Tropical Cyclone 09L (Ian) / Invest 99L
Tuesday, September 27, 2022

Current Snapshot

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By PDC’s Senior Weather
Specialist Glenn James

CURRENT TROPICAL CYCLONES:

Tropical Cyclone 09L (Ian)…is located about 110 miles southwest of Naples, Florida

 

Tropical Cyclone 09L (Ian)

IAN EXPECTED TO CAUSE LIFE-THREATENING STORM SURGE, CATASTROPHIC
WINDS AND FLOODING IN THE FLORIDA PENINSULA

NHC Advisory number 20

Ian is moving toward the north-northeast near 10 mph (17 km/h). This general motion with a reduction in forward speed is forecast tonight and Wednesday, followed by a turn toward the north on Thursday.

On the forecast track, the center of Ian is expected to pass west of the Florida Keys within the next few hours, and approach the west coast of Florida within the hurricane warning area on Wednesday. The center of Ian is forecast to move over central Florida Wednesday night and Thursday morning and emerge over the western Atlantic by late Thursday.

Maximum sustained winds are near 120 mph (195 km/h) with higher gusts. Ian is a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale. Strengthening is expected until the hurricane makes landfall. Ian is forecast to approach the west coast of Florida as an extremely dangerous major hurricane.

Hurricane-force winds extend outward up to 40 miles (65 km) from the center and tropical-storm-force winds extend outward up to 140 miles (220 km). The Key West International Airport just reported sustained winds of 52 mph (84 km/h) with a gust to 79 mph (127 km/h).

HAZARDS AFFECTING LAND

STORM SURGE: The combination of storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline. The water could reach the following heights above ground somewhere in the indicated areas if the peak surge occurs at the time of high tide…

* Middle of Longboat Key to Bonita Beach, including Charlotte Harbor…8-12 ft
* Bonita Beach to Chokoloskee…6-10 ft
* Anclote River to Middle of Longboat Key, including Tampa Bay…4-6 ft
* Suwannee River to Anclote River…3-5 ft
* Mouth of the St. Mary’s River to Altamaha Sound…4-6 ft
* Chokoloskee to East Cape Sable…4-7 ft
* Dry Tortugas…3-5 ft
* Flagler/Volusia County Line to Mouth of the St. Mary’s River, including St. Johns River…3-5 ft
* Altamaha Sound to Savannah River…3-5 ft
* St. Johns River south of Julington…2-4 ft
* Savannah River to South Santee River…2-4 ft
* East Cape Sable to Card Sound Bridge…2-4 ft
* Florida Keys…2-4 ft
* Patrick Air Force Base to Flagler/Volusia County Line…1-3 ft
* Indian Pass to Suwanee River…1-3 ft

The deepest water will occur along the immediate coast near and to the right of the center, where the surge will be accompanied by large waves. Surge-related flooding depends on the relative timing of the surge and the tidal cycle, and can vary greatly over short distances.

WIND: Hurricane conditions are expected along the west coast of Florida within the Hurricane Warning area on Wednesday morning, with tropical storm conditions possibly beginning tonight.

Tropical storm conditions are occurring in the warning area in the Florida Keys, and will continue overnight. Tropical storm conditions are expected in the warning area on the east coast of Florida beginning early Wednesday, and should spread up to Georgia and South Carolina on Thursday. Tropical storm conditions are expected within the warning area in Cuba for the next few hours.

RAINFALL: Ian is expected to produce the following rainfall through Thursday:

* * Florida Keys and South Florida: 6 to 8 inches, with local maxima up to 12 inches.
* Central and Northeast Florida: 12 to 18 inches, with local maxima up to 24 inches.
* Eastern Georgia and Coastal South Carolina: 4 to 8 inches, with local maxima of 12 inches.

Widespread catastrophic flash, urban, and river flooding is expected across central Florida. Widespread considerable flash, urban, and river flooding is expected across portions of southern Florida through tomorrow and northeast Florida, southeastern Georgia, and coastal South Carolina later this week through the weekend. Limited flash, urban, and river flooding is possible over portions of the Southeast and southern Mid-Atlantic later this week through the weekend.

TORNADOES: Tornadoes are possible through Wednesday across central and south Florida.

SURF: Swells generated by Ian are affecting the western Caribbean and the Florida Keys, and will spread northward throughout the eastern Gulf of Mexico through Wednesday.

These swells are likely to cause life-threatening surf and rip current conditions.

>>> Invest 99L

Showers and thunderstorms associated with an area of low pressure located several hundred miles west of the Cabo Verde Islands have become better organized over the past several hours.

Although environmental conditions are expected to be marginally conducive for development, only a slight increase in organization would result in the formation of a short-lived tropical depression tonight or
tomorrow.

Further development will become less likely by the end of the week due to increasing upper-level winds. The disturbance is forecast to meander for the next day or so and then turn north-northwestward by Thursday.

* Formation chance through 48 hours…high…70 percent
* Formation chance through 5 days…high…70 percent