National Weather Service NWS Middle Atlantic Flooding in Facts Spring Mills, PA, Forecast Center January 1996. The National Weather Service (NWS) provides • On average, cause more deaths than any weather, hydrologic, and climate forecasts and warnings OUR MISSION other weather-related event… for the United States, its territories, adjacent waters and The NWS Middle Atlantic River Forecast Center (MARFC) • Most flood-related deaths occur in motor vehicles ocean areas, for the protection of life and property and supports the overall NWS mission of protecting life and and many also occur at night… the enhancement of the national economy. NWS data property and aiding in the economic and environmental and products form a national weather, water and climate well-being of the Nation. The MARFC provides timely and • Just two feet of water will carry away database, which can be used by other governmental accurate hydrologic forecasts and information to support most vehicles… agencies, the private sector, the public, and the global NWS customers and partners, using the best scientific • Only the National Weather Service issues official flood community. The NWS is part of the National Oceanic principles to integrate and model water, weather and and severe weather watches and warnings… and Atmospheric Administration (NOAA), an agency climate information. of the U.S. Department of Commerce. • NOAA Weather Radio All Hazards is the fastest way to receive NWS watches and warnings… OUR SERVICE AREA • Most homeowner’s insurance policies DO NOT National Weather Service NWS River Forecast Centers The MARFC has hydrologic responsibility for one of cover losses caused by flooding… the most flood-prone and populous regions in the Nation. The NWS operates 13 regional hydrologic centers Our area of responsibility • Federal flood insurance is available to most across the U.S. known as River Forecast Centers (RFCs). encompasses some homeowners. Your insurance agent can help you NWS RFCs prepare river and flood forecasts and other 87,000 square miles and with questions concerning flood insurance… hydrologic information. Most of this information is includes all or portions Middle Atlantic River distributed to the public and other users directly through of the seven states of the internet and/or through the national network of New York, Pennsylvania, Forecast Center 122 NWS Weather Forecast Offices (WFOs). New Jersey, West Virginia, A critical function of all RFCs is to prepare Maryland, Delaware MARFC hydrologic forecasts during floods. These “flood forecasts” and Virginia, as well Area of Responsibility provide the expected crests (maximum height) as Washington, D.C. NWS Middle Atlantic River will reach at specific forecast points and the expected Major river basins located within the MARFC service Forecast Center time of occurrence. Flood forecasts also indicate the area include the Susquehanna, Delaware, Passaic, Raritan, NOAA/National Weather Service U.S. DEPARTMENT OF COMMERCE approximate times when flooding will begin and end at Potomac, Shenandoah, Rappahannock, James and National Oceanic and Atmospheric Administration 328 Innovation Boulevard, Suite 330 each forecast point based on a predetermined “flood stage” Appomattox, along with numerous other smaller river National Weather Service unique to each forecast point. The NWS considers systems. Seven NWS WFOs receive hydrologic forecasts State College, PA 16803-6609 flood stage to be the level at which property damage and guidance from the MARFC for distribution to the (814) 231-2404 begins or access roads become inundated. public and other users. Each NWS WFO has its own www.weather.gov/marfc Other RFC activities include the issuance of daily hydrologic area of river stage and streamflow forecasts, longer-range responsibility called probabilistic river forecasts, and rainfall and drought Hydrologic Service data and information. This information aids in the Areas (HSAs). optimum management of water resources used for home and industry, power generation, recreation, Top front cover and background cover photos agriculture, flood control, transportation/navigation, courtesy of Centre Daily Times, 1996. Page 4 photo courtesy of Suzanne Yenchko, 1996. fisheries management, and others. RFCs also produce “ guidance,” which estimates how much WFOs/HSAs in and Publication printed on recycled paper Flooding in rain must fall in certain time periods for small near the MARFC Area of Responsibility Walton, NY, flooding to begin. (8/06) June 2006. 12 OUR KEY FUNCTIONS forecasts of the amount, type, distribution and duration and SERVICES of precipitation for input into our hydrologic forecast River is essential to the NWS mission model. They ensure the quality of observed temperature OUR STAFF OUR HISTORY of saving lives and reducing property damage. Heavy and precipitation data and monitor real-time hydro- MARFC’s most important resource—our staff— MARFC’s origin goes back nearly 70 years when the rainfall can result in river flooding during any month of meteorological conditions, providing updates to our is comprised of 16 people with varied backgrounds Federal-State River Forecast Center was formed largely the year in our service area. To predict floods, the MARFC Hydrologists as necessary. Our HAS forecasters also in hydrology, meteorology, engineering, information as a result of the record-setting flood of March 1936. utilizes the NWS River Forecast System (NWSRFS), a coordinate with other local, regional and national NWS technology, and other disciplines. We are open 365 The early center focused on Pennsylvania and was a complex hydrologic model comprised of a series of computer- offices