US STOCKS-Futures fall on Ukraine tension ahead of Yellen comments
* Investors look to Yellen for insight into weather impact
* Weekly jobless claims, Jan durable goods data on tap
* J.C. Penney and Best Buy rally in premarket after results
* Futures down: Dow 48 pts, S&P 5.4 pts, Nasdaq 6.75 pts
By Ryan Vlastelica
NEW YORK, Feb 27 (Reuters) - U.S. stock index futures fell on Thursday, with the S&P 500 poised to recede further from record levels amid political uncertainty in Ukraine and ahead of comments from Federal Reserve Chair Janet Yellen.
* Investor concerns about geopolitical tensions mounted after armed men seized the regional government headquarters and parliament in Ukraine's Crimea and raised the Russian flag. Kiev's new rulers urged Moscow not to abuse its navy base rights on the peninsula by moving troops around.
* Yellen will address the Senate Banking Committee in a semiannual testimony about monetary policy, and investors are especially looking for insight into how an unexpectedly harsh winter has impacted economic activity. Yellen's appearance, originally scheduled for Feb. 13, was postponed because of a snowstorm.
* Recent data has largely come in under expectations, with a few bright spots, such as January new home sales. Many analysts have chalked the misses to the impact of weather instead of worsening fundamentals, a theory that has helped indexes shrug off the disappointments and send the S&P 500 to a record high earlier this week. Continuación...