There are several observing networks and programs that provide the real-time data and observations useful for mariners. Often, this data is compiled by and disseminated through national centers or local forecast offices. These include:
- National Data Buoy Center (compiles data from buoy networks and the Coastal-Marine Automated Network, or C-MAN)
- Voluntary Observing Programs (including the U.S. Voluntary Observing Ships Program, SKYWARN, MAREP, and MAROBS)
- Physical Oceanographic Real-Time System (PORTS©)
- National Water Level Observation Network (NWLON)
- nowCOAST™
- Automated Surface and Weather Observing Systems (ASOS and AWOS)
- U.S. High Frequency (HF) Radar Network
- Land-Based Cloud-to-Ground Lightning Detection Network
Descriptions of these networks and programs can be found below.
National Data Buoy Center (NDBC)
The National Data Buoy Center (NDBC) provides quality observations in the marine environment to support the understanding and predictions of changes in weather, climate, oceans, and coast. The NDBC compiles coastal and offshore weather observations from NOAA fixed and drifting data buoys and C-MAN stations. Moored buoys are deployed in all U.S. coastal and offshore waters, from the western Atlantic to the Pacific Ocean around Hawaii, and from the Bering Sea to the South Pacific. NDBC's moored buoys measure and transmit barometric pressure; wind direction, speed, and gust; air and sea temperature; and wave energy spectra from which significant wave height, dominant wave period, and average wave period are derived. Even the direction of wave propagation is measured on many moored buoys.
The National Weather Service’s C-MAN was established by the NDBC in the early 1980's. C-MAN stations have been installed on lighthouses, at capes and beaches, near shore islands, and offshore platforms. C-MAN station data typically includes barometric pressure, wind direction, speed and gust, and air temperature. Some C-MAN stations are designed to also measure sea water temperature, water level, waves, relative humidity, precipitation, and visibility. These datasets are processed and transmitted hourly to users in a manner almost identical to moored buoy data. In addition to the conventional method of data transmission, certain C-MAN stations are equipped with telephone modems that allow more frequent data acquisition, data quality control, and remote payload reconfiguration or restarting.
U.S. Voluntary Observing Ship (VOS) Program
The U.S. Voluntary Observing Ships (VOS) Program is organized for the purpose of obtaining weather and oceanographic observations from moving ships. VOS is an international program under the World Meteorological Organization and includes 49 countries with over 900 participating vessels. The U.S. program is the largest in the world. Observations are coded in a special format known as the ship's synoptic code, or BBXX format, and are distributed on national and international circuits for use by meteorologists, oceanographers, ship routing services, fishermen, and many others.
Other voluntary marine observation programs include the National Weather Service’s SKYWARN, MAREP, and MAROBS programs. SKYWARN is a nationwide network of volunteer weather spotters who report to and are trained by NWS. These spotters report many forms of significant or severe weather (e.g., severe thunderstorms, hail, flooding, etc.). The MAREP program allows mariners to report current coastal weather conditions to local weather forecast offices. Unlike the VOS and SKYWARN programs, pre-registration and training is not usually a prerequisite for participation. Local NWS Weather Forecast Offices can provide more information on SKYWARN and MAREP activities. Finally, the MAROBS Program is an experimental NWS program that is seeking the participation of any mariner not already involved in the VOS program. The goal is to collect as many marine observations as possible. The MAROBS report format will be identical to coded reports of the VOS Program, with the exception that MAROBS will replace BBXX. There will be additional differences between MAROBS and VOS, such as MAROBS observation elements representing only a subset of those collected in the full VOS report.
NOS Physical Oceanographic Real-Time System (PORTS©)
The National Ocean Service’s PORTS system provides commercial vessel operators with accurate and reliable real-time information for marine and weather conditions in and around U.S. seaports. PORTS includes observations and predictions for conditions such as water levels, currents, bridge air gap, and many meteorological parameters (e.g., winds, waves, atmospheric pressure, visibility, air and water temperatures). This data is recorded and disseminated every six minutes.
