Hurricane John (1994)
| Category 5 hurricane ( SSHWS ) | ||
|---|---|---|
 |
||
| Emergence | August 11th | |
| resolution | September 10 | |
|
Peak wind speed |
|
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| Lowest air pressure | ≤ 929 mbar ( hPa ; 27.4 inHg ) | |
| dead | 0 | |
| Property damage | $ 15 million (1994) | |
|
Affected areas |
Hawaii , Johnston Atoll | |
| Season overview: Pacific hurricane season 1994 Pacific typhoon season 1994 |
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Hurricane John or Typhoon John , JMA order designation 9420 , designation of JTWCs 10E , formed during the Pacific hurricane season 1994 in the eastern Pacific and became the longest lasting tropical cyclone and the cyclone with the second longest trajectory that has been recorded worldwide since the beginning of systematic weather observations has been. John formed during the strong El Niño from 1991 to 1994 and peaked as a Category 5 hurricane on the Saffir-Simpson hurricane wind scale .
During its existence, the storm center covered a distance of more than 13,000 km in 31 days, from the eastern Pacific to the western Pacific and back to the central Pacific. Due to his existence in two observation areas of tropical cyclones, John was one of the few cyclones in the Pacific that were classified as both a hurricane and a typhoon. Although John existed for a month, due to the size of the Pacific, he had almost no impact on land - the Hawai'i archipelago and Johnston Atoll were minimally affected.
Storm course
The National Hurricane Center (NHC) later identified a tropical wave that broke off the coast of West Africa on July 25 as the origin of what would later become Hurricane John. Conditions in the Atlantic were unfavorable for the development of a tropical system and so the wave continued its migration westward without development until it reached the Pacific Ocean on August 8th. Slow organization began there, and on August 11th the system was classified by the NHC as Tropical Depression Ten-E when it was located approximately 300 nautical miles south-southeast of Acapulco , Mexico. The prerequisites for a development were not ideal, nevertheless the system formed band structures and a well-defined outflow and during the day the low pressure area intensified to a tropical storm, which was named John .
A high pressure ridge over the northeastern Pacific Ocean forced John onto a westerly trajectory where high wind shear limited John's strength to that of a tropical storm. The strength of the storm fluctuated significantly as the wind shear was not even. More than once, the wind shear removed much of John's cloud system and almost caused it to weaken into a tropical depression. However, after eight days of migration across the Pacific, the wind shear subsided significantly on August 19, and by 5:00 p.m. PDT (12:00 a.m. UTC on August 20), John reached hurricane strength. During the following eighteen hours, John intensified into a severe Category 3 hurricane. On August 20, at 6:00 p.m. UTC, he entered the Central Pacific and the area of responsibility of the Central Pacific Hurricane Center when he exceeded the 140th degree west longitude .
The hurricane continued its slow westward migration, intensifying as conditions south of Hawaii were favorable; on August 22nd, John had reached the highest category on the Saffir-Simpson hurricane wind scale. A few hours later it reached its greatest intensity with continuous wind speeds of 280 km / h. On that day (in the time zone in which the Hawaiian Islands are located) the storm made its closest approach to the archipelago, which it passed about 500 km to the south. A few days earlier it looked like John would turn north and threaten the islands; however, the high pressure ridge that typically protects the islands from hurricanes kept John on his southerly path. Heavy rain and stormy winds from the outer rainbands, however, affected the islands.
After the hurricane Hawai'i had left behind, John began a gentle curve to the north and took an almost direct course to Johnston Atoll, only from a military base of the United States is busy. The wind shear increased again and as a result John slowly lost strength. John only reached wind speeds of 145 km / h, a category 1 hurricane. On August 25, local time, John reached the closest distance to the atoll , which he passed only 25 km north. Continuous wind speeds of 95 km / h were measured at the base, i.e. the strength of a tropical storm and gusts reached up to 120 km / h.
Leaving Johnston Atoll, John turned northwest and began to intensify again as the wind shear subsided. On August 27, local time, John reached a secondary climax with winds of 210 km / h. Shortly afterwards, John crossed the date line at about 22 ° north latitude and came into the observation area of the Joint Typhoon Warning Center (JTWC) on Guam . Hurricane John became Typhoon John through his stay in the western Pacific Ocean. Shortly after crossing the date line, John weakened again and the forward movement almost came to a standstill. On September 1, Typhoon John had weakened to a tropical storm and hardly changed its position just west of the date line. The storm stayed there for the next six days, during which John looped a number of days in a counterclockwise direction until a trough entered the area on September 7 and John quickly moved northeast. On September 8th, John crossed the date line again to the east and came back to the central Pacific.
Once there, John reached his tertiary climax with wind speeds of 145 km / h as a strong Category 1 hurricane, a good distance north of the Midway Islands . The trough dismantled John's structure and the cold waters of the north-central Pacific did the rest. On September 10, the 120th storm warning was issued to John declaring the system extra-tropical , some 1,600 miles south of Unalaska .
Prediction problems
During the time John spent in the western Pacific Ocean, the Joint Typhoon Warning Center (JTWC) had difficulty forecasting and even assessing the current intensity. John weakened after the transition to the western Pacific and before the later revision four successive storm analyzes were published, which declared John to be a tropical depression. Each of these announcements heralded the impending dissolution. When John continued to exist and did not resolve according to the JTWC's predictions, the system was upgraded to the minimal tropical storm. At this point in time, two ships reported sustained wind speeds of at least 55 knots (100 km / h), far stronger than the official wind speed of 35 knots (65 km / h). Believing all of the JTWC's predictions, John intensified into a Category 1 hurricane after re-entering the Central Pacific Basin. In its subsequent follow-up analysis, the JTWC increased the presumed wind speed for each of its storm warnings between September 1, 12:00 UTC and the last warning exactly one week later by 5–25 knots (10–45 km / h).
