Ground weather in a specific area at a specific time.

(2) b

(3) Northwest? southwestward

(4) ②? ② Isobar is the densest.

This topic investigates the comprehensive analysis of isobar weather map. (1) As shown in the figure, the isobar at A is closed, and the central air pressure is higher than that around it. It is judged as a high-pressure center, controlled by high pressure, with prevailing downward flow and fine weather. (2)a is a ridge of high pressure and will not form a front; According to the fact that the northern part of the northern hemisphere is cold air and the cyclone horizontal airflow converges counterclockwise, it is judged that a warm front is formed at B. (3) Draw the wind direction map of B and C. According to the horizontal pressure gradient force perpendicular to the isobar, draw the wind direction map from high pressure to low pressure and the northern hemisphere to the right. (4) The denser the isobar, the greater the horizontal pressure gradient force and the greater the wind force.