Marine Link
Monday, March 18, 2024

Weathering The Storm. National Weather Service Modernization to provide the maritime industry with improved weather prediction

The National Weather Service (NWS) is making its most ambitious change in its 125-year history. New technologies are going into operation, and services expected to bring major improvements in weather warnings and forecasts for the nation's maritime community are being reorganized. Technological advances are taking place in four major areas: weather radar; surface weather observation; weather satellites; and information processing and communications. The following is an article which assesses the current situation, the changes to come, and the benefits to the maritime community.

by Paul A. Jacobs, manager, marine weather services, Office of Meteorology, National Weather Service NEW TECHNOLOGY Forty-year-old weather surveillance radars are being replaced by new radar systems. The old radars only display reflected echoes of precipitation patterns and coarse estimates of storm intensity and vertical extent. The new radars are based on the Doppler principle in which transmitted radio waves change frequency when reflected from a moving target. Doppler weather radars, known as WSR-88D, measure internal storm structure in fine detail and calculate wind fields within storms. In addition, the radars can detect wind patterns in clear air by reflection of the radio waves from suspended particles such as aerosols, dust, and insects.

The radar's capabilities enable it to detect the conditions that lead to severe storm formation, helping to increase the lead time and accuracy of severe weather warnings.

The NWS is installing 120 WSR-88D Doppler radars around the country. Doppler radars, also being installed by the military and the FAA, will support NWS operations in certain areas of the lower 48 states and in Puerto Rico, Alaska, Hawaii, and Guam.

A major part of weather forecasting is taking and reporting weather observations from 1,200 locations around the country. Observations have been taken by personnel in the NWS, FAA and the military. However, the issuance of a warning to save lives and property can delay an important weather observation.

The Automated Surface Observing System (ASOS) solves this problem by allowing people to devote more time and expertise to the service aspects of NWS programs without interrupting the weather observing function.

The first two of a new series of geostationary satellites have been launched to replace a satellite over the Atlantic that had failed, and the Pacific satellite that was operating on "borrowed time." The new satellites can take four pictures every 30 minutes, compared with the earlier generation's one picture per half hour capability. The imagery has much finer detail for storm analysis. The satellites include improved infrared sensors for severe weather investigation to complement the data measured by the Doppler radar.

Also included are sensors that probe the atmosphere's temperature and moisture in the vertical, even while the imagery is being taken. These "soundings" provide critical data to help in analyzing and predicting storm intensification or improvement.

Warnings and forecasts issued by NWS field offices are prepared on an outmoded computer system based on technology from the 1970s. It now has limited capability for data collection, processing and display.

Many new requirements over the years had to be met by "hanging" various types of personal computers onto the system. It will be replaced by the Advanced Weather Information Processing System (AWIPS), supported by high speed, satellite communications. AWIPS workstations will process substantially more data faster, running a variety of programs to automate the preparation and issuance of warnings and forecasts, and displaying weather maps, satellite imagery, and Doppler radar data on a single system.

As is the case with the ASOS system, AWIPS will relieve the meteorologist from many time consuming, manual tasks such as data gathering and typing forecasts from scratch, allowing him or her to concentrate on analyzing and predicting the weather, and keeping people informed.

Other new technologies include: new National Oceanic and Atmospheric Administration (NOAA) Weather Radio recording consoles for greater flexibility in broadcast programming and improved warning dissemination; next-generation mainframe computers and new workstations at the National Centers for Environmental Prediction for faster processing of complex atmospheric and air-sea prediction models; and wind profilers to measure the vertical distribution of winds above the earth's surface more frequently and efficiently than by balloon-borne soundings. RESTRUCTURED NWS FIELD OPERATIONS To get the most benefit from these new technologies, the NWS field organization will be restructured from the present 52 Weather Service Forecast Offices and 197 smaller Weather Service Offices to a network of 119 Weather Forecast Offices (WFO). Instead of operating two types of field offices with different staffs and levels of training, issuing different products for the same weather event, the NWS is creating a uniform network of professionally staffed WFOs based on the surveillance area of each Doppler radar and all other surface, upper air, and satellite data within the radar's area of coverage. This plan will result in equivalent capabilities among NWS field offices, and more uniform weather services to the public and the marine community.

MARINE WEATHER SERVICES What does NWS modernization and restructuring mean for the coastal marine environment? Forty-three of the 119 WFOs will provide warning, forecast, data and information services to the coastal population and recreational, commercial, and scientific maritime interests.

This is an increase of 19 offices over the number providing marine weather services today. Thirtythree WFOs will be located along, and provide services for oceanic coastlines, including Hawaii, Puerto Rico and Guam. Ten WFOs will serve the Great Lakes. These changes in field office operations, together with the technological capabilities described above, will allow NWS to redistribute geographic areas for improved marine warnings and forecasts.

The marine warning and forecast program consisting of Coastal, Offshore, and High Seas services will be modified into a two-tiered structure: • Coastal areas out to 100 NM: Coastal forecast areas, which now vary from 20 to 60 nautical miles (nm) seaward (depending on coastal region), will be redesigned into uniform areas extending out to approximately 100 nm, and realigned at new coastal landmarks to take the fullest advantage of Doppler radar capabilities and other data sources. Coastal Doppler radars will provide greater capability to monitor and predict detailed local storm hazards as they move from land to sea and vice versa over the 100-nm seaward coverage area. In a few cases such as in New England and Alaska, the new seaward coastal forecast boundary varies due to geography and other considerations.

