Wet and short runway with variable winds, so presumabely crew knows there is not much extra runway, and wants to touchdown maybe slightly earlier than usually. PAPIs U/S or not, water refraction creates the illusion of being high, resulting in a more shallow glidepath. Any other lights than PAPIs will strenghten the illusion even further.
Edit: Seeing the plate above, those REILs would appear to be much closer than they actually are in moderate rain.
Last edited by Pirrex; 29th Sep 2018 at 10:20.
Reason: REIL