Development Strategies and Technical Measures
of Short-term Forecast Operational Platform
System in Ningixa
HU Wen-dong1,2 ZHAO Guang-ping2 DING Jian-jun1,2
(1Key Laboratory of Meteorological Disaster Preventing and
Reducing in Ningxia, 2Ningxia Meteorological Observatory,
Yinchuan China, 750002)
Introduction
• China Meteorological administration initiated the plan to setup a 126Doppler- radar network for the first stage in 1998, in order to improve
the monitoring and forecasting standard [1]. The first Doppler radar in
Ningxia was setup in Yinchuan city as the key to the project mesoscale disaster weather warning system, and the monitoring and
warning level was elevated. In recent years, Ningxia meteorological
bureau has completed many achievements both in hardware and
software. For the purpose of turning hardware advance into socialeconomic benefit and raising the ability of operational forecast, and
integrating of operational system with other equipments and products
had been completed, and building up a new type forecast body, the
short term forecast platform system was developed
• Many kinds of data with a very huge amount were involved in this
platform system and the temporal need for operational work is very
strict. The strategies must be paid extra attention and special measures
must be taken.
1.
Technical base of short term forecast
• Ningxia meteorological bureau bought a SGI ORIGIN 300
computer with the peak speed of 12 billion/s in 2002. On
this computer the local meso-scale numerical weather
predict (NWP) was set up based on MM5V3. After
redeveloping on local NWP, a system of more than 170
kinds of element with a horizontal resolution of 20km and
temporal resolution of 1h was completed, and the refined
forecast system was primarily established on June 7 2003 to
provide public forecast products each 6h routinely for all of
the counties in Ningxia[2,3]. With 21 auto meteorological
stations, Doppler radar, meteorological satellite meso-scope
utilizing station and delivered NWP products, the condition
to develop a short term forecast platform system based on
the practical environment is mature.
2. Analysis on characteristics and
requirement of short term forecast system
• 2.1 Consideration to build the short term forecast system
• Bearn[4] pointed out that radar is the key instrument to short term
forecast. The forecasters in the US think Doppler radar is the most
important technology introduction in the half of the last century [5],
Doppler radar products should be the most concernment of the short
term forecast, especially for the monitoring and warning of disaster
weathers.
• The route to realize the short term forecast system is, to integrate the
Doppler radar data, NWP data, refined short range weather forecast
data, satellite data, auto-meteorological station data in high spatial and
temporal resolution and the conventional meteorological data, develop
the different forecast models by the means of meso-scale synoptic,
diagnosis, radar and satellite weather analysis. In the operational
network environment of Ningxia meteorological bureau, taking
windows as computer operational system, develop a convenient and
efficient operational platform system and make the issue.
2.2 Requirement characteristics of short term
forecast system
• It is obvious that the short-term system must be supported by multitype meteorological data, and under nowadays situation, the available
data are abundant. In less than 20 or even several minutes the Doppler
radar can finish a volume scan and provide data as much as 20mb or
more. Considering the huge amount data of the satellite, auto
meteorological stations, NWP products, the data are colossal in total.
In the limited time to make forecast products, it is absolutely
necessary to collect, transmit and process the data, to form the original
version of forecast, to scientifically organize weather background and
similar events for the forecasters, to provide them with powerful
facility to revise the forecast for the forecasters.
• So the first should be remarked is the huge amount and multi-type of
the data for the short term forecast system.
• The task of top priority or short term forecast system is, to monitor
hazardous weather and issue the dangerous warning dynamically in
high frequency and to revise and make out the detail about suddenly
occurred weather disaster according to the last information. The
weather disaster always caused by meso-scale system, and its lifespan
is quite short. In order to monitor and forecast effectively, all the work
relevant to the short term forecast must be completed within the life
expanse or equivalent, or it is out of date.
• The 2nd characteristic of short term forecast system is the stringency of
time.
• The short term forecast system depends on different data of type.
Because of the fault of detecting equipment, communication systems,
it is almost impossible both to keep the integrity of data and to expect
them arrive in time. And it is crucial to ensure the normal ability to
carry out the routine for the operational system.
• Here comes the 3rd characteristic of short-term forecast system, the
stability of system even without entire information
• China meteorology administration is developing swiftly, the new
equipment, new data are being implemented rapidly, new systems and
new approaches are being setup and gotten perfect swiftly. The short
term forecast system connects to many instruments, multivariate data,
and it is affected greatly by all of them. It is very important to
guarantee the lifespan of the system with thoughtful strategies.
• The 4th and last characteristic of short-term forecast system we think
is expandability and compatibility.
