MARCH 2024

SOUTH AMERICA

Bolivia, Brazil and Peru have been badly affected by severe floods that have displaced citizens, destroyed buildings and isolated entire cities.  Drone video shows water swamping the ground floor of city buildings and submerging roads and railway tracks, with boats escorting people to safety.  The mayor of Machu Picchu said this kind of disaster had not been seen before, and Brasília's mayor said it was the second-worst flood the city had ever seen.

Brazil was hit by devastating floods over the weekend that have so far claimed 20 lives in the resultant landslides and mudslides. There was heavy rainfall in parts of the south-east, including Rio de Janeiro, Petrópolis and the larger Espírito Santo region, with hourly rainfall totals of about 20mm recorded in places. Cumulative totals from Friday through Sunday were close to 250mm, particularly along the coast: this is far higher than the monthly average.  Landslides and mudslides occurred across the region, and a number of houses collapsed. Rescue operations are under way to look for people who may have been stranded by the floods. Although there may still be a few showers over the following days, the worst of the rain has now passed. 

EUROPE

Extreme weather has brought avalanches, storms, strong winds and landslides to Italy and France.  A 16-year-old boy died after being hit by an avalanche while skiing off-piste in Plan in Val Passiria in Italy’s South Tyrol region, near the Austrian border. The avalanche risk in the area stands at level three, or “considerable”, on the European avalanche danger scale. The boy is the second person to be killed by an avalanche in the region in recent days.  More than 6,000 people living in three villages in the Gressoney area of the Aosta valley, the Alpine region near the French border, have been isolated since Sunday as a result of avalanches, which also blocked a tunnel.

The Iberian peninsula experienced some high temperatures over the last week, with daytime highs locally reaching in excess of 30C (86F) in southern Spain, which is about 10C greater than the seasonal average here. Night-time temperatures have also been much higher than average, particularly in the south, where these remained in the mid to high teens on Thursday and Friday night. Then on Saturday in eastern parts of Andalucía the minimum overnight temperature was 24C (75.2F), which is particularly warm for March.  However, heading into the new week, temperatures could plummet well below the seasonal norm. This is linked to a large area of low pressure developing in the north-east Atlantic, which will introduce cooler maritime air to the peninsula. The daytime temperature will widely be in the high single figures or low double digits across both Spain and Portugal, a good 15-20C lower than last week. This cooler air mass will also bring some wetter conditions, allowing for some snowfall to develop over higher parts of central Spain, as well as over th  Pyrenees, where up to a metre of snow could fall by Friday.

UNITED STATES

A dangerous winter storm has arrived in California, battering the Sierra Nevada with snowfall, gale-force winds and blizzard conditions as authorities urge residents to shelter in place and prepare for power outages. Perilous conditions in the mountain region are expected to get significantly worse on Friday evening and over the weekend, with a high risk of whiteout conditions, near-zero visibility and avalanches across the mountain range, making travel impossible, according to the National Weather Service (NWS). The severe weather, which forecasters described as life-threatening, could break snowfall records.

Last week (Mar. 22), central parts of the U.S. experienced a severe outbreak of tornadoes with more than two dozen forming across the states of Ohio and Indiana, resulting in at least three deaths and multiple injuries.  A number of intense supercell thunderstorms travelled eastwards across central Indiana late in the afternoon and evening of 14 March, from which tornadoes formed. Many of these were weak with estimated maximum wind speeds of 65-85mph – the requirement to be categorised as an EF-0 tornado. A few were stronger, however. One initially damaged nearly half of the buildings in the small town of Selma, Indiana, before strengthening into an EF-3 tornado in Winchester. At the tornado’s peak, wind speeds of 155-165mph were estimated, with homes severely damaged and trees uprooted. The intensity then gradually decreased before it crossed into Ohio, although not without some further damage.

AFRICA

South Sudan is closing all schools from Monday in preparation for an extreme heatwave expected to last two weeks. The health and education ministries have advised parents to keep all children indoors as temperatures are expected to soar to 45C (113F).  They warned that any school found open during the warning period would have its registration withdrawn, but the statement issued late on Saturday did not specify how long schools would remain closed.  The ministries said they “will continue to monitor the situation and inform the public accordingly”.

SOUTH PACIFIC

Semarang, the provincial capital of Central Java in Indonesia, experienced severe flooding overnight on Wednesday. This rainfall was linked to a low-pressure system to the south of Java, which brought close to 200mm of rainfall to the area by Thursday daytime. Further rainfall is forecast over the coming week.  Flood depths of up to 80cm have been reported in the old town, with many roads and one railway station closed. There have been 10 reported landslides, and the authorities have advised people who live under clifftops and close to riverbanks to evacuate the area. The mayor of the city issued a statement saying the rainfall, and consequent flooding, was not expected. Similar flooding has been reported in the past, with flood depths of up to 70cm recorded in November 2023, and again earlier that year. It has been suggested that poor drainage in the city is responsible for such severe flooding, with past cases having been linked to rubbish blocking waterways as well as damaged or breached embankments.

TROPICAL

Top End communities are braced for Monday’s arrival of severe Tropical Cyclone Megan, with destructive wind gusts of up to 200km/h expected to bring widespread damage, heavy rainfall and potential flooding to coastal communities into next week.  The weather system intensified to category three on Sunday and Miriam Bradbury from the Bureau of Meteorology said it was expected to remain a category three as it crossed the coast on Monday.  “There is a fractional chance we could see further intensification,” she told ABC News Breakfast. “But at this stage the official forecast is that it will remain at category three and cross the coast at category three strength as well.”

Madagascar was unexpectedly hit by Cyclone Gamane as it veered into the island country’s northern district of Vohemar during the early hours of Wednesday, resulting in at least 11 deaths. The storm was expected to skim the coast, but it changed course and went into the island causing disruption to 7,000 people with hundreds of homes destroyed. The slow-moving nature of the storm exacerbated its impact, with persistent rainfall and prolonged strong winds causing devastation to infrastructure and significant flooding. The cyclone moved across the island with an average wind speed of 93mph (150km/h) while gusts of up to 130mph were recorded, making it a category 1 storm on the Saffir-Simpson scale. Cyclone Gamane has since weakened to a tropical storm and is expected to clear the island on Friday.