If a weather forecast predicts that the pressure difference between two regions will decrease substantially, what is the most likely outcome?

The wind direction will reverse.

A weather station on a mountain top records a barometric pressure of 950 millibars, while a station in a valley below records 1010 millibars. Assuming no other factors, which direction would the wind blow?

From the mountain top down to the valley.

There would be no wind due to the altitude difference.

From the valley up towards the mountain top.

The wind would blow parallel to the mountain.

The magnitude of the pressure difference between two places

The amount of moisture in the atmosphere

Air pressure is significantly higher in City A than in City B.

Air pressure is slightly higher in City B than in City A.

Air pressure is nearly identical in both cities.

Air pressure is significantly lower in City A than in City B.