The weather system responsible for the scorching Sun Belt heat wave -- already blamed for 145 deaths, along with destroying poultry and sapping water supplies -- might stay in position the rest of the summer, a National Weather Service forecaster says.

The siege of heat, in its 12th day in some sections, has spread to six states.

Forecasters could offer no encouragement. In fact, a weather service meteorologist in Oklahoma City said the subtropical high pressure system causing the record temperatures could be lodged where it is all summer.

An Arkansas coroner's report issued Thursday raised the heat wave death toll by a score.

The state medical examiner and county coroners had attributed at least 21 deaths to the heat, but Garland County Coroner Gary Thomas increased that figure to 41, saying his office had worked 20 cases since June 26 in which heat contributed to death.

In Texas, authorities said 31 deaths were caused directly by the heat and 47 were heat related; Oklahoma reported 24 heat wave deaths; five were recorded in Kansas; one in Missouri and one in Mississippi.

Most of the victims in the six-state area were the poor and elderly who could find no relief from the triple-digit temperatures in their sealed-up, non air-conditioned rooms.