A319
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Other / Unknown
Flight Crew Returned To Gate; General Flight Cancelled / Delayed
Weather; Company Policy; Manuals; Procedure
Conditions on preflight went from overcast and dry to moderate snow in a matter of minutes. Deicing at ZZZ was thorough and routine; Type I and Type IV; just off the gate with a 20 foot deep pushback.This year's procedure calls for 'Flaps UP' on the Pre Deicing Configuration checklist. This is a change from years past.Reconfiguration checklist performed appropriately.After a short taxi out to Runway 06 for departure; I as the PIC (Pilot in Command); decided to do a 'Cabin Check' to be conservative. Our holdover time was calculated to be 0:30-0:35 minutes so this Cabin Check was NOT required; since moderate snow was falling and we were well under our holdover time.Upon viewing the aircraft wings; there was fully 1 inch of snow on the flaps (which had been lowered AFTER deicing). Snow was accumulated on the entire length of the wingspan on the normally stowed section of the flaps.Flight returned to the gate to re-assess conditions and deice a second time with the flaps selected 'down.'Quite simply; event occurred due to new procedures requiring the flaps to be 'UP' during deicing. Thus the flaps are not treated while the rest of the wing is being treated. In the case of moderate snow or greater; snow will collect on the flaps in violation of the clean control surface requirement for takeoff.It was shocking to me; how fast snow was able to build up on the flaps in this incident. While deicing a second time; we noticed several aircraft from other air carriers deicing with the flaps 'down.'If I had not been proactive and accomplished the pre takeoff cabin check; (which is by its nature uncomfortable for the passengers)...There could have been serious consequences.Highly recommend [the company] re-adopt a flaps down deicing procedure; at the very least during active frozen precipitation.
A319 Captain reported observing snow accumulation on the flaps after de-icing. Returned to gate for second de-icing.