# Hurricane Debby (1982)

Hurricane Debby was the strongest tropical cyclone of the 1982 Atlantic hurricane season, with sustained winds reaching 130 mph (210 km/h). The fourth named storm, second hurricane, and the only major hurricane of the season, Debby developed near the north coast of Hispaniola from a westward moving tropical wave on September 13. Forming as a tropical depression, it headed northwestward and strengthened into Tropical Storm Debby the following day. Thereafter, Debby rapidly intensified into a hurricane early on September 15. The hurricane then curved northeastward and grazed Bermuda as a Category 2 hurricane on September 16. It continued to strengthen, and by September 18, Debby briefly peaked as a Category 4 hurricane on the Saffir–Simpson Hurricane Scale. After reaching peak intensity, Debby slowly weakened and passed south of Newfoundland early on September 19. Thereafter, the system accelerated, moving eastward as swiftly as 60 mph (97 km/h) as it weakened to a tropical storm the next day. Debby became extratropical cyclone well west of the British Isles later on September 20, while the remnants were quickly absorbed into a larger storm system.
Overall, impact was generally minor in the Lesser Antilles, with only light to moderate rainfall in the Dominican Republic and United States Virgin Islands. However, parts of Puerto Rico reported heavy rainfall, causing about 600 families to evacuate due to the threat of flooding. Water entered a number of homes in Guayanilla. One person drowned near Naguabo. Landslides also damaged many interior roads. Although expected to strike the island, Debby passed west of Bermuda. Although high winds caused some power outages and knocked over trees, damage overall was minor. In addition, Debby dropped rainfall and generated moderately strong winds on Newfoundland. The storm system that Debby was absorbed by reached northern Finland on September 22, where it produced intense winds and storm surge, causing two deaths.

## Meteorological history

A weather system moved off the coast of Africa on September 3. The disturbance was small and became unidentifiable within 24 hours of formation. Satellite imagery indicated that the disturbance may have acquired a circulation on September 7, but the circulation was gone by the next day. The remaining tropical wave moved into the Lesser Antilles on September 11 and a reconnaissance aircraft was deployed. The aircraft found circulation; however, by the next day, only a strong wave was detected. Atmospheric conditions became more favorable for development, yielding lower wind shear near Hispaniola for several days. The system moved into this area as the latest reconnaissance aircraft was deployed, declaring it a tropical depression on September 13 near the Dominican Republic.
The next reconnaissance aircraft that investigated the system discovered a minimal pressure of 1005 mbar (28.67 inHg) and winds of 45 mph (72 km/h) in the depression's center, prompting an upgrade to Tropical Storm Debby on the morning of September 14. Uncertainty arose as to whether Debby would interact with an approaching trough or enter the influence of a ridge over the southeastern United States. The storm was later picked up by the trough, moving generally northward and away from the United States. Debby strengthened further, becoming a minimal hurricane late on September 14. The hurricane deepened further, reaching maximum winds of 110 mph (180 km/h), a Category 2 storm. Debby approached Bermuda in this time, and on September 16, Debby passed 80 miles (130 km) west of the island and continued north.
Debby briefly decelerated to as slow as 5 mph (8.0 km/h) early on September 17 as another trough in the westerlies arrived and the system entered it. As the hurricane entered the trough, its forward speed picked up from 5 to 30 mph (8.0 to 48.3 km/h). During this time, Debby strengthened into a Category 4 hurricane, peaking with maximum sustained winds of 130 mph (210 km/h) and a minimal atmospheric pressure of 950 mbar (28 inHg) around 00:00 UTC on September 18. Consequently, the cyclone became the most intense of the 1982 season. Early on September 19, Debby passed roughly 30 to 40 mi (48 to 64 km) south of Cape Race, Newfoundland, before accelerating to the east as fast as about 60 mph (97 km/h) on the following day. Debby weakened to a tropical storm at 06:00 UTC September 20, but remained a tropical cyclone while crossing the North Atlantic Ocean for most of that day. However, about 12 hours later, as the system rapidly approached the British Isles, it transitioned into an extratropical cyclone approximately 580 mi (930 km) west of Ireland. Shortly thereafter, the extratropical system was absorbed into a major storm system situated over the British Isles. However, meteorologists noted that the major storm system, which included the remnants of Debby, re-intensified over Ireland and later crossed Scandinavia, reaching northern Finland on September 22.
Starting in the 1982 season (with Debby), the Hurricane Hunter Aircraft (also known as P-3s) began running a new mission for NOAA's Hurricane Research Division. The mission was to drop dropsondes that deployed very-low Omega frequency signals. These signals were to estimate the dropsonde's motion compared to the aircraft in certain areas in a storm. The National Oceanic and Atmospheric Administration noted in retrospect that "The P-3s were not optimal for this experiment; nevertheless, the flights added an extra dimension to the art and science of hurricane forecasting", improving the accuracy of tropical cyclone forecast tracks by about 15%.

## Preparations and impact

Rainfalls from Debby in Puerto Rico ranged between 3 in (76 mm) around the northern end of the island to 10 in (250 mm) in the southern ridge of the island. Rains on the island peaked at 12.86 in (327 mm) in Penuelas. Consequently, flooding occurred across the southern portion of the island, while landslides damaged many roads in the interior. The Guayanilla River overflowed, causing floodwaters to enter many businesses and homes in the town of Guayanilla. In turn, this led to about 600 families, mostly from Guayanilla or Humacao, to seek shelter. One person drowned near Naguabo after the car he was a passenger of drove into an overflowing stream. Additionally, winds downed a number of trees and inflicted minor losses to crops. The United States Virgin Islands reported rain of about 3 in (76 mm), while about 5 in (130 mm) of precipitation fell over far eastern Dominican Republic.
The United States Navy removed its 700 personnel on Bermuda's Air Force Base, placing them in a gymnasium nearby. Thousands of tourists took last-minute flights out of Bermuda on September 16 as Debby drew near. Some of the airlines had pulled back the number of flights going in and out of the island. Eastern Airlines dropped from five flights to two, with them going to only New York City, Newark, New Jersey, and Boston, Massachusetts. The storm had sustained winds of 110 mph (180 km/h) winds, and forecasters were predicting that the hurricane's eye would be Bermuda on September 16. Airlines canceled flights, buildings boarded up, and cruise liners were hurried out of their harbors in the time before Debby arrived. Rescue teams evacuated workers from Mobil oil rigs in Debby's path as it neared. Bermuda experienced heavy gusts of wind, which caused minor damage with no injuries or fatalities. Power outages were reported on the island, though electricity was quickly restored. Numerous trees were knocked down on the island due to high winds. As the storm was approaching Canada, some oil rigs offshore of Newfoundland were evacuated and a science expedition off Grand Banks was discontinued. Onshore, Debby produced light rainfall in the southeastern portions of Newfoundland, with precipitation peaking at approximately 3.5 inches (89 mm). In addition, a few areas experienced tropical storm forces winds, though damage was minimal.
The remains of Debby maintained plenty of intensity over northern Europe, and on September 21 it struck northern parts of Finland (where it was named Storm Mauri) as one of the most powerful windstorms in the country's recorded history. Winds over 100 mph (160 km/h) felled millions of cubic metres of forest, and a storm surge severely damaged the cities of Kemi and Tornio, claiming two lives.