Mexico: Disruptions due to flooding ongoing across parts of Sonora State as of early Aug. 9

Event

Heavy rainfall has caused flooding and associated disruptions across parts of Sonora State in recent days. As of early Aug. 9, authorities have reported two fatalities after a vehicle was swept away by an overflowing stream near Hermosillo. Flooding also inundated many streets in Hermosillo Aug. 6-7 and stranded several vehicles. Power outages have been reported in parts of the city. Flooding from the Cabullona River has stranded around 250 vehicles. Authorities in Nogales have reported multiple landslides across the municipality as of Aug. 7, and numerous roads across affected parts of the state are reportedly blocked by flooding and landslides.

The Mexican National Meteorological Service (SMN) has forecast further heavy rains over parts of Sonora in the coming days. Rainfall accumulations of 7.5-15 cm (3-6 inches) are forecast in Sonora Aug. 9 and Aug. 12, and 5-7.5 cm (2-3 inches) Aug. 10-11. Further heavy downpours could result in additional flooding and landslides, exacerbating the current situation and hampering ongoing recovery efforts.

Hazardous Conditions
Sustained heavy rainfall could trigger flooding in low-lying communities near rivers, streams, and creeks. Urban flooding is also possible in developed areas with easily overwhelmed stormwater drainage systems. Sites located downstream from large reservoirs or rivers may be subject to flash flooding after relatively short periods of intense rainfall. Landslides are possible in hilly or mountainous areas, especially where the soil has become saturated by heavy rainfall.

Authorities could issue mandatory evacuation orders for flood-prone communities over the coming days. Disruptions to electricity and telecommunications services are possible where significant flooding or landslides impact utility networks.

Transport
Floodwaters and debris flows may render some bridges, rail networks, or roadways impassable, impacting overland travel in and around affected areas. Ponding on road surfaces could cause hazardous driving conditions on regional highways. Authorities could temporarily close some low-lying routes that become inundated by floodwaters. Flooding could block regional rail lines; freight and passenger train delays and cancellations are likely in areas that see heavy rainfall and potential track inundation.

Localized business disruptions may occur in low-lying areas; some businesses might not operate at full capacity because of flood damage to facilities, possible evacuations, and some employees' inability to reach work sites.

Advice

Monitor local media for weather updates and related advisories. Confirm all transport reservations and business appointments before travel. Make allowances for localized travel delays and potential supply chain disruptions where flooding has been forecast. Do not drive on flooded roads. Charge battery-powered devices in the case of prolonged electricity outages.

Resources

Mexican National Meteorological Service (SMN)