The California weather is expected to be cooler and more unsettled this week, with temperatures expected to drop from the upper 80s to near 70 by Tuesday. However, an approaching storm system is predicted to develop, which lacks moisture from the subtropical Pacific, leading to rain showers and possible snow in the Sierra Nevada. This system is essentially a "failed" Atmospheric River, which is not typically associated with a true AR and will result in light rainfall, with most areas receiving less than a tenth of an inch of rain. Despite this, California only received 105% of normal rainfall in 2015–16, compared to only 105% rainfall in 1997–98. Long-range models suggest an El Niño pattern developing, possibly a strong one, possibly due to another pool of warm water in the Pacific. This is not directly related to El Niño, a seasonal reversal of the Trade Winds that shift towards North America when the trade Winds weaken, causing the built-up warm water to be pushed towards the eastern Pacific Ocean.