Diesel prices could surge above $A4 a litre ($NZ4.86) in coming months under a scenario modelled by economists at National Australia Bank, potentially spelling a much more severe economic fallout than forecast by the Reserve Bank. Fears of service stations running dry are a distant memory and petrol prices are back under the $A2 a litre mark following government efforts to secure additional supplies to Australia. But the oil shock has not gone away and the ongoing blockade of the Strait of Hormuz shows no sign of ending soon. Countries continue to run down stockpiles, which have been keeping a lid on prices, with about 9.5 percent of global oil demand disrupted, according to CBA commodities analyst Vivek Dhar. Fresh forecasts released by the RBA on Tuesday showed a dire outlook for inflation and economic activity, even with relatively benign assumptions that the benchmark oil price will fall to $US82 a barrel by the end of the year, from just under $US110 currently.…