1986 Atlantic hurricane season

The 1986 Atlantic hurricane season was a very inactive season that produced 10 depressions, 6 named storms, 4 hurricanes, and no major hurricanes. The season officially began on June 1, 1986, and lasted until November 30, 1986. These dates conventionally delimit the period of each year when most tropical cyclones form in the Atlantic basin. During the 1986 season, the first subtropical depression formed in the first week of June, while the last tropical cyclone dissipated at the end of the third week of November. The 1986 season had lower than average activity because of an ongoing El Niño, and was the least active season in the North Atlantic since the 1983 Atlantic hurricane season. This was also the first season since 1972 to have no major hurricanes.

The season started on June 5 when Subtropical Depression One formed near the Bahamas, which would later gain tropical characteristics and become the first tropical storm of the season; Tropical Storm Andrew. On June 9, Andrew would later be absorbed by a larger low pressure system. On June 23, the season's first hurricane formed; Bonnie, although it attained hurricane status on June 25, just two days after Bonnie's formation. Two more tropical depressions followed suit later in the season. On August 13, the season's fifth tropical depression formed and would later become Hurricane Charley four days later. After Charley dissipated, two more tropical depressions formed on August 31 and September 1. Both dissipated on September 4. On September 7, Tropical Storm Danielle formed and would dissipate on September 10. Just after Danielle dissipated, Hurricane Earl formed and would later become the strongest system of the 1986 Atlantic hurricane season, peaking as a 105 mph Category 2 hurricane and 979 mbars in lowest pressure. No tropical cyclones formed during the months of October and the first half of November. That is, until Hurricane Frances became the latest sixth named storm on record since tropical cyclones were first named in 1950. The season came to a close on November 21, which was when Frances dissipated.

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Seasonal forecasts +Predictions of tropical activity in the 1986 seasonSourceDateNamedstormsHurricanesMajorhurricanesRefAverage (1981–2010) 12.1 6.4 2.7 Record high activity30157†Record low activity10†0†WRC Early 1986 11 5 N/A CSU May 29, 1986 8 4 N/A CSU July 28, 1986 7 4 N/A Actual activity 6 4 0

Forecasts of hurricane activity are issued before each hurricane season by noted hurricane experts such as Dr. William M. Gray and his associates at Colorado State University (CSU). A normal season, as defined by the National Oceanic and Atmospheric Administration (NOAA) in the period from 1981 to 2010, has approximately twelve named storms, with six of those reaching hurricane status. About three hurricanes strengthen into major hurricanes, which are tropical cyclones that reach at least Category 3 intensity on the Saffir–Simpson scale. In early 1986, the Weather Research Center (WRC) predicted eleven tropical storms and five hurricanes.

CSU issued forecasts on May 29 and July 28 indicating within both forecasts the anticipation of a below normal hurricane season, the former citing the absence of an El Niño event and eastward winds associated with the quasi-biennial oscillation. In May, a total of 8 named storms were expected, with four hurricanes expected, 15 days with hurricanes, and a total of 35 days with a tropical storm active in the northern Atlantic Ocean. In July, the numbers were dropped to a total of 7 named storms, 4 hurricanes, 10 hurricane days, and 25 days with a named tropical storm, which almost perfectly verified. CSU lowered their numbers from the previous prediction after data indicated high sea-level pressure anomalies over the Caribbean Sea and Gulf of Mexico and westward-oriented zonal wind anomalies, both of which favored less tropical cyclone activity.

Season summary

June 1 0000 UTC (8:00 p.m. EDT May 31) – The 1986 Atlantic hurricane season officially begins. June 5 0000 UTC (8:00 p.m. EDT June 4) – Subtropical Depression One formed near the Bahamas. June 6 0000 UTC (8:00 p.m. EDT June 5) – Subtropical Depression One acquired tropical characteristics and strengthened into Tropical Storm Andrew. June 7 1200 UTC (8:00 a.m. EDT June 6) – Tropical Storm Andrew attained its peak intensity with maximum sustained winds of and a minimum barometric pressure of . June 9 0000 UTC (8:00 p.m. EDT June 8) – Tropical Storm Andrew was absorbed by a low pressure system. June 23 1800 UTC (1:00 p.m. CDT) – Tropical Depression Two formed in the eastern Gulf of Mexico. June 24 1800 UTC (1:00 p.m. CDT) – Tropical Depression Two strengthened into Tropical Storm Bonnie. June 25 1800 UTC (1:00 p.m. CDT) – Tropical Storm Bonnie strengthened into Category 1 hurricane. June 26 0900 UTC (4:00 a.m. CDT) – Hurricane Bonnie attained its peak intensity with winds of and a minimum pressure of 990 mbar (hPa; 29.23 inHg). 1000 UTC (5:00 a.m. CDT) – Hurricane Bonnie made landfall near High Island, Texas with winds of . 1800 UTC (1:00 p.m. CDT) – Hurricane Bonnie weakened back to a tropical storm. June 27 0000 UTC (7:00 p.m. CDT June 26) – Tropical Storm Bonnie weakened back to a tropical depression. June 28 1200 UTC (7:00 a.m. CDT) - Tropical Depression Bonnie dissipated in Missouri.

July 23 1200 UTC (8:00 a.m. EDT) – Tropical Depression Three formed north of Bermuda. July 28 1200 UTC (8:00 a.m. EDT) – Tropical Depression Three dissipated.

