Eta expected to strengthen to tropical storm as it nears Florida Keys
In this recorded Facebook Live, Dr. Ryan Truchelut from WeatherTiger breaks down expected rain and wind impacts across the Florida peninsula on Friday, Nov. 6, 2020.
After a three-day inundation of inland Central America, Eta has re-emerged into the western Caribbean as a sprawling storm that will bring widespread rain and gusty winds to South Florida this weekend, and linger in the Gulf deep into next week.
As of 4 p.m. Friday afternoon, the broad center of Tropical Depression Eta is located just east of Belize, with maximum sustained winds of 35 mph. Because Eta is loosely organized, motion is tough to estimate, but the overall circulation has been shifting east-northeast at about 10 mph for the last 12 hours.
Eta’s next move is northeast across the Caribbean and east-central Cuba as it pivots around an upper-level low in the western Gulf of Mexico. While shear will be a fairly brisk 20 to 25 knots, look for Eta to restrengthen to a large tropical storm with sustained winds in the 60 to 70 mph range by the time it emerges into the Florida Straits on Sunday afternoon.
Expected weather conditions in Florida
Late Sunday and Monday, Eta will abruptly swerve west-northwest as it merges with the upper low. Depending on the timing of this interaction, the center of Eta may pass through the Florida Straits, over the Florida Keys, or through South Florida, probably as a strong tropical storm or potentially as a low-end Category 1 hurricane.
“Don’t focus on the exact track” is a fundamental rule of hurricane preparedness that is particularly applicable here. In any of the plausible scenarios, most of the Keys and South Florida will be in the stronger half of an expansive tropical system Sunday and Monday. There is high confidence in widespread rain totals of 4 to 8 inches south of Lake Okeechobee, with higher accumulations resulting in localized flash flooding.
Widespread wind impacts are also likely well away from the center. Expect tropical storm force wind gusts north to the Space Coast and coastal Southwest Florida.
In Southeast Florida, there is potential for coastal wind gusts of 60 to 70 mph and inland tropical storm force gusts. This will be coupled with at least a couple feet of coastal surge over the entire Florida East Coast due to strong onshore flow. Tropical storm or hurricane watches are expected to be raised for South Florida overnight, as the worst conditions are expected late Sunday or early Monday.
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The center of Eta should pull slowly west of southwest Florida or the Keys by late Monday, though intermittent heavy rainfall is expected to persist into at least midweek in South Florida. Forecast confidence tails off in four or five days, but the most likely scenario is that Eta moves gradually northwest across the eastern Gulf through Wednesday, spreading some gusty winds and rain chances throughout the Florida peninsula. This is highly dependent on exactly how far the storm is offshore, so stay tuned.
Eta will probably remain a tropical storm in this timeframe, though intensity forecasting beyond three days is always fraught. Dry air and shear will impinge on the storm from the west and may keep it in check or start to weaken it by the middle of next week.
A conservative model guidance for Eta
One caveat to bear in mind is that model guidance has been overly conservative in the Gulf this season, as with Hurricane Zeta last week. Sea surface temperatures are warm enough to support a hurricane, and a stronger Eta in the Gulf is a possibility depending on exactly where it lands after moving near or across Florida and how upper-level features line up.
Eta’s final destination remains speculative, though model guidance is in modestly better agreement today.
Hurricane Eta slams into Central America
A rare, Category 4 Hurricane Eta hit Nicaragua with 140-mile-per-hour winds, and could eventually make it’s way to the United States.
A front pushing into the Deep South next week will weaken East Coast ridging and should cause Eta to turn northeast back towards Florida in five or six days.
Depending on how far west Eta gets, both the Florida Panhandle and peninsular Gulf Coast remain at risk.
It should be noted that today’s model trends are generally farther south and weaker with this possible second landfall than yesterday. This is positive, but also should not be trusted at this range given this year’s persistent intensity forecast biases.
One side note: the entire U.S. coast from southern Texas to New England has been under a tropical storm/hurricane watch or warning at some point in the 2020 season, except for the Florida shoreline between Apalachee Bay and the Everglades. We will see if that area pulls even this week with the number of warnings issued this year for hurricane hotspots like eastern Maine (Isaias) and the mountains of western Virginia (Zeta).
In the shorter term, South Florida is on deck for widespread rain and wind impacts late this weekend. Plan on completing necessary preparations on Saturday, as weather conditions will likely worsen early Sunday as this broad and atypical late-season tropical threat approaches.
Keep watching the skies.
Dr. Ryan Truchelut is chief meteorologist at WeatherTiger, a Tallahassee start-up providing advanced weather and climate analytics, forensic meteorology and expert witness consulting, and agricultural and hurricane forecasting subscription services. For more information, visit us at weathertiger.com or get in touch at email@example.com.