Long-range forecasting, like seasonal forecasting, meteorologists no longer look at weather models like we do for the day to day forecast, we look at teleconnections. Two of the best known teleconnections are El Niño and La Niña which are part of the El Niño Southern Oscillation or ENSO. We have been in the neutral phase of El Niño for the past 3 years, but there may be some change on the horizon. According to the Climate Prediction Center, which is a part of the National Oceanic and Atmospheric Administration, there is an above 65 percent chance for El Niño to develop by the end of the year.
El Niño impacts tend to show up most clearly during the Winter months, so there isn’t much correlation we can look at for Summer forecasting. So I went back and looked at the last 40 years of data and found years in which we transitioned from a neutral ENSO to El Niño and found that Summer overall will be hot and dry…no surprise there! June will have an equal chance of below or above average precipitation but across the board July and August showed up dry, with a similar weather setup. In fact last year in a neutral ENSO there was no rain reported at the Rogue Valley International Medford Airport in July! The potential for no rain is possible in both July and August again this year.
This means that our drought conditions will likely persist or intensify this Summer, but there is some hope for some relief this Winter. As I mentioned, El Niño has the biggest impacts during the Winter months. If El Niño does develop we can expect to see drought relief for California this Winter!
Meteorologist Megan Parry