The wind at 5,000 feet AGL is southwesterly while the surface wind is southerly. This difference in direction is primarily due to

Explanation

Above the friction layer, wind blows nearly parallel to the isobars as pressure gradient and Coriolis force balance. Within roughly the lowest 2,000 feet, friction with the surface slows the wind, which weakens the Coriolis force. The wind then turns toward lower pressure, which is why a southwesterly wind aloft becomes more southerly at the surface (PHAK Ch. 12). Coriolis force is weaker, not stronger, at the surface, and the pressure gradient is not what causes the directional change.