Mexico, Central America, & the Caribbean: Water deficits forecast for southern Mexico, surpluses in Nicaragua

November 29, 2016

The Big Picture
The 12-month forecast for August 2016 through July 2017 (below) indicates an overall pattern much like that of the forecast released last month, but with a slight uptick in the intensity of water deficits in Baja California, Mexico – based on exceptional deficits observed in the region in October – and of water surpluses in parts of Central America and the Caribbean.

Primarily moderate (5 to 10 years) deficits are forecast scattered across many parts of Mexico with small pockets of extreme (20 to 40 years) to exceptional (more than 40 years) deficits in Michoacán and Oaxaca. Deficits are also forecast for Guatemala, western Cuba, and western Puerto Rico. Moderate to extreme surpluses are forecast for eastern Honduras, Nicaragua, northern Costa Rica, and eastern Panama. Exceptional surpluses are forecast in southern Haiti into the Dominican Republic.

Impacts
Heavy rains in parts of Tamaulipas, Veracruz and Chihuahua states of Mexico have caused flooding and damaged thousands of houses and bridges, killing at least two people.

An unusually late hurricane, Hurricane Otto, crossed Nicaragua, Panama and Costa Rica, dumping up to 120 mm (4.72 inches) of rainfall in 3 hours. A total of 22 people were killed and damages of over $20 million (USD) have been reported.

The north coast of the Dominican Republic has been inundated by heavy rainfall following Hurricane Matthew in August, displacing 20,000 people.

Forecast Breakdown
The 3-month maps (below) show the evolving conditions in more detail.

The forecast for November 2016 through January 2017 indicates water deficits of varying severity throughout much of Mexico with pockets of exceptional deficits in Oaxaca. Deficits in Baja California are expected to diminish considerably in severity, while to the south in Baja California Sur moderate deficits will emerge. Moderate to severe deficits are forecast to persist in western Cuba and emerge in eastern Cuba. Conditions in Puerto Rico are expected to return to nearly normal during this period. In Central America deficits are expected to persist in Guatemala. Moderate to extreme surpluses are forecast to persist in eastern Honduras, Nicaragua, and northern Costa Rica, though these surpluses are not expected to reach exceptional severity as observed in the region from August through October.

In the February through April map yellow and lighter shades of orange across northern Mexico indicate diminished severity of water deficits and – as shown in white – even a return to normal in parts of Sonora. The forecast for southern Mexico, however, shows the persistence of moderate to exceptional deficits especially in Michoacán, Guerrero, Oaxaca, and parts of the Yucatán. Deficits are expected to persist in Guatemala though diminish slightly in severity. Surpluses will persist in parts of Honduras and Nicaragua, and surpluses in northern Costa Rica will transition to both deficits and surpluses.

The final quarter of the forecast period indicates the absence of significant water anomalies with the exception of moderate to severe deficits predicted for the Baja Peninsula.

(It should be noted that forecast skill declines with longer lead times.)