Swollen rivers in east Texas aren’t expected to crest until later this week, but federal officials are already predicting Tropical Storm Harvey will drive 30,000 people into shelters and spur 450,000 victims to seek some sort of disaster assistance. And yet, forecasters say, more rain is coming. Lots more. Several locales have already received 2 feet or more of rain, and forecasters say a reprieve won’t arrive till week’s end at the earliest. By then, rain totals could reach another 2 feet -- with isolated instances of 40 to 50 more inches -- along the upper Texas coast.