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Rare Hurricane Pounds Cape Verde Islands

By: Jeff Masters and Bob Henson 4:23 PM GMT on August 31, 2015

For the first time since 1892, a full-fledged hurricane is pounding the Cape Verde islands, as Hurricane Fred heads northwest at 12 mph through the islands in the far eastern North Atlantic. The eye of Fred passed just southwest of Boa Vista Island in the Republic of Cabo Verde (formerly called the Cape Verde Islands) near 8 am EDT Monday, with the northeastern eyewall likely hitting the island. The center of Fred is expected to pass over or very close to the northwestern Cape Verde islands of Sao Nicolou, Santa Luzuia, Sao Vicente, and Sao Antao by Monday night. All three reporting stations in the islands went off-line early Monday morning, so we have no observations to report. Despite their name (which translates to “green cape” in English), the Cape Verde islands have a semi-desert climate, with an average annual rainfall of only around 10 inches. The torrential rains of 4 - 6" predicted from Fred, with isolated totals of up to 10”, are likely to cause unprecedented flood damage on the islands. Fred may well turn out to be the Republic of Cabo Verde's most expensive natural disaster in history.

Figure 1. MODIS image of Hurricane Fred from NASA's Terra satellite taken at approximately 11:15 am EDT Monday August 31, 2015. At the time, Fred had top sustained winds of 85 mph. Image credit: NASA.

Figure 2. MODIS image of Hurricane Fred from NASA's Aqua satellite taken at approximately 8:15 am EDT Monday, August 31, 2015. At the time, Fred had top sustained winds of 80 mph. Image credit: NASA.

Most easterly hurricane formation location ever observed
Fred was able to form and intensify at an unusually easterly location, due to a pocket of anomalously warm waters (1-2°C above average, or about 27-28°C) that surround the Cape Verde islands. Since ocean temperatures are often just marginally warm enough to support tropical cyclones near the islands, it is rare to see a tropical storm or hurricane affect them. When Fred became a hurricane at 2 am EDT Monday at 22.5°W longitude, this was the easternmost formation location for any hurricane in the historical record; the previous record was held by Hurricane Three of 1900, which became a hurricane at 23°W, south of the Cape Verde islands. There have been six other hurricanes in the historical records that existed at a more easterly longitude, but all were recurving storms that formed much farther to the west than Fred. (The easternmost hurricane ever observed was Hurricane Faith of 1966, which maintained hurricane status to a position north of the British Isles, at 2.9°W.)

Figure 3. Tracks of all tropical cyclones in the vicinity of the Cape Verde islands from the NOAA historical database, which extends back to 1851 (although reports were scanty from the far eastern Atlantic until the satellite era began in the 1960s). Only a handful of tropical depressions (blue lines) and tropical storms (green lines) have affected the islands, and no direct hurricane landfalls (yellow lines) have been recorded. The two yellow tracks labeled above are an unnamed 1892 hurricane and 1998’s Hurricane Jeanne. When the National Hurricane Center named Fred at 5:00 am EDT Sunday, it was located at 18.9°W longitude; only three other named storms have existed at a more easterly longitude since hurricane records began in 1851. Ginger of 1967 at 18.1°W; Storm 3 of 1900 at 18.5°W; and Storm 6 of 1988 at 18.5°W. Image credit: NOAA Historical Hurricane Tracks.

A historic hurricane for the Cape Verdes?
The Atlantic's most terrifying and destructive hurricanes typically start as tropical waves that move off the coast of Africa and pass near the Cape Verde islands. This class of storms is referred to as "Cape Verde hurricanes", in reference to their origin. Despite the fact that the Atlantic's most feared type of hurricanes are named after the Cape Verde islands, the islands themselves rarely receive significant impacts from one of their namesake storms. This is because tropical waves coming off the coast of Africa have very little time to organize into tropical storms before arriving at the Cape Verde islands, which lie just 350 miles west of the African coast. There is no reliable record of any bona fide hurricane having made landfall on the Cape Verde islands (see Figure 2). The closest analogue for Fred is an 1892 storm that bisected the islands, moving between the northern cluster (Ilhas do Barlavento, or windward islands) and the southern cluster (Ilhas do Sotavento, or leeward islands). This 1892 storm reportedly intensified to hurricane strength while passing south of the northwestern Cape Verde islands. Another close approach came from 1998’s Hurricane Jeanne, which reached hurricane strength while passing about 100 miles south of the southern islands. Decaying tropical cyclones in the open Atlantic have occasionally circled southeastward to take a swipe at the Cape Verdes as extratropical storms, but none have reached the island at hurricane strength.

According to EM-DAT, the International Disaster Database, there have been only two deadly tropical cyclones in Cape Verde history. Like Jeanne, they both passed south of the Ilhas do Sotavento. The deadliest was Tropical Storm Fran of 1984, which brushed the southernmost islands on September 16 as a tropical storm with 50-mph winds. Fran brought sustained winds of 35 mph and torrential rains to the islands. The rains triggered flash flooding that killed more than two dozen people and caused damages of almost $3 million (1984 dollars.) The other deadly named storm was Tropical Storm Beryl of 1982, which passed about 30 miles south of the southwestern islands on August 29, with 45-mph winds. The storm's heavy rains killed three people on Brava Island, injured 122, and caused $3 million in damage.

