About the Tampa Bay

Located in the southeastern U.S., Tampa Bay is Florida’s largest open-water estuary. More than 100 tributaries flow into Tampa Bay, including dozens of creeks and four rivers— the Hillsborough, Alafia, Manatee, and Little Manatee.


Tampa Bay is one of the few estuaries in the U.S. that is not associated with a large river. Located in west-central Florida, where the winters are warm and the summers are hot and humid, the total Tampa Bay watershed (comprised of the Hillsborough, Alafia, Little Manatee, and Manatee Rivers) receives an average of 50 to 56 inches of precipitation each year, depending on the location. More than half (60%) of the precipitation occurs from June to September. (M.S. Flannery, “Tampa and Sarasota Bays: Watersheds and Tributaries” NOAA Estuary of the Month, pp 18-48.)

Tampa Bay is a broad, shallow, well-mixed tidal estuary with a surface area of 346 square miles and an average depth of 12 feet. The tidal range is also small, about 2 feet. These features lead to primarily horizontal circulation with the ebb and flood tides not necessarily exactly canceling. (C.R. Goodwin, “Circulation of Tampa and Sarasota Bays” NOAA Estuary of the Month, pp 49-64.) GNOME does not simulate these tidal recirculation areas, but these features are generally small (4 nm in diameter or less).

Current Patterns

The circulation of Tampa Bay and the surrounding areas is simulated with four tidal patterns and an offshore pattern. The tidal patterns were selected because they are each representative of different circulation regimes and have significant tidal phase differences (approximately one hour). The tide stations listed below were used to scale the current patterns in their areas:

  • Clearwater Pass (0.2 mi NE of Sand Key) 27° 57.4’ N, 82°, 49.4’ W

  • Blind Pass 27° 45.4’ N, 82°, 45.7’ W

  • Tampa Bay Entrance (Egmont Channel) 27° 36.26’ N, 82°, 45.62’ W

  • Longboat Pass 27° 26.5’ N, 82°, 41.4’ W

Clearwater Pass drives the circulation in the southern portion of St. Joseph Sound through Clearwater Harbor and The Narrows, including Hurricane Pass, Dunedin Pass, and Clearwater Pass. Blind Pass drives the circulation through south of The Narrows through Boca Ciega Bay, including Johns Pass and Blind Pass. Tampa Bay Entrance drives the circulation throughout Tampa Bay. Longboat Pass drives the circulation from Anna Maria Sound south through Sarasota Bay.

The Offshore current pattern is tied to the northerly component of the wind forecast and is scaled so that a south wind of 4.5 m/s will generate a 15 cm/s current to the north (after Cragg and Sturges 1974).



Cragg, J. and W. Sturges (1974). Wind-Induced Currents and Sea Surface Slopes in the Eastern Gulf of Mexico. Florida State University Technical Report.

NOAA Estuary-of-the-Month Seminar series No. 11 (December 1989). “Tampa and Sarasota Bays: Issues, Resources, Status and Management.” Edited by Ernest D. Estavez.

Tampa Bay Physical Oceanographic Real-Time System (PORTS) web site

Real-time data for the Tampa Bay region.

NOAA NOS Center for Operational Oceanographic Products and Services (CO-OPS)

Real-time tide, current, and meteorological conditions at the Tampa PORTS stations.

University of South Florida Department of Marine Science Ocean Modeling and Prediction Laboratory

Links to the department’s Tampa Bay Circulation Model and the Tampa Bay PORTS site.

Wind and Weather

NOAA National Weather Service Internet Weather Source

A summary of current conditions, weather forecasts, and wind data from local airports over the previous 24 hours.

NOAA National Weather Service, Tampa Bay, Florida

Current conditions and weather forecasts.

Florida Weather Center, part of Tampa Bay Online

Current conditions and weather forecasts.


Current weather observations, forecasts, and warnings for the entire U.S.

NOAA NWS graphical version

National and world weather, live weather images, weather videos.

Oil Spill Response

NOAA's Emergency Response Division (ERD)

Tools and information for emergency responders and planners, and others concerned about the effects of oil and hazardous chemicals in our waters and along our coasts.