The Christmas snow was no problem for sport-themed fashion chain JD Sports Fashion, which did so well it now thinks full-year profits will beat expectations.Like for like sales for the five weeks ended 1 January grew 2.5% and cumulative like for like sales for the 48 weeks are up 3.1%. They were up 2.8% in the 30 weeks to 28 August.JD estimates profit before tax and exceptional items for the year ending 29 January will top consensus analyst expectations of £75.4m. Results are out on 13 April.The comany said in November the outcome for the 12 months would depend on sales and margins in December and January. But there was a note of caution today as the company faces "significant challenges" due to the impact of both the recent VAT increase to 20%, and inflationary pressures, mostly from rising raw material prices. Executive chairman Peter Cowgill called today's numbers "pleasing"."Nevertheless the trading environment facing all retailers, and perhaps clothing retailers in particular, will provide additional challenges in the year to come," he said.