Early 2000 Madagascar floods

Severe Tropical Storm Gloria

Severe tropical storm (SWIO scale)
Tropoical storm (SSHWS)
Satellite image of Gloria near landfall
Formed	February 27, 2000
Dissipated	March 10, 2000
Highest winds	10-minute sustained: 95 km/h (60 mph) 1-minute sustained: 95 km/h (60 mph)
Lowest pressure	985 hPa (mbar); 29.09 inHg
Fatalities	At least 66
Areas affected	Madagascar, Mozambique
Part of the 1999-00 South-West Indian Ocean cyclone season

Severe Tropical Storm Gloria was a deadly tropical cyclone that brought additional flooding to Madagascar just two weeks after Cyclone Leon-Eline moved across the country.

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

On February 27, the monsoon trough developed an area of convection, or thunderstorms, halfway between Diego Garcia and St. Brandon in the south-west Indian Ocean. A circulation was present within the system on the edge of the convection, displaced due to wind shear from the east-northeast. At 09:30 UTC on February 27, the Joint Typhoon Warning Center (JTWC) issued a tropical cyclone formation alert, noting the potential for rapid tropical cyclogenesis. A few hours later, the Météo-France (MFR) began tracking the system as Tropical Disturbance 8. The shear was gradually decreasing, allowing the thunderstorms to become more circular and for outflow to form. With a ridge to the south, the disturbance moved quickly to the west, bringing it 300 km (185 mi) north of St. Brandon early on February 28. Also on that day, the JTWC began issuing advisories on the system as Tropical Cyclone 15S. The thunderstorms waxed and waned at first, but sufficiently organized for the MFR to upgrade the disturbance to tropical depression status on February 29.

With the ridge to the south strengthening, the depression turned more to the west-northwest, causing it to pass 350 km (215 mi) north of Tromelin Island on February 29. However, a motion to the west and southwest occurred as the system reached the periphery of the ridge. Continued, albeit lessening wind shear displaced the thunderstorms mostly to the west of the circulation at first, although the thunderstorms were able to organize more into a central dense overcast on March 1. Early that day, the depression intensified into Moderate Tropical Storm Gloria, named by the Meteorological Service of Madagascar. At that time, the storm was only 150 km (95 mi) from the northeast coast of Madagascar. Gloria continued quickly to the southwest, gradually intensifying and developing an eye on Special sensor microwave/imager. Based on the appearance, the MFR estimated that the storm attained 10 minute winds of 95 km/h (60 mph), making it a severe tropical storm, by the time it made landfall 10 km (6 mi) north of Sambava. The landfall pressure was estimated at 985 mbar (29.1 inHg), based partially on a pressure reading of 990 mbar (29 inHg) at Sambava. Operationally, the JTWC upgraded Gloria to the equivalent of a minimal hurricane, with 1 minute winds of 120 km/h (75 mph), although the agency downgraded the storm to the same peak as the MFR.

After moving ashore, Gloria initially maintained a well-defined cloud pattern. By March 3, the convection had largely diminished over the center, although thunderstorms were still active to the south. By that time, the circulation was becoming difficult to locate on satellite imagery. The JTWC continued to track Gloria, anticipating restrengthening in the Mozambique Channel. On March 4, the system exited Madagascar into the Mozambique Channel with scattered thunderstorms slowly reforming. On the next day, the JTWC discontinued advisories, although the MFR continued monitoring the system. A weak circulation tracked southwestward away from Madagascar, developing a small area of convection that warranted it being reclassified as a tropical disturbance on March 8. Later that day, Gloria made landfall near Inhambane in southeastern Mozambique before turning to a southward drift, dissipating on March 10.

Impact

As a developing disturbance, Gloria produced winds approaching gale-force on St. Brandon. Similar conditions were reported on Tromelin.

When Gloria struck Madagascar, it was producing strong winds near the center, although there were no such observations near landfall. Antalaha, about 70 km (45 mi) south of Sambava, recorded 10 minute winds of 72 km/h (45 mph). The storm brought heavy rainfall, totaling over 150 mm (6 in) over 24 hours in some locations. Nosy Be along the northwest coast recorded a 24 hour rainfall total of 165 mm (6.5 in), which is over half the average monthly precipitation. Mananjary reported a two day total of 427 millimetres (16.8 in). Later, Gloria produced sporadic rainfall in southern Madagascar, in part due to increased humidity.

The rains from Gloria occurred less than two weeks after Cyclone Leon–Eline struck the country, bringing additional flooding, landslides, and damage. In the area where the storm moved ashore, communities were temporarily isolated due to the flooding. Thousands were left homeless across the country. In Sambava, near where Gloria moved ashore, the storm killed 18 people, destroyed hundreds of homes, and damaged a road connecting the area to the capital of Madagascar, Antananarivo. Farther inland, the cyclone killed 40 people at Andapa. Floods from the two storm inundated 70% of homes and wrecked 70% of the crops in the districts of Andapa, Sambava, Antalaha, and Vohemar. Collectively, 12,230 people were left without access to clean water.

Before Gloria emerged into the Mozambique Channel, various news outlets noted the potential for the storm to affect storm-ravaged Mozambique. However, the anticipated effects much worse than the minimal rainfall that accompanied Gloria's final landfall.

Aftermath

The additional damage from Gloria caused outbreaks of malaria and cholera while also decreasing food supplies. Due to the combined impacts of Eline and Gloria, the government of Madagascar requested for international assistance on March 7, which was coordinated through the United Nations Office for the Coordination of Humanitarian Affairs. In response, the government of the United Kingdom donated £1.3 million to Madagascar. The World Food Programme flew about 400 tons of food to affected residents across the country, and Médecins Sans Frontières sent about 35 tons of supplies, such as medicine, water purifying devices, and food.

See also

• Tropical Cyclone Josie - weak tropical storm that struck northern Madagascar about two weeks after another powerful cyclone – Gretelle – struck the nation