’s perspective(all cases in late July to early Aug of 2011 with R1hmax>50mm)
Boulder, Oct. 2011
Lasting 16h
83.7mm/h
Lasting 6h
80.2mm/h
Under strong synoptic forcing
Under weak synoptic forcing
Boulder, Oct. 2011
Look into meso-scale features
Under strong
synoptic forcing; Longer lasting
Under weak synoptic forcing; Short lived
R1h, R3h features (time, shape, distribution, amount, movement), cells
BJRUC (0-24h)
8 runs in a day-cycle, and targeting whole raining period
R1h features, cell formation, evolution and reflectivity
BJANC (0-2h)
Every 6 min, and targeting whole raining period
Boulder, Oct. 2011
Under strong synoptic forcingThe meso- spatial and temporal features of 1~ 3h
accumulated precipitation over Beijing area could be captured reasonably well within 24h.
QPF products valid at the same time from cycled runs within 24h period provide generally consistent information in terms of the raining time, rainfall location, amount and movement etc.
“spin up” effect has clear impacts to the “cold start” run of the BJRUC.
BJRUC Results-1BJRUC Results-1
Boulder, Oct. 2011
Initiation:2011/08/14 08:00 (12-15h)
Initiation: 2011/08/14 14:00 (6-9h)
Initiation: 2011/08/14 20:00 (0-3h)
2011/08/14 20:00-23:00
From the cold start run
R3h of OBS versus that of BJRUC
Boulder, Oct. 2011
Under weak synoptic forcing
There are visible bias on QPF products generally.The information of QPF products from cycled runs valid
at the same time tends to diverse run to run. BJRUC could predict quite well the torrential rain induced
by short-lived convections, occasionally, when signals of the local convective potential had occurred in model initial time and was captured by the model properly.
BJRUC Results-2BJRUC Results-2
Boulder, Oct. 2011
2011/08/09 OBS
15:00-16:00 16:00-17:00 17:00-18:00 18:00-19:00 19:00-20:00
Initiation:2011/08/08 20:00
Initiation:2011/08/09 08:00
20h
12h10h8h
22h 24h
Boulder, Oct. 2011
23:00-00:00 00:00-01:00 01:00-02:00 02:00-03:00 03:00-04:00
2011/08/14 OBS
Initiation:2011/08/13 14:00
11h 12h 13h 14h
Boulder, Oct. 2011
hPa
℃
200 1000
185 925
170 850
140 700
120 600
100 500
80 400
60 300
50 250
40 200-80
-80
-70
-70
-60
-60
-50
-50
-40
-40
-30
-30
-20
-20
-10
-10
0
0
10
10
20
20
30
30
40
40
-60
-40
-20
0
20
40
60
80
100
120
140
160
180
-60
-40
-20
0
20
4060
8010012
0140160180
0.05 0.1 0.2 0.5 1 1.5 2 3 4 6 8 12 16 2024 30
0℃
-10℃
-20℃
-30℃
LCL
LFC
CCL1km
2km
3km
6km
9km
温度对数压力图54511()测站：
11 08 13 20年 月 日 时
0℃
-10℃
-20℃
-30℃
LCL
LFC
CCL1km
2km
3km
6km
9km
温度对数压力图54511()测站：
11 08 13 20年 月 日 时
0℃
-10℃
-20℃
-30℃
LCL
LFC
CCL1km
2km
3km
6km
9km
温度对数压力图54511()测站：
11 08 13 20年 月 日 时
0℃
-10℃
-20℃
-30℃
LCL
LFC
CCL1km
2km
3km
6km
9km
温度对数压力图54511()测站：
11 08 13 20年 月 日 时
0℃
-10℃
-20℃
-30℃
LCL
LFC
CCL1km
2km
3km
6km
9km
温度对数压力图54511()测站：
11 08 13 20年 月 日 时
0℃
-10℃
-20℃
-30℃
LCL
LFC
CCL1km
2km
3km
6km
9km
温度对数压力图54511()测站：
11 08 13 20年 月 日 时
0℃
-10℃
-20℃
-30℃
LCL
LFC
CCL1km
2km
3km
6km
