Dominican Republic, Haiti: Adverse weather forecast across both countries through at least April 27

Severe weather is forecast across much of Haiti and the Dominican Republic through at least April 27. A surface trough moving over the region is expected to bring heavy rainfall, thunderstorms, and strong winds April 25-26 before the system begins to weaken in intensity from April 27. The adverse weather could trigger flooding, landslides, and associated disruptions in areas of the affected countries.

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

The Hydro-Meteorological Unit of Haiti (UHM) has warned of thunderstorms accompanied by heavy rainfall over much of the country. Flash flooding is possible in parts of the Artibonite, Centre, Grand'Anse, Nippes, and Sud departments.

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.