Hurricane Iota explosively intensified into a category 5 hurricane overnight, becoming the latest category 5 storm ever observed in the Atlantic. Iota is predicted to make landfall in northern Nicaragua on Monday night at or just below category 5 strength, bringing catastrophic winds and a storm surge of 15-20 feet to northern Nicaragua.
Catastrophic rains of 10-20 inches, with isolated amounts of up to 30 inches, will affect a large region of Central America, with northern portions of Nicaragua, Honduras, and Guatemala at highest risk of devastating flooding. These are the same regions still recovering from catastrophic Hurricane Eta, which hit northern Nicaragua as a category 4 storm with 140 mph winds on November 3.
Iota is likely to make landfall within 50 miles of where Hurricane Eta made landfall. There is no historical precedent for two Atlantic hurricanes of at least category 4 strength hitting the same location just two weeks apart. That this may occur in November, when major hurricanes are rare, is particularly extraordinary. The closest analogue may be in September 2017, when Hurricane Irma and Hurricane Maria, both at category 5 strength, affected the Virgin Islands two weeks apart. However, Maria did not make a direct landfall in the Virgin Islands, passing about 75 miles to the southwest of Irma’s path.
If there is a bright side to this tragedy, it is that Iota will be hitting one of the most sparsely populated areas of the Central American coast. Nicaragua proved it could successfully evacuate its vulnerable population before Eta hit the same region two weeks ago, and the official death toll in the nation from Eta totaled two people. As Iota’s most extreme winds and storm surge will be affecting some of the same regions most severely affected by Eta, Iota is not considered likely to cause a great deal of additional damage, as these regions were already mostly destroyed.
Unprecedented onslaught of late-season hurricanes
The “Greek” storms have given 2020 an unprecedented series of late-season rapidly intensifying hurricanes (See Tweet by Sam Lillo). Iota is just the second Atlantic category 5 hurricane recorded in November in the Atlantic, the other being the 1932 Cuba hurricane, at category 5 strength from November 5-8, 1932.
Iota is the second major hurricane this November, along with Hurricane Eta, which peaked as a category 4 storm with 150 mph winds early in November. Eta and now Iota make 2020 the first Atlantic hurricane season to record two major hurricanes in November.
Iota is the tenth 2020 Atlantic named storm to rapidly intensify by at least 35 mph in 24 hours. According to statistics compiled by Tomer Berg, 2020 therefore ties a record set in 1995 for most rapidly intensifying Atlantic storms in a single year (using statistics going back to 1979).
Furthermore, Iota gives the Atlantic five consecutive years with a category 5 hurricane. Matthew (2016), Irma and Maria (2017), Michael (2018), and Lorenzo and Dorian (2019), were the others. This is the first time on record that the Atlantic has experienced category 5 hurricanes in five consecutive years.
Iota gives Colombia’s Providencia Island a tremendous pounding
Between 4 a.m. and 6 a.m. Monday morning, the southern eyewall of Iota passed over Colombia’s Providencia Island (population 5,000). An Air Force Reserve Hurricane Hunter aircraft about two hours later measured sustained category 5 winds of 160 mph in the southern eyewall of Iota, but these winds may have been just north of the island. Wind damage on Providencia was likely devastating, and possibly catastrophic.
Iota on course for a Monday night landfall in Nicaragua
At 1 p.m. EST Monday, Iota was 80 miles east-southeast of Puerto Cabezas, Nicaragua, headed west at 9 mph. Iota at that point was a low-end category 5 hurricane with top winds of 160 mph, and a central pressure of 918 mb.
Satellite imagery early Monday afternoon showed Iota to be a very impressive hurricane with an eye surrounded by a solid eyewall with heavy thunderstorms having very cold cloud tops. Upper-level outflow was good to excellent in all quadrants, and the outer spiral bands of Iota were lashing northeastern Nicaragua and Honduras.
Track forecast for Iota
The track forecast for Iota is straightforward. A ridge of high pressure to Iota’s north will force the hurricane on a westerly to west-northwesterly track at 7-10 mph until landfall occurs in northern Nicaragua on Monday night near midnight. Predictions then call for steering currents to shift, putting Iota on a more westerly to west-southwesterly path deep into Central America. Dissipation is expected to occur about two days after landfall, when Iota will be over El Salvador, near the Pacific coast. Iota is not expected to regenerate over the Pacific Ocean.
Intensity forecast for Iota
The National Hurricane Center in its 10 a.m. EST Monday intensity forecast called for Iota to intensify until landfall, peaking as a category 5 hurricane with 165 mph winds. Conditions will be favorable for development through landfall, with the SHIPS model predicting moderate wind shear near 10 knots, warm sea surface temperatures of 28.5-29 degrees Celsius (83-84°F), and a moist atmosphere with a mid-level relative humidity of 70%. Data from the Hurricane Hunters on Monday showed no signs of concentric eyewalls, so an eyewall replacement cycle – the process common in intense hurricanes where the inner eyewall shrinks, grows unstable, and collapses, resulting in a weakening of 10-20 mph in the winds of the storm – does not appear imminent.
Nicaragua previously has been hit only twice by category 5 hurricanes: Hurricane Edith (1971) and Hurricane Felix (2007).
Tropical Storm Kappa may affect Central America late this week
Recent runs of the GFS and European model have been consistently predicting that an area of low pressure capable of developing into a tropical storm will form late this week over the southwestern Caribbean Sea, off the coast of Costa Rica. Conditions for development will be favorable, with moderate wind shear of 10 – 20 knots, warm sea surface temperatures of 29 degrees Celsius (84°F), and a moist atmosphere. Steering currents favor a westerly to west-southwesterly motion at 5-10 mph, putting Costa Rica and southern Nicaragua at greatest risk of experiencing a landfall.
None of the 51 members of the 0Z Monday run of the European model ensemble and fewer than 20% of the 31 members of the 6Z GFS model ensemble members, predicted a more northerly track, with a threat to northern Nicaragua. In multiple recent runs, the GFS model has been predicting that this disturbance will develop into a tropical storm by Friday, make landfall as a tropical storm near the Costa Rica/Nicaragua border on Saturday, then cross into the Eastern Pacific Ocean and reorganize, bringing heavy rains to the Pacific coast of Central America early next week. The next name on the Atlantic list of storms is Kappa, the 10th letter of the Greek alphabet. The storm would likely keep the name Kappa after crossing into the Northeast Pacific and reorganizing into a tropical storm (if it were still identifiably the same cyclone).
If Kappa does form as the GFS model has been predicting, the storm is unlikely to have sufficient time over water to develop into a hurricane, and it would be a relatively small tropical storm. However, Kappa would be a significant heavy rain threat for southern Nicaragua, Costa Rica, and Panama, with 5-10 inches of rain possible Friday through Sunday. As of Monday afternoon EST, it does not appear that this potential future storm would be a heavy rain threat for the areas of northern Nicaragua and Honduras facing devastation from Hurricane Iota, although broader easterly flow across the region may continue to keep intermittent rains over the Iota-affected region for a number of days.
In a 1 p.m. EST Monday tropical weather outlook, NHC gave 2-day and 5-days odds of development of 0% and 40%, respectively, to this future disturbance. Given the way the 2020 Atlantic hurricane season has unfolded, the 5-day odds should probably be hiked up to 60%.
Posted on November 16, 2020(2:21pm EST).