Investing.com - Oil prices rose 5% on Friday to scale the $30 mark breached last week, as cold U.S. and European weather as well as firmer financial markets gave traders reason to cash in on record short positions. While crude futures on both sides of the Atlantic were poised for their first weekly gain this year, analysts cautioned that the bounce in prices could be driven by sentiment given soaring inventories amid persistent overproduction. Brent was up 5.23% at $30.80 per barrel, off its low of $27.10 and is headed for a more than 6% weekly gain. U.S. crude was up 4.25% at $30.83 per barrel at 10.05 GMT, more than $4 away from a 12- year low of $26.19 and is set for a weekly rise above 4%. Oil prices drew support from freezing weather conditions and snowstorms that have gripped the U.S. East Coast and parts of continental Europe, lifting demand for heating oil.