User:Hurricanefan25/Cyclone Giovanna

Intense Tropical Cyclone Giovanna
Intense tropical cyclone (SWIO scale)
Category 4 tropical cyclone (SSHWS)
	Intense Tropical Cyclone Giovanna near peak intensity on February 13, 2012
Formed	February 9, 2012
Dissipated	Currently active
Highest winds	10-minute sustained: 185 km/h (115 mph) ; 1-minute sustained: 230 km/h (145 mph) ;
Lowest pressure	932 hPa (mbar); 27.52 inHg
Fatalities	At least 2
	Part of the 2011–12 South-West Indian Ocean cyclone season

Intense Tropical Cyclone Giovanna

Meteorological history

Map plotting the storm's track and intensity, according to the Saffir–Simpson scale

Map key

Saffir–Simpson scale

Tropical depression (≤38 mph, ≤62 km/h)
Tropical storm (39–73 mph, 63–118 km/h)
Category 1 (74–95 mph, 119–153 km/h)
Category 2 (96–110 mph, 154–177 km/h)
Category 3 (111–129 mph, 178–208 km/h)
Category 4 (130–156 mph, 209–251 km/h)
Category 5 (≥157 mph, ≥252 km/h)
Unknown

Storm type

Tropical cyclone

Subtropical cyclone

Extratropical cyclone, remnant low, tropical disturbance, or monsoon depression

Cyclone Giovanna's origins were from the interaction of a monsoon trough and tropical wave associated with irregular convection with a clockwise circulation oriented east-west in the Mozambique Channel on 8 February. The system was forecasted to progress along the northwestern fringe of a subtropical ridge, and low-level inflow and sea-surface temperatures were conducive for development.^[1] Influenced by weak vertical wind shear, a low-level circulation center formed soon thereafter, but convection remained disorganized and wavering,^[2] though the circulation center swiftly coalesced. Near 2300 UTC, banding convection started to become established around the circulation center, and upper-level outflow was favorable for the formation of a tropical cyclone; the Joint Typhoon Warning Center (JTWC) subsequently issued a Tropical Cyclone Formation Alert, indicating a high chance of the system becoming a tropical cyclone.^[3]

The storm was designated as Tropical Depression Nine by RSMC La Réunion at 0600 UTC on 9 February, although its organization continued to waver. It sustained the path along the subtropical ridge, but was projected to slow down as a result of a fracture in an anticyclonic belt to the south.^[4] Six hours later, the JTWC also began releasing advisories on the storm, designating it 12S.^[5]

References

^ "Bulletin for cyclonic activity and significant tropical weather in the Southwest Indian Ocean". La Réunion: Météo-France. 2012-02-08. Retrieved 2012-02-15.
^ "Significant tropical weather advisory for the Indian Ocean". Pearl Harbor, Hawaii: Joint Typhoon Warning Center. 2012-02-08. Retrieved 2012-02-16.
^ "Significant tropical weather advisory for the Indian Ocean". Pearl Harbor, Hawaii: Joint Typhoon Warning Center. 2012-02-08. Retrieved 2012-02-16.
^ "Tropical Depression 8 (Giovanna) Warning Number 1". La Réunion: Météo-France. 2012-02-09. Retrieved 2012-02-16.
^ "Tropical Cyclone 12S (Twelve) Warning Number 1". Pearl Harbor, Hawaii: Joint Typhoon Warning Center. 2012-02-09. Retrieved 2012-02-16.

[MFR-1-1] "Bulletin for cyclonic activity and significant tropical weather in the Southwest Indian Ocean". La Réunion: Météo-France. 2012-02-08. Retrieved 2012-02-15.

[JTWC-1-2] "Significant tropical weather advisory for the Indian Ocean". Pearl Harbor, Hawaii: Joint Typhoon Warning Center. 2012-02-08. Retrieved 2012-02-16.

[JTWC-2-3] "Significant tropical weather advisory for the Indian Ocean". Pearl Harbor, Hawaii: Joint Typhoon Warning Center. 2012-02-08. Retrieved 2012-02-16.

[MFR-2-4] "Tropical Depression 8 (Giovanna) Warning Number 1". La Réunion: Météo-France. 2012-02-09. Retrieved 2012-02-16.

[JTWC-3-5] "Tropical Cyclone 12S (Twelve) Warning Number 1". Pearl Harbor, Hawaii: Joint Typhoon Warning Center. 2012-02-09. Retrieved 2012-02-16.

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