1951 Hawaii cyclone

The 1951 Hawaii cyclone was an unusual system in the central Pacific Ocean. The system first formed from a warm-core kona storm. It acquired tropical characteristics, and the Joint Typhoon Warning Center (JTWC) began tracking the storm on March 21. It had winds of 30 mph, as it headed away from Hawaii. Then, on March 23, the storm turned south and began to head toward Hawaii. It later made its first landfall near Hauula. It crossed the island of Oahu southward, and later traveled back north to the island. The system made its second landfall near Mākaha, and scraped the northwestern coast of the island. The storm turned west and later made its last landfall near Kealia on the island of Kauai. The storm dissipated eighteen hours later, on March 30. In the Hawaiian Islands, tropical storm warnings were posted as the storm was expected to come nearby. Strong wind and heavy rain were reported in the island of Oahu, but there was no damage or fatalities reported.

The system had different classifications. JTWC and the American Meteorological Society (AMS) considered the storm tropical, while the National Hurricane Center (NHC) and Central Pacific Hurricane Center (CPHC) consider it neither tropical or subtropical.

Meteorological history
A warm-core kona storm transitioned into a tropical cyclone at 0000 UTC on March 21, west of the Necker Island, and JTWC began tracking it. It had winds of 30 mph, the strength of a tropical depression. The system began traveling eastward, and later sped up northeastward at 1800 UTC on March 22. Then, it turned sharply southward towards Hawaii twelve hours later of the same day, maintaining depression strength. The system kept traveling south, until it turned southwest toward the Hawaiian Islands at 0600 UTC of March 25. The system made its first landfall near Hauula on Oahu at 1200 UTC on March 26. The system lost intensity as it passed through the island of Oahu. By six hours later, the system left the island and continued southward. It slowed down and curved back north toward Oahu. The system made a second landfall on Oahu near Mākaha, just past 0000 UTC of March 28. Later, the system scrapped the northwestern coast of the island. It re-entered the ocean six hours later and turned west. The system then sped up and made its last landfall near Kealia just past 0000 UTC of March 29. It moved quickly across the island, and it left the island about six hours later. JTWC stopped tracking the system east of the island of Nihoa eighteen hours later, after it started to move across the Northwestern Hawaiian Islands.

The system has been considered a tropical or a extratropical cyclone. JTWC and the American Meteorological Society (AMS) consider the storm as a tropical cyclone. Although, the Regional Specialized Meteorological Center for the eastern north Pacific, the National Hurricane Center (NHC) and Central Pacific Hurricane Center (CPHC) do not include the system in their archives. Due to this, the system was not considered tropical or subtropical officially.

Preparations and impact
On March 25, tropical storm warnings were posted for the Hawaiian Islands as the storm was expected to pass over again. Winds of 60 mph were reported in Oahu as the storm came near the island. In Honolulu, 6 in of rain were reported.

The system contributed to the already above-average rainfall in the Hawaiian Islands. The rainfall amount for March 1951 was nearly 200 to 700 percent above normal. The rainfall set records for that month, but they were later broken in 2006.