April 7, 2023

Drought Status Update for Puerto Rico and the U.S. Virgin Islands

Drought conditions continue to deteriorate across all islands

Moderate drought conditions are now observed across Puerto Rico and Saint Thomas with severe drought conditions noted in Saint Croix. 

The most likely scenario during the next few weeks is for the persistence and expansion of drought conditions across all islands. The rainfall during the month of May will be crucial to determine if drought conditions will prevail during the summer months. Farmers are preparing now for the dry season ahead.

Key Points

• Puerto Rico Conditions: Limited rainfall activity has been observed across the local islands during the past few months. As a result, abnormally dry to moderate drought (D1) conditions continue to expand across nearly all of Puerto Rico, but especially along the southern coast, from Guayama west to Cabo Rojo. Some hints of severe drought (D2) are beginning to show near Aguadilla and parts of the municipalities of Moca, Isabela, and Mayaguez. The National Weather Station (NWS) station at Coloso in the municipality of Mayaguez has reported only 4.45” of rain through April 4th. This is the driest year-to-date total since 2014. 
• U.S. Virgin Islands Conditions: Sporadic rain is occurring in the USVI, but wind and high temperatures are causing the loss of water from the soil and preventing the rains from saturating the soil. While the rainy season helped replenish some groundwater, drought is expanding and intensifying across the USVI, especially in St. Croix. Over the past 60 days, Rohlsen Airport has reported only 1.22” of rain, or about 40% of normal. This is the 4th driest such period in 63 years of data, or about 1 in 15 years of dryness, reflective of the severe drought (D2) being reported in the U.S. Drought Monitor.
• Puerto Rico Impacts: The fire danger weather in Puerto Rico continues to increase as dryness intensifies. There are reports of soil cracking, and dried and brown grass. A decreasing trend in water levels continued to be observed at reservoirs, rivers, and aquifers across Puerto Rico.
• U.S. Virgin Islands Impacts: Vegetation is beginning to show signs of distress due to the drier-than-normal conditions. Poultry farmers across the USVI are reporting a decrease in egg production due to heat.
• Looking Ahead: The most likely scenario during the next few months is for the persistence and expansion of drought conditions across the islands. The rainfall during the month of May will be crucial to determine if drought conditions will prevail entering the summer months. 
• Looking Ahead: The months of February-April are typically the driest of the year for Puerto Rico and the USVI. However, the precipitation outlooks indicate that there is only a 25% chance of drier-than-average conditions.

For weather information specific to your area, please monitor products issued by the National Weather Service in San Juan, Puerto Rico.

This bi-monthly PR/USVI Drought Update can also be accessed and shared via this webpage on drought.gov.

Drought Conditions

Puerto Rico: Nearly 75% of Puerto Rico is currently considered dry or in drought according to the U.S. Drought Monitor, with 45% categorized as Moderate Drought (D1) and 30% categorized as Abnormally Dry (D0) which is often a precursor to drought. The Moderate Drought (D1) conditions are now focused across the northwestern quadrant of the island as well as the southern slopes (Figure 1). This is expected to increase and worsen through April.

U.S. Virgin Islands: Moderate Drought (D1) conditions are observed across Saint Thomas while Severe Drought (D2) conditions persist across Saint Croix (Figure 1). St. John is considered to be abnormally dry (D0).

Figure 1. Latest weekly drought assessment for Puerto Rico and U.S. Virgin Islands, based on data issued by the US Drought Monitor and released on April 6, 2022.

Sector Impacts

General conditions

• Puerto Rico. Dry and windy conditions in parts of Puerto Rico are leading to dry soil and, vegetation, and an increased risk of wildfires. 
• U.S. Virgin Islands. Ranchers note that conditions have been drier than normal, and vegetation is showing signs of distress. Farmers note that even with short and scattered rain, the wind and consistent heat are evaporating precipitation before the soil fully saturates. Poultry farmers across the USVI are reporting a decrease in egg production due to heat.

