Rwy 09 was in used so assumed that they were cleared for the VOR/DME Rwy 09.
It is a non precision approach at published MDA of 470ft. It was a VMC by the time METAR in WADD indicated. However, I am not sure that either heavy rain on final restricted their view after the MDA caused
undershoot.
The wipers on B738 (9) gives very limited view and doesn't work well under the heavy rain.
If windsher was indicated in ATIS, then it's clear sign of TS adjacent to the airport.
The pictuere taken just after the accident shows grey rainy cloud just west of the airport assumed that there was rain maybe on the final approach path for Rwy 09.
B738 (9) has both Windshear and Predective Windshear Warnings to notify pilots and we have procedures to follow so unless intentionally ignored by the crewmembers, I would not think that this is a major factor for the accident.
I speculate that the crew reached the MDA after the VOR/DME appraoch but heavy rain on short final affect their judgement to deviate form correct path to the runway. Nither any of crew members called go-around after the successful landing could not be made due to the loss of visual with runway caused airplane to undershoot but the actual cause is unknown at the moment. I am looking forward to read the investigation report as we fly often this approach and fly the same aircraft type.