Hurricane Debbie (1969)
| Category 3 hurricane ( SSHWS ) | ||
|---|---|---|
 |
||
| Emergence | August 14, 1969 | |
| resolution | August 25, 1969 | |
|
Peak wind speed |
|
|
| Lowest air pressure | 951 mbar ( hPa ; 28.1 inHg ) | |
| dead | ||
| Property damage | Unknown | |
|
Affected areas |
Newfoundland | |
| Season overview: 1969 Atlantic hurricane season |
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Hurricane Debbie was an intense and long-lived hurricane that formed during the second half of August 1969. The fifth tropical cyclone and second major hurricane of the 1969 Atlantic hurricane season formed in the central Atlantic on August 14 and followed a roughly northwest course before finally moving north. The storm was characterized by numerous fluctuations in its intensity, with continuous wind speeds corresponding to category 3 of the Saffir-Simpson hurricane wind scale , which was only introduced later, at four different times . The hurricane passed Bermuda southeast on August 22, before finally brushing Newfoundland with strong winds . It dissolved over the cold water east of Greenland . Although Debbie had little impact on land, the hurricane has been extensively studied and was the subject of a weather control project , Project Stormfury , which "inoculated" the clouds with silver iodide .
Storm course
A disturbance associated with a tropical wave intensified into a tropical depression on August 14th. The system was noticeably better organized by August 15 and reached the strength of a tropical storm at 12:00 UTC . After the system was named, Debbie moved west-northwest at a forward speed of around 15 km / h and the meteorologists assumed a steady increase in Debbie's strength. Debbie became a hurricane on August 16 and was turning in a more northwest direction. The hurricane continued to develop and around 12:00 UTC the next day it reached wind speeds corresponding to Category 2. On August 18, Debbie became a severe hurricane.
Then, however, the hurricane quickly lost its force and on August 19 reached only the strength of a minimal hurricane. At around this time, Debbie started a more westward movement, although the roughly northwest trajectory was retained. The abrupt weakening may be the result of the experiment carried out under the name Project Stormfury , which should lead to the resolution of the hurricane. In the course of the day, however, Debbie began to gain strength again and on August 20, despite a fluctuation in strength, reached Category 3 again. During this phase, the cyclone reached its lowest recorded air pressure of 951 millibars with sustained wind speeds of 195 km / h .
On August 21, Debbie turned north and finally turned northeast. Debbie weakened to a Category 2 hurricane, but was able to reach the strength of a major hurricane a fourth time. The hurricane then passed Bermuda well to the southeast, and it is believed that the presence of Hurricane Camille , which crossed the waters of the Atlantic Ocean from the mainland on August 20, prevented Debbie from further west closer to the Island passed. The hurricane maintained its intensity through August 22nd and assumed a northeast direction.
On August 23, the hurricane began to weaken and was moving north. The next day, the cyclone, which had meanwhile weakened to a Category 1 hurricane, grazed the southeastern tip of Newfoundland. Debbie began to lose tropical characteristics as the storm accelerated in a northeast direction and weakened to a tropical storm in the early part of August 25th. As the storm hit increasingly colder water, it broke up east of Greenland.
Impact and Project Stormfury
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Debbie was the subject of a weather manipulation experiment called Project Stormfury to see if tropical cyclones could be mitigated by "inoculating" them with silver iodide . The storm was an excellent opportunity to test the effects of the measures envisaged in the experiment. It was ideal for the "vaccination" in several respects: the storm did not endanger any country, it was within range of the aircraft used for the "vaccination", it was sufficiently intense and had one eye. On August 18th and again on August 20th, a total of thirteen planes flew out to observe the storm and to scatter the silver iodide. The wind speeds fell by 31 percent on the first day and by 18 percent on the second day. Both changes were consistent with the hypotheses put forward for Project Stormfury. As a result, it was stated that “a generously expanded research program was planned” for this reason. Among other results, it was concluded that “vaccination” would be necessary at regular intervals of about an hour.
Debbie stayed mostly at sea on the 4800 km long railway and therefore caused little damage. When the storm hit Bermuda, there was little or no damage to the island. Wind speeds of 80 to 85 km / h were measured over eastern Newfoundland when the storm passed.
The name Debbie was not removed from the list of tropical cyclone names after it was used in 1969 , but it was no longer used due to a change in the way the names were given in the Atlantic Basin. Previously, the name Debbie was given in the Atlantic hurricane seasons of 1957 , 1961 and 1965 . Under the different spelling Debby, five hurricanes in the Atlantic have been given a similar name since 1982.
Individual evidence
- ↑ a b c d e f g h i j Atlantic hurricane research division: Atlantic hurricane database (HURDAT) “best track” (1851–2008) ( English ) National Oceanic and Atmospheric Administrations. 2009. Archived from the original on March 9, 2010. Retrieved on May 1, 2010.
- ^ Forecaster Simpson: National Hurricane Center Bulletin 10 AM EDT Friday August 15 1969 ( English , JPG) National Hurricane Center. August 15, 1969. Retrieved May 1, 2010.
- ^ Forecaster Hope: Tropical Storm Debbie Public Advisory Number 1 ( English , JPG) National Hurricane Center. August 15, 1969. Retrieved May 1, 2010.
- ^ Forecaster Herbert: Hurricane Debbie Public Advisory Number 18 ( English , JPG) National Hurricane Center. August 19, 1969. Retrieved May 1, 2010.
- ↑ a b c d e f R.H. Simpson et al .: The Atlantic Hurricane Season of 1969 ( English , PDF; 17.8 MB) Weather Bureau. April 1970. Retrieved May 1, 2010.
- ^ Forecaster Kraft: Hurricane Debbie Public Advisory Number 24 ( English , JPG) National Hurricane Center. August 21, 1969. Retrieved May 1, 2010.
- ^ Forecaster Pelissier: Hurricane Debbie Public Advisory Number 37 ( English , JPG) National Hurricane Center. August 24, 1969. Retrieved May 1, 2010.
- ↑ a b Forecaster Herbert: Hurricane Debbie Public Discussion Number 38 ( English , JPG) National Hurricane Center. August 24, 1969. Retrieved January 27, 2010.
- ^ ABC Whipple: Storm . Time-Life Books, Alexandria, Va 1982, ISBN 0-8094-4312-0 .
- ↑ HE Willoughby, DP Jorgensen; RA Black; & SL Rosenthal: Project STORMFURY: A Scientific Chronicle 1962-1983 . In: Bulletin of the American Meteorological Society . Vol. 66, No. 5, May 1985. Retrieved September 14, 2012.
- ↑ Pete Davies: Inside the Hurricane: Face to Face with Nature's Deadliest Storms . Henry Holt and Company, New York 2000, ISBN 0-8050-6574-1 .
- ^ RH Simpson and Paul Herbert: The Atlantic Hurricane Season of 1972 ( English , PDF; 20.3 MB) Weather Bureau. April 1970. Retrieved May 1, 2010.
- ^ Forecaster Sugg: Hurricane Debbie Bulletin ( English , JPG) National Hurricane Center. August 21, 1969. Retrieved May 1, 2010.
- ^ Gary Padgett: Monthly Global Tropical Cyclone summary: August 2007 ( English ) Australian Severe Weather. January 1st, 2008. Archived from the original on October 7th, 2010. Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. Retrieved May 1, 2010.
- ↑ Worldwide Tropical Cyclone Names ( English ) National Hurricane Center. 2010. Retrieved May 1, 2010.
