Central Chile remains in the midst of an extreme several-year-long drought, but some relief is in sight starting in July.
Much like the southwestern United States, central Chile relies on rainfall during the winter to offset the significantly drier summer months. Unfortunately, winter rainfall has been substantially lacking in recent years.
Santiago has not experienced a year with an annual rainfall total more than half of normal since 2008. In fact, the city received only 36 percent of its normal rainfall since Jan. 1, 2009, leading to a rainfall shortage of 1,478 mm (58 inches).
"Since Jan. 1, 2010, Santiago has had only four months with rainfall of 90 percent or more of normal," stated AccuWeather Senior Meteorologist Jason Nicholls. "The most recent ‘normal' month was May 2013."
Nicholls explained that there have been several factors in recent years to the prolonged drought.
Persistent cool water offshore of northern Chile has worked to stabilize the atmosphere, putting a lid on rain and thunderstorm development.
In addition, an area of high pressure has been unusually strong and located farther north than normal. That has diverted the storm track south of central Chile and caused any cold fronts that managed to press northward to lose rainfall.
The good news for Chile is that changes are coming to these factors that should finally lead to normal rainfall in July.
"El Nino is getting stronger, so that should shrink the cool pool of water offshore of northern Chile and there are signs that the area of high pressure is weakening," added Nicholls. "In addition, a pulse [that leads to enhanced areas of rising air and instability] is moving eastward."
GFS shows high dropping south toward Bellinghausen Sea in early July; more favorable storm track for central Chile. pic.twitter.com/IwddJ1F8zw— Jason Nicholls (@jnmet) June 22, 2015
"The result will be a turn to a more unsettled pattern during the week of July 6 to 13," Nicholls continued.
This pattern should continue through winter and may even carry over into the spring. There will still be some breaks to the wet weather, but the rainfall will definitely be beneficial.
"While not totally erasing the drought, the upcoming rain will chip away at it," stated Nicholls.
The same can be said for the snowfall deficits that the neighboring Andes are experiencing.
Nicholls added the storms that have gotten to the Andes have been too warm and failed to produce significant snowfall, much to the dismay of the ski industry and those whose water supply comes from the reservoirs that runoff from the melting snow feeds into.
As the wetter pattern develops, "there will be some snow July and into August," he said.