In the northern hemisphere winds usually back and decrease in strength with descending altitude.
So if you've got 270/20 at 5000' and 260/15 at 2000', at ground level it's likely to be in the order of 250 or even 240 /10 unless your airfield has some really weird local features.
Cue:onslaught of differing views.
Safe flying and remember if you ask for an opinion on an internet forum you'll usually get ten differing opinions.
E&OE
Safe flying
Cusco