• Beyond the coastal areas: Marine warnings and forecasts for the oceans beyond the approximate 100-nm coastal boundary will be provided by the Marine Prediction Center in Washington, D.C.; the Tropical Prediction Center in Miami, Fla.; and the NWS offices in Anchorage, Honolulu and Guam. The Marine and Tropical Prediction Centers are two of the seven new National Centers for Environmental Prediction.

These offices have the resources and staffing to deal with weather conditions over the large offshore and high seas areas beyond 100 nm.

Thus, the field offices that were responsible for these large ocean areas can now concentrate on the localized weather hazards within the coastal areas monitored continuously by their Doppler radars.

GREAT LAKES Marine warnings and forecasts for the Great Lakes consist of open lake and near shore services. They will remain basically unchanged in terms of areas of responsibility assigned to the local weather offices.

This is because the Doppler radar will provide extensive overlapping coverage of the entire U.S. portion of the Great Lakes, as shown in Figure 1.

The only major changes will be: • Realignment of some of the near shore areas (0-5 nm out) in the upper lakes with different coastal landmarks as the individual Doppler radars become operational.

• Transfer of responsibility for Lake Superior warnings and forecasts from the Romeoville, 111., office to the future WFO in Marquette, Mich., after the AWIPS computer system becomes operational.

COOPERATION WITH THE PRIVATE SECTOR The NWS marine warnings and forecasts are general products designed to provide basic information on winds, waves, weather, ice, and visibility as they affect safety of life and property at sea. These marine products and services are developed and refined from a broad consensus of requirements put forth by all sectors of the maritime community.

Specialized marine weather analyses, forecasts, data sets, and packaged information to meet specific requirements of individual maritime users or segments of the community are the responsibility of the private weather information industry. For example, the NWS will not issue forecasts of wind or wave conditions for specific locations and times upon request of a marine user requiring such services. It is the strict policy of the NWS to refer all such requests for specialized or tailored services to the private sector.

To assist the private sector in providing specialized products and services and to promote the economic viability of the industry, the NWS provides subscriber access to the Family of Services computer system for receipt of a whole range of data and products. The NWS encourages users to take advantage of these specialized services offered by the private weather information industry in the hope that access to a combination of NWS and private sector weather products will provide the user with the most complete and comprehensive weather information to enhance maritime safety and productivity.

The Doppler radar and the other new observing technologies are proving to be valuable tools for predicting severe weather conditions that impact marine safety ranging from localized severe thunderstorms and squalls, to major ocean storms. Installation of AWIPS systems is scheduled to begin in 1997, soon after completion of the coastal Doppler radar network. A more streamlined field office structure, staffed with highly trained meteorologists and supported by improved National Center guidance, will allow NWS to derive maximum benefit from the technological advances. The growing partnership between NWS and the private weather information industry will afford marine users an extra margin of safety and efficiency through a combination of basic warnings and forecasts, and highly specialized weather information to meet unique operational requirements.

NWS is confident that by the end of the decade, people who live, work and play along the nation's coastline and at sea will experience a substantially higher level of weather services for the protection of life and property in support of their daily activities.

COASTAL AND OFFSHORE RECONFIGURATION After delivery and operation of the new AWIPS computer system to the field, the WFO office structure will begin to take effect. At that time (early 1998), the new coastal marine forecast areas shown in Figure 3 will start to be redistributed as coastal WFOs are commissioned, resembling that shown in Figure 4.

Due to the extension of the coastal forecast boundary further out to sea, it will be impractical to describe the overwater area of the forecast by simply giving coastal landmarks and saying "out to 100 nm." To ensure that the marine community understands and becomes accustomed to the descriptions, NWS will advertise the new areas through revised Marine Weather Service Charts, revised nautical charts, updated NWS brochures, U.S. Coast Guard and Defense Mapping Agency publications, articles such as this and other outreach efforts. A dual description (geographic coordinates plus descriptor) will also be used for a period of time in the coastal forecast heading to help mariners become accustomed to the descriptors.

As indicated earlier, the present marine warning and forecast program includes services for offshore and high seas areas. Figure 2 shows these areas and the NWS offices responsible for them.

In spring 1997, when all the coastal Doppler radars are operational and the coastal forecast areas are extended uniformly out to about 100 nm from new coastal landmarks, the offshore forecasts will no longer be issued by the field offices.

Except for the NWS offices in Anchorage and Honolulu, all warnings and forecasts for the ocean beyond the coastal areas shown in Figure 3 will be issued in conjunction with the High Seas program operated by the National Marine Prediction Center and the National Tropical Prediction Center.

At this time, it is uncertain whether the offshore forecasts shown in Figure 2 will continue to be issued in their present form or as part of the High Seas forecast package. The NWS is examining several options to ensure that maritime interests operating beyond 100 nm from shore receive the weather information necessary to their safety and productivity.

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