Narrative:

Prior to departure I studied surface winds at the airport and winds aloft at surrounding key terrain features at the airport and along the departure procedure route. The first officer (first officer) and I discussed the possibility for excursions in speed and sink pertaining along the departure procedure and mitigated this with active monitoring and adjusting speed; power setting; and pitch to remain in compliance with the lateral and vertical confines of the SID (standard instrument departure). We did not anticipate a windshear escape and did not discuss corresponding actions. A few minutes prior to our takeoff a light jet departed and we were cleared to line up and wait. Tower reported the winds which were within 30 degrees of the nose with an approximate 10 kt gust spread; different from what was advertised on the ATIS (shift in direction and magnitude). We discussed that we were within limits for a full static takeoff and to be prepared to release brakes immediately following takeoff thrust stabilization due to us departing with opposite direction traffic on a 6NM final. Tower cleared us for takeoff and remarked that the preceding departing traffic had a windshear warning. We did not hear this report and based on the timeliness of it (a few minutes) I assumed this traffic had encountered it farther along the departure route where we had discussed we would encounter some shear. Due to the opposite direction traffic we had no time to sit still on the runway and having already prepared for the possibility for some shear along the departure climb (not at lift-off) I elected to continue the takeoff. At 100 feet AGL (above ground level) encountered trends in speed and sink indicative of windshear and in order to sustain the SID climb gradient we applied maximum thrust until 2;000 feet AGL. We received no alert or warning; reported our encounter with tower; set takeoff thrust again; configured; and continued the departure. We remained within the lateral and vertical limits of the SID at all times. We did encounter a TCAS RA (resolution advisory) with the opposite direction traffic; but we had it in sight prior to that event when tower reported its position to us; additionally this is an anticipated event at this airport.the central issue is that we decided to takeoff knowing of a windshear warning reported by a preceding aircraft. We are prohibited from taking off with microburst alerts; but windshear is a matter of discretion to go vs. Delay and what is done to prepare for and mitigate that threat. We let our judgment be rushed by the urgency of ATC and constraints of this demanding airport. We did not fully develop this threat and placed ourselves in an unsafe situation that could have been avoided by refusing a takeoff clearance and gathering more information.first; we assumed the windshear was somewhere it was not. We should have cleared the runway and asked for exactly where and when this warning occurred and the magnitude of gains/losses. Second; ATC should have reported the warning from the other aircraft and asked us if we could accept a takeoff clearance. I let myself be rushed to making a decision without all the facts. With a brief pause I would have felt more compelled to clear the runway as opposed to rushing to takeoff because I was merely 'cleared to takeoff.' third; we are well trained and have excellent publications for operating at this airport and as operators we deal with these conditions every day. Windshear is the norm here and that cheapened the threat-had this been another airport where windshear is not normal; I would not have taken off since that is a condition not associated with that locale. I recommend the briefing guide have specific language encouraging crews to solicit time; location; and magnitude of shear before accepting a take-off clearance.

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Original NASA ASRS Text

Title: CRJ flight crew reported electing to takeoff after ATC informed them of a windshear warning reported by a preceding departing aircraft without proper preparation.

Narrative: Prior to departure I studied surface winds at the airport and winds aloft at surrounding key terrain features at the airport and along the departure procedure route. The FO (First Officer) and I discussed the possibility for excursions in speed and sink pertaining along the departure procedure and mitigated this with active monitoring and adjusting speed; power setting; and pitch to remain in compliance with the lateral and vertical confines of the SID (Standard Instrument Departure). We did not anticipate a windshear escape and did not discuss corresponding actions. A few minutes prior to our takeoff a light jet departed and we were cleared to line up and wait. Tower reported the winds which were within 30 degrees of the nose with an approximate 10 kt gust spread; different from what was advertised on the ATIS (shift in direction and magnitude). We discussed that we were within limits for a full static takeoff and to be prepared to release brakes immediately following takeoff thrust stabilization due to us departing with opposite direction traffic on a 6NM final. Tower cleared us for takeoff and remarked that the preceding departing traffic had a windshear warning. We did not hear this report and based on the timeliness of it (a few minutes) I assumed this traffic had encountered it farther along the departure route where we had discussed we would encounter some shear. Due to the opposite direction traffic we had no time to sit still on the runway and having already prepared for the possibility for some shear along the departure climb (not at lift-off) I elected to continue the takeoff. At 100 feet AGL (Above Ground Level) encountered trends in speed and sink indicative of windshear and in order to sustain the SID climb gradient we applied maximum thrust until 2;000 feet AGL. We received no alert or warning; reported our encounter with Tower; set takeoff thrust again; configured; and continued the departure. We remained within the lateral and vertical limits of the SID at all times. We did encounter a TCAS RA (Resolution Advisory) with the opposite direction traffic; but we had it in sight prior to that event when Tower reported its position to us; additionally this is an anticipated event at this airport.The central issue is that we decided to takeoff knowing of a windshear warning reported by a preceding aircraft. We are prohibited from taking off with microburst alerts; but windshear is a matter of discretion to go vs. delay and what is done to prepare for and mitigate that threat. We let our judgment be rushed by the urgency of ATC and constraints of this demanding airport. We did not fully develop this threat and placed ourselves in an unsafe situation that could have been avoided by refusing a takeoff clearance and gathering more information.First; we assumed the windshear was somewhere it was not. We should have cleared the runway and asked for exactly where and when this warning occurred and the magnitude of gains/losses. Second; ATC should have reported the warning from the other aircraft and asked us if we could accept a takeoff clearance. I let myself be rushed to making a decision without all the facts. With a brief pause I would have felt more compelled to clear the runway as opposed to rushing to takeoff because I was merely 'cleared to takeoff.' Third; we are well trained and have excellent publications for operating at this airport and as operators we deal with these conditions every day. Windshear is the norm here and that cheapened the threat-had this been another airport where windshear is not normal; I would not have taken off since that is a condition not associated with that locale. I recommend the briefing guide have specific language encouraging crews to solicit time; location; and magnitude of shear before accepting a take-off clearance.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.