El Nino is here for the first time since 2010, according to the National Oceanic and Atmospheric Administration—but it's too late and too weak to be much use where it's most needed. It won't provide "much relief for drought-stricken California, as California's rainy season is winding down," Mike Halpert, deputy director of the NOAA's Climate Prediction Center, tells the LA Times, explaining that the Pacific Ocean weather pattern will only help drought-stricken areas if it persists into the next rainy season. Forecasters say this El Nino won't have much effect on US weather patterns at all, since it's arriving too late to create the usual wet, cool conditions, though it may bring temperatures up elsewhere in the world, reports Scientific American.
The NOAA—which describes El Nino as an "ocean-atmospheric phenomenon marked by warmer-than-average sea surface temperatures in the central Pacific Ocean"—first spotted signs of the phenomenon a year ago, and Halpert tells the AP that experts aren't sure why it has taken so long to turn up. The agency says there is a 50% to 60% chance that this weak, late, and unusual El Nino might persist through the summer, which could lead to a decrease in the number of Atlantic hurricanes, though Halpert warns that 1992's Hurricane Andrew struck during an El Nino summer. (NOAA researchers say climate change isn't to blame for the California drought.)