 |
Japan Meteorological Agency | ||||||||
Weather/Marine Forecasting Services
Forecasting services encompass JMA conducts a wide range of information such as forecasts, warnings, and advisories. Its objective is is to meet the comprehensive needs of various sectors including the general public, industries, transportationand transportation for the meteorological information that is essential for the protection of life and property and the enhancement of the national economy. Today, in implementation of forecasting services outputs of various NWP isnumerical weather prediction is crucial as the basis of are implementation of these services.
- Warning and Advisory Services for Severe Weather
- Daily Forecasts
- Very Short-range Forecasting of Prediction
- Typhoon Bulletins
- One-week Forecast
- Long-range Forecast
- Marine Forecasts and Warnings
- Flood Forecasting Services
- Other Forecasting Services
- Dissemination of Forecasts and Warnings
 |
Warning and Advisory Services for Severe Weather |
| In case a hazardous weather condition is expected, JMA delivers various
messages including warnings, advisories and bulletins to the general public
and disaster prevention authorities so that appropriate measures can be
taken against possible hazards. These messages are issued by Local Meteorological
Observatories (LMOs) for each of the sub-divisions in their respective
prefectures; a total of 362 sub-divisions are designated in consideration
of their meteorological characterisitics and administrative boundaries
as of March 2004. Warnings are issued when weather conditions are expected
to be catastrophic and meet warning criteria, while advisories are issued
when weather conditions are expected to be disastrous and meet advisory
criteria but are expected to remain below the warning criteria. Bulletins
give information to supplement the warnings and advisories. All such information
is delivered to the public through mass media and delivered directly to
disaster prevention authorities. Example of criteria of warning/advisory for heavy rain (Tokyo)
|
Warnings
Advisories
JMA Radar Observation Network |
|
Daily Forecasts |
| Daily forecasts in text form contain weather predictions for today,
tomorrow, and the day after tomorrow. They are issued three times a day
at 0500, 1100, and 1700 Japan Standard Time (JST) for a total of 141 forecast
blocks across the country (as of March 2004).These daily forecasts also
contain information about winds, coastal ocean waves, maximum/minimum temperatures,
and probabilities of precipitation. In addition to the forecasts in plain text, JMA provides forecasts in graphic form such as Area Distribution Forecasts and Time Sequence Forecasts. Area Distribution Forecasts show spatial distributions of weather, precipitation, and maximum/minimum temperatures for the whole country with a resolution of 20km. Time Sequence Forecasts are issued on 3-hourly changes, including weather, temperature, and wind speed/direction at 140 designated points across the county. Both kinds of forecast are issued 3 times a day at 0600, 1200 and 1800 JST and offer the forecast up to 24 hours ahead (30 hours ahead at 1800 JST). |
 Area Distribution Forecast  Time Sequence Forecast |
|
Very Short-range Forecasting of Precipitation |
A Very Short-range Forecast of Precipitation is issued twice an hour to provide forecasts of one-hour precipitation amounts for the next six hours with 5km resolution. This forecast is derived from the combination of the Mesoscale Model (MSM) predictions and the extrapolation of Radar/AMeDAS composite precipitation data.
|
Typhoon Bulletins |
| JMA issues Typhoon Bulletins 8 times a day to provide information
on tropical cyclones including analysis and forecast of their center positions
and intensity. When a tropical cyclone is moving onshore or in the vicinity
of Japan, the Bulletin is issued on an hourly basis. JMA also delivers
tropical cyclone information including post-analysis data to the National
Meteorological and Hydrological Services (NMHSs) in the western North Pacific
area to carry out its responsibility as Regional Specialized Meteorological
Center (RSMC) Tokyo-Typhoon Center, one of the six tropical cyclone RSMCs
of WMO. |
 Typhoon center position forecast |
|
One-Week Forecast |
One-Week Forecast covers a seven-day period starting from tomorrow. It is issued daily at 1100 JST to provide a day-to-day forecast of weather, precipitation probability and maximum/minimum temperatures for the 58 prefectural areas of the country. Ensemble prediction techniques, which take advantage of multiple results of numerical prediction, have been employed as the main basis of the one-week forecast.
|
Long-range Forecast |
Weather outlooks for the next month to several months are provided by long-range forecasts. These outlooks offer a prognosis on temperature and precipitation (and sunshine duration for one-month forecasts) in three categories; "above normal", "near normal", and "below normal". Ensemble prediction techniques also play an increasing role in the long-range forecasting at JMA. They are used as a unique basis for one-month forecasts and are used in combination with statistical techniques for three-month and warm/cold season outlooks.
|
Marine Forecasts and Warnings |
| Marine meteorological forecasts and warnings such as those of gale,
storm, typhoon, and fog are provided for the safety and efficiency of shipping,
fisheries and offshore activities. In the winter season, sea ice forecasts
and bulletins are also issued. |
 Ocean wave forecast |
|
Flood Forecasting Services |
JMA also takes the responsibility of flood forecasting services, which are performed in collaboration with central and local government agencies. These services include flood warnings, flood advisories, and flood bulletins covering 214 rivers in total (as of 1 April 2004) across the country, which were identified by the aforementioned agencies as the rivers carrying the potential for flood disasters. Among the 214 rivers, 193 are managed by JMA and the River Bureau of the Ministry of Land, Infrastructure and Transport (MLIT), and 21 are managed by JMA and civil engineering bureaus of prefectural governments.
|
Other Forecasting Services |
Fire weather alerts are issued to prefectural governments for their fire fighting efforts, when meteorological conditions such as low relative humidity and strong winds raise the risk of fire. Photo-chemical smog bulletins are proper bases for prefectural governments for their announcement of photo-chemical smog alarms. These bulletins provide outlook of the concentration of photochemical oxidants in the air for the day or the following day.
|
Dissemination of Forecasts and Warnings |
For the dissemination of forecasts and warnings, JMA maintains dial-up answering systems and direct communication links between meteorological offices and central/local governments as well as mass media. Recently, JMA has actively introduced information technologies, including Internet, into the meteorological information services. A high-speed communication network called the Information Network for Disaster Prevention (INDiP) is an example. The INDiP connects indivisual LMOs/DMOs and JMA Headquarters to complement the preestablished communication network. It allows for effective and rapid dissemination of information in both text and graphic forms to mass media and disaster prevention authorities.
Information for maritime users is transmitted by the JMA radio facsimile broadcast (JMH) and fishery radio communications. It is also disseminated within the framework of the Global Maritime Distress and Safety System (GMDSS), i.e. via the NAVTEX broadcast service of the Japan Coast Guard for the seas in the vicinity of Japan, and via the Safety-Net broadcast service for ships in the high seas through INMARSAT, the maritime satellite.