The National Weather Service has predicted that a significant increase in temperatures across the New Jersey area, with highs expected to rise to 62 by Friday, 65 on Saturday, and possibly up to 70 in some parts of the region on Sunday. Some light to moderate rainfall is possible in two main bursts: Friday night, with a 70 percent chance of showers and up to a quarter inch falling, and a lesser storm Sunday night into Monday morning. Shifts in the jet stream are likely to continue to bring cold air down across the midwest and northeast over the coming weeks, with more warming periods expected.