Labor analyst says drop 'is the backside' of the unexpected surge in claims last wk from 4 southeast states - they are among largest decreases this wk. Seasonal factors expected a 4.2% drop in NSA, or about 20k. Actual NSA claims -5.5%, or -26,633, to 459,683. Puerto Rico estimated. 4-wk moving avg +1k to 430,500. Cont. claims +84k to 3.925m in Jan. 22 wk.