Weather records
| Surname | season |
|---|---|
| Patsy | 1959 |
| "Mexico" | 1959 |
| Ava | 1973 |
| Emilia | 1994 |
| Gilma | 1994 |
| John | 1994 |
| Guillermo | 1997 |
| Linda | 1997 |
| Elida | 2002 |
| Hernan | 2002 |
| Kenna | 2002 |
| Ioke | 2006 |
| Rick | 2009 |
| Celia | 2010 |
| Patricia | 2015 |
During its 31-day existence, John set a number of weather records. It is the longest lasting tropical cyclone not only in the Pacific Ocean, but worldwide, leaving the previous record holder in the Pacific Hurricane Tina of 1992 with 24 days and worldwide, the San Ciriaco Hurricane of 1899 with 28 days behind. In addition, despite his mostly low train speed, John covered the largest distance of a tropical cyclone in the eastern Pacific at 13,000 kilometers; in a global comparison, only super typhoon Ophelia covered a longer distance in 1960.
The barometric pressure observations from John's peak are incomplete because the CPHC did not monitor barometric pressure at the time, but an Air Force Reserve aircraft took a near-surface measurement that measured 929 mbar ( hPa ). This made John one of the most intense hurricanes ever recorded in the Central Pacific; Hurricane Gilma reached lower atmospheric pressure in 1994 but reached slower wind speeds. (The intensity is assessed on the basis of the air pressure, which is related to the wind speeds but has no direct influence.) John was only the third hurricane to reach category 5 on the Saffir-Simpson hurricane wind scale in the Central Pacific, after the Hurricanes Patsy 1959 and Gilma, earlier in the 1994 season. John achieved the highest wind speeds in the Central Pacific Basin at 280 km / h. Since 1994, there has only been one other Category 5 hurricane in the Central Pacific, Hurricane Ioke , which reached lower wind speeds with lower air pressure than John. Since John's air pressure records are incomplete, it is entirely plausible that John could have had a lower air pressure at the time of his greatest strength; At the time of the measurement of 929 mbar, the wind speed was 260 km / h.
In addition, John was one of only three known tropical cyclones that reached the central Pacific Ocean from the west. Previously, this only applied to Tropical Storm Carmen in 1980 and Tropical Storm Skip in 1985 .
Effects
John had an impact on the Hawai'i Islands and the Johnston Atoll, but these were rather minor.
As John passed about 550 km south of Hawaii, stronger winds and rough surf were noticeable on the southeast and southern coasts of the islands and later, as John moved westward, on the southwest and western shores as well. The waves reached heights of two to three meters, which submerged areas near the beach in Kailua-Kona . Heavy rain caused less damage on Hawai'i through local flooding and brief road closures. In Hawaii, John did not cause any personal injury.
By the time John passed Johnston Atoll within 15 miles, the hurricane had weakened into a Category 1 system. In addition, the strongest winds and heavy rains in the northern hemisphere occur on the right side of the path of a tropical cyclone, so that the atoll on the southern side of the hurricane was spared the greatest force of the hurricane. Nevertheless, as a precaution, the approximately 1,100 soldiers garrison on the Johnston Atoll had been evacuated when John approached the atoll. The damage to structures was clear, but the small size of the island and the functional construction on the base meant that the damage remained low overall. Nevertheless, the property damage totaled around 15 million US dollars.
Despite the record-breaking time of John, there was no reason to because of the low impact of the hurricane / typhoon World Meteorological Organization , John of the tropical cyclone list of names to be deleted. It was used again in 2000 and 2006 and is on the list for the 2012 season.
Web links
- National Hurricane Center Report on Hurricane John (English)
- Central Pacific Hurricane Center Report on Hurricane John (English)
- Joint Typhoon Warning Center Report on Typhoon John (10E) ( Memento of March 18, 2009 in the Internet Archive ) (English, PDF)
Individual evidence
- ↑ a b c d e f Lawrence, Miles: Hurricane John Preliminary Report (page 1) ( English , GIF) NOAA . 1995. Retrieved November 22, 2008.
- ^ A b c Lawrence, Miles: Hurricane John Preliminary Report (page 2) ( English , GIF) NOAA . 1995. Retrieved May 23, 2006.
- ↑ a b c d e f g h Central Pacific Hurricane Center: Hurricane John Preliminary Report ( English , GIF) NOAA . 2004. Retrieved May 24, 2006. (Note: The report does not include the changes made in follow-up analyzes.)
- ^ Joint Typhoon Warning Center : JTWC Report on Typhoon John (10E) ( English , PDF) JTWC. 1994. Archived from the original on March 18, 2009. Retrieved November 22, 2008.
- ^ Dorst, Neal: Which tropical cyclone lasted the longest? . In: NOAA Tropical cyclone FAQ . NOAA . 2004. Retrieved November 22, 2008.
- ^ Dorst, Neal: What is the farthest a tropical cyclone has traveled? . In: NOAA Tropical cyclone FAQ . NOAA . 2004. Retrieved November 22, 2008.
- ↑ National Climatic Data Center: Event Report for Hawaii ( English ) 1994. Archived from the original on January 12, 2012. Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. Retrieved November 23, 2008.
