A high pressure ridge off the coast of California that cut off moisture to the Sierra Nevada may break up on Tuesday allowing a change in the weather and bringing snow.That would be a welcome change for Carson Valley ranchers who are watching the water locked in the mountain snowpack dwindle from double at the end of December down to 91 percent.While a cold January helped to preserve the snow that fell in the first quarter of the water year, February so far has been dry and relatively warm with high temperatures nearing 60 degrees in Carson Valley.In a joint …