Lake Okeechobee water levels are often a concern when a hurricane hits Florida. The 25-30 foot-tall, 143-mile-long Herbert Hoover Dike surrounding the lake was built in the 1930s out of gravel, rock, limestone, sand, and shell using old engineering methods, and is vulnerable to leaking and failure when heavy rains bring high water levels to the lake. The dike has received billions of dollars in upgrades in recent years, and is in better shape to resist Hurricane Ian’s flood waters than it was for Hurricane Irma in 2017.
Fortunately, before Hurricane Ian hit, water levels on the lake were about 2.5 feet below average for this time of year. In fact, just two weeks before the hurricane hit, the low lake levels were creating water shortage concerns for South Florida’s coming winter dry season. In an article in the Palm Beach Post, Lake Worth Drainage District Executive Director Tommy Strowd said, “We are going to need a big rainmaker, a tropical storm. I don’t want to say the word hurricane. You know you are in trouble when you are praying for a hurricane.”
As a result of Lake Okeechobee’s low water levels before the hurricane, the lake level can rise three feet before high water level management needs to occur, and water levels can rise more than five feet before there is a danger of dike failure. The Lake Okeechobee watershed, predominantly consisting of a 40-mile-wide corridor of land that extends northward along the Kissimmee River to Orlando, received two to six inches of rain from Ian along the lower half of its extent, and 6-15 inches along the upper half (see tweet above). For comparison, Hurricane Irma dumped widespread rainfall amounts of 8 – 12 inches over the entire Lake Okeechobee watershed, causing the lake to rise by about three feet over three weeks, even though the Army Corps of Engineers was draining the lake at the fastest rate possible – about 0.4 inches per day.
It appears that the total rainfall from Ian in the Lake Okeechobee watershed was about 20-30% less than that delivered by Irma in 2017, and can thus be expected to raise lake levels by 2 – 3 feet. As of Saturday, the lake had risen 0.76 feet since Monday. The coming rise in water levels over the next three weeks – as runoff from Ian’s rains reaches the lake – may require the Army Corps to begin releasing water from the lake later in October, in case another hurricane or tropical storm with torrential rains affects Florida during the remainder of this hurricane season. On Friday, though, the Army Corps announced that they have no plans to release water from the lake. Water releases from the lake are problematic, because the water is heavily polluted with fertilizer runoff that kills marine life and creates toxic algae blooms.
Two Atlantic disturbances to watch
A disturbance still not yet classified as an “invest”, located several hundred miles south of the Cabo Verde Islands in the eastern tropical Atlantic, is likely to develop into a tropical depression by mid-week. Satellite images on Sunday showed the system was very disorganized, with little spin or heavy thunderstorm activity. Nevertheless, the system has favorable conditions for development, and has strong model support for becoming a tropical depression by Thursday. A break in the subtropical ridge of high pressure to its north should allow the incipient system to angle northward during the week, with no threat to any land areas. In its Tropical Weather Outlook issued at 8 a.m. EDT Sunday, the National Hurricane Center gave the system 2-day and 5-day odds of development of 30% and 70%, respectively.
A tropical wave located several hundred miles east of the Windward Islands was headed west at 15-20 mph. This system has mostly favorable conditions for development, with warm waters and moderate wind shear, though dry air to its north and west was hampering development. The wave was showing increasing organization on satellite imagery on Sunday, and will pass through the Lesser Antilles Islands on Wednesday, bringing gusty winds and heavy rain showers. The Sunday morning runs of the GFS and European ensemble model forecasts gave the wave modest support for development by late this week, when it is expected to be in the central Caribbean. In its Tropical Weather Outlook issued at 8 a.m. EDT Sunday, the National Hurricane Center gave the system 2-day and 5-day odds of development of 10% and 20%, respectively. A hurricane hunter aircraft is scheduled to investigate this wave on Tuesday, if necessary.
The next name on the Atlantic list of storms is Julia.
Hurricane Orlene headed for Mexico’s Pacific Coast
The next North American landfall from a tropical cyclone will likely be Hurricane Orlene, moving northward toward Mexico’s Pacific Coast on Sunday. Orlene underwent an impressive burst of rapid intensification overnight, going from a tropical storm with 65 mph winds to a category 4 hurricane with 130 mph winds in the 24 hours ending at 5 a.m. EDT Sunday.
Orlene is a small hurricane, and small hurricanes are able to undergo rapid changes in intensity. Fortunately, wind shear from strong upper-level winds out of the southwest began to affect Orlene on Sunday morning, and the hurricane weakened to a 125-mph category 3 storm by 11 a.m. EDT. Continued weakening is expected, with Orlene expected to hit Las Islas Marias (population 1,000) as a category 2 storm with 100 mph winds on Monday morning. A second Mexican landfall, at category 1 strength, is predicted for Monday night, in the vicinity of Mazatlan.
Hurricane Ian is not done with us yet
The remnants of Hurricane Ian have parked themselves off of the Mid-Atlantic coast, and are in no hurry to move off. Over the next three days, this area of low pressure, in combination with strong high pressure over New England, will be funneling a strong northeasterly flow of air into the coast, from New York to North Carolina. On Monday and Tuesday, the powerful onshore winds are predicted to bring major coastal flooding to Delaware, Virginia, and North Carolina, and moderate coastal flooding to New York, New Jersey, and Maryland.
At these tide gauges with long periods of record, the water levels are predicted to be among the top six on record:
Lewes, DE (Tue): 6th highest on record
Kiptopeke, VA (Mon): 4th
Chesapeake Bay Bridge Tunnel, VA (Mon): 6th
Sewell’s Point, VA (Mon): 6th
Duck, NC (Mon): 3rd
The Chesapeake Bay Bridge Tunnel, VA, site only has data back to 2018 at the current location, and Monday’s water level is predicted to be the highest since then. If comparing to the long-term record (back to 1975), the Monday high tide is predicted to have the 6th highest water level on record.
Please donate to help hurricane victims
To help out with Hurricane Ian or Hurricane Fiona recovery efforts, please consider donating to one of these worthy causes:
The Partnership for Inclusive Disaster Strategies (Formerly Portlight.org), helping disabled people recover from the hurricanes.
Bob Henson contributed to this post.
Editor’s note: this post was corrected to add the long-term water level records for the Chesapeake Bay Bridge Tunnel.
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