I doubt that weather had any part in this. Little wind, and adequate visibility , although a fairly low cloud base shouldnt have presented any difficulties.
The investigators are now saying that the engines 'effectively stalled'. This might mean running out of fuel, fuel mismanagement, or even another double bird strike. But the difference between the BA 777 crash at Heathrow and this one might be the piloting strategy. If the engines cut out, the need is to overide the automatics, lower the nose to maintain some flying speed and some control, and prevent a stall, which is what the BA pilots at Heathrow did. If , after the engine stall, the pilots in this 737 responded instinctively to an automatic 'pull up' call by pulling up hard, the aircraft would nose up, stall and fall to the ground with little wforward speed, which seems to have been the case here.