9km
温度对数压力图54511()测站：
11 08 13 20年 月 日 时
0℃
-10℃
-20℃
-30℃
LCL
LFC
CCL1km
2km
3km
6km
9km
温度对数压力图54511()测站：
11 08 13 20年 月 日 时
0℃
-10℃
-20℃
-30℃
LCL
LFC
CCL1km
2km
3km
6km
9km
温度对数压力图54511()测站：
11 08 13 20年 月 日 时
0℃
-10℃
-20℃
-30℃
LCL
LFC
CCL1km
2km
3km
6km
9km
温度对数压力图54511()测站：
11 08 13 20年 月 日 时
0℃
-10℃
-20℃
-30℃
LCL
LFC
CCL1km
2km
3km
6km
9km
温度对数压力图54511()测站：
11 08 13 20年 月 日 时
0℃
-10℃
-20℃
-30℃
LCL
LFC
CCL1km
2km
3km
6km
9km
温度对数压力图54511()测站：
11 08 13 20年 月 日 时
0℃
-10℃
-20℃
-30℃
LCL
LFC
CCL1km
2km
3km
6km
9km
温度对数压力图54511()测站：
11 08 13 20年 月 日 时
0℃
-10℃
-20℃
-30℃
LCL
LFC
CCL1km
2km
3km
6km
9km
温度对数压力图54511()测站：
11 08 13 20年 月 日 时
0℃
-10℃
-20℃
-30℃
LCL
LFC
CCL1km
2km
3km
6km
9km
温度对数压力图54511()测站：
11 08 13 20年 月 日 时
hPa
℃
200 1000
185 925
170 850
140 700
120 600
100 500
80 400
60 300
50 250
40 200-80
-80
-70
-70
-60
-60
-50
-50
-40
-40
-30
-30
-20
-20
-10
-10
0
0
10
10
20
20
30
30
40
40
-60
-40
-20
0
20
40
60
80
100
120
140
160
180
-60
-40
-20
0
2040
6080
10012
0140160180
0.05 0.1 0.2 0.5 1 1.5 2 3 4 6 8 12 16 2024 30
0℃
-10℃
-20℃
-30℃
LCL
LFC
EL
CCL1km
2km
3km
6km
9km
温度对数压力图54511()测站：
11 08 13 14年 月 日 时
0℃
-10℃
-20℃
-30℃
LCL
LFC
EL
CCL1km
2km
3km
6km
9km
温度对数压力图54511()测站：
11 08 13 14年 月 日 时
0℃
-10℃
-20℃
-30℃
LCL
LFC
EL
CCL1km
2km
3km
6km
9km
温度对数压力图54511()测站：
11 08 13 14年 月 日 时
0℃
-10℃
-20℃
-30℃
LCL
LFC
EL
CCL1km
2km
3km
6km
9km
温度对数压力图54511()测站：
11 08 13 14年 月 日 时
0℃
-10℃
-20℃
-30℃
LCL
LFC
EL
CCL1km
2km
3km
6km
9km
温度对数压力图54511()测站：
11 08 13 14年 月 日 时
0℃
-10℃
-20℃
-30℃
LCL
LFC
EL
CCL1km
2km
3km
6km
9km
温度对数压力图54511()测站：
11 08 13 14年 月 日 时
0℃
-10℃
-20℃
-30℃
LCL
LFC
EL
CCL1km
2km
3km
6km
9km
温度对数压力图54511()测站：
11 08 13 14年 月 日 时
0℃
-10℃
-20℃
-30℃
LCL
LFC
EL
CCL1km
2km
3km
6km
9km
温度对数压力图54511()测站：
11 08 13 14年 月 日 时
0℃
-10℃
-20℃
-30℃
LCL
LFC
EL
CCL1km
2km
3km
6km
9km
温度对数压力图54511()测站：
11 08 13 14年 月 日 时
0℃
-10℃
-20℃
-30℃
LCL
LFC
EL
CCL1km
2km
3km
6km
9km
温度对数压力图54511()测站：
11 08 13 14年 月 日 时
0℃
-10℃
-20℃
-30℃
LCL
LFC
EL
CCL1km
2km
3km
6km
9km
温度对数压力图54511()测站：
11 08 13 14年 月 日 时
0℃
-10℃
-20℃
-30℃
LCL
LFC
EL
CCL1km
2km
3km
6km
9km
温度对数压力图54511()测站：
11 08 13 14年 月 日 时
0℃
-10℃
-20℃
-30℃
LCL
LFC
EL
CCL1km
2km
3km
6km
9km
温度对数压力图54511()测站：
11 08 13 14年 月 日 时
0℃
-10℃
-20℃
-30℃
LCL
LFC
EL
CCL1km
2km
3km
6km
9km
温度对数压力图54511()测站：
11 08 13 14年 月 日 时
0℃
-10℃
-20℃
-30℃
LCL
LFC
EL
CCL1km
2km
3km
6km
9km
温度对数压力图54511()测站：
11 08 13 14年 月 日 时2011/08/13 14:00 (Initiation time)
2011/08/13 20:00 (3h ahead rain)
Initiation: (6h)2011/08/13 14:00
K SI CAPE LCL
OBS
14:00
29 -0.78 610 913
OBS
20:00
34 -1.18 1157 925
BJRUC
20:00
34 -3.2 1355 884
Boulder, Oct. 2011
2011/08/13 23:00 BJT 2011/08/14 00:00 BJT 2011/08/14 01:00 BJT
2011/08/14 02:00 BJT 2011/08/14 03:00 BJT 2011/08/14 04:00 BJT
BJRUC Initiation: 2011/08/13 14:00 BJT
9h 10h
12h 13h
11h
14h
Boulder, Oct. 2011
0-1h nowcasting products (the track, trend, reflectivity and quantitative precipitation etc) are precise and reliable generally.
