If at any time after the lien date the board believes that the collection of all or part of the tax imposed by this part will be jeopardized by delay, it shall immediately determine the assessed value of the property and the tax rate to be applied. From these it shall compute the amount of tax together with any interest and penalties. The amount so determined shall be due and payable upon service of a notice of assessment upon the person assessed and shall be final 10 days after service unless the person assessed within such 10-day period petitions for reassessment.