After a week of positive employment data, jobless claims shot back up for the week ending Oct. 13, derailing confidence in the economic recovery.

The Labor Department reported 388,000 jobless claims for the week, an increase of 46,000 filings from the prior week’s revised figure of 342,000.

The four-week moving average hit 365,500, which is higher than the 364,750 level established a week prior.

Seasonal adjustments in California contributed to the quick jump in claims, Econoday researchers said Thursday. The jump was expected at the beginning of the quarter, but came in the second week of the period, the research firm said.

“This is a major factor behind violent swings in weekly jobless claims, up 46,000 in the October 13 week after dropping a revised 27,000 in the prior week,” Econoday said. “Swings like this, which weekly data are subject to, put in focus the four-week average which is only slightly higher, up less than 1,000 to 365,500.”

The news disrupts a few weeks of moderately optimistic reports with the unemployment rate falling to 7.8% in September as nonfarm payrolls rose by 114,000 positions, according to the U.S. Bureau of Labor Statistics.