Tropical Storm — Coastal St. Johns, Florida

2024-10-09 to 2024-10-10 · Coastal St. Johns, Florida

Event narrative

Highest wind gusts measured ranged from 50-70 mph in the St. Augustine, Vilano Beach, and Ponte Vedra Beach areas, where widespread power outages and trees down were reported, as well as significant damage to barns. Winds begin to ramp up in the evening of Oct. 9th with peak winds occurring on Oct. 10th between 1-4 AM EDT. On 10/9 at 9:20 PM, FSWN St. Johns County Fire Station reported wind gusts of 51 mph with sustained winds of 40 mph. At 11 pm, the C-man station SAUF1 measured sustained winds of 44 mph with gusts to 49 mph. At 11:20 pm, a mesonet site at JFRD fire station reported sustained winds of 44 mph with gusts to 60 mph. At 11:20 pm, a mesonet site in the City of St. Augustine measured a wind gust of 52 mph. At 11:56 pm, the AWOS at the St. Augustine Airport measured a wind gust of 52 mph. On 10/10, at 12 am, a mesonet site at the St. Johns County Fire Station 2 miles SSE of South Ponte Vedra measured a wind gust of 62 mph. Also at 12 am, the C-Man station SAUF1 measured sustained winds o f46 mph with a gust of 54 mph. At 12:38 am, the AWOS at the St. Augustine airport measured a gust of 55 mph. At 1:25 am, the airport AWOS measured a wind gust of 59 mph. At 1:50 am, a mesonet site in the City of St. Augustine measured a wind gust of 55 mph. At 1:55 am, a mesonet site 2 miles NW of St. Augustine called Lewis measured a gust of 60 mph. At 1:56 am, the St. Augustine airport AWOS measured a sustained wind of 52 mph with a gust of 60 mph. Also at 1:56 am, a mesonet site 1 mile SSE of Crescent Beach called Summerhouse measured a gust of 55 mph. At 2 AM, AWOS station KSGJ St Augustine measured a sustained wind of 52 mph with a wind gust of 60 mph. At 2:10 am, a mesonet site 2 miles NW of St. Augustine called Lewis measured a wind gust of 63 mph. At 2:20 am, a mesonet site 2 miles SSE of South Ponte Vedra Beach measured a wind gust of 67 mph. At 2:30 AM, FSWN St. Johns County Fire Station measured a peak wind gust of 70 mph. At 2:30 AM, the St. Johns EOC about 5 miles east of Bakerville measured a gust of 48 mph (this location is just west of I-95 and just south of the State Road 16 interchange). At 2:40 am, a mesonet site in the City of St. Augustine measured a wind gust of 59 mph. At 2:41 am, a mesonet site 1 mile SSE of Crescent Beach called Summerhouse measured a wind gust of 63 mph. At 2:55 AM, XLWS Lewis reported a sustained wind of 44 mph with a gust to 64 mph. At 3 AM, SAUF1 1 NNE Saint Augustine Beach reported sustained winds of 56 mph with a wind gust of 67 mph. At 3:30 am, a mesonet site in the City of St. Augustine measured a sustained wind of 55 mph with a gust of 61 mph. At 4:29 am, law enforcement reported a tree was blown down and blocked the road on San Juliane Circle in St. Augustine. This was one of numerous trees down across the county.

On 10/9, St. Johns County EM reported around 2:45 pm that the King Street bridge in downtown St. Augustine was closed due to high water levels during high tide due to storm surge. At 12:52 am, broadcast media reported that the Matanzas River in St. Augustine was starting to overtop the sea wall and flood into parking lots. Storm surge impacted the historic section of St. Augustine. Water started to overtop the seawalls of the Matanzas River during the pre-dawn hours of 10/10. Between 3-6 AM, surge flooding occurred in Downtown St. Augustine along Avenida Menendez, King St, Malaga St, Orange St, and Ponce De Leon Blvd. Floodwaters reached businesses along King St and Avenida Menendez. The King Street bridge over the San Sebastian River in downtown St. Augustine was closed around 12 pm on 10/10 due to the surge flooding. By 3 pm, emergency management reported that the Bridge of Lions was closed due to storm surge flooding inundation approaching the base of the bridge. At 4:45 pm, county emergency management reported that about 2 feet of water from tidal flooding/storm surge was near the intersection of State Road 16 and Lewis Speedway in St. Augustine. On a NWS storm survey, about 10 inches of surge was measured along Coquina Ave, Riberia St, and Duero St and 7 inches was measured on buildings along Avenida Menendez. The surge also caused significant beach erosion on Anastasia Island and the waves knocked down the Dondanville Road sign.

Heavy rainfall from Milton's rainbands the morning of Oct. 9th led to 3 to 5 inches of rain falling across much of St. Johns county in a short time span (4 hours). Mostly continuous rainfall led to widespread 5-9 inches of rainfall that fell for areas mainly along and south of St. Augustine and Elkton. The highest rainfall amounts were along the coast near St. Augustine where a CoCoRAHs observer measured 9.52 inches of storm total rainfall.

As of October 14th, 136 structures in the county were reported as affected by Milton. 40 homes and/or businesses sustained at least some level of damage, with 5 of these sustaining major damage and 1 destroyed. Estimated damages in the county were $11 million dollars. Due to the potential flood threat, a mandatory evacuation order went into effect on Wednesday (Oct 9) at 8 AM for all of Zone A, Zone B, and only areas south of State Road 206 in Zone F. This included the City of St Augustine, St Augustine Beach, and low-lying/waterfront properties.

Wider weather episode

A tropical disturbance over the southwest Gulf of Mexico quickly developed into Tropical Storm

Milton on Saturday, October 5th. Milton then moved slowly east-southeastward, strengthening into a

hurricane the following day. On Monday, October 7th, the storm underwent rapid intensification,

reaching Category 5 strength as it neared the northwestern coast of Mexico's Yucatn Peninsula. Late

on Monday and into Tuesday, Milton shifted eastward and then northeastward across the

southeastern Gulf of Mexico.

As Milton approached Florida's Gulf coast on Wednesday, October 9th, it began to gradually weaken,

but still maintained major hurricane status. The storm made landfall that evening near Siesta Key on

Florida's west coast as a strong Category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale.

While it weakened further as it crossed central Florida overnight, Milton remained a hurricane. By

early Thursday morning, October 10th, it emerged off Florida's Atlantic coast as a Category 1 storm.

Milton caused widespread impacts across north-central and northeast Florida, as well as coastal

southeast Georgia. Flagler County, along with large portions of St. Johns, Putnam, and Marion

counties, experienced sustained tropical storm-force winds and hurricane-force gusts. Rainfall

amounts ranged from 7 to 11 inches as outer rainbands and the storm's powerful northern side

swept through these areas late Wednesday night into early Thursday morning.

This heavy rainfall caused Deep Creek, a tributary of the St. Johns River in St. Johns County, to reach

record levels on Thursday, October 10th, surpassing the previous record set during Hurricane Irma in

2017. This led to extensive flooding throughout the southern half of St. Johns County, particularly in

the Flagler Estates community and the towns of Hastings and Spuds. Additionally, record flooding was

observed along Haw Creek in western Flagler County, exceeding the previous record set in the

aftermath of Hurricane Ian in 2022.

Storm surge flooding of around 3 feet above Mean Higher High Water (MHHW) was recorded along

the St. Johns River and the northeast Florida coast. Significant inundation was reported along the

lower St. Johns River, with widespread flooding in areas such as Welaka, FL.

Source: NOAA Storm Events Database, event_id 1219088. Narrative written by the NWS forecast office that issued the report.