2016 Monthly average temperature and total rainfall charts for the Rio Grande Valley

Temperature and Precipitation Trends Brownsville, Harlingen, McAllen, in 2016 Warm was the Word in 2016. After a seasonal start to the year (January), warm to hot weather dominated the remaining 11 months of the year, finishing with a December flourish (~6°F above average) which locked up the Valley's all-time warmest year on record in most areas, with some records dating back more than 100 years. Periodic rainy episodes for the first half of the year proved to be a boon for crop growers, particularly for cotton, corn, and grain sorghum. The mild and dry February allowed for clean planting, and was followed by just enough rain in March to water in the first plantings. Above average but periodic rainfall with dry breaks from April through early June was the perfect tonic for spring/early summer growth of said crops. The wetness helped keep June temperatures in check before La Canícula arrive in force in July as is wont to do, and brought the necessary hot, dry conditions to cash out a bumper crop for many Valley grain/cotton growers by the end of August. Unfortunately, La Canícula decided to stick around right into early November, setting a potentially tough start for spring 2017 planting with soil moisture significantly limited due to the lack of September rainfall for the first time since 2012, followed by a record hot October and a four month (July-October) heat record with total rainfall slack resulting in the 10th driest on record for the agriculture belt of the Valley (Cameron, Hidalgo, and Willacy County) since records began in 1895. For 2017, without significant rainfall, this will impact growth potential even with likely irrigation should late winter and early spring rainfall fail to materialized. One of the more interesting results of 2016 was the perceived forecast "bust" for a wet and cool winter (December 2015-February 2016) through spring (March-May 2016). The very low probabilities for the reverse, which generally ranged from the single numbers to the teens (in percent), were indeed the result. Much of the forecast was a result of the expectations from a moderate to strong El Niño that led into early 2016; other factors, including a persistent atmospheric ridge parked along/west of Baja California, with no development of a subtropical jet until a one-off late March event, dominated the sensible weather response. As El Niño quickly reversed to a weak La Niña (by monthly values) toward the end of the year, warm/dry forecasts with higher confidence verified nicely. Finally, Falcon International Reservoir remained at around one-third capacity (37% Texas share) as 2016 ended and 2017 began. Lack of flows into the reservoir combined with the near-record to record heat and high evaporation rates were the cause of some concern. At the same time, sufficient flows of water into Amistad International Reservoir along the Texas Big Bend near Del Rio maintained a high capacity (84.5 percent Texas share), the highest level since the post-Alex values in late 2010 through much of 2011. The Amistad supply offers some relief to growers who, lacking sufficient late winter and early spring rainfall, may need to tap Falcon's sources with a potential release at Amistad to help resupply at some point in 2017, lacking any unforeseen rains in the Rio Grande Basin or Rio San Juan Basin.