3. Development strategies and technical
approach
• Just as Browning[6] indicated, it should be planed as whole
to design the system aimed at the three taches of data
acquirement including detection and communication,
comprehensive processing or analysis and forecast and
products delivering according to the features of meso-scale
system under the circumstance of best ratio of performance
to price.
3.1 Reducing the expense of time
• Because of the strictly limited working time cycle of short term
forecast system, the time expense must be well calculated.
• In allusion to the peculiarity of multi-type of information, huge
amount of data, and strictly demanded of time, the principle strategy
on the point of detection and communication is, many distributed
computers process simultaneously, and the data were collected by
high speed local network, and it is accomplished by comprehensively
organization. Most of preprocess were carried out in the same time by
different computers located in different position, and the data were
sent to operational network, the efficiency to prepare the data for the
system is guaranteed. As the most important information, the Doppler
radar data were ensured by a specific server. The satellite data are
colossal also but the region to forecast is limited. By trimming out the
unnecessary data, the amount decreased greatly. There are many
reports of auto meteorological stations, in order to cut down the
spending of opening and closing file operation, and provide a good
condition for quality control; the reports of different stations in the
same time were merged into one file.
3.2 Efficiency of calling the data
• The amount of data to be called during analyzing is rather big; it is
of great importance to make sure that the data calling is with high
efficiency. This system provided several manners to display the
NWP and observation as here below concerning the different
favorites of forecast work: geographic distribution of
meteorological observation, temporal series change of observation,
grid field such as conventional element, energy, stabilities.
Measures were taken to achieve the goal of convenience:
• 1) Screen was set to display window and control window, the
change of windows and overlaying caused by item choosing and
displaying was avoided, the process of calling data is much more
simple.
• 2) Multi-layer trees were applied to make sure the client could
get the wanted data according to the sort, level and forecast time.
The order to choose is consistent with the habit of forecaster
and it is very easy to learn and to use.
• 3) As for calling the grid field, the MICAPS was employed
because the forecasters are familiar with it. A specific program
was developed for the geographic and temporal distribution of
observation. It is not only attained the efficiency but the higher
quality also comparing with the MICAPS.
3.3 Stability
• For the general exuberance of system, the processes that
would cause failure such as opening file, changing
directory, being divided by zero etc. were checked in
advance to avoid the problem. If the test fails the error
process and adjust flow will be started up, and crash of
system should be turned away.
• In the same way, the uncompleted information was
countered and settled, according to the actual situation
turned to different disposal flow to make sure the stability.
3.4 Expandability and compatibility
• Considering the expandability and compatibility, the main
functions in the system were designed as relative independent
modules, and they were assembled by main menu program call
and, the running control was realized. By adding the
independent modules into menu the function of system was
enhanced. The configure files were employed at both the main
program and the module level, and it is very flexible. The file
and directory setting are open to the client and easy to change
with the development of operational work. All items in configure
were noted with clear text for better understanding.
3.5 System detection
• The short term forecast system is relevant to many hardware and
software systems, the connection is quite complex, it is significant
to monitor all important parts and the environment. The dynamic
monitoring on SGI computer, local network and computer
environment were conducted by developed software. The running
step, start time, processed level etc. of complex tasks such as local
meso-scale model, derived element calculation were recorded.
The dynamic monitoring and real-time feedback mechanism was
setup at any time.
• The network is one of the keys to the system; the local network
status was investigated also to ensure the information
communication. For the computer the forecast system was built in,
the occupied percentage of CPU, memory, thread, file system,
user and system resources etc. can be checked.
• 3.6 Two flows
•
Ningxia located in Northwestern part of China with a continental
climate. There are sudden occurred server convections caused by
meso-scale weather system, and in winter the weather is stable
relatively. Based on the local climate specialty, two flows were
designed to meet the different needs in summer with lot of disasters
event and in winter, not too much. The efficiency is improved further
more.
• 3.7 Convenient method to make forecast products
•
The combination of text and graph was utilized to make the
forecast. As for the precipitation, the most important element, the
graphic background of precipitation was generated by using satellite
model, radar model and NWP products. The forecaster can revise with
mouse in the precipitation picture according to his or her experiment
and relevant information. It is very simple to modify the area and
amount of rain by drawing picture, and the result can be converted
into text automatically. In the products-making interface, other
element can be made by using meteorological dictionary and graph
easily.
4. Brief summary
• Along with the development of meteorological hardware
and software in Ningxia, the condition to setup the short
term forecast system is well provided.
• The short term forecast system has its own particularity.
The specific requirement of the short term forecast system
was analyzed in the detecting manner, information
characteristics, and time request. The strategies were
discussed and the concrete measures were adopted to
develop the operational system in Ningxia.
Reference
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