Titan U glossary

Weather Prediction CenterWPC

The Weather Prediction Center (WPC) is the national center that forecasts heavy rain, winter storms and the overall weather pattern for the United States. Part of the National Centers for Environmental Prediction (NCEP) and based in College Park, Maryland, it produces precipitation forecasts, flash flood outlooks, winter weather guidance, surface analyses and medium-range forecasts.

Storm Forecasting Agencies and Data

The Weather Prediction Center (WPC) is the national center that forecasts heavy rain, winter storms and the overall weather pattern for the United States. Part of the National Centers for Environmental Prediction (NCEP) and based in College Park, Maryland, it produces precipitation forecasts, flash flood outlooks, winter weather guidance, surface analyses and medium-range forecasts.

Rain and flash flooding

WPC's quantitative precipitation forecasts (QPF) give expected rainfall amounts. Its Excessive Rainfall Outlook shows the potential for flash flooding across the continental United States, based on the chance that rain will exceed the flash flood guidance values issued by River Forecast Centers.

For the near term, WPC issues Mesoscale Precipitation Discussions, which describe areas where forecasters expect conditions that may cause flash flooding over the next 6 hours.

Winter storms

WPC's Winter Weather Desk issues heavy snow and icing products. These include probability maps for snow and freezing rain and the Winter Storm Severity Index, which estimates potential impacts.

Its stated mission is to tell the nation's daily weather story and lead operational prediction of rain storms, winter storms and extreme temperature events.

The bigger pattern

WPC's surface analysis is part of the NWS Unified Surface Analysis, done jointly with the Ocean Prediction Center and the National Hurricane Center. Its medium-range forecasters prepare forecasts for days 3 through 7, and a separate team covers Alaska for days 4 through 8.

WPC also issues public advisories on a tropical cyclone after it moves inland in the United States or nearby Mexico, weakens below tropical storm strength, and the National Hurricane Center stops advising, while the system can still produce flooding rains.

Reading WPC products in context

WPC outlooks describe chances over broad areas, so they can smooth over local detail such as terrain-driven rain or a narrow snow band. Read them as the national frame, then check local NWS forecasts and headlines for the details.

WPC handles rain and winter weather, and the Storm Prediction Center handles severe thunderstorms. On many active days both centers have products out for the same storm system.

Keep going

How Weather Prediction Center connects

Part of 1

  • National Weather Service

    The Weather Prediction Center is one of the national centers within the National Weather Service.

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Contrasts with 3

  • Storm Prediction Center

    The Storm Prediction Center handles severe thunderstorms, while the Weather Prediction Center handles heavy rain and winter weather, often for the same system.

  • Weather Forecast Office

    WPC guidance gives the national frame for rain and snow, while local offices still issue the flood and winter watches, warnings and advisories.

  • Climate Prediction Center

    The CPC covers the longer range, while the Weather Prediction Center handles specific rain and winter events in the days ahead.