The most recent named storm to affect the islands was Hurricane Humberto of 2013, which passed the islands to the south as a tropical storm. Humberto brought wind gusts of up to 35 mph and heavy rain squalls to the islands, triggering flooding that washed out roads and damaged homes. Hurricane Julia of 2010, the easternmost Category 4 hurricane ever recorded in the Atlantic, passed about 50 miles south of Sao Filipe, on the island of Fogo in the southern Cape Verde islands, as a tropical storm with 45 mph winds, bringing wind gusts of 30 mph and some minor flooding.

Figure 4. Track of Tropical Storm Fran of 1984, which brushed the southwestern Cape Verde islands on September 16 as a tropical storm with 50 mph winds. Torrential rains from Fran killed at least 29 people in the Cape Verde islands, making it the deadliest storm in their history.

Hurricane historian Mike Chenoweth, who has spent innumerable hours poring over dusty old ship logs, has published a number of histories of old hurricanes. Here are his comments on the history of hurricanes in the Cape Verde islands:

"There is very little data from land stations in the islands even for storms we know about that pass over or near the islands, particularly before the mid-20th century. The only hurricane in the HURDAT record (1892) is based on a single press account which does not specify any particular island that received the damage (it took a month for the news to get from the islands to Lisbon).

"It is very likely that the storm history for the islands is under-estimated given the paucity of available land and ship data in existing data bases. For example, storm 2 of 1927 has a tropical storm passing between the islands (without a direct island landfall as in 1892) but there are no accounts of any effects the storm may have had on the islands. That such effects probably occurred but remain unrecovered is supported by the report of a hurricane near the Cape Verde islands reported by the "E.R. Sterling" which sailed from Port Adeliade, Australia on 16 April 1927 for London. The ship was damaged in a storm north of the Falkland Islands on 4 July and partially dismasted but continued northward. It then encountered a hurricane near the Cape Verde islands on 4 September and lost her foremast and the Chief Officer was killed. The ship was forced to put into St. Thomas, Virgin Islands on 15 October. So the storm was apparently stronger than indicated in HURDAT and may have been stronger in the Cape Verde islands as well. Source: http://www.dragonsearch.asn.au/nletters/MLSSA_NL_370_October_2009.htm.

"In 1901, a storm was estimated to have passed south of the northern islands of the Cape Verde islands based on press accounts that I provided to the Best Track Change Committee. At the time there were no land reports from the islands in the map series or from press accounts. Today, I located a press item from the local Cape Verde press that indicates that on 29 August on Santo Antao two vessels were lost, much of the coffee and sugar cane was blown down and washed away and that mighty winds swept houses away and killed livestock and people. Most of the other islands reported at least torrential rains and flood damage. Source: "O Ultramarino" (Cidade de Praia), 17 de Outburo de 1901, nº 64, ano3, p. 2.

"In 1880, the Bremen brig "Asante" encountered a tropical storm in 15.5N 20.2W on 17 August, lowest pressure 752.3mm (1003mb) maximum winds encountered force 11 from the south. (Deutsche Seewarte, Segelhandbuch für den Atlantischen Ozean, 1899, p.187). A brig drove off from her anchorage on the night of 17-18 August on the Island of Sal in the northeast Cape Verde islands during a "severe hurricane" and was lost on the island and the crew saved (Lloyd's List, 8 September 1880).

"The most severe storm on record in the Cape Verde Republic's history pre-dates the official North Atlantic record. This was a hurricane and was felt on 2 September 1850. The first account of it was in the Boston Atlas of 3 December 1850 which reported a hurricane had caused great destruction of property; on the island of St. Antonio alone more than 600 houses were destroyed by the wind and rain combined; several American vessels were wrecked or damaged at the islands of Sal and Boa Vista. The London Times of 1 February 1851 had additional information. It stated that the storm on the island of San Nicolas was a "fearful hurricane" it began early in the morning before daylight and although it continued until the next morning, all of the damage was done in the first 3 or 4 hours, the wind blowing with such terrific violence during that short period that nearly all the crops and 600 houses were completely destroyed...the whole of the sattara root had been torn up and destroyed by the hurricane.

"In short, the official records are incomplete and although hurricane impacts are rare in the Cape Verde Islands they are not quite the unicorns we have thought to date."

Figure 3. The view from inside the eye of Hurricane Ignacio on Sunday, August 30, 2015, from an Air Force hurricane hunter aircraft. At the time, Ignacio was a Category 4 storm with 140 mph winds. Image credit: Air Force Reserve 403rd Wing. There is also an impressive video from inside the eye on their Twitter page.

Ignacio no longer a threat to Hawaii; Pacific storm show goes on
In the Central Pacific, all watches and warnings have been dropped for Hawaii due to Hurricane Ignacio, which has weakened to Category 2 strength and is expected to skirt the islands over 300 miles to their northeast. Ignacio, will, however, bring dangerous high surf to the islands, and a High Surf Warning for waves of 12 - 20 feet along east shores of the Big Island has been posted. Impressive Category 4 Hurricane Jimena, and Category 4 Hurricane Kilo continue to put on a show over the open waters of the Eastern Pacific, but neither of these storms are a threat to land. All three hurricanes reached Category 4 strength on Saturday and remained there on Sunday morning, the first time since the satellite era began in the 1960s that three simultaneous Category 4 hurricanes had existed in the waters of the Eastern Pacific, east of the Date Line.

Storm surge expert Hal Needham has a Monday morning post on the storm surge potential for Fred in the Cape Verde islands.

Live webcam from Sal Island in Cabo Verde.

Live blog on Fred (in Portugese) from the islands.

We’ll be back with another update on Tuesday.

Jeff Masters and Bob Henson


The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.