August 4 0600 UTC (1 a.m. CST) – A tropical depression developed in the western Gulf of Mexico. August 5 1200–1800 UTC (7:00 a.m.–1:00 p.m. CST) – The tropical depression made landfall in North Padre Island, Texas. 1800 UTC (1:00 p.m. CST) – The tropical depression dissipated over southern Texas. August 13 1200 UTC (8:00 a.m. EDT) – A subtropical depression formed over the Florida Panhandle. August 15 1200 UTC (8:00 a.m. EDT) – The subtropical depression transitioned into a tropical depression southeast of Charleston, South Carolina. 1200 UTC (2:00 p.m. EDT) – The tropical depression strengthened into Tropical Storm Charley. August 17 1200 UTC (8:00 a.m. EDT) – Tropical Storm Charley strengthened into Category 1 hurricane. 1400 UTC (10:00 a.m. EDT) – Hurricane Charley made landfall near Cape Fear, North Carolina with winds of . 2200 UTC (6:00 p.m. EDT) – Hurricane Charley attained its peak intensity with maximum sustained winds of and a minimum barometric pressure of . August 18 1200 UTC (8:00 a.m. EDT) – Hurricane Charley weakened back to a tropical storm. August 21 0000 UTC (8:00 p.m. EDT) – Tropical Storm Charley transitioned into an extratropical storm. August 30 1200 UTC (8:00 a.m. EDT) – Tropical Depression Five formed in the mid-Atlantic.

September 1 1200 UTC (8:00 a.m. EDT) – Tropical Depression Six formed in the Gulf of Mexico. September 4 Around 0600 UTC (1:00 a.m. CST) – Tropical Depression Six made landfall near Altamira, Tamaulipas, Mexico. 1200 UTC (8:00 a.m. EDT) – Tropical Depression Five dissipated east-southeast of Bermuda. 1200 UTC (7:00 a.m. EDT) – Tropical Depression Six dissipated over Mexico. September 7 2:00 a.m. EDT (0600 UTC) - Tropical Depression Seven formed several hundred miles east of the Windward Islands. 2:00 p.m. EDT (1800 UTC) - Tropical Depression Seven strengthened into Tropical Storm Danielle. September 8 0600 UTC (2:00 a.m. EDT) – Tropical Storm Danielle attained its peak intensity with maximum sustained winds of and a minimum barometric pressure of . September 9 1800 UTC (2:00 p.m. EDT) – Tropical Storm Danielle weakened back to a tropical depression. September 10 1200 UTC (8:00 a.m. EDT) – Tropical Depression Danielle dissipated in the western Caribbean. 1800 UTC (2:00 p.m. EDT) – Tropical Depression Eight developed east-northeast of Puerto Rico. September 11 0000 UTC (8:00 p.m. EDT September 10) – Tropical Depression Eight strengthened into Tropical Storm Earl. 1800 UTC (2:00 p.m. EDT) – Tropical Storm Earl strengthened into a Category 1 hurricane. September 12 1200 UTC (8:00 a.m. EDT) – Hurricane Earl strengthened into a Category 2 hurricane. September 14 1200 UTC (8:00 a.m. EDT) – Hurricane Earl attained its peak intensity with maximum sustained winds of and a minimum barometric pressure of . September 16 0000 UTC (8:00 p.m. EDT September 15) – Hurricane Earl weakened back to a Category 1 hurricane. September 19 0000 UTC (98:00 p.m. EDT September 18) – Hurricane Earl transitioned into an extratropical cyclone.

There was no tropical cyclone activity in the Atlantic basin during October 1986.

November 18 1800 UTC (2:00 p.m. EDT) – Tropical Depression Nine formed north of the Leeward Islands. November 19 0600 UTC (2:00 a.m. EDT) – Tropical Depression Nine strengthened into Tropical Storm Frances. November 20 0600 UTC (2:00 a.m. EDT) – Tropical Storm Frances strengthened into a Category 1 hurricane. 1200 UTC (8:00 a.m. EDT) – Hurricane Frances attained its peak intensity with maximum sustained winds of and a minimum pressure of . November 21 1200 UTC (8:00 a.m. EDT) – Hurricane Frances weakened back into a tropical storm. November 22 0000 UTC (8:00 p.m. EDT) – Tropical Storm Frances merged with an extratropical storm. November 30 2359 UTC (7:59 p.m. EDT) – The 1986 Atlantic hurricane season officially ended.

The season's activity was reflected with a cumulative accumulated cyclone energy (ACE) rating of 36, which is classified as "below normal". ACE is, broadly speaking, a measure of the power of the hurricane multiplied by the length of time it existed, so storms that last a long time, as well as particularly strong hurricanes, have high ACEs. ACE is only calculated for full advisories on tropical systems at or exceeding or tropical storm strength. Subtropical cyclones are excluded from the total.

Systems

Tropical Storm Andrew

In early June, a large area of disturbed weather persisted over the Greater Antilles, bringing heavy rains to the islands. The area moved northward, developing a circulation over the Bahamas. Strong upper-level winds caused the structure to resemble a subtropical cyclone, and as a result, the system was classified as a subtropical depression on June 5. The depression moved to the northwest and transitioned into a tropical storm on June 6; it was named Andrew about southeast of Charleston, South Carolina. The storm approached the South Carolina coast within before recurving to the northeast on June 7. The storm passed within of Cape Hatteras while near its peak intensity with winds of 50 mph (85 km/h) and a minimum pressure of . Andrew accelerated northeastward and briefly crossed into the forecasting territory of Environment Canada. before being absorbed by a low pressure system over Canada on June 8.

While active, Andrew posed a threat to the Carolinas. Gale warnings were posted from Cape Lookout, North Carolina, to south of Virginia Beach, Virginia, on June 7. Waves reached heights of off the coast of the Carolinas, which killed a person on Ocracoke Island. Three companions were also swept out, all of whom made it back to shore. At Wrightsville Beach and Carolina Beach, at least 40 swimmers were caught in the currents, four of whom were hospitalized. The precursor to the storm produced heavy rainfall across Jamaica that caused a deadly flood event.

Hurricane Bonnie