Alternative Text Description for Moderate High Tide Flooding (NOAA)

TABLE OF CONTENTS

MAP OVERVIEW

This map depicts areas along Florida's coastline that are potentially vulnerable to moderate high tide flooding as defined by the National Ocean Service. The map shows the extent of inundation that could occur when tide levels exceed flooding thresholds at monitored tide stations, referenced to the Mean Higher High Water (MHHW) tidal datum. These areas represent locations that would be affected by National Weather Service Coastal Flood Advisories during moderate high tide flooding events.

GEOGRAPHIC CONTEXT

The map covers the entire state of Florida and portions of neighboring states including southern Georgia and Alabama. Major cities labeled on the map include Pensacola in the Florida Panhandle, Jacksonville and Palm Coast on the northeast coast, Orlando in the interior, Tampa and St. Petersburg on the west coast, Cape Coral and Fort Myers on the southwest coast, and Miami and Coral Springs on the southeast coast. Other notable locations shown include Tallahassee, Gainesville, Lakeland, Palm Bay, West Palm Beach, Montgomery (Alabama), Dothan (Alabama), Albany (Georgia), Valdosta (Georgia), and Savannah (Georgia). The map extends south to include the Florida Keys and shows Havana, Cuba at the southern edge. The map shows both the Atlantic Ocean coastline on the east and the Gulf of America coastline on the west and northwest.

KEY INSIGHTS

Moderate high tide flooding vulnerability follows Florida's extensive coastline, with notable patterns of inland penetration in specific areas. The most substantial inland extent of potential flooding occurs along the Big Bend region of the Gulf of America coast between the Tallahassee area and the Tampa Bay region, where low-lying topography allows tidal waters to potentially reach several miles inland. Significant coastal exposure is visible around the Tampa Bay and St. Petersburg metropolitan area, with flooding extent extending into the bay system. The southeast Florida coast from Miami through Palm Beach shows a relatively narrow band of vulnerability along the immediate shoreline. The northeast Florida coast near Jacksonville displays moderate inland penetration along river systems and coastal waterways. The Pensacola area in the western Panhandle and the Cape Coral region on the southwest coast show localized areas of potential inundation. The Florida Keys at the southern tip of the state show vulnerability throughout the island chain.

VISUAL ELEMENTS

Moderate High Tide Flooding Extent

This layer represents coastal areas that could experience inundation during moderate high tide flooding events.

Extent of Moderate HTF (bright turquoise/cyan polygons)

Appearance:

The potentially flooded areas are shown in bright turquoise or cyan colored polygons that stand out distinctly against the gray base map background.

Distribution:

The turquoise polygons follow the entire perimeter of Florida's coastline, including both the Atlantic Ocean side and the Gulf of America side, as well as surrounding the Florida Keys. The features appear along portions of the Georgia and Alabama coasts where these states meet the ocean.

Notable locations:

Major concentrations of potential flooding extent include the Big Bend coastal region between Tallahassee and Tampa, the Tampa Bay metropolitan area, the area around Jacksonville and the St. Johns River mouth, scattered locations along the Panhandle coast near Pensacola, the Cape Coral and Fort Myers vicinity, the entire Florida Keys island chain, and the Miami metropolitan area extending north through Palm Beach.

Spatial patterns:

The flooding extent varies considerably in width along different portions of the coast. In areas with steeper topography, the turquoise zones remain narrow and confined to the immediate shoreline. In low-lying coastal areas, particularly along the Big Bend region and around estuaries and bay systems, the potential flooding zones extend much farther inland. The pattern shows linear arrangements along river corridors and coastal waterways where tidal influence can propagate upstream. Small scattered polygons appear offshore representing low-lying islands and sandbars vulnerable to submersion.

Overlapping Patterns

The moderate high tide flooding zones show clear relationships with natural coastal features such as barrier islands, estuaries, tidal creeks, and river mouths where tidal influence extends inland along waterway corridors.

SYMBOL GUIDE

ADDITIONAL INFORMATION

This map represents potential inundation extent based on elevation and tidal modeling rather than actual observed flooding. The data should be interpreted as showing the general scale and extent of vulnerability rather than precise boundaries of flooding. The visualization depicts areas that would be subject to National Weather Service Coastal Flood Advisories during moderate high tide flooding conditions. The map does not account for factors such as wave action, storm surge, erosion, subsidence, or future changes in coastal hydrodynamics. Local drainage systems, seawalls, or other coastal protection infrastructure are not represented in this visualization.

DATA CONTEXT

Data Source:

The data is produced by the National Oceanic and Atmospheric Administration (NOAA) using a modified bathtub modeling approach that accounts for local and regional tidal variability. Source datasets include Digital Elevation Models (DEM), a tidal surface model created using NOAA National Geodetic Survey's VDATUM datum transformation software representing the Mean Higher High Water (MHHW) tidal datum in orthometric values (North American Vertical Datum of 1988), and interpolated threshold surfaces based on National Ocean Service formulas derived from tide stations across the United States. Data source layer: NOAA_HTF_MODERATE.

Definition Query:

No definition query or data filter was applied. The map shows the complete dataset of moderate high tide flooding extent.

Scale Information:

The map shows a regional scale view of the entire state of Florida and surrounding areas. This scale is appropriate for understanding overall patterns of coastal vulnerability and identifying which general coastal regions face moderate high tide flooding risk.

Coordinate System:

NAD_1983_HARN_Florida_GDL_Albers (WKID 3087)

Time Period of Content:

The time period for data collection and validity is not specified in the provided information.

Limitations:

The modeling methods used to produce these data do not account for erosion, subsidence, or any future changes in an area's hydrodynamics. The data should not be used to determine exact locations of flooding but rather to visualize the potential scale and extent of inundation from moderate high tide flooding events. Known data gaps or specific methodological limitations beyond those mentioned are not specified in the provided information.

Map Coverage:

The map covers the entire state of Florida, including the Panhandle, peninsula, and Florida Keys, extending from the Georgia-Alabama border region in the north to Cuba in the south. Portions of southern Georgia and Alabama are shown for geographic context.

The alternative text description of this map was AI-generated and may contain inaccuracies.