In 2018, the National Weather Service in Jacksonville reconfigured the zone alignment in St. Johns County, transitioning from a single forecast zone (Public and Fire) to two zones divided along Interstate 95. However, this change has proven inadequate for addressing potential coastal flooding in both the Atlantic Ocean/Intracoastal Waterway (ICWW) and the inland tidal areas of the St. Johns River.
As a result, our maps still indicate the risk of coastal flooding for the entire county, even during local northeaster events. Additionally, the current scheme does not effectively address winter cold weather events in the interior, which may not impact the warmer coastal areas. Furthermore, we are collaborating with the National Hurricane Center (NHC) to modernize Hurricane Breakpoints in St. Johns County for wind and surge watches and warnings, which will necessitate further subdivision of the county.
After coordinating with local officials and NHC, we have determined that the tidal areas of the Oceanfront/Intracoastal Waterway (ICWW) and St. Johns River will have new zones aligned as closely as possible with the Sea, Lake, Ocean, Surges from Hurricanes (SLOSH) model, specifically targeting the furthest inland extent for the Category Five hurricane Maximum of Maximums (MOMs). This approach is intentionally conservative and is designed to cover any conceivable coastal flooding event in the county.
To enhance clarity and support the new NHC watch/Warning breakpoints, we will further divide the ocean and inland zones along State Road 16, creating two oceanfront/ICWW zones (NE Coastal St. Johns and SE Coastal St. Johns) and two inland zones (Northern Inland St. Johns and Southern Inland St. Johns).
Additionally, a fifth zone along the St. Johns River and Julington Creek will remain as a single "river" zone, designated as “Western St. Johns.” Currently, given the coastal flood program and Tropical Program’s, Storm Surge Communication Points along the St. Johns River, we have determined that a split into northern and southern zones is not desirable.
This zone realignment is scheduled for March 18, 2025
If severe weather precludes the original implementation, the primary backup date is March 19,2025
YES! To enhance our services, the local National Weather Service (NWS) office has reconfigured our forecast zones/areas in southeast Georgia and northeast Florida several times over the past twenty years. Similarly, other offices nationwide have undertaken zone reconfigurations to better address their local weather variations. These adjustments have consistently resulted in increased forecast accuracy, particularly in relation to fire weather, coastal flooding and tropical watches and warnings.
Below are two maps illustrating the county-scale changes outlined above. The first map depicts the current configuration, while the second illustrates our 2025 end state forecast zones. Please note that the Fire Weather Zones are identical to the Public Zones. Additionally, Interstate 95 is marked as a reference to help viewers easily identify the 2024 zone demarcation in the 2025 maps.
|
Figure 1
|
Figure 2
|
|||
 |
 |
|||
| Click to Enlarge the Image | ||||
.
This illustration is designed to demonstrate the process of establishing the new coastal zones. The bright green border indicates the boundaries developed for the new “NE Coastal St. Johns Zone” (FLZ233), while the various shades ranging from tan to red represent the water depths associated with the Category Five Maximum of Maximums (MOM). The turquoise areas indicate land expected to remain dry during a Category Five hurricane and are also included within the new zone. Notably, the limited presence of turquoise reflects the careful consideration taken to accurately depict the inland extent of potential coastal flooding. Finally, the southern boundary of the zone is situated at Florida State Road 16 in Vilano Beach, accommodating the new National Hurricane Center wind/surge watch and warning breakpoint.
|
Figure 3
|
|
 |
This zone extends northward from Florida State Road 16 in Vilano Beach (excluding the St. Augustine Inlet) to the Duval County Line near the Intracoastal Waterway (ICWW). It encompasses the inland extent of the Maximum of Maximums storm surge inundation associated with a Category Five hurricane. This area includes, but is not limited to, Ponte Vedra Beach, Sawgrass, Palm Valley, Mickler’s Landing, North Ponte Vedra Beach, Guana River Wildlife Preserve, Vilano Beach (north of SR 16), North Florida Regional Airport (KSGJ), the Florida School for the Deaf and the Blind (FSDB), the Stokes Landing area, Palencia, and portions of Nocatee near the ICWW, as well as sections of the City of St. Augustine.
|
Figure 4
|
||||
 |
||||
| Click to Enlarge the Image | ||||
This zone extends southward from Florida State Road 16 in Vilano Beach (excluding the St. Augustine Inlet) to the Flagler County Line/Pellicer Creek. It encompasses the inland extent of the Maximum of Maximums storm surge inundation associated with a Category Five hurricane. This area includes Matanzas, Summerhaven, Crescent Beach, Butler Beach, St. Augustine Beach, Davis Shores, a significant portion of the City of St. Augustine, South St. Augustine, and St. Augustine Shores.
|
Figure 5
|
||||
 |
||||
| Click to Enlarge the Image | ||||
This new zone will cover inland areas north of Florida State Road 16, excluding regions near Durbin and Julington Creeks due to the potential for coastal flooding from these water bodies (St. Johns River Basin). Those areas will be served by the Western St. Johns Zone (FLZ633). Communities included in this new zone comprise, but are not limited to, Sampson, St. Johns County Club, Silverleaf, and World Golf Village.
|
Figure 6
|
||||
 |
||||
| Click to Enlarge the Image | ||||
This new zone will cover inland areas south of Florida State Road 16, excluding regions near Hastings and Flagler Estates due to the risk of coastal flooding from Deep Creek (St. Johns River Basin). These areas will be served by the Western St. Johns Zone (FLZ633). Communities included in this new zone comprise, but are not limited to, Murabella, Vermont Heights, Elkton, and Armstrong.
|
Figure 7
|
||||
 |
||||
| Click to Enlarge the Image | ||||
This zone includes, but is not limited to, areas along and near the St. Johns River basin, encompassing Julington Creek, Durbin Creek, Sixmile Creek, Trout Creek, Deep Creek, Flagler Estates, Racey Point, Riverdale, Tocoi, Picolata, Pacetti Point, Heritage Landing, Rivertown, Switzerland, Fruit Cove, St. Johns, Silverleaf, Shearwater, Sampson, Beachwalk, and Greenleaf Village.
|
Figure 8
|
||||
 |
||||
| Click to Enlarge the Image | ||||
Weather.gov Preview: NOAA's National Weather Service Office of Operational Systems NWS Internet Dissemination SystemNWS CMS 7.0.9-1.19760.5571fc2.el8 CMS original author: Dan Arnold CMS additional authors: NCEP/NCO Software Development Branch, CMS last modified: January 21st 2020, 12:06pm
Follow us on X
Follow us on Facebook
Follow us on YouTube
JAX RSS Feed