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Hurricane John (1994)

2007 Schools Wikipedia Selection. Related subjects: Natural Disasters

   CAPTION: Hurricane John

   Category 5 hurricane ( SSHS)
   Hurricane John at peak intensity.
   Hurricane John at peak intensity.
     __________________________________________________________________

   Formed August 11, 1994
   Dissipated September 10, 1994
   Highest
   winds
   175 mph (280 km/h) sustained (1-minute sustained)
   Lowest pressure ≤929 mbar ( hPa)
   Damage $15 million (1994 USD)
   $19 million (2005 USD)
   Fatalities 0
   Areas
   affected Hawaii, Johnston Atoll
   Part of the
   1994 Pacific hurricane season
   1994 Pacific typhoon season

   Hurricane John (also Typhoon John) formed during the 1994 Pacific
   hurricane season and became both the longest-lasting and
   second-farthest-traveling tropical cyclone ever observed. John formed
   during the strong El Niño of 1991 to 1994 and peaked as a Category 5
   hurricane on the Saffir-Simpson Hurricane Scale, the highest
   categorization for hurricanes.

   Over the course of its existence, it followed an 8,000  mile (13,000
   km) path from the eastern Pacific to the western Pacific and back to
   the central Pacific, lasting 31 days in total. Because it existed in
   both the eastern and western Pacific, John was one of a small number of
   tropical cyclones to be designated as both a hurricane and a typhoon.
   Despite lasting for a full month, John barely affected land at all,
   bringing only minimal effects to the Hawaiian islands and a United
   States military base on Johnston Atoll.

Storm history

   Storm path
   Enlarge
   Storm path

   The United States' National Hurricane Centre (NHC) later identified the
   precursor to Hurricane John as a tropical wave that moved off the coast
   of Africa on July 25, 1994. The environment in the Atlantic Ocean was
   hostile to tropical development, so the wave continued without
   developing until reaching the Eastern Pacific on August 8. It slowly
   organized, and on August 11 was recognized as Tropical Depression Ten-E
   300 nautical miles south-southeast of Acapulco, Mexico. Conditions were
   not ideal for development, but it quickly developed banding features
   and well-defined outflow, and was upgraded to a tropical storm and
   named Tropical Storm John later that day.

   A strong ridge of high pressure over the Northeastern Pacific Ocean
   forced John westward, where upper level wind shear kept John a tropical
   storm. Intensity fluctuated considerably, however, as shear levels
   varied. More than once, shear cleared away most of the clouds above
   John and nearly caused it to weaken to a tropical depression. However,
   after eight days of slow westward movement across the Pacific Ocean,
   shear lessened greatly on August 19, and John intensified significantly
   and was designated as a hurricane at 1700 PDT. During an eighteen-hour
   period between August 19 and August 20, John further strengthened from
   a weak Category 1 hurricane to a major Category 3 hurricane. Around
   1100 PDT on August 20, it crossed into the central Pacific, the first
   of three basin crosses John would make.
   Category 5 Pacific hurricanes
   Name     Season Name      Season
   Patsy    1959   Guillermo 1997
   "Mexico" 1959   Linda     1997
   Ava      1973   Elida     2002
   Emilia   1994   Hernan    2002
   Gilma    1994   Kenna     2002
   John     1994   Ioke      2006
   Main article: List of Category 5 Pacific hurricanes

   After entering the central Pacific, John left the area monitored by the
   NHC and was instead monitored by the Central Pacific Hurricane Centre
   (CPHC). As it moved slowly westward, Hurricane John continued to
   strengthen considerably in an increasingly favorable environment well
   south of the Hawaiian Islands; on 22 August John was designated a
   Category 5 hurricane on the Saffir-Simpson Hurricane Scale (the highest
   classification for hurricanes) and later that day (by Hawaii Standard
   Time) reached its peak winds of 175  miles per hour (280 km/h). Also on
   August 22 (by Hawaii Standard Time), John made its closest approach to
   the Hawaiian Islands, 345 miles (500 km) to the south. John had
   threatened to turn north and affect the islands days before, but the
   ridge of high pressure that typically shields the islands from
   hurricanes kept John on its southerly path. Nonetheless, heavy rains
   and wind from the outer bands of John impacted the islands.

