Answer:
When upper-level divergence of air above a surface low pressure area is stronger than the convergence of surface air, the surface pressure will decrease and the storm itself will intensify.
Step-by-step explanation:
Above the surface concentration of air is lower spreads out and gets diverged . This makes converging surface air to get rise and flow to top of the air column below the tropopause, which acts as a constraint for the vertical motions.
When the upper-level divergence is more than the surface convergence , Hence ,
more amount of air is taken out at top than which is brought in at bottom , and the surface pressure decreases and the storm intensifies .