Surveyors plunged a pole into the Sierra Nevada snowpack on Tuesday and took the first manual measurement of the wet season, finding water content was about half of normal as California flirts with a possible sixth year of drought. Surveyors took the reading at 6,000 feet near Lake Tahoe 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.