Santa Clara County property owners who disagree with this year's assessment of their home's taxable value -- due to arrive in mailboxes starting Saturday -- can use new online tools to scrutinize how the figure was calculated and file a formal appeal.

With nearly 43,000 properties emerging from being underwater and coming on the tax rolls with a significantly higher valuation, some homeowners can expect to see a big jump in assessment.

"The residential real estate market has been so strong that some property owners will receive double-digit increases," said Assessor Larry Stone.

Some of those rebounds are happening in the areas with properties that took the hardest hit in the recession, such as Morgan Hill and Gilroy. About 38,000 homes throughout the county remain valued below their purchase price.

Stone said that a negligible increase in the state's Consumer Price Index -- which is tied to the assessment for homes that were not underwater -- means most property owners won't see much of a change.

While Stone's office has been adding online services for years, property owners can now take a closer look at how the value was calculated, including directly comparing the parcels and homes used to make the assessment. Residents can ask for an informal review or go ahead with a formal appeal using the online tools. More information is available at www.sccassessor.org.

The Santa Clara County Assessor's Office announced Thursday that this year's property rolls show the third highest jump in total value in the county's history -- an increase of about $23 billion to $357 billion, or nearly 7 percent. It continues a trend started last year, which was the second highest one-year gain after the biggest spike, seen back in 2001.

Contact Eric Kurhi at 408-920-5852. Follow him at Twitter.com/erickurhi.