Weather experts spent much of this winter cautiously optimistic. There were still weeks to go in the wet season and the reservoirs were full, thanks to last winter’s near record-breaking rain and snow. Now, even the professionals are getting more than a little nervous. There have been weeks of hardly any rain. The Sierra Nevada has received record-low amounts of snow. Meanwhile, the calendar is flipping ever closer to California’s blast furnace dry season. “The outlook isn’t good,” said David Rizzardo, chief of snow surveys with the Department of Water Resources.