Although the nowcasting skill reduces with forecast valid time, 2h nowcasting is still quite valuable under strong synoptic forcing.
Because of the quick update (in 6 min) on radar data, the bias of nowcasting products could be adjusted fast by the system itself so that make less impacts to the proper use of the products in operation in general.
BJANC Results-1BJANC Results-1
Boulder, Oct. 2011
2011/08/14 01:59 BJT 2011/08/14 02:59 BJT
2011/08/14 02:00-03:001h rain OBS
2011/08/14 01:59 BJT 1h rain nowcast valid at
2011/08/14 02:59
2011/08/14 00:59 BJT
After 1h
After 2h
After 1h
Boulder, Oct. 2011
Limitations on Identification of the initiation of convective cellsProper prediction on the track/trend/QPF of new cells
in their very early development stage (about 0-18min after initiation)
Reasonable prediction on cell-evolution in the mountainous and transitional areas
BJANC Results-2BJANC Results-2
Boulder, Oct. 2011
2011/07/26
21:06
21:18
21:24 21:30
Rapid development
Rainfall rateMax 10.2mm/5min
Boulder, Oct. 2011
2011/07/26 21:12 BJTCell identification
2011/07/26 21:06 BJTCell formation
2011/07/26 21:06 BJT
Beginning stage
With limitation on identifying & predicting new cells
2011/07/26 21:24 BJTCorrect nowcasting
30min trend
30min rainfall noecast
Bias in early stage but adjusted quickly
Boulder, Oct. 2011
With difficult on predicting cell evolution down to the mountain
2011/08/09 15:36 BJTBias on track
2011/08/09 16:00 BJTDown to the mountain
2011/08/09 16:06 BJTformation of new cell
2011/08/09 16:18 BJTBias on track
2011/08/09 16:36 BJTCorrect track
2011/08/09 17:36 BJTVerification on cell merging
Boulder, Oct. 2011
Impacts of sever weather to Beijing city1
2
Contents
Concluding remarks3
Performances of existing operational systems(BJ-ANC and BJ-RUC)
Boulder, Oct. 2011
Gaps In SW warning In objective techniques
(BJRUC, BJANC)
In capacity of forecasters
Items
SW type (hail, gust wind) nowcasting without or lack of objective guidanceEarly issuing of SW warning (6h ahead)lack of reliable objective guidance
Inconsistency of BJRUC guidance run to run, mainly under weak synoptic forcing, caused by:deficient initial condition “spin up” in cold start runLimitation on BJANC nowcastingnew cell formation and its very early developmentcell evolution over complex terrain
Limited knowledge and experiences on the new tech:objective nowcast / forecast techniquesremote sensing dataLimited knowledge on the mechanism of convection
Steps
Hybrid approach: (objective methods + high resolution OBS + forecaster’s knowledge & experiences on SW)
Improving the objective methodsDeveloping new techniques
(pay more attention to the causes behind in weak synoptic forcing situation)
Training to forecasters Investigation on SW & performance of BJANC, BJRUC…
Main gaps in operational nowcasting in BMB
Boulder, Oct. 2011
Future Development
Blending (BJANC and BJRUC) on QPF Improvement of BJRUC’s initial condition (radar data
assimilation, initialization scheme, etc.) Improvement of BJANC’s key algorithms on identifying
new cells and forecasting storm quick evolution (combining forecaster’s experiences)
Radar QC Product generation (VDRAS, SW type based on
conceptual model, interpretation to BJRUC guidance, etc.)
Boulder, Oct. 2011
Acknowledgement
Thanks to my colleagues for their support to this investigation:
Min Chen
Chenyun Sun
Guorong Wang
Xiaoqing Ma
Jisong Sun
et al.
Boulder, Oct. 2011
Thanks!