Agricultural conditions

• Puerto Rico. In some regions, reduced rainfall is leading to low soil moisture, dry pastures, and affected crops. Browning vegetation and cracks in the soil show the effects of dry conditions (Photo 1). In Santa Isabel, dry conditions may be of concern to some farmers who rely on irrigation canals to provide water for their crops. One farmer reportedly constructed a structure to divert water from the irrigation canal to provide more water to their farm (Photos 3 and 4). Conditions appear to be increasingly dry in Toa Alta where one farmer shared that the soil is beginning to crack due to a reduction in rainfall in the past month (Photo 2). In San Germán, reported minimal rainfall and high winds have led to dry conditions. 
• St. Thomas. Farmers are reporting hot, dry weather which is adding to issues faced by farmers in the region, including that full ponds are beginning to evaporate due to heat. High winds have impacted soil moisture which has been reported at or above 20 MPH daily. Due to concerns over drought season, many are planning and preparing irrigation and water efficiency actions to better manage water as part of a longer-term mitigation and conservation plan, including the use of permaculture to aid them with soil moisture. Specialty and row crop farmers are working to manage water usage plans now and many are moving to drought-tolerant crops to keep production up while still conserving water. Livestock farmers are rotating to various areas to increase access to feed.
• St. John. Row and specialty crop farmers in St. John are reporting that they have had intermittent rain. The winds are high, which is impacting soil moisture, and farmers are preparing for a long, hot dry season. Most are currently focusing on microgreens, fruit trees, and quick crops to keep production levels up.
• St. Croix. Livestock farmers are working to plan for feed shortages later this summer due to a lack of grass during the hotter months. The Virgin Islands Department of Agriculture (VIDA) is currently buying and storing hay. Ranchers are looking at their drought mitigation strategies to plan for vegetation distress. Poultry farmers are now indicating that egg production has been reduced by up to 50% due to the heat. Poultry farmers also report they are concerned about conditions moving into the warmer months due to the demand for water required to produce. Furthermore, concerns about weather impacts and sales have plagued egg production farmers as they point to increased demand by consumers and their limited ability to address this demand due to the onset of drought and heat. Farmers who have poultry including both broilers and/or egg production have smaller numbers due to the fact they must collect water in containers or use cistern water. VIDA on St Croix reported in February they provided more than 1,000,040 gallons of water to farmers and in March supplied 1,105,000 gallons to farmers.

Photos 1 and 2. Browning vegetation and cracks in the soil show the effects of dry conditions in Guanica (Photo 1) and Toa Baja (Photo 2). Photo credits: Distrito de Conservación del Suroeste, and Ian Pagán Roig, Agroecological project El Josco Bravo, respectively, March 23, 2023.

Photos 3 and 4. A concerned farmer in Santa Isabel diverted water from an agricultural irrigation channel to provide more water to their farmland. Photos by Agronomist Duamed Colón Carrión, March 9, 2023. 

Photos 5 and 6. On the left is a picture of Inner and Outer Brass on St Thomas, Dec. 28, 2020; the picture on the right shows signs of distress to vegetation, April 1, 2023. Photos by Christina Chanes.

Photos 7 and 8. These are photos of Mary’s Point, Trunk Bay, St. John, USVI. The left is from June 11, 2022, and the right is from March 21, 2023. Photos by Rafe Boulon.  

Photo 9.  Photo of soil cracking on Burton Farms in St Croix which is in the midlands of the island. March 22, 2023, taken by Mr. Charles Burton of Burton Family Farms.

Rainfall Trends

Short-term rainfall deficits are observed across all islands, but especially over the past 60 days. The 60-day rainfall deficits are now ranging between 2 and 4 inches across most of Puerto Rico with locally higher amounts of 4”-8” over the northwest quadrant of the island. As for the U.S. Virgin Islands, the year-to-date rainfall deficits are now running 2”-3”  below normal (Figure 2). 

Figure 2. The 60-day rainfall departure from normal. NOAA National Weather Service.

Soil Moisture Conditions

The latest soil moisture data from the Puerto Rico Agricultural Water Management (PRAGWATER) the driest soils and highest crop stress in Puerto Rico is currently observed in the northwest quadrant of the island, as well as in the southern slopes.  In St. Thomas, the water level at the USGS Grade 3 School Well has dropped nearly 10 feet from 2 feet below the surface in mid-November to nearly 12 feet below the surface. (Figures 3, 4, and 5). 

