Hurricane Milton slams Florida but spares Tampa from catastrophic storm surge » Yale Climate Connection

At 8:30 pm ET on October 9th, Hurricane Milton slammed into the west coast of Florida near Sarasota as a Category 3 storm with 120 mph winds and a central pressure of 954 MW, displaying a stunning display of Shockingly atmospheric violence. Milton brought a once-in-500-year rainfall event to the Tampa Bay area, severe wind damage across the state, an outbreak of violent and deadly tornadoes, and a devastating storm surge of unknown magnitude. Despite the dire conditions in Milton, Florida got a major breakthrough when the eye of the storm made landfall 20 miles south of the entrance to Tampa Bay, saving Florida's most vulnerable city from a 10-foot storm surge. This storm surge could cause tens of billions of dollars in damage.

The impact of Milton's storm surge was devastating but still unclear

Milton's path brought storm surges of more than 5 feet to Naples and Fort Myers, the second-highest levels since records began in 1965. Siesta Key) 80 miles of coastline (near Sarasota) to Port Charlotte. There are no permanent tide gauges along the coast, but Jamie Roehm, a storm surge expert with the National Hurricane Center, said last night that he was “very confident” that a storm surge of 9 to 13 feet was occurring in the area. Drone images taken in Englewood, 20 miles south of Sarasota, and nearby barrier island Manasota Island appear to confirm this estimate (see tweet below). We will know the exact strength of the surge in the coming days once data from eight portable surge and wave sensors deployed by the USGS between Naples and Crystal River are available.

Here are the eight highest water levels (above mean high water, or MHHW) in Fort Myers since 1965. Surprisingly, three incidents occurred this year:

1. 7.26 feet, September 28, 2022, Hurricane Ian
2. 5.27 feet, October 9, 2024, Hurricane Milton
3. 5.12 feet, September 27, 2024, Hurricane Helen
4. 3.41 feet, Tropical Storm Keith, November 23, 1988
5. 3.31 feet, September 14, 2001, Hurricane Gabriel
6. 3.30 feet, June 18, 1982, unnamed subtropical storm
7. 3.27 feet, August 4, 2024, Hurricane Debbie
8. 3.2 feet, August 30, 2023, Hurricane Idalia

Of note, there were multiple reports of flooding from Hurricane Donna in the 1960s, with water levels ranging from 8 to 12 feet in the Naples area and 7 to 11 feet in the Fort Myers area.

Here are the eight highest water levels (above mean high water, or MHHW) in Naples, Florida since 1965. Again surprisingly, three incidents occurred this year:

1. 6.18 feet, September 28, 2022, Hurricane Ian (tide gauge failed before peak water level was recorded)
2. 5.08 feet, October 9, 2024, Hurricane Milton
3. 4.02 feet, September 10, 2017, Hurricane Irma
4. 4.01 ft. September 26, 2024, Hurricane Helen
5. 3.11 feet, August 4, 2024, Hurricane Debbie
6. 3.11 feet, December 22, 1972, winter storm
7. 3.08 feet, January 17, 2016, winter storm
8. 3.02 feet, September 28, 2023, Hurricane Idalia

As hurricane expert Michael Lowry noted in his Substack post today, “Coastal flooding in Fort Myers and Naples occurs on average every 30 to 60 years, but has occurred three times in two years, according to NOAA .

Record rainfall causes massive flooding

As Milton interacted with a stationary front over central Florida, heavy rain developed north of Milton's path, particularly in the northeastern Tampa Bay area. Rainfall totals of 18.54 inches were reported at St. Petersburg's Albert Whitt Airport, the highest single-day rainfall since records began in 1998. , 5.09 inches of rain fell in just one hour.

In Tampa, where records date back to 1890, the 11.43 inches measured Wednesday at Tampa International Airport nearly matched Tampa's all-time record for any calendar day, which was 11.45 inches on May 8, 1979. Sarasota International Airport Bradenton, 11.06 Wednesday recorded the wettest rainfall on record in 1999.

Heavy rains in Milton are still flowing into rivers and will cause severe flooding in many locations from west-central to northeast Florida Thursday into the weekend. At least one location is expected to reach record levels: Cypress Creek at SR 54 Worthington Gardens, at 15 feet (the previous record was 13.78 feet on September 11, 2004).

Tornadoes hit south and central Florida

As Milton approached Florida on Wednesday, the southern half of the peninsula experienced an unusually strong round of hurricane-related tornadoes that caused massive damage and killed at least four people. These tornadoes often develop into “mini-supercell” thunderstorms that appear in clusters or lines, especially ahead and to the right of the hurricane's landfall path (right front quadrant), where wind shear favorable to the tornado is often greatest.

Wednesday's tornado was unusually pronounced for a hurricane-related outbreak, likely because there was a sufficient amount of dry air swirling around Milton's south and east sides to maintain high visibility. Once the air rises, kilometers of dry air can also increase atmospheric instability, leading to tornado outbreaks.

Wednesday set a state record for a single-day warning since the Doppler radar era, which dates back to 1986. Because timing is critical for tornado events, many warnings are based on clues seen on radar, such as small, strong rotations that mean a tornado is approaching. Therefore, the number of observed tornadoes is typically less than would be suggested by the large number of warnings issued during a tornado outbreak.

The NOAA Storm Prediction Center has recorded 38 preliminary reports of tornadoes so far following Wednesday's major tornado outbreak in Florida. Florida's largest tornado outbreak occurred over four days from September 4 to 7, 2004, when Category 2 Hurricane Frances produced a total of 103 tornadoes in an area of ​​six states. The third-highest number of tornadoes, behind Category 3 Hurricane Ivan from September 15 to 18, 2004 (120 tornadoes, including 18 in Florida, killing 6 people) and Category 3 Hurricane Ivan in 1967 (115 tornadoes in Florida).

One of the tornadoes spawned by Hurricane Frances was the strongest known to be spawned by a hurricane: an F3 (EF3 on the Enhanced Fujita Scale) tornado, which affected an area near Camden, South Carolina, causing widespread damage. Given the severe damage visible in photos and videos, it is likely that one or more of Wednesday's tornadoes will be officially classified at this level once damage assessments are conducted (note that real-time estimates based on radar data or storm tracking videos are not Applicable) for Fujita official rankings). The strict building codes implemented by Florida after Hurricane Andrew may have resulted in lower structural damage than in other states experiencing the same tornadoes.

Congratulations to the NHC for the fantastic forecast

Forecasts of impact locations made four to five days in advance were within 20 miles (32 kilometers) of Hurricane Milton's forecasts and varied little throughout the storm. Predictions of intensity at landfall were equally accurate. These accurate forecasts give Florida residents ample time to prepare and take the necessary steps to protect life and property. Well done, National Health Commission! Special thanks also go to the Air Force and NOAA Hurricane Hunters, who flew around the clock, endured extreme turbulence on multiple missions, and sent back the necessary information that allowed NHC to make these excellent forecasts.

What’s next for Atlantic after Milton?

After Milton, the Atlantic will likely remain calm with no new storms for at least a week. The NHC is monitoring a tropical wave off the coast of Africa, with a 20% chance of developing in the next 2 to 7 days. This disturbance does not pose a threat to residential areas.

However, by the end of next week we will need to start monitoring the western Caribbean, where the GFS model has repeatedly predicted the potential for tropical storm formation. General weather conditions for tropical storm formation will become more favorable during the last week of October and the first week of November.