   With the Hawaiian islands behind it, John began a slow turn to the
   north, taking near-direct aim at Johnston Atoll, a small group of
   islands populated only by a United States military base. The storm
   slowly weakened from its peak as a Category 5 hurricane in the face of
   increasing shear, dropping down to a Category 1 hurricane with 90 miles
   per hour (145 km/h) maximum winds. On August 25 local time, John made
   its closest approach to the Johnston Atoll only 15 miles (24 km) to the
   north. On Johnston Atoll, sustained winds were reported up to 60 miles
   per hour (95 km/h), the equivalent of a strong tropical storm, and
   gusts up to 75 miles per hour (120 km/h) were recorded.
   Hurricane John at its tertiary peak strength in the far north-central
   Pacific Ocean
   Enlarge
   Hurricane John at its tertiary peak strength in the far north-central
   Pacific Ocean

   Clearing Johnston Atoll, John turned to the northwest and began
   strengthening again as shear decreased. On August 27 local time, John
   reached a secondary peak strength of 135 miles per hour (210 km/h), and
   shortly thereafter it crossed the International Date Line at
   approximately 22° N and came under the surveillance of the Guam branch
   of the Joint Typhoon Warning Centre (JTWC). By crossing into the
   western Pacific, John also became a typhoon and was referred to as
   Typhoon John during its time in the western Pacific. Immediately after
   crossing the Date Line, John again weakened and its forward motion
   stalled. By September 1, John had weakened to a tropical storm and was
   nearly motionless just west of the Date Line. There, John lingered for
   six days while performing a multi-day counterclockwise loop. On
   September 7, a trough moved into the area and quickly moved John to the
   northeast. John crossed the Date Line again on September 8 and
   reentered the central Pacific.

   After reentering the central Pacific, John briefly reached a tertiary
   peak strength of 90 miles per hour (145 km/h), a strong Category 1
   hurricane, well to the north of Midway Island. However, the trough was
   rapidly pulling apart John's structure, and the cold waters of the
   northern central Pacific were not conducive to a tropical cyclone. On
   September 10, the 120th advisory was released on the system, finally
   declaring John to have become extratropical approximately 1000 miles
   (1600 km) south of Unalaska Island.

Records

   Its 31-day existence made John the longest-lasting tropical cyclone
   recorded in both the Pacific Ocean and worldwide, surpassing both
   Hurricane Tina's previous record in the Pacific of 24 days in the 1992
   season and Hurricane San Ciriaco's previous world record of 28 days in
   the 1899 Atlantic season. In addition, despite its slow movement
   throughout much of its path, John was the second-farthest-traveling
   tropical cyclone worldwide and the farthest-traveling in the eastern
   Pacific, out-distancing previous record holder Hurricane Fico. John's
   travel distance of 8,000 miles (13,000 km) was farther than that of any
   tropical cyclone save Super Typhoon Ophelia of the 1960 Pacific typhoon
   season.

   Pressure readings from John's peak are not consistently available as
   the CPHC did not monitor pressures at the time, but Air Force Reserve
   aircraft did measure a surface pressure of 929 mbar ( hPa), making John
   one of the most intense hurricanes recorded in the central Pacific;
   Hurricane Gilma recorded a lower pressure in the central Pacific
   earlier in the 1994 season, but with lower wind speeds. (Intensity is
   measured by minimum central pressure, which correlates with but is not
   directly linked to wind speeds.) John was also only the third Category
   5 hurricane recorded in the central Pacific (the first was Hurricane
   Patsy in 1959 and the second, Hurricane Gilma earlier in 1994), and
   possessed the highest recorded wind speed in a central Pacific
   hurricane, 175 miles per hour (280 km/h). Since 1994, only one Category
   5 hurricane, Hurricane Ioke, has formed in or entered into the Central
   Pacific; Ioke, like Gilma, had a lower central pressure but lower wind
   speeds than John.

   Additionally, John was only the third tropical cyclone to enter the
   central Pacific from the western Pacific. Tropical Storms Carmen and
   Skip in 1980 and 1985, respectively, had done so previously.

Impact

   John impacted both the Hawaiian Islands and Johnston Atoll, but only
   lightly. While John passed over 345 miles (550 km) to the south of
   Hawaii, the islands did experience strengthened trade winds and rough
   surf along the southeast- and south-facing shores, and, as John moved
   westward, on west-facing shores as well. The waves, ranging from 6 to
   10 feet in height, flooded beach parks in Kailua-Kona. Additionally,
   heavy rains on the Big Island of Hawaii caused minor, localized
   flooding and some short-term road closings. No deaths, injuries or
   significant damages were reported in Hawaii.

   Although John passed within 15 miles (25 km) of Johnston Atoll, it had
   weakened greatly to a Category 1 system by closest approach.
   Additionally, in the Northern Hemisphere, the strongest winds and
   heaviest rain lie to the north of a tropical cyclone, so the atoll,
   which lay to the south of the storm's path, was spared the brunt of the
   storm. Nonetheless, the 1,100-man personnel for the United States
   military base on Johnston Island had been evacuated to Honolulu as a
   precaution while John approached. Damages to structures were
   considerable, but the size of the island and relative functionality of
   the base led to low damages; damages were estimated at close to $15
   million (1994 USD).

   Despite John's record-setting endurance, the name John was not retired
   following the storm due to low damages.

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