Figure 3. The latest assessment of soil saturation for Puerto Rico. Soil saturation: 1=Saturated.

Figure 4. Latest assessment of crop stress factor for Puerto Rico. Crop Stress Coefficient: 1=No Stress, 0=Extreme Stress.

Figure 5. Depth below the surface of the water table at the USGS Grade 3 School Well has dropped nearly 10 feet since mid-November to now being about 12 feet below the surface.

Streamflow and Reservoir Conditions in Puerto Rico

The real-time 28-day average streamflow from the U.S. Geological Survey (USGS) river gauge network (Figure 5) indicates most streamflows running below normal or well below normal across eastern and south Puerto Rico. Reservoir levels continued to recede with the Guajataca reservoir under close observation. Groundwater levels continued to recede across all islands as well.      

Figure 6. The current map (4/4/23) of 28-day average streamflow compared to historical streamflow retrieved from the U.S. Geological Survey.

Rainfall Outlook

Based on the 3-month extended forecast for April, May, and June by the North American Multi-Model Ensemble (NMME) the entire Caribbean basin, including PR and the USVI, are forecast to have drier than normal conditions (Figure 7). However, climatologically speaking, the month of May is wet. The rainfall during the month of May will be crucial to determine if drought conditions will prevail during the summer months.

Figure 7. The forecast for the April, May, and June (AMJ) time period from the North American Multi-Model Ensemble (NMME) shows below-normal rainfall across the entire Caribbean region, including PR and the USVI.

For More Information

• NWS Weather Forecast Office - San Juan. Climate and Drought Information. https://www.weather.gov/sju/dss_climo
• NWS Drought Information Statements for Puerto Rico and the U.S. Caribbean. https://forecast.weather.gov/product.php?site=NWS&product=DGT&issuedby=SJU
• Drought.gov
• Puerto Rico page. https://drought.gov/states/puerto-rico
• USVI page. https://www.drought.gov/states/us-virgin-islands
• Caribbean Drought Bulletins. Caribbean Regional Climate Center, Caribbean Institute for Meteorology and Hydrology (CIMH), Barbados. http://rcc.cimh.edu.bb/drought-bulletin-caribbean/
• USDA Caribbean Climate Hub drought and disaster assistance resources for tropical forestry and agriculture. https://caribbeanclimatehub.org/resources/

Prepared By

Odalys Martinez

Senior Service Hydrologist, NWS Weather Forecast Office San Juan

Meredith Muth

NOAA/National Integrated Drought Information System (NIDIS)

William Gould, Nora Alvarez, Eva Holupchinski, and Luis Alexis Rodriguez Cruz

USDA Caribbean Climate Hub, USFS International Institute of Tropical Forestry

Christina Chanes, Gregory Guannel

University of Virgin Islands

Héctor J. Jiménez

Office of Climatology, University of Puerto Rico

Victor Murphy

Climate Services Program Manager, National Weather Service Southern Region

Brad Rippey

USDA Office of the Chief Economist

Acknowledgments:

Puerto Rico Reporting Input:  Thanks to the Agricultural Extension Service, College of Agricultural Sciences, University of Puerto Rico-Mayaguez. Special thanks to Eric Harmsen, Professor of Agricultural Engineering UPR-M; Isela Ortiz, Southwest Soil and Water Conservation District Inc. (DCSAS), Ian Pagán Roig, Agroecological Project el Josco Bravo; Agronomist Duamed Colón Carrión; and Professor. José L. Zamora.

USVI Reporting Input: Several individuals contributed to this report and we are acknowledging the following for their support including the farming community across the USVI, UVI faculty, staff and collaborators of the UVI School of Agriculture, UVI Physics Program, UVI Etelman Observatory, UVI Agricultural Experiment Station, VI Department of Agriculture, as well as the USDA Office Chief Economist, National Parks Service in St. Croix, VI Department of Planning and Natural Resources, USDA Farm Service Agency, Coral Bay Community Council and the many volunteer drought reporters and farmers from across the territory.