Thu Feb 21, 2013 1:24pm EST * Initial jobless claims rise, Philly Fed well below forecasts * Stocks on track for biggest two-day drop since November * Wal-Mart climbs after earnings, Safeway soars * Semiconductor stocks fall, weighing on Nasdaq * Dow off 0.5 pct, S&P 500 off 0.8 pct, Nasdaq off 1.2 pct By Ryan Vlastelica NEW YORK, Feb 21 (Reuters) –…