National Water Level Observation Network (NWLON)
The National Water Level Observation Network is an observation network with more than 200 permanent water level stations on the coasts and Great Lakes. This system allows NOAA to provide the nation with official tidal predictions. Accurate water level data is critical for safe and efficient marine navigation and for the protection of infrastructure along the coast. The NWLON also provides the national standards for tide and water level reference datums used for nautical charting, coastal engineering, international treaty regulation, and boundary determination. The NWLON is widely recognized as the key federal component of the Integrated Ocean Observing System (IOOS).
nowCOAST™
nowCOAST is NOAA’s web-mapping portal for near real-time observations, analysis, tide predictions, model guidance, watches/warnings, and forecasts for the coastal United States. It incorporates information from across NOAA, other federal agencies, and regional ocean and weather observing systems. Users can display maps of this information using the nowCOAST interactive map viewer or by connecting to its map services. Mariners can utilize nowCOAST for real-time observations of marine weather, surface winds, sea-surface temperatures, and precipitation. For future conditions, nowCOAST provides information on marine weather advisories, watches, and warnings; surface winds; waves; water levels; temperature; salinity; and currents.
Automated Surface and Weather Observing Systems (ASOS and AWOS)
The Automated Surface Observing System serves as the nation's primary surface weather observing network. It is a joint product of the National Weather Service (NWS), the Federal Aviation Administration (FAA), and the Department of Defense (DOD). For mariners, ASOS stations located along the coast can provide real-time observations for the following weather variables: wind direction, speed, and character; visibility and obstructions to vision; and basic current weather conditions. ASOS detects significant changes and disseminates hourly and special observations from ASOS stations. An ASOS station transmits a special report when conditions exceed preselected weather element thresholds (e.g., visibility decreases to less than three miles).
The Automated Weather Observing System (AWOS) is a nationwide network operated and controlled by the FAA. The system predates ASOS and is designed to support aviation operations, as well as weather forecast activities. AWOS stations are located at airports and heliports along the coast and offshore. AWOS stations can be level I, II, III, or IV depending on what sensors are installed. The most common level is AWOS III, which reports the following variables: wind speed and wind gusts, wind direction, visibility, sky condition, cloud ceiling, air temperature and dew point temperature.
U.S. High Frequency (HF) Radar Network
NOAA provides maps of near-real-time surface water currents in coastal and some offshore waters based on data from the U.S. National High-Frequency (HF) Radar Network and the Canadian network. The radars utilize high frequency radio waves to measure the direction and speed of surface-water currents in the coastal ocean. Radar antennas, typically in pairs, are positioned on the coast and can measure surface water-currents (located at the top 3-6 feet, or 1-2 meters, of the water column) up to 125 miles (200 kilometers) away, with spatial resolutions ranging from 310 miles (500 kilometers) to 3.7 miles (6 kilometers) depending on the individual radar’s frequency. The observations of the surface current speed and direction are usually one-hour averages (e.g., 11:30 to 12:30).
Surface-current data based on HF Radar can be accessed through interactive maps via the Integrated Ocean Observing System (IOOS). Additionally, NOAA’s Center for Operational Ocean Products and Services (CO-OPS) HF Radar product displays both near-real-time surface current observations and surface tidal current predictions.
Land-Based Cloud-to-Ground Lightning Detection Network
The NWS Ocean Prediction Center provides near-real-time lightning strike density data. The purpose of this data product is to provide mariners and others with enhanced awareness of developing and transitory thunderstorm activity, to give users the ability to determine whether a cloud system is producing lightning, and if that activity is increasing or decreasing. Lightning strike density, as opposed to display of individual strikes, highlights the location of lightning cores and trends of increasing and decreasing activity. The 15-minute gridded source data is updated every 15 minutes at 10 minutes past the valid time. NOAA’s nowCoast web mapping portal also displays the latest lightning-strike data.
