WASHINGTON (AP) — Mortgage application volume skyrocketed for the second consecutive week, rising 28.4 percent during the week ending Jan. 11, according to the Mortgage Bankers Association’s weekly application survey.

The MBA’s application index rose to 906.4 from 706 the previous week, which was shortened due to the New Year’s holiday. Mortgage volume slows during the winter, which can lead to greater volatility. Application volume jumped 39 percent during the same week a year ago.

Refinance volume rose 43.4 percent, while purchase volume jumped 11.4 percent. Refinance volume accounted for 62.7 percent of total application volume, compared with 57.7 percent the previous week.

The index peaked at 1,856.7 during the week ending May 30, 2003, at the height of the housing boom.

An index value of 100 is equal to the application volume on March 16, 1990, the first week the MBA tracked application volume. A reading of 906.4 means mortgage application activity is 9.064 times higher than it was when the MBA began tracking the data.

The survey provides a snapshot of mortgage lending activity among mortgage bankers, commercial banks and thrifts. It covers about 50 percent of all residential retail mortgage originations each week.

Applications rose as interest rates continued to fall. The average interest rate for traditional, 30-year fixed-rate mortgages fell to 5.62 percent from 5.73 percent. The average interest rate for 15-year fixed-rate mortgages — which are typically used to refinance loans — fell to 5.07 percent from 5.21 percent.

Rates for one-year adjustable-rate mortgages fell to 5.77 percent from 6.04 percent