B737 Undifferentiated or Other Model
Situational Awareness
Flight Deck / Cabin / Aircraft Event Other / Unknown
Air Traffic Control Issued Advisory / Alert; Flight Crew Took Evasive Action
Weather; Human Factors
In both cases the Tower Controller issued a 'Windshear Alert; loss of 20 knots at departure end' type alert. One happened when we were in position on the runway awaiting takeoff clearance; the other while taxiing out nearing the approach end of the runway. Both Captains were very senior (20 years or more with the Company).  One suggested we would be OK as long as we did a precautionary windshear takeoff profile. The other Captain appeared to not be worried about the windshear alert. Both Captains agreed to delay the departure once I stated that I was not comfortable with the conditions. For the record; on both occasions we had pushed early and on-time pressures were not a factor; any more than they are for every flight. I think Flight Operations needs to re-emphasize that the key to handling windshear situations is AVOIDANCE. The Precautionary Takeoff Profile is not intended to be used to allow you to take off during an active windshear alert; but rather should be used when conditions MAY produce windshear. I think some of our senior Pilots are so comfortable with the B737 that they think they can handle anything thrown their way. When you combine that with our famous attitude; rush-rush default mode that many senior pilots learned at the Company; you set yourself up for trouble. At an old airline I used to work for; the FOM prohibited takeoffs and landings when thunderstorms were within five miles of the airport boundary. That's probably a bit excessive; but so is taking off during an active windshear alert.
First Officer voices objection to the intent of two senior Captains to takeoff with a reported windshear alert. The takeoff is delayed.