YEAGER: I've spent some time in the small town of Corcoran between LA and San Francisco. SIMON: And how are the people who live there coping? Towns near the formerly dry lake - Tulare Lake - are in a mad dash to set up sandbags, shore up levees, and protect themselves from the encroaching water. I mean, there's literal waves lapping at the dirt. As far as the eye can see, only the occasional power pole or farm building kind of pokes out. Thousands of acres of farmland are underwater. Eight months ago, this region was experiencing severe drought, and now there's a sprawling lake. YEAGER: Well, it's hard to overstate just how different the landscape looks. We have at least four more months of warm weather ahead of us. But this heat wave is only the first chip in the snowpack's armor. But the good news is dam managers here have been shooting torrents of water out of reservoirs to make room for the coming snowmelt, so things are expected to be good for this weekend at least. SIMON: And that means even more snowmelt? And more concerningly, lows up there will stay above freezing. Up in the mountains, where all that snow is, temperatures will be 60 degrees. And today, the high here on the valley floor is pushing triple digits. In some spots, there were four times more snow than average.

In the San Joaquin Valley, where I am, the snowpack broke all-time records this year. And that's a big deal not only for the park, but for the communities that rely on tourism here. And the world's largest tree in Sequoia National Park will be off limits through summer after all the damage winter storms did.

Yosemite National Park is closed through Wednesday due to flood concerns. YEAGER: Well, a lot of snow is going to melt. Joshua Yeager of KVPR joins us now from Bakersfield, Calif. And in California, there are worries about hot weather and the massive snowpack in the Sierra Nevadas. The upper Mississippi River has already reached major flood stage. Winter snow is starting to melt in the West and the Midwest.

The wave susan