Hurricane Gustav puffed up the number of new unemployment claims last week.

Initial jobless claims rose unexpectedly last week to a seasonally adjusted 455,000, up 10,000 from the previous week.

Last week’s unemployment number is the first to include claims following job losses caused by Hurricane Gustav. The storm hit the Louisiana coast over the Labor Day weekend.

Unemployment claims have now exceeded 400,000 for 9 nine weeks in a row, a level many economists view as evidence of a struggling economy. The total stood at about 320,000 a year ago.

The 4-week average of new claims -- a more reliable gauge because it evens out unexpected spikes -- increased by 5,000 to 445,000. However, the number of people continuing to receive unemployment benefits dropped 55,000, to 3.48 million.

Unemployment is a key measure of economic health because consumer spending accounts for about two-thirds of the economy. Analysts say retail sales during this year’s holiday season will be no cause for celebration.

In a separate report, the Conference Board, a business group based in New York, said its monthly forecast of future economic activity declined 0.5% in August. The group cited a decline in building permits as an increase in unemployment for its darkening economic outlook. Wall Street economists expected a 0.2% drop.