Dominican Republic, Haiti: Adverse weather forecast to continue across both countries through at least May 11

Severe weather is forecast to continue across much of Haiti and the Dominican Republic through at least May 11. A trough has brought heavy rainfall, thunderstorms, and strong winds across the region in recent days, causing flooding and associated disruptions in parts of the region. Although the trough is expected to begin to move away from May 9, further showers and storms are expected across the region over the coming days.

Authorities in Haiti have reported at least 17 fatalities associated with the heavy rainfall in recent days. More than 4,000 homes have been flooded, with northern parts of the country the worst affected. Flooding has also been reported in various parts of the Dominican Republic and water supply issues are ongoing in many areas due to damage to infrastructure.

As of early May 9. the Dominican Republic's National Office of Meteorology (ONAMET) has issued weather warnings (the highest level on a two-tier scale) for Duarte, El Seibo, Elias Pina, Espaillat, Hato Mayor, La Vega, Maria Sanchez Trinidad, Monsenor Nouel, Monte Plata, Puerto Plata, San Cristobal, Sanchez Ramirez, Santiago, Santiago Rodriguez, and Santo Domingo (including the Distrito Nacional) provinces due to the possibility of flooding and landslides. Weather alerts are in place for Dajabon, Hermanas Mirabal, La Altagracia, Samana, and San Pedro de Macoris provinces.

The Dominican Republic Emergency Operations Center (COE) has also issued alerts due to the persistent unstable weather conditions. Red alerts (the highest level on a three-tier scale) have been issued for Duarte, La Vega, Monte Cristi, Puerto Plata, and Santiago Rodriguez provinces. Yellow and green alerts are in place across much of the rest of the country.

The Hydro-Meteorological Unit of Haiti (UHM) has issued a flood warning due to the severe weather forecast to continue across the country over the coming days. Flooding is particularly likely in parts of Artibonite, Centre, Grand'Anse, Nippes, Sud-Est, and Sud departments; residents are advised to remain vigilant for possible flooding and landslides.

Authorities will likely issue new alerts or update/rescind existing advisories as weather conditions change over the coming days.

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 heavy rainfall has saturated the soil.

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.

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.

Severe weather could also trigger flight delays and cancellations at regional airports. If strong winds trigger hazardous sea conditions, authorities may temporarily suspend port operations or close beach fronts. 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.