Multiple floods, one cyclone and "prevailing economic conditions" are the three factors cited by Bank of Queensland to explain its second profit downgrade of the summer.In an ASX announcement yesterday, the bank said it had reduced its profit guidance by A$35 million to a revised range of $175 million to $195 million.The bank said it increased its provisioning levels for the first half (which ends in February 2011) by $45 million, as a result of a "one-off management overlay resulting from a number of weather-related factors and prevailing economic conditions".Two months ago, BOQ put its projected full-year profit at $210 million to $230 million. On that occasion the bank blamed "an extensive review of its commercial lending portfolio" and "weaker than expected trading conditions" in this portfolio.Two weeks ago, in its quarterly "Pillar 3" report, BOQ said that impaired loans climbed by at A$100 million, or 70 per cent, over the three months to November 2010.Loans 90 days or more past due at the end of November increased by $14 million, or five per cent, to $320 million.At the time, the bank classed most of the worsening in impaired loans (or $92 million of the rise) over the November quarter as "other retail" under APRA's definition. The rest mainly relate to commercial loans.