to ensure consistency in daily operations. days a year from 6 a.m. to 11 p.m., except during cooperative effort between the U.S. Weather Bureau based hydrologic applications and mathematical calculations. flood events when we implement 24-hour operations. (now the NWS) and the State of Pennsylvania. In 1948 Observed, estimated and predicted hydrometeorological the Harrisburg River Forecast Center was established, data are used as input to the model, while the output are OUR ADDITIONAL ACTIVITIES at which time the service area was expanded to include hydrographs, which estimate future river stages for more than Other functions of our center include issuing routine OUR LOCATION the Delaware River Basin. Then in 1970 the Potomac, 155 locations throughout our service area. These hydrographs river forecasts, flash flood and headwater guidance, The MARFC is collocated with the Central Pennsylvania James and Rappahannock River Basins were added. In help our Hydrologists to predict how high a river will get at winter/spring flood potential outlooks, drought guidance, NWS Weather Forecast Office at Penn State University’s 1972, record flooding from the remnants of Hurricane specific locations and when water levels will begin to recede again. five-day significant flood outlooks, multi-sensor precipita- (PSU) Innovation Park complex in State College, PA. Agnes impacted much of the Harrisburg RFC service area. Our flood forecasts are sent to seven NWS WFOs, which fine tion estimates and precipitation departure information. Data, information and resources are shared between This flood event increased national awareness of the tune the forecasts, if necessary, before disseminating the We also develop and maintain hydrologic computer systems, the two NWS offices, while the proximity of the NWS devastation caused by major river floods, and prompted information to the public and other users through NOAA calibrate hydrologic models, provide Geographical facility to PSU creates educational and collaborative major enhancements to the flood forecasting services Weather Radio All Hazards, the internet, television, commercial Information System (GIS) mapping support, maintain research opportunities. provided by the Harrisburg RFC. In the 1980s, the center radio and local emergency management agencies. and update internet pages, perform and publish hydro- was renamed the The Advanced Hydrologic Prediction Services (AHPS) meteorological research and participate in educational MiddleMARFC Atlantic are a relatively new and essential component of the NWS outreach. Our information also helps support ecosystem RFC, and in Hydrology Program. AHPS provide users with web-based management programs such as the State of Maryland’s 1993 relocated graphical forecast Shellfish Harvesting Program, the State of New Jersey’s Marine to downtown products that take Monitoring Program, and the State of Pennsylvania’s State College, PA. advantage of recent Black Fly Suppression Program. We cooperate with Then in December advances in science numerous federal, state, and local government agencies 2005, MARFC and technology. and private organizations, including other NOAA moved to its The AHPS products agencies, the USGS, the U.S. Army Corps of Engineers, current location assist Water Resources both the Susquehanna and Delaware River Basin at PSU. Managers, Emergency Commissions, the Interstate Commission on the Managers, and others Potomac River Basin, and academic organizations. involved in flood and Office location of both the NWS Icy floodwaters destroy the drought mitigation An example of a graphic available Middle Atlantic River Forecast Center old Walnut Street Bridge in programs in making through the Advanced Hydrologic OUR FUTURE and the State College Weather Forecast Office. Harrisburg, PA, in January 1996. Prediction Services web pages. better decisions, MARFC is always working to improve and expand its including when to evacuate people and move property. services to our customers. Additional AHPS enhancements SUSQUEHANNA FLOOD FORECASTING INITIATIVE The NWS continues to actively develop, test and implement include expanding short-term probabilistic forecasts and Recognizing the need for the protection and management of water resources, the Susquehanna River Basin new AHPS products in cooperation with our customers flood inundation maps. Other future activities include Commission (SRBC) was established in 1971. Shortly thereafter, flooding from Agnes in 1972 made it evident and partners. enhancing flash flood guidance, increasing data and that flood forecasting services could be enhanced in the Susquehanna basin. To this end, the SRBC helped establish The Hydrometeorological Analysis and Support (HAS) information exchange with partners, implementing the Susquehanna Flood Forecasting Initiative, which allowed for the expansion of the hydrologic gaging network function capitalizes on the newest technology and science, probabilistic river forecasts, improving flood forecasting in the 1980s. This enhanced network is maintained primarily by the U.S. Geological Survey (USGS). Today, the along with today’s much higher-resolution data, to bring services, expanding GIS mapping capabilities, and SRBC coordinates a committee comprised of numerous federal and state organizations. The committee operates cohesiveness to the unique fields of hydrology and meteorology. exploring and implementing new and improved and maintains what is now considered to be one of the nation’s best flood forecast and warning systems. Our HAS forecasters are Meteorologists that prepare critical hydrologic modeling techniques.

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