Embraer 170 Captain reported a wind shear and crosswind encounter during the landing flare which resulted in a loss of control and bank angle warning. The Captain regained aircraft control prior to touchdown and landed.

Narrative

The descent and approach into ZZZZ was uneventful. Approach was stable by 1000AGL. I crossed the threshold over center line with a left crab into the wind. Around 30ft AGL I encountered a very unusual weather phenomenon resembling severe crosswind wind shear that lasted no more than a few seconds and then immediately died out. It started just below 50ft AGL with a strong crosswind pushing the aircraft slightly right of centerline so I corrected towards centerline. Around 20ft AGL it turned immediately into a severe wind shear crosswind from the left side that caused a momentary pitch up attitude and bank. The weather phenomenon was so severe that as I corrected to remain over the runway centerline we received a bank angle warning. Immediately after receiving the bank angle warning the weather phenomenon died out and I settled the aircraft down on the runway with a slight float. We ended up touching down abeam the 1 intersection or just slightly past it. I proceeded to apply reverse thrusters and brakes; slowed down the aircraft and by the 2 intersection we were around normal taxi speed. I continued the rollout all the way down to the runway to turn around at the end on the designed turn around area; made a u-turn; back taxied on the runway until the 2 intersection and exited the runway via 2 and taxied via 2 to the gate without further incidents or complications.Cause: Severe crosswind wind shear from the left side while landing on runway XXL.Suggestions: The weather phenomenon was so severe without warning and it also died out immediately afterwards that I believe that the best action was to land the aircraft since we immediately settled down on the ground after the phenomenon dissipated. In hind sight; it's probable that the best course of action was to execute a go around as soon as we started to experience the right drift. In the future I will execute a go around immediately if there are any indications of wind shift/wind shear while landing.