2001 Taurus Lock-Up Torque Converter Problem

I have a 2001 Taurus with Vulcan V-6 (12 Valve 3.0 Liter) showing 135,000 miles. Lately, (since the weather's gotten cold) it's taken between 6 and 10 miles of my morning commute for the torque converter to lock up. Once it's warm and locked up it works fine for the rest of the day, but I'd like to get it fixed before it stops working all together.
Thanks in advance! And Merry Christmas!
Jon

That's normal. It doesn't lock up so the transmission can heat up some. 135000 that's alot of miles. Do you know what transmission you have?