The first manual survey this year of California’s snowpack revealed Tuesday that it holds about half as much water as normal, casting a shadow on the state that’s hoping to dodge a sixth straight year of drought, officials said. Surveyors, however, took the reading at 6,000 feet near Lake Tahoe in the Sierra Nevada as major cold and windy storms were expected to dump four to five feet of snow through Thursday in areas above 4,500 feet in Northern and Central California, while mountain areas below that could get two